Update version

UTF-8: https://datatracker.ietf.org/doc/html/rfc3629

.github/pull_request_template.md

@@ -0,0 +1,6 @@
+<!--
+Please read the contribution guidelines before submitting a pull request:
+https://github.com/fmtlib/fmt/blob/master/CONTRIBUTING.md.
+By submitting this pull request, you agree that your contributions are licensed
+under the {fmt} license, and agree to future changes to the licensing.
+-->

.github/workflows/doc.yml

@@ -0,0 +1,23 @@
+name: doc
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    # Use Ubuntu 20.04 because doxygen 1.8.13 from Ubuntu 18.04 is broken.
+    runs-on: ubuntu-20.04
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Create Build Environment
+      run: |
+        sudo apt install doxygen python3-virtualenv
+        sudo npm install -g less clean-css
+        cmake -E make_directory ${{runner.workspace}}/build
+
+    - name: Build
+      working-directory: ${{runner.workspace}}/build
+      env:
+        KEY: ${{secrets.KEY}}
+      run: $GITHUB_WORKSPACE/support/build-docs.py

.github/workflows/linux.yml

@@ -0,0 +1,78 @@
+name: linux
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        cxx: [g++-4.8, g++-10, clang++-9]
+        build_type: [Debug, Release]
+        std: [11]
+        os: [ubuntu-18.04]
+        include:
+          - cxx: g++-4.8
+            install: sudo apt install g++-4.8
+            os: ubuntu-18.04
+          - cxx: g++-8
+            build_type: Debug
+            std: 14
+            install: sudo apt install g++-8
+            os: ubuntu-18.04
+          - cxx: g++-10
+            build_type: Debug
+            std: 17
+            os: ubuntu-18.04
+          - cxx: g++-10
+            build_type: Debug
+            std: 20
+            os: ubuntu-20.04
+          - cxx: clang++-9
+            build_type: Debug
+            fuzz: -DFMT_FUZZ=ON -DFMT_FUZZ_LINKMAIN=ON
+            std: 17
+            os: ubuntu-18.04
+          - cxx: clang++-11
+            build_type: Debug
+            std: 20
+            os: ubuntu-20.04
+          - cxx: clang++-11
+            build_type: Debug
+            std: 20
+            cxxflags: -stdlib=libc++
+            os: ubuntu-20.04
+            install: sudo apt install libc++-11-dev libc++abi-11-dev
+          - shared: -DBUILD_SHARED_LIBS=ON
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Create Build Environment
+      run: |
+        ${{matrix.install}}
+        sudo apt install locales-all
+        cmake -E make_directory ${{runner.workspace}}/build
+
+    - name: Configure
+      working-directory: ${{runner.workspace}}/build
+      env:
+        CXX: ${{matrix.cxx}}
+        CXXFLAGS: ${{matrix.cxxflags}}
+      run: |
+        cmake -DCMAKE_BUILD_TYPE=${{matrix.build_type}} ${{matrix.fuzz}} ${{matrix.shared}} \
+              -DCMAKE_CXX_STANDARD=${{matrix.std}} -DFMT_DOC=OFF \
+              -DCMAKE_CXX_VISIBILITY_PRESET=hidden -DCMAKE_VISIBILITY_INLINES_HIDDEN=ON \
+              -DFMT_PEDANTIC=ON -DFMT_WERROR=ON $GITHUB_WORKSPACE
+
+    - name: Build
+      working-directory: ${{runner.workspace}}/build
+      run: |
+        threads=`nproc`
+        cmake --build . --config ${{matrix.build_type}} --parallel $threads
+
+    - name: Test
+      working-directory: ${{runner.workspace}}/build
+      run: ctest -C ${{matrix.build_type}}
+      env:
+        CTEST_OUTPUT_ON_FAILURE: True

.github/workflows/macos.yml

@@ -0,0 +1,37 @@
+name: macos
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: macos-10.15
+    strategy:
+      matrix:
+        build_type: [Debug, Release]
+        include:
+          - shared: -DBUILD_SHARED_LIBS=ON
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Create Build Environment
+      run: cmake -E make_directory ${{runner.workspace}}/build
+
+    - name: Configure
+      working-directory: ${{runner.workspace}}/build
+      run: |
+        cmake -DCMAKE_BUILD_TYPE=${{matrix.build_type}} ${{matrix.shared}} \
+              -DCMAKE_CXX_VISIBILITY_PRESET=hidden -DCMAKE_VISIBILITY_INLINES_HIDDEN=ON \
+              -DFMT_DOC=OFF -DFMT_PEDANTIC=ON -DFMT_WERROR=ON $GITHUB_WORKSPACE
+
+    - name: Build
+      working-directory: ${{runner.workspace}}/build
+      run: |
+        threads=`sysctl -n hw.logicalcpu`
+        cmake --build . --config ${{matrix.build_type}} --parallel $threads
+
+    - name: Test
+      working-directory: ${{runner.workspace}}/build
+      run: ctest -C ${{matrix.build_type}}
+      env:
+        CTEST_OUTPUT_ON_FAILURE: True

.github/workflows/windows.yml

@@ -0,0 +1,60 @@
+name: windows
+
+on: [push, pull_request]
+
+jobs:
+  build:
+    runs-on: ${{matrix.os}}
+    strategy:
+      matrix:
+        # windows-2016 and windows-2019 have MSVC 2017 and 2019 installed
+        # respectively: https://github.com/actions/virtual-environments.
+        os: [windows-2016, windows-2019]
+        platform: [Win32, x64]
+        build_type: [Debug, Release]
+        standard: [11, 17, 20]
+        include:
+          - os: windows-2016
+            platform: Win32
+            build_type: Debug
+            shared: -DBUILD_SHARED_LIBS=ON
+        exclude:
+          - os: windows-2016
+            platform: Win32
+          - os: windows-2016
+            standard: 17
+          - os: windows-2016
+            standard: 20
+          - os: windows-2019
+            standard: 11
+          - os: windows-2019
+            standard: 20
+            platform: Win32
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Create Build Environment
+      run: cmake -E make_directory ${{runner.workspace}}/build
+
+    - name: Configure
+      # Use a bash shell for $GITHUB_WORKSPACE.
+      shell: bash
+      working-directory: ${{runner.workspace}}/build
+      run: |
+        cmake -DCMAKE_BUILD_TYPE=${{matrix.build_type}} ${{matrix.shared}} \
+              -A ${{matrix.platform}} \
+              -DCMAKE_CXX_STANDARD=${{matrix.standard}} \
+              $GITHUB_WORKSPACE
+
+    - name: Build
+      working-directory: ${{runner.workspace}}/build
+      run: |
+        $threads = (Get-CimInstance Win32_ComputerSystem).NumberOfLogicalProcessors
+        cmake --build . --config ${{matrix.build_type}} --parallel $threads
+
+    - name: Test
+      working-directory: ${{runner.workspace}}/build
+      run: ctest -C ${{matrix.build_type}} -V
+      env:
+        CTEST_OUTPUT_ON_FAILURE: True

.gitignore

@@ -9,6 +9,7 @@ gradle/
 gradlew*
 local.properties
 build/
+support/.cxx
 
 bin/
 /_CPack_Packages

.travis.yml

@@ -1,101 +0,0 @@
-language: cpp
-dist: trusty
-sudo: false
-
-os: linux
-
-git:
-  depth: 1
-
-env:
-  global:
-    - secure: |-
-        a1eovNn4uol9won7ghr67eD3/59oeESN+G9bWE+ecI1V6yRseG9whniGhIpC/YfMW/Qz5I
-        5sxSmFjaw9bxCISNwUIrL1O5x2AmRYTnFcXk4dFsUvlZg+WeF/aKyBYCNRM8C2ndbBmtAO
-        o1F2EwFbiso0EmtzhAPs19ujiVxkLn4=
-
-matrix:
-  include:
-      # Documentation
-    - env: BUILD=Doc
-      sudo: required
-      # g++ 6 on Linux with C++14
-    - env: COMPILER=g++-6 BUILD=Debug STANDARD=14
-      compiler: gcc
-      addons:
-        apt:
-          update: true
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-6
-    - env: COMPILER=g++-6 BUILD=Release STANDARD=14
-      compiler: gcc
-      addons:
-        apt:
-          update: true
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-6
-     # g++ 8 on Linux with C++17
-    - env: COMPILER=g++-8 BUILD=Debug STANDARD=17
-      compiler: gcc
-      addons:
-        apt:
-          update: true
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-8
-    - env: COMPILER=g++-8 BUILD=Release STANDARD=17
-      compiler: gcc
-      addons:
-        apt:
-          update: true
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-8
-
-      # Apple clang on OS X with C++14
-    - env: BUILD=Debug STANDARD=14
-      compiler: clang
-      os: osx
-    - env: BUILD=Release STANDARD=14
-      compiler: clang
-      os: osx
-      # clang 6.0 on Linux with C++14 (builds the fuzzers as well)
-    - env: COMPILER=clang++-6.0 BUILD=Debug STANDARD=14 ENABLE_FUZZING=1
-      compiler: clang
-      addons:
-        apt:
-          update: true
-          packages:
-            - clang-6.0
-          sources:
-            - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty
-            - llvm-toolchain-trusty-6.0
-      # clang 4.0 on Linux with C++14
-    - env: COMPILER=clang++-4.0 BUILD=Debug STANDARD=11
-      compiler: clang
-      addons:
-        apt:
-          update: true
-          packages:
-            - clang-4.0
-          sources:
-            - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty
-            - llvm-toolchain-trusty-4.0
-      # g++ 4.8 on Linux with C++11
-    - env: COMPILER=g++-4.8 BUILD=Debug STANDARD=11
-      compiler: gcc
-
-before_script:
-  - if [[ "${TRAVIS_OS_NAME}" == "linux" ]]; then export CXX=${COMPILER}; fi
-  - if [[ "${BUILD}" != "Doc" ]]; then ${CXX} --version; fi
-
-script:
-  - support/travis-build.py

CMakeLists.txt

@@ -7,10 +7,12 @@ endif()
 
 # Determine if fmt is built as a subproject (using add_subdirectory)
 # or if it is the master project.
-set(MASTER_PROJECT OFF)
-if (CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
-  set(MASTER_PROJECT ON)
-  message(STATUS "CMake version: ${CMAKE_VERSION}")
+if (NOT DEFINED FMT_MASTER_PROJECT)
+  set(FMT_MASTER_PROJECT OFF)
+  if (CMAKE_CURRENT_SOURCE_DIR STREQUAL CMAKE_SOURCE_DIR)
+    set(FMT_MASTER_PROJECT ON)
+    message(STATUS "CMake version: ${CMAKE_VERSION}")
+  endif ()
 endif ()
 
 # Joins arguments and places the results in ${result_var}.
@@ -22,6 +24,17 @@ function(join result_var)
   set(${result_var} "${result}" PARENT_SCOPE)
 endfunction()
 
+function(enable_module target)
+  if (MSVC)
+    set(BMI ${CMAKE_CURRENT_BINARY_DIR}/${target}.ifc)
+    target_compile_options(${target}
+      PRIVATE /interface /ifcOutput ${BMI}
+      INTERFACE /reference fmt=${BMI})
+  endif ()
+  set_target_properties(${target} PROPERTIES ADDITIONAL_CLEAN_FILES ${BMI})
+  set_source_files_properties(${BMI} PROPERTIES GENERATED ON)
+endfunction()
+
 include(CMakeParseArguments)
 
 # Sets a cache variable with a docstring joined from multiple arguments:
@@ -44,7 +57,7 @@ endfunction()
 # Set the default CMAKE_BUILD_TYPE to Release.
 # This should be done before the project command since the latter can set
 # CMAKE_BUILD_TYPE itself (it does so for nmake).
-if (MASTER_PROJECT AND NOT CMAKE_BUILD_TYPE)
+if (FMT_MASTER_PROJECT AND NOT CMAKE_BUILD_TYPE)
   set_verbose(CMAKE_BUILD_TYPE Release CACHE STRING
               "Choose the type of build, options are: None(CMAKE_CXX_FLAGS or "
               "CMAKE_C_FLAGS used) Debug Release RelWithDebInfo MinSizeRel.")
@@ -61,12 +74,28 @@ option(FMT_WERROR "Halt the compilation with an error on compiler warnings."
        OFF)
 
 # Options that control generation of various targets.
-option(FMT_DOC "Generate the doc target." ${MASTER_PROJECT})
-option(FMT_INSTALL "Generate the install target." ${MASTER_PROJECT})
-option(FMT_TEST "Generate the test target." ${MASTER_PROJECT})
+option(FMT_DOC "Generate the doc target." ${FMT_MASTER_PROJECT})
+option(FMT_INSTALL "Generate the install target." ${FMT_MASTER_PROJECT})
+option(FMT_TEST "Generate the test target." ${FMT_MASTER_PROJECT})
 option(FMT_FUZZ "Generate the fuzz target." OFF)
 option(FMT_CUDA_TEST "Generate the cuda-test target." OFF)
 option(FMT_OS "Include core requiring OS (Windows/Posix) " ON)
+option(FMT_MODULE "Build a module instead of a traditional library." OFF)
+
+set(FMT_CAN_MODULE OFF)
+if (CMAKE_CXX_STANDARD GREATER 17 AND
+    # msvc 16.10-pre4
+    MSVC AND CMAKE_CXX_COMPILER_VERSION VERSION_GREATER 19.29.30035)
+  set(FMT_CAN_MODULE ON)
+endif ()
+if (NOT FMT_CAN_MODULE)
+  set(FMT_MODULE OFF)
+  message(STATUS "Module support is disabled.")
+endif ()
+if (FMT_TEST AND FMT_MODULE)
+  # The tests require {fmt} to be compiled as traditional library
+  message(STATUS "Testing is incompatible with build mode 'module'.")
+endif ()
 
 # Get version from core.h
 file(READ include/fmt/core.h core_h)
@@ -102,6 +131,18 @@ if (${index} GREATER -1)
 endif ()
 message(STATUS "Required features: ${FMT_REQUIRED_FEATURES}")
 
+if (FMT_MASTER_PROJECT AND NOT DEFINED CMAKE_CXX_VISIBILITY_PRESET)
+  set_verbose(CMAKE_CXX_VISIBILITY_PRESET hidden CACHE STRING
+              "Preset for the export of private symbols")
+  set_property(CACHE CMAKE_CXX_VISIBILITY_PRESET PROPERTY STRINGS
+               hidden default)
+endif ()
+
+if (FMT_MASTER_PROJECT AND NOT DEFINED CMAKE_VISIBILITY_INLINES_HIDDEN)
+  set_verbose(CMAKE_VISIBILITY_INLINES_HIDDEN ON CACHE BOOL
+              "Whether to add a compile flag to hide symbols of inline functions")
+endif ()
+
 if (CMAKE_CXX_COMPILER_ID MATCHES "GNU")
   set(PEDANTIC_COMPILE_FLAGS -pedantic-errors -Wall -Wextra -pedantic
       -Wold-style-cast -Wundef
@@ -113,13 +154,13 @@ if (CMAKE_CXX_COMPILER_ID MATCHES "GNU")
       -Wconversion -Wswitch-enum -Wundef
       -Wno-ctor-dtor-privacy -Wno-format-nonliteral)
   if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.6)
-      set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS} -Wnoexcept
+      set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS}
          -Wno-dangling-else -Wno-unused-local-typedefs)
   endif ()
   if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5.0)
       set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS} -Wdouble-promotion
           -Wtrampolines -Wzero-as-null-pointer-constant -Wuseless-cast
-          -Wvector-operation-performance -Wsized-deallocation)
+          -Wvector-operation-performance -Wsized-deallocation -Wshadow)
   endif ()
   if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 6.0)
       set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS} -Wshift-overflow=2
@@ -130,7 +171,8 @@ endif ()
 
 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   set(PEDANTIC_COMPILE_FLAGS -Wall -Wextra -pedantic -Wconversion -Wundef
-      -Wdeprecated -Wweak-vtables)
+      -Wdeprecated -Wweak-vtables -Wshadow
+      -Wno-gnu-zero-variadic-macro-arguments)
   check_cxx_compiler_flag(-Wzero-as-null-pointer-constant HAS_NULLPTR_WARNING)
   if (HAS_NULLPTR_WARNING)
     set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS}
@@ -144,7 +186,7 @@ if (MSVC)
   set(WERROR_FLAG /WX)
 endif ()
 
-if (MASTER_PROJECT AND CMAKE_GENERATOR MATCHES "Visual Studio")
+if (FMT_MASTER_PROJECT AND CMAKE_GENERATOR MATCHES "Visual Studio")
   # If Microsoft SDK is installed create script run-msbuild.bat that
   # calls SetEnv.cmd to set up build environment and runs msbuild.
   # It is useful when building Visual Studio projects with the SDK
@@ -183,9 +225,12 @@ function(add_headers VAR)
 endfunction()
 
 # Define the fmt library, its includes and the needed defines.
-add_headers(FMT_HEADERS chrono.h color.h compile.h core.h format.h format-inl.h
-                        locale.h os.h ostream.h posix.h printf.h ranges.h)
-if (FMT_OS)
+add_headers(FMT_HEADERS args.h chrono.h color.h compile.h core.h format.h
+                        format-inl.h locale.h os.h ostream.h printf.h ranges.h
+                        xchar.h)
+if (FMT_MODULE)
+  set(FMT_SOURCES src/fmt.cc)
+elseif (FMT_OS)
   set(FMT_SOURCES src/format.cc src/os.cc)
 else()
   set(FMT_SOURCES src/format.cc)
@@ -211,6 +256,9 @@ endif ()
 if (FMT_PEDANTIC)
   target_compile_options(fmt PRIVATE ${PEDANTIC_COMPILE_FLAGS})
 endif ()
+if (FMT_MODULE)
+  enable_module(fmt)
+endif ()
 
 target_compile_features(fmt INTERFACE ${FMT_REQUIRED_FEATURES})
 
@@ -294,6 +342,13 @@ if (FMT_INSTALL)
     INSTALL_DESTINATION ${FMT_CMAKE_DIR})
 
   set(INSTALL_TARGETS fmt fmt-header-only)
+
+  # Install the library and headers.
+  install(TARGETS ${INSTALL_TARGETS} EXPORT ${targets_export_name}
+          LIBRARY DESTINATION ${FMT_LIB_DIR}
+          ARCHIVE DESTINATION ${FMT_LIB_DIR}
+          RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+
   # Use a namespace because CMake provides better diagnostics for namespaced
   # imported targets.
   export(TARGETS ${INSTALL_TARGETS} NAMESPACE fmt::
@@ -306,12 +361,6 @@ if (FMT_INSTALL)
   install(EXPORT ${targets_export_name} DESTINATION ${FMT_CMAKE_DIR}
           NAMESPACE fmt::)
 
-  # Install the library and headers.
-  install(TARGETS ${INSTALL_TARGETS} EXPORT ${targets_export_name}
-          LIBRARY DESTINATION ${FMT_LIB_DIR}
-          ARCHIVE DESTINATION ${FMT_LIB_DIR}
-          RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
-
   install(FILES $<TARGET_PDB_FILE:${INSTALL_TARGETS}>
           DESTINATION ${FMT_LIB_DIR} OPTIONAL)
   install(FILES ${FMT_HEADERS} DESTINATION "${FMT_INC_DIR}/fmt")
@@ -340,7 +389,7 @@ if (FMT_FUZZ)
 endif ()
 
 set(gitignore ${PROJECT_SOURCE_DIR}/.gitignore)
-if (MASTER_PROJECT AND EXISTS ${gitignore})
+if (FMT_MASTER_PROJECT AND EXISTS ${gitignore})
   # Get the list of ignored files from .gitignore.
   file (STRINGS ${gitignore} lines)
   list(REMOVE_ITEM lines /doc/html)

ChangeLog.rst

@@ -1,3 +1,672 @@
+8.0.0 - 2021-06-21
+------------------
+
+* Enabled compile-time format string check by default.
+  For example (`godbolt <https://godbolt.org/z/sMxcohGjz>`__):
+
+  .. code:: c++
+
+     #include <fmt/core.h>
+
+     int main() {
+       fmt::print("{:d}", "I am not a number");
+     }
+
+  gives a compile-time error on compilers with C++20 ``consteval`` support
+  (gcc 10+, clang 11+) because ``d`` is not a valid format specifier for a
+  string.
+
+  To pass a runtime string wrap it in ``fmt::runtime``:
+
+  .. code:: c++
+
+     fmt::print(fmt::runtime("{:d}"), "I am not a number");
+
+* Added compile-time formatting
+  (`#2019 <https://github.com/fmtlib/fmt/pull/2019>`_,
+  `#2044 <https://github.com/fmtlib/fmt/pull/2044>`_,
+  `#2056 <https://github.com/fmtlib/fmt/pull/2056>`_,
+  `#2072 <https://github.com/fmtlib/fmt/pull/2072>`_,
+  `#2075 <https://github.com/fmtlib/fmt/pull/2075>`_,
+  `#2078 <https://github.com/fmtlib/fmt/issues/2078>`_,
+  `#2129 <https://github.com/fmtlib/fmt/pull/2129>`_,
+  `#2326 <https://github.com/fmtlib/fmt/pull/2326>`_).
+  For example (`godbolt <https://godbolt.org/z/Mxx9d89jM>`__):
+
+  .. code:: c++
+
+     #include <fmt/compile.h>
+
+     consteval auto compile_time_itoa(int value) -> std::array<char, 10> {
+       auto result = std::array<char, 10>();
+       fmt::format_to(result.data(), FMT_COMPILE("{}"), value);
+       return result;
+     }
+
+     constexpr auto answer = compile_time_itoa(42);
+
+  Most of the formatting functionality is available at compile time with a
+  notable exception of floating-point numbers and pointers.
+  Thanks `@alexezeder (Alexey Ochapov) <https://github.com/alexezeder>`_.
+
+* Optimized handling of format specifiers during format string compilation.
+  For example, hexadecimal formatting (``"{:x}"``) is now 3-7x faster than
+  before when using ``format_to`` with format string compilation and a
+  stack-allocated buffer (`#1944 <https://github.com/fmtlib/fmt/issues/1944>`_).
+
+  Before (7.1.3)::
+
+    ----------------------------------------------------------------------------
+    Benchmark                                  Time             CPU   Iterations
+    ----------------------------------------------------------------------------
+    FMTCompileOld/0                         15.5 ns         15.5 ns     43302898
+    FMTCompileOld/42                        16.6 ns         16.6 ns     43278267
+    FMTCompileOld/273123                    18.7 ns         18.6 ns     37035861
+    FMTCompileOld/9223372036854775807       19.4 ns         19.4 ns     35243000
+    ----------------------------------------------------------------------------
+
+  After (8.x)::
+
+    ----------------------------------------------------------------------------
+    Benchmark                                  Time             CPU   Iterations
+    ----------------------------------------------------------------------------
+    FMTCompileNew/0                         1.99 ns         1.99 ns    360523686
+    FMTCompileNew/42                        2.33 ns         2.33 ns    279865664
+    FMTCompileNew/273123                    3.72 ns         3.71 ns    190230315
+    FMTCompileNew/9223372036854775807       5.28 ns         5.26 ns    130711631
+    ----------------------------------------------------------------------------
+
+  It is even faster than ``std::to_chars`` from libc++ compiled with clang on
+  macOS::
+
+    ----------------------------------------------------------------------------
+    Benchmark                                  Time             CPU   Iterations
+    ----------------------------------------------------------------------------
+    ToChars/0                               4.42 ns         4.41 ns    160196630
+    ToChars/42                              5.00 ns         4.98 ns    140735201
+    ToChars/273123                          7.26 ns         7.24 ns     95784130
+    ToChars/9223372036854775807             8.77 ns         8.75 ns     75872534
+    ----------------------------------------------------------------------------
+
+  In other cases, especially involving ``std::string`` construction, the
+  speed up is usually lower because handling format specifiers takes a smaller
+  fraction of the total time.
+
+* Added the ``_cf`` user-defined literal to represent a compiled format string.
+  It can be used instead of the ``FMT_COMPILE`` macro
+  (`#2043 <https://github.com/fmtlib/fmt/pull/2043>`_,
+  `#2242 <https://github.com/fmtlib/fmt/pull/2242>`_):
+
+  .. code:: c++
+
+     #include <fmt/compile.h>
+
+     using namespace fmt::literals;
+     auto s = fmt::format(FMT_COMPILE("{}"), 42); // 🙁 not modern
+     auto s = fmt::format("{}"_cf, 42);           // 🙂 modern as hell
+
+  It requires compiler support for class types in non-type template parameters
+  (a C++20 feature) which is available in GCC 9.3+.
+  Thanks `@alexezeder (Alexey Ochapov) <https://github.com/alexezeder>`_.
+
+* Format string compilation now requires ``format`` functions of ``formatter``
+  specializations for user-defined types to be ``const``:
+
+  .. code:: c++
+
+     template <> struct fmt::formatter<my_type>: formatter<string_view> {
+       template <typename FormatContext>
+       auto format(my_type obj, FormatContext& ctx) const {  // Note const here.
+         // ...
+       }
+     };
+
+* Added UDL-based named argument support to format string compilation
+  (`#2243 <https://github.com/fmtlib/fmt/pull/2243>`_,
+  `#2281 <https://github.com/fmtlib/fmt/pull/2281>`_). For example:
+
+  .. code:: c++
+
+     #include <fmt/compile.h>
+
+     using namespace fmt::literals;
+     auto s = fmt::format(FMT_COMPILE("{answer}"), "answer"_a = 42);
+
+  Here the argument named "answer" is resolved at compile time with no
+  runtime overhead.
+  Thanks `@alexezeder (Alexey Ochapov) <https://github.com/alexezeder>`_.
+
+* Added format string compilation support to ``fmt::print``
+  (`#2280 <https://github.com/fmtlib/fmt/issues/2280>`_,
+  `#2304 <https://github.com/fmtlib/fmt/pull/2304>`_).
+  Thanks `@alexezeder (Alexey Ochapov) <https://github.com/alexezeder>`_.
+
+* Added initial support for compiling {fmt} as a C++20 module
+  (`#2235 <https://github.com/fmtlib/fmt/pull/2235>`_,
+  `#2240 <https://github.com/fmtlib/fmt/pull/2240>`_,
+  `#2260 <https://github.com/fmtlib/fmt/pull/2260>`_,
+  `#2282 <https://github.com/fmtlib/fmt/pull/2282>`_,
+  `#2283 <https://github.com/fmtlib/fmt/pull/2283>`_,
+  `#2288 <https://github.com/fmtlib/fmt/pull/2288>`_,
+  `#2298 <https://github.com/fmtlib/fmt/pull/2298>`_,
+  `#2306 <https://github.com/fmtlib/fmt/pull/2306>`_,
+  `#2307 <https://github.com/fmtlib/fmt/pull/2307>`_,
+  `#2309 <https://github.com/fmtlib/fmt/pull/2309>`_,
+  `#2318 <https://github.com/fmtlib/fmt/pull/2318>`_,
+  `#2324 <https://github.com/fmtlib/fmt/pull/2324>`_,
+  `#2332 <https://github.com/fmtlib/fmt/pull/2332>`_,
+  `#2340 <https://github.com/fmtlib/fmt/pull/2340>`_).
+  Thanks `@DanielaE (Daniela Engert) <https://github.com/DanielaE>`_.
+
+* Made symbols private by default reducing shared library size
+  (`#2301 <https://github.com/fmtlib/fmt/pull/2301>`_). For example there was
+  a ~15% reported reduction on one platform.
+  Thanks `@sergiud (Sergiu Deitsch) <https://github.com/sergiud>`_.
+
+* Optimized includes making the result of preprocessing ``fmt/format.h``
+  ~20% smaller with libstdc++/C++20 and slightly improving build times
+  (`#1998 <https://github.com/fmtlib/fmt/issues/1998>`_).
+
+* Added support of ranges with non-const ``begin`` / ``end``
+  (`#1953 <https://github.com/fmtlib/fmt/pull/1953>`_).
+  Thanks `@kitegi (sarah) <https://github.com/kitegi>`_.
+
+* Added support of ``std::byte`` and other formattable types to ``fmt::join``
+  (`#1981 <https://github.com/fmtlib/fmt/issues/1981>`_,
+  `#2040 <https://github.com/fmtlib/fmt/issues/2040>`_,
+  `#2050 <https://github.com/fmtlib/fmt/pull/2050>`_,
+  `#2262 <https://github.com/fmtlib/fmt/issues/2262>`_). For example:
+
+  .. code:: c++
+
+     #include <fmt/format.h>
+     #include <cstddef>
+     #include <vector>
+
+     int main() {
+       auto bytes = std::vector{std::byte(4), std::byte(2)};
+       fmt::print("{}", fmt::join(bytes, ""));
+     }
+
+  prints "42".
+
+  Thanks `@kamibo (Camille Bordignon) <https://github.com/kamibo>`_.
+
+* Implemented the default format for ``std::chrono::system_clock``
+  (`#2319 <https://github.com/fmtlib/fmt/issues/2319>`_,
+  `#2345 <https://github.com/fmtlib/fmt/pull/2345>`_). For example:
+
+  .. code:: c++
+
+     #include <fmt/chrono.h>
+
+     int main() {
+       fmt::print("{}", std::chrono::system_clock::now());
+     }
+
+  prints "2021-06-18 15:22:00" (the output depends on the current date and
+  time). Thanks `@sunmy2019 <https://github.com/sunmy2019>`_.
+
+* Made more chrono specifiers locale independent by default. Use the ``'L'``
+  specifier to get localized formatting. For example:
+
+  .. code:: c++
+
+     #include <fmt/chrono.h>
+
+     int main() {
+       std::locale::global(std::locale("ru_RU.UTF-8"));
+       auto monday = std::chrono::weekday(1);
+       fmt::print("{}\n", monday);   // prints "Mon"
+       fmt::print("{:L}\n", monday); // prints "пн"
+     }
+
+* Improved locale handling in chrono formatting
+  (`#2337 <https://github.com/fmtlib/fmt/issues/2337>`_,
+  `#2349 <https://github.com/fmtlib/fmt/pull/2349>`_,
+  `#2350 <https://github.com/fmtlib/fmt/pull/2350>`_).
+  Thanks `@phprus (Vladislav Shchapov) <https://github.com/phprus>`_.
+
+* Deprecated ``fmt/locale.h`` moving the formatting functions that take a
+  locale to ``fmt/format.h`` (``char``) and ``fmt/xchar`` (other overloads).
+  This doesn't introduce a dependency on ``<locale>`` so there is virtually no
+  compile time effect.
+
+* Made parameter order in ``vformat_to`` consistent with ``format_to``
+  (`#2327 <https://github.com/fmtlib/fmt/issues/2327>`_).
+
+* Added support for time points with arbitrary durations
+  (`#2208 <https://github.com/fmtlib/fmt/issues/2208>`_). For example:
+
+  .. code:: c++
+
+     #include <fmt/chrono.h>
+
+     int main() {
+       using tp = std::chrono::time_point<
+         std::chrono::system_clock, std::chrono::seconds>;
+       fmt::print("{:%S}", tp(std::chrono::seconds(42)));
+     }
+
+  prints "42".
+
+* Formatting floating-point numbers no longer produces trailing zeros by default
+  for consistency with ``std::format``. For example:
+
+  .. code:: c++
+
+     #include <fmt/core.h>
+
+     int main() {
+       fmt::print("{0:.3}", 1.1);
+     }
+
+  prints "1.1". Use the ``'#'`` specifier to keep trailing zeros.
+
+* Dropped a limit on the number of elements in a range and replaced ``{}`` with
+  ``[]`` as range delimiters for consistency with Python's ``str.format``.
+
+* The ``'L'`` specifier for locale-specific numeric formatting can now be
+  combined with presentation specifiers as in ``std::format``. For example:
+
+  .. code:: c++
+
+     #include <fmt/core.h>
+     #include <locale>
+
+     int main() {
+       std::locale::global(std::locale("fr_FR.UTF-8"));
+       fmt::print("{0:.2Lf}", 0.42);
+     }
+
+  prints "0,42". The deprecated ``'n'`` specifier has been removed.
+
+* Made the ``0`` specifier ignored for infinity and NaN
+  (`#2305 <https://github.com/fmtlib/fmt/issues/2305>`_,
+  `#2310 <https://github.com/fmtlib/fmt/pull/2310>`_).
+  Thanks `@Liedtke (Matthias Liedtke) <https://github.com/Liedtke>`_.
+
+* Made the hexfloat formatting use the right alignment by default
+  (`#2308 <https://github.com/fmtlib/fmt/issues/2308>`_,
+  `#2317 <https://github.com/fmtlib/fmt/pull/2317>`_).
+  Thanks `@Liedtke (Matthias Liedtke) <https://github.com/Liedtke>`_.
+
+* Removed the deprecated numeric alignment (``'='``). Use the ``'0'`` specifier
+  instead.
+
+* Removed the deprecated ``fmt/posix.h`` header that has been replaced with
+  ``fmt/os.h``.
+
+* Removed the deprecated ``format_to_n_context``, ``format_to_n_args`` and
+  ``make_format_to_n_args``. They have been replaced with ``format_context``,
+  ``format_args` and ``make_format_args`` respectively.
+
+* Moved ``wchar_t``-specific functions and types to ``fmt/wchar.h``.
+  You can define ``FMT_DEPRECATED_INCLUDE_WCHAR`` to automatically include
+  ``fmt/wchar.h`` from ``fmt/format.h`` but this will be disabled in the next
+  major release.
+
+* Fixed handling of the ``'+'`` specifier in localized formatting
+  (`#2133 <https://github.com/fmtlib/fmt/issues/2133>`_).
+
+* Added support for the ``'s'`` format specifier that gives textual
+  representation of ``bool``
+  (`#2094 <https://github.com/fmtlib/fmt/issues/2094>`_,
+  `#2109 <https://github.com/fmtlib/fmt/pull/2109>`_). For example:
+
+  .. code:: c++
+
+     #include <fmt/core.h>
+
+     int main() {
+       fmt::print("{:s}", true);
+     }
+
+  prints "true".
+  Thanks `@powercoderlol (Ivan Polyakov) <https://github.com/powercoderlol>`_.
+
+* Made ``fmt::ptr`` work with function pointers
+  (`#2131 <https://github.com/fmtlib/fmt/pull/2131>`_). For example:
+
+  .. code:: c++
+
+     #include <fmt/format.h>
+
+     int main() {
+       fmt::print("My main: {}\n", fmt::ptr(main));
+     }
+
+  Thanks `@mikecrowe (Mike Crowe) <https://github.com/mikecrowe>`_.
+
+* Fixed ``fmt::formatted_size`` with format string compilation
+  (`#2141 <https://github.com/fmtlib/fmt/pull/2141>`_,
+  `#2161 <https://github.com/fmtlib/fmt/pull/2161>`_).
+  Thanks `@alexezeder (Alexey Ochapov) <https://github.com/alexezeder>`_.
+
+* Fixed handling of empty format strings during format string compilation
+  (`#2042 <https://github.com/fmtlib/fmt/issues/2042>`_):
+
+  .. code:: c++
+
+     auto s = fmt::format(FMT_COMPILE(""));
+
+  Thanks `@alexezeder (Alexey Ochapov) <https://github.com/alexezeder>`_.
+
+* Fixed handling of enums in ``fmt::to_string``
+  (`#2036 <https://github.com/fmtlib/fmt/issues/2036>`_).
+
+* Improved width computation
+  (`#2033 <https://github.com/fmtlib/fmt/issues/2033>`_,
+  `#2091 <https://github.com/fmtlib/fmt/issues/2091>`_). For example:
+
+  .. code:: c++
+
+     #include <fmt/core.h>
+
+     int main() {
+       fmt::print("{:-<10}{}\n", "你好", "世界");
+       fmt::print("{:-<10}{}\n", "hello", "world");
+     }
+
+  prints
+
+  .. image:: https://user-images.githubusercontent.com/576385/
+             119840373-cea3ca80-beb9-11eb-91e0-54266c48e181.png
+
+  on a modern terminal.
+
+* The experimental fast output stream (``fmt::ostream``) is now truncated by
+  default for consistency with ``fopen``
+  (`#2018 <https://github.com/fmtlib/fmt/issues/2018>`_). For example:
+
+  .. code:: c++
+
+     #include <fmt/os.h>
+
+     int main() {
+       fmt::ostream out1 = fmt::output_file("guide");
+       out1.print("Zaphod");
+       out1.close();
+       fmt::ostream out2 = fmt::output_file("guide");
+       out2.print("Ford");
+     }
+
+  writes "Ford" to the file "guide". To preserve the old file content if any
+  pass ``fmt::file::WRONLY | fmt::file::CREATE`` flags to ``fmt::output_file``.
+
+* Fixed moving of ``fmt::ostream`` that holds buffered data
+  (`#2197 <https://github.com/fmtlib/fmt/issues/2197>`_,
+  `#2198 <https://github.com/fmtlib/fmt/pull/2198>`_).
+  Thanks `@vtta <https://github.com/vtta>`_.
+
+* Replaced the ``fmt::system_error`` exception with a function of the same
+  name that constructs ``std::system_error``
+  (`#2266 <https://github.com/fmtlib/fmt/issues/2266>`_).
+
+* Replaced the ``fmt::windows_error`` exception with a function of the same
+  name that constructs ``std::system_error`` with the category returned by
+  ``fmt::system_category()``
+  (`#2274 <https://github.com/fmtlib/fmt/issues/2274>`_,
+  `#2275 <https://github.com/fmtlib/fmt/pull/2275>`_).
+  The latter is similar to ``std::sytem_category`` but correctly handles UTF-8.
+  Thanks `@phprus (Vladislav Shchapov) <https://github.com/phprus>`_.
+
+* Replaced ``fmt::error_code`` with ``std::error_code`` and made it formattable
+  (`#2269 <https://github.com/fmtlib/fmt/issues/2269>`_,
+  `#2270 <https://github.com/fmtlib/fmt/pull/2270>`_,
+  `#2273 <https://github.com/fmtlib/fmt/pull/2273>`_).
+  Thanks `@phprus (Vladislav Shchapov) <https://github.com/phprus>`_.
+ 
+* Added speech synthesis support
+  (`#2206 <https://github.com/fmtlib/fmt/pull/2206>`_).
+
+* Made ``format_to`` work with a memory buffer that has a custom allocator
+  (`#2300 <https://github.com/fmtlib/fmt/pull/2300>`_).
+  Thanks `@voxmea <https://github.com/voxmea>`_.
+
+* Added ``Allocator::max_size`` support to ``basic_memory_buffer``.
+  (`#1960 <https://github.com/fmtlib/fmt/pull/1960>`_).
+  Thanks `@phprus (Vladislav Shchapov) <https://github.com/phprus>`_.
+
+* Added wide string support to ``fmt::join``
+  (`#2236 <https://github.com/fmtlib/fmt/pull/2236>`_).
+  Thanks `@crbrz <https://github.com/crbrz>`_.
+
+* Made iterators passed to ``formatter`` specializations via a format context
+  satisfy C++20 ``std::output_iterator`` requirements
+  (`#2156 <https://github.com/fmtlib/fmt/issues/2156>`_,
+  `#2158 <https://github.com/fmtlib/fmt/pull/2158>`_,
+  `#2195 <https://github.com/fmtlib/fmt/issues/2195>`_,
+  `#2204 <https://github.com/fmtlib/fmt/pull/2204>`_).
+  Thanks `@randomnetcat (Jason Cobb) <https://github.com/randomnetcat>`_.
+
+* Optimized the ``printf`` implementation
+  (`#1982 <https://github.com/fmtlib/fmt/pull/1982>`_,
+  `#1984 <https://github.com/fmtlib/fmt/pull/1984>`_,
+  `#2016 <https://github.com/fmtlib/fmt/pull/2016>`_,
+  `#2164 <https://github.com/fmtlib/fmt/pull/2164>`_).
+  Thanks `@rimathia <https://github.com/rimathia>`_ and
+  `@moiwi <https://github.com/moiwi>`_.
+
+* Improved detection of ``constexpr`` ``char_traits``
+  (`#2246 <https://github.com/fmtlib/fmt/pull/2246>`_,
+  `#2257 <https://github.com/fmtlib/fmt/pull/2257>`_).
+  Thanks `@phprus (Vladislav Shchapov) <https://github.com/phprus>`_.
+
+* Fixed writing to ``stdout`` when it is redirected to ``NUL`` on Windows
+  (`#2080 <https://github.com/fmtlib/fmt/issues/2080>`_).
+
+* Fixed exception propagation from iterators
+  (`#2097 <https://github.com/fmtlib/fmt/issues/2097>`_).
+  
+* Improved ``strftime`` error handling 
+  (`#2238 <https://github.com/fmtlib/fmt/issues/2238>`_,
+  `#2244 <https://github.com/fmtlib/fmt/pull/2244>`_).
+  Thanks `@yumeyao <https://github.com/yumeyao>`_.
+
+* Stopped using deprecated GCC UDL template extension.
+
+* Added ``fmt/args.h`` to the install target
+  (`#2096 <https://github.com/fmtlib/fmt/issues/2096>`_).
+
+* Error messages are now passed to assert when exceptions are disabled
+  (`#2145 <https://github.com/fmtlib/fmt/pull/2145>`_).
+  Thanks `@NobodyXu (Jiahao XU) <https://github.com/NobodyXu>`_.
+
+* Added the ``FMT_MASTER_PROJECT`` CMake option to control build and install
+  targets when {fmt} is included via ``add_subdirectory``
+  (`#2098 <https://github.com/fmtlib/fmt/issues/2098>`_,
+  `#2100 <https://github.com/fmtlib/fmt/pull/2100>`_).
+  Thanks `@randomizedthinking <https://github.com/randomizedthinking>`_.
+
+* Improved build configuration
+  (`#2026 <https://github.com/fmtlib/fmt/pull/2026>`_,
+  `#2122 <https://github.com/fmtlib/fmt/pull/2122>`_).
+  Thanks `@luncliff (Park DongHa) <https://github.com/luncliff>`_ and
+  `@ibaned (Dan Ibanez) <https://github.com/ibaned>`_.
+
+* Fixed various warnings and compilation issues
+  (`#1947 <https://github.com/fmtlib/fmt/issues/1947>`_,
+  `#1959 <https://github.com/fmtlib/fmt/pull/1959>`_,
+  `#1963 <https://github.com/fmtlib/fmt/pull/1963>`_,
+  `#1965 <https://github.com/fmtlib/fmt/pull/1965>`_,
+  `#1966 <https://github.com/fmtlib/fmt/issues/1966>`_,
+  `#1974 <https://github.com/fmtlib/fmt/pull/1974>`_,
+  `#1975 <https://github.com/fmtlib/fmt/pull/1975>`_,
+  `#1990 <https://github.com/fmtlib/fmt/pull/1990>`_,
+  `#2000 <https://github.com/fmtlib/fmt/issues/2000>`_,
+  `#2001 <https://github.com/fmtlib/fmt/pull/2001>`_,
+  `#2002 <https://github.com/fmtlib/fmt/issues/2002>`_,
+  `#2004 <https://github.com/fmtlib/fmt/issues/2004>`_,
+  `#2006 <https://github.com/fmtlib/fmt/pull/2006>`_,
+  `#2009 <https://github.com/fmtlib/fmt/pull/2009>`_,
+  `#2010 <https://github.com/fmtlib/fmt/pull/2010>`_,
+  `#2038 <https://github.com/fmtlib/fmt/issues/2038>`_,
+  `#2039 <https://github.com/fmtlib/fmt/issues/2039>`_,
+  `#2047 <https://github.com/fmtlib/fmt/issues/2047>`_,
+  `#2053 <https://github.com/fmtlib/fmt/pull/2053>`_,
+  `#2059 <https://github.com/fmtlib/fmt/issues/2059>`_,
+  `#2065 <https://github.com/fmtlib/fmt/pull/2065>`_,
+  `#2067 <https://github.com/fmtlib/fmt/pull/2067>`_,
+  `#2068 <https://github.com/fmtlib/fmt/pull/2068>`_,
+  `#2073 <https://github.com/fmtlib/fmt/pull/2073>`_,
+  `#2103 <https://github.com/fmtlib/fmt/issues/2103>`_
+  `#2105 <https://github.com/fmtlib/fmt/issues/2105>`_
+  `#2106 <https://github.com/fmtlib/fmt/pull/2106>`_,
+  `#2107 <https://github.com/fmtlib/fmt/pull/2107>`_,
+  `#2116 <https://github.com/fmtlib/fmt/issues/2116>`_
+  `#2117 <https://github.com/fmtlib/fmt/pull/2117>`_,
+  `#2118 <https://github.com/fmtlib/fmt/issues/2118>`_
+  `#2119 <https://github.com/fmtlib/fmt/pull/2119>`_,
+  `#2127 <https://github.com/fmtlib/fmt/issues/2127>`_,
+  `#2128 <https://github.com/fmtlib/fmt/pull/2128>`_,
+  `#2140 <https://github.com/fmtlib/fmt/issues/2140>`_,
+  `#2142 <https://github.com/fmtlib/fmt/issues/2142>`_,
+  `#2143 <https://github.com/fmtlib/fmt/pull/2143>`_,
+  `#2144 <https://github.com/fmtlib/fmt/pull/2144>`_,
+  `#2147 <https://github.com/fmtlib/fmt/issues/2147>`_,
+  `#2148 <https://github.com/fmtlib/fmt/issues/2148>`_,
+  `#2149 <https://github.com/fmtlib/fmt/issues/2149>`_,
+  `#2152 <https://github.com/fmtlib/fmt/pull/2152>`_,
+  `#2160 <https://github.com/fmtlib/fmt/pull/2160>`_,
+  `#2170 <https://github.com/fmtlib/fmt/issues/2170>`_,
+  `#2175 <https://github.com/fmtlib/fmt/issues/2175>`_,
+  `#2176 <https://github.com/fmtlib/fmt/issues/2176>`_,
+  `#2177 <https://github.com/fmtlib/fmt/pull/2177>`_,
+  `#2178 <https://github.com/fmtlib/fmt/issues/2178>`_,
+  `#2179 <https://github.com/fmtlib/fmt/pull/2179>`_,
+  `#2180 <https://github.com/fmtlib/fmt/issues/2180>`_,
+  `#2181 <https://github.com/fmtlib/fmt/issues/2181>`_,
+  `#2183 <https://github.com/fmtlib/fmt/pull/2183>`_,
+  `#2184 <https://github.com/fmtlib/fmt/issues/2184>`_,
+  `#2185 <https://github.com/fmtlib/fmt/issues/2185>`_,
+  `#2186 <https://github.com/fmtlib/fmt/pull/2186>`_,
+  `#2187 <https://github.com/fmtlib/fmt/pull/2187>`_,
+  `#2190 <https://github.com/fmtlib/fmt/pull/2190>`_,
+  `#2192 <https://github.com/fmtlib/fmt/pull/2192>`_,
+  `#2194 <https://github.com/fmtlib/fmt/pull/2194>`_,
+  `#2205 <https://github.com/fmtlib/fmt/pull/2205>`_,
+  `#2210 <https://github.com/fmtlib/fmt/issues/2210>`_,
+  `#2211 <https://github.com/fmtlib/fmt/pull/2211>`_,
+  `#2215 <https://github.com/fmtlib/fmt/pull/2215>`_,
+  `#2216 <https://github.com/fmtlib/fmt/pull/2216>`_,
+  `#2218 <https://github.com/fmtlib/fmt/pull/2218>`_,
+  `#2220 <https://github.com/fmtlib/fmt/pull/2220>`_,
+  `#2228 <https://github.com/fmtlib/fmt/issues/2228>`_,
+  `#2229 <https://github.com/fmtlib/fmt/pull/2229>`_,
+  `#2230 <https://github.com/fmtlib/fmt/pull/2230>`_,
+  `#2233 <https://github.com/fmtlib/fmt/issues/2233>`_,
+  `#2239 <https://github.com/fmtlib/fmt/pull/2239>`_,
+  `#2248 <https://github.com/fmtlib/fmt/issues/2248>`_,
+  `#2252 <https://github.com/fmtlib/fmt/issues/2252>`_,
+  `#2253 <https://github.com/fmtlib/fmt/pull/2253>`_,
+  `#2255 <https://github.com/fmtlib/fmt/pull/2255>`_,
+  `#2261 <https://github.com/fmtlib/fmt/issues/2261>`_,
+  `#2278 <https://github.com/fmtlib/fmt/issues/2278>`_,
+  `#2284 <https://github.com/fmtlib/fmt/issues/2284>`_,
+  `#2287 <https://github.com/fmtlib/fmt/pull/2287>`_,
+  `#2289 <https://github.com/fmtlib/fmt/pull/2289>`_,
+  `#2290 <https://github.com/fmtlib/fmt/pull/2290>`_,
+  `#2293 <https://github.com/fmtlib/fmt/pull/2293>`_,
+  `#2295 <https://github.com/fmtlib/fmt/issues/2295>`_,
+  `#2296 <https://github.com/fmtlib/fmt/pull/2296>`_,
+  `#2297 <https://github.com/fmtlib/fmt/pull/2297>`_,
+  `#2311 <https://github.com/fmtlib/fmt/issues/2311>`_,
+  `#2313 <https://github.com/fmtlib/fmt/pull/2313>`_,
+  `#2315 <https://github.com/fmtlib/fmt/pull/2315>`_,
+  `#2320 <https://github.com/fmtlib/fmt/issues/2320>`_,
+  `#2321 <https://github.com/fmtlib/fmt/pull/2321>`_,
+  `#2323 <https://github.com/fmtlib/fmt/pull/2323>`_,
+  `#2328 <https://github.com/fmtlib/fmt/issues/2328>`_,
+  `#2329 <https://github.com/fmtlib/fmt/pull/2329>`_,
+  `#2333 <https://github.com/fmtlib/fmt/pull/2333>`_,
+  `#2338 <https://github.com/fmtlib/fmt/pull/2338>`_,
+  `#2341 <https://github.com/fmtlib/fmt/pull/2341>`_).
+  Thanks `@darklukee <https://github.com/darklukee>`_,
+  `@fagg (Ashton Fagg) <https://github.com/fagg>`_,
+  `@killerbot242 (Lieven de Cock) <https://github.com/killerbot242>`_,
+  `@jgopel (Jonathan Gopel) <https://github.com/jgopel>`_,
+  `@yeswalrus (Walter Gray) <https://github.com/yeswalrus>`_,
+  `@Finkman <https://github.com/Finkman>`_,
+  `@HazardyKnusperkeks (Björn Schäpers) <https://github.com/HazardyKnusperkeks>`_,
+  `@dkavolis (Daumantas Kavolis) <https://github.com/dkavolis>`_
+  `@concatime (Issam Maghni) <https://github.com/concatime>`_,
+  `@chronoxor (Ivan Shynkarenka) <https://github.com/chronoxor>`_,
+  `@summivox (Yin Zhong) <https://github.com/summivox>`_,
+  `@yNeo <https://github.com/yNeo>`_,
+  `@Apache-HB (Elliot) <https://github.com/Apache-HB>`_,
+  `@alexezeder (Alexey Ochapov) <https://github.com/alexezeder>`_,
+  `@toojays (John Steele Scott) <https://github.com/toojays>`_,
+  `@Brainy0207 <https://github.com/Brainy0207>`_,
+  `@vadz (VZ) <https://github.com/vadz>`_,
+  `@imsherlock (Ryan Sherlock) <https://github.com/imsherlock>`_,
+  `@phprus (Vladislav Shchapov) <https://github.com/phprus>`_,
+  `@white238 (Chris White) <https://github.com/white238>`_,
+  `@yafshar (Yaser Afshar) <https://github.com/yafshar>`_,
+  `@BillyDonahue (Billy Donahue) <https://github.com/BillyDonahue>`_,
+  `@jstaahl <https://github.com/jstaahl>`_,
+  `@denchat <https://github.com/denchat>`_,
+  `@DanielaE (Daniela Engert) <https://github.com/DanielaE>`_,
+  `@ilyakurdyukov (Ilya Kurdyukov) <https://github.com/ilyakurdyukov>`_,
+  `@ilmai <https://github.com/ilmai>`_,
+  `@JessyDL (Jessy De Lannoit) <https://github.com/JessyDL>`_,
+  `@sergiud (Sergiu Deitsch) <https://github.com/sergiud>`_,
+  `@mwinterb <https://github.com/mwinterb>`_,
+  `@sven-herrmann <https://github.com/sven-herrmann>`_,
+  `@jmelas (John Melas) <https://github.com/jmelas>`_,
+  `@twoixter (Jose Miguel Pérez) <https://github.com/twoixter>`_,
+  `@crbrz <https://github.com/crbrz>`_,
+  `@upsj (Tobias Ribizel) <https://github.com/upsj>`_.
+
+* Improved documentation
+  (`#1986 <https://github.com/fmtlib/fmt/issues/1986>`_,
+  `#2051 <https://github.com/fmtlib/fmt/pull/2051>`_,
+  `#2057 <https://github.com/fmtlib/fmt/issues/2057>`_,
+  `#2081 <https://github.com/fmtlib/fmt/pull/2081>`_,
+  `#2084 <https://github.com/fmtlib/fmt/issues/2084>`_,
+  `#2312 <https://github.com/fmtlib/fmt/pull/2312>`_).
+  Thanks `@imba-tjd (谭九鼎) <https://github.com/imba-tjd>`_,
+  `@0x416c69 (AlιAѕѕaѕѕιN) <https://github.com/0x416c69>`_,
+  `@mordante <https://github.com/mordante>`_.
+
+* Continuous integration and test improvements
+  (`#1969 <https://github.com/fmtlib/fmt/issues/1969>`_,
+  `#1991 <https://github.com/fmtlib/fmt/pull/1991>`_,
+  `#2020 <https://github.com/fmtlib/fmt/pull/2020>`_,
+  `#2110 <https://github.com/fmtlib/fmt/pull/2110>`_,
+  `#2114 <https://github.com/fmtlib/fmt/pull/2114>`_,
+  `#2196 <https://github.com/fmtlib/fmt/issues/2196>`_,
+  `#2217 <https://github.com/fmtlib/fmt/pull/2217>`_,
+  `#2247 <https://github.com/fmtlib/fmt/pull/2247>`_,
+  `#2256 <https://github.com/fmtlib/fmt/pull/2256>`_,
+  `#2336 <https://github.com/fmtlib/fmt/pull/2336>`_,
+  `#2346 <https://github.com/fmtlib/fmt/pull/2346>`_).
+  Thanks `@jgopel (Jonathan Gopel) <https://github.com/jgopel>`_,
+  `@alexezeder (Alexey Ochapov) <https://github.com/alexezeder>`_ and
+  `@DanielaE (Daniela Engert) <https://github.com/DanielaE>`_.
+  
+7.1.3 - 2020-11-24
+------------------
+
+* Fixed handling of buffer boundaries in ``format_to_n``
+  (`#1996 <https://github.com/fmtlib/fmt/issues/1996>`_,
+  `#2029 <https://github.com/fmtlib/fmt/issues/2029>`_).
+
+* Fixed linkage errors when linking with a shared library
+  (`#2011 <https://github.com/fmtlib/fmt/issues/2011>`_).
+
+* Reintroduced ostream support to range formatters
+  (`#2014 <https://github.com/fmtlib/fmt/issues/2014>`_).
+
+* Worked around an issue with mixing std versions in gcc
+  (`#2017 <https://github.com/fmtlib/fmt/issues/2017>`_).
+
+7.1.2 - 2020-11-04
+------------------
+
+* Fixed floating point formatting with large precision
+  (`#1976 <https://github.com/fmtlib/fmt/issues/1976>`_).
+
 7.1.1 - 2020-11-01
 ------------------
 
@@ -247,8 +916,8 @@
 
   Thanks `@Naios (Denis Blank) <https://github.com/Naios>`_.
 
-* Made the ``#`` specifier emit trailing zeros in addition to the decimal point
-  (`#1797 <https://github.com/fmtlib/fmt/issues/1797>`_). For example
+* Made the ``'#'`` specifier emit trailing zeros in addition to the decimal
+  point (`#1797 <https://github.com/fmtlib/fmt/issues/1797>`_). For example
   (`godbolt <https://godbolt.org/z/bhdcW9>`__):
 
   .. code:: c++

README.rst

@@ -1,8 +1,14 @@
 {fmt}
 =====
 
-.. image:: https://travis-ci.org/fmtlib/fmt.png?branch=master
-   :target: https://travis-ci.org/fmtlib/fmt
+.. image:: https://github.com/fmtlib/fmt/workflows/linux/badge.svg
+   :target: https://github.com/fmtlib/fmt/actions?query=workflow%3Alinux
+
+.. image:: https://github.com/fmtlib/fmt/workflows/macos/badge.svg
+   :target: https://github.com/fmtlib/fmt/actions?query=workflow%3Amacos
+
+.. image:: https://github.com/fmtlib/fmt/workflows/windows/badge.svg
+   :target: https://github.com/fmtlib/fmt/actions?query=workflow%3Awindows
 
 .. image:: https://ci.appveyor.com/api/projects/status/ehjkiefde6gucy1v
    :target: https://ci.appveyor.com/project/vitaut/fmt
@@ -20,9 +26,9 @@
 **{fmt}** is an open-source formatting library providing a fast and safe
 alternative to C stdio and C++ iostreams.
 
-If you like this project, please consider donating to BYSOL,
-an initiative to help victims of political repressions in Belarus:
-https://www.facebook.com/donate/759400044849707/108388587646909/.
+If you like this project, please consider donating to the BYSOL
+Foundation that helps victims of political repressions in Belarus:
+https://bysol.org/en/bs/general/.
 
 `Documentation <https://fmt.dev>`__
 
@@ -131,13 +137,13 @@ Output::
 
 Output::
 
-    {1, 2, 3}
+    [1, 2, 3]
 
 **Check a format string at compile time**
 
 .. code:: c++
 
-    std::string s = fmt::format(FMT_STRING("{:d}"), "don't panic");
+    std::string s = fmt::format(FMT_STRING("{:d}"), "I am not a number");
 
 This gives a compile-time error because ``d`` is an invalid format specifier for
 a string.
@@ -283,6 +289,13 @@ Then you can run the speed test::
 or the bloat test::
 
     $ make bloat-test
+    
+Migrating code
+--------------
+
+`clang-tidy-fmt <https://github.com/mikecrowe/clang-tidy-fmt>`_ provides clang
+tidy checks for converting occurrences of ``printf`` and ``fprintf`` to
+``fmt::print``.
 
 Projects using this library
 ---------------------------
@@ -290,6 +303,8 @@ Projects using this library
 * `0 A.D. <https://play0ad.com/>`_: a free, open-source, cross-platform
   real-time strategy game
 
+* `2GIS <https://2gis.ru/>`_: free business listings with a city map
+
 * `AMPL/MP <https://github.com/ampl/mp>`_:
   an open-source library for mathematical programming
 
@@ -310,7 +325,7 @@ Projects using this library
 * `ClickHouse <https://github.com/ClickHouse/ClickHouse>`_: analytical database
   management system
 
-* `CUAUV <http://cuauv.org/>`_: Cornell University's autonomous underwater
+* `CUAUV <https://cuauv.org/>`_: Cornell University's autonomous underwater
   vehicle
 
 * `Drake <https://drake.mit.edu/>`_: a planning, control, and analysis toolbox
@@ -321,8 +336,15 @@ Projects using this library
 
 * `FiveM <https://fivem.net/>`_: a modification framework for GTA V
 
+* `fmtlog <https://github.com/MengRao/fmtlog>`_: a performant fmtlib-style
+  logging library with latency in nanoseconds
+
 * `Folly <https://github.com/facebook/folly>`_: Facebook open-source library
 
+* `Grand Mountain Adventure
+  <https://store.steampowered.com/app/1247360/Grand_Mountain_Adventure/>`_:
+  A beautiful open-world ski & snowboarding game
+
 * `HarpyWar/pvpgn <https://github.com/pvpgn/pvpgn-server>`_:
   Player vs Player Gaming Network with tweaks
 

doc/api.rst

@@ -6,18 +6,18 @@ API Reference
 
 The {fmt} library API consists of the following parts:
 
-* :ref:`fmt/core.h <core-api>`: the core API providing argument handling
-  facilities and a lightweight subset of formatting functions
-* :ref:`fmt/format.h <format-api>`: the full format API providing compile-time
-  format string checks, wide string, output iterator and user-defined type
-  support
-* :ref:`fmt/ranges.h <ranges-api>`: additional formatting support for ranges
-  and tuples
+* :ref:`fmt/core.h <core-api>`: the core API providing main formatting functions
+  for ``char``/UTF-8 with compile-time checks and minimal dependencies
+* :ref:`fmt/format.h <format-api>`: the full format API providing additional
+  formatting functions and locale support
+* :ref:`fmt/ranges.h <ranges-api>`: formatting of ranges and tuples
 * :ref:`fmt/chrono.h <chrono-api>`: date and time formatting
 * :ref:`fmt/compile.h <compile-api>`: format string compilation
 * :ref:`fmt/color.h <color-api>`: terminal color and text style
+* :ref:`fmt/os.h <os-api>`: system APIs
 * :ref:`fmt/ostream.h <ostream-api>`: ``std::ostream`` support
 * :ref:`fmt/printf.h <printf-api>`: ``printf`` formatting
+* :ref:`fmt/xchar.h <xchar-api>`: optional ``wchar_t`` support 
 
 All functions and types provided by the library reside in namespace ``fmt`` and
 macros have prefix ``FMT_``.
@@ -27,38 +27,56 @@ macros have prefix ``FMT_``.
 Core API
 ========
 
-``fmt/core.h`` defines the core API which provides argument handling facilities
-and a lightweight subset of formatting functions. In the header-only mode
-include ``fmt/format.h`` instead of ``fmt/core.h``.
+``fmt/core.h`` defines the core API which provides main formatting functions for
+``char``/UTF-8 with compile-time checks. It has minimal include dependencies for
+better compile times. This header is only beneficial when using {fmt} as a
+library and not in the header-only mode.
 
 The following functions use :ref:`format string syntax <syntax>`
 similar to that of Python's `str.format
-<http://docs.python.org/3/library/stdtypes.html#str.format>`_.
-They take *format_str* and *args* as arguments.
+<https://docs.python.org/3/library/stdtypes.html#str.format>`_.
+They take *fmt* and *args* as arguments.
 
-*format_str* is a format string that contains literal text and replacement
+*fmt* is a format string that contains literal text and replacement
 fields surrounded by braces ``{}``. The fields are replaced with formatted
-arguments in the resulting string. A function taking *format_str* doesn't
+arguments in the resulting string. A function taking *fmt* doesn't
 participate in an overload resolution if the latter is not a string.
 
 *args* is an argument list representing objects to be formatted.
 
 .. _format:
 
-.. doxygenfunction:: format(const S&, Args&&...)
-.. doxygenfunction:: vformat(const S&, basic_format_args<buffer_context<type_identity_t<Char>>>)
+.. doxygenfunction:: format(format_string<T...> fmt, T&&... args) -> std::string
+.. doxygenfunction:: vformat(string_view fmt, format_args args) -> std::string
 
-.. doxygenfunction:: fmt::format_to(OutputIt, const S&, Args&&...)
-.. doxygenfunction:: fmt::format_to_n(OutputIt, size_t, const S&, const Args&...)
-.. doxygenfunction:: fmt::formatted_size(string_view, Args&&...)
+.. doxygenfunction:: format_to(OutputIt out, format_string<T...> fmt, T&&... args) -> OutputIt
+.. doxygenfunction:: format_to_n(OutputIt out, size_t n, format_string<T...> fmt, const T&... args) -> format_to_n_result<OutputIt>
+.. doxygenfunction:: formatted_size(format_string<T...> fmt, T&&... args) -> size_t
+
+.. doxygenstruct:: fmt::format_to_n_result
+   :members:
 
 .. _print:
 
-.. doxygenfunction:: print(const S&, Args&&...)
-.. doxygenfunction:: vprint(string_view, format_args)
+.. doxygenfunction:: fmt::print(format_string<T...> fmt, T&&... args)
+.. doxygenfunction:: vprint(string_view fmt, format_args args)
 
-.. doxygenfunction:: print(std::FILE *, const S&, Args&&...)
-.. doxygenfunction:: vprint(std::FILE *, string_view, format_args)
+.. doxygenfunction:: print(std::FILE *f, format_string<T...> fmt, T&&... args)
+.. doxygenfunction:: vprint(std::FILE *f, string_view fmt, format_args args)
+
+Compile-time Format String Checks
+---------------------------------
+
+Compile-time checks are enabled when using ``FMT_STRING``. They support built-in
+and string types as well as user-defined types with ``constexpr`` ``parse``
+functions in their ``formatter`` specializations.
+
+.. doxygendefine:: FMT_STRING
+
+To force the use of compile-time checks, define the preprocessor variable
+``FMT_ENFORCE_COMPILE_STRING``. When set, functions accepting ``FMT_STRING``
+will fail to compile with regular strings. Runtime-checked
+formatting is still possible using ``fmt::vformat``, ``fmt::vprint``, etc.
 
 Named Arguments
 ---------------
@@ -110,11 +128,16 @@ times and reduces binary code size compared to a fully parameterized version.
 .. doxygenclass:: fmt::basic_format_args
    :members:
 
-.. doxygenstruct:: fmt::format_args
+.. doxygentypedef:: fmt::format_args
 
 .. doxygenclass:: fmt::basic_format_arg
    :members:
 
+.. doxygenclass:: fmt::basic_format_context
+   :members:
+
+.. doxygentypedef:: fmt::format_context
+
 Compatibility
 -------------
 
@@ -122,7 +145,6 @@ Compatibility
    :members:
 
 .. doxygentypedef:: fmt::string_view
-.. doxygentypedef:: fmt::wstring_view
 
 Locale
 ------
@@ -142,17 +164,8 @@ locale::
 Format API
 ==========
 
-``fmt/format.h`` defines the full format API providing compile-time format
-string checks, wide string, output iterator and user-defined type support.
-
-Compile-time Format String Checks
----------------------------------
-
-Compile-time checks are enabled when using ``FMT_STRING``. They support built-in
-and string types as well as user-defined types with ``constexpr`` ``parse``
-functions in their ``formatter`` specializations.
-
-.. doxygendefine:: FMT_STRING
+``fmt/format.h`` defines the full format API providing additional formatting
+functions and locale support.
 
 .. _udt:
 
@@ -166,14 +179,12 @@ template and implement ``parse`` and ``format`` methods::
 
   struct point { double x, y; };
 
-  template <>
-  struct fmt::formatter<point> {
+  template <> struct fmt::formatter<point> {
     // Presentation format: 'f' - fixed, 'e' - exponential.
     char presentation = 'f';
 
     // Parses format specifications of the form ['f' | 'e'].
-    constexpr auto parse(format_parse_context& ctx) {
-    // auto parse(format_parse_context &ctx) -> decltype(ctx.begin()) // c++11
+    constexpr auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
       // [ctx.begin(), ctx.end()) is a character range that contains a part of
       // the format string starting from the format specifications to be parsed,
       // e.g. in
@@ -200,8 +211,7 @@ template and implement ``parse`` and ``format`` methods::
     // Formats the point p using the parsed format specification (presentation)
     // stored in this formatter.
     template <typename FormatContext>
-    auto format(const point& p, FormatContext& ctx) {
-    // auto format(const point &p, FormatContext &ctx) -> decltype(ctx.out()) // c++11
+    auto format(const point& p, FormatContext& ctx) -> decltype(ctx.out()) {
       // ctx.out() is an output iterator to write to.
       return format_to(
           ctx.out(),
@@ -280,43 +290,29 @@ conversion.
 .. doxygenclass:: fmt::basic_format_parse_context
    :members:
 
-Output Iterator Support
------------------------
-
-.. doxygenfunction:: fmt::format_to(OutputIt, const S&, Args&&...)
-.. doxygenfunction:: fmt::format_to_n(OutputIt, size_t, const S&, const Args&...)
-.. doxygenstruct:: fmt::format_to_n_result
-   :members:
-
 Literal-based API
 -----------------
 
 The following user-defined literals are defined in ``fmt/format.h``.
 
-.. doxygenfunction:: operator""_format(const char *, size_t)
+.. doxygenfunction:: operator""_format(const char *s, size_t n) -> detail::udl_formatter<char> 
 
-.. doxygenfunction:: operator""_a(const char *, size_t)
+.. doxygenfunction:: operator""_a(const char *s, size_t) -> detail::udl_arg<char>
 
 Utilities
 ---------
 
-.. doxygenstruct:: fmt::is_char
+.. doxygenfunction:: fmt::ptr(T p) -> const void*
+.. doxygenfunction:: fmt::ptr(const std::unique_ptr<T> &p) -> const void*
+.. doxygenfunction:: fmt::ptr(const std::shared_ptr<T> &p) -> const void*
 
-.. doxygentypedef:: fmt::char_t
+.. doxygenfunction:: fmt::to_string(const T &value) -> std::string
 
-.. doxygenfunction:: fmt::ptr(const T *)
-.. doxygenfunction:: fmt::ptr(const std::unique_ptr<T>&)
-.. doxygenfunction:: fmt::ptr(const std::shared_ptr<T>&)
+.. doxygenfunction:: fmt::to_string_view(const Char *s) -> basic_string_view<Char>
 
-.. doxygenfunction:: fmt::to_string(const T&)
+.. doxygenfunction:: fmt::join(Range &&range, string_view sep) -> join_view<detail::iterator_t<Range>, detail::sentinel_t<Range>>
 
-.. doxygenfunction:: fmt::to_wstring(const T&)
-
-.. doxygenfunction:: fmt::to_string_view(const Char *)
-
-.. doxygenfunction:: fmt::join(Range&&, string_view)
-
-.. doxygenfunction:: fmt::join(It, Sentinel, string_view)
+.. doxygenfunction:: fmt::join(It begin, Sentinel end, string_view sep) -> join_view<It, Sentinel>
 
 .. doxygenclass:: fmt::detail::buffer
    :members:
@@ -328,18 +324,14 @@ Utilities
 System Errors
 -------------
 
-fmt does not use ``errno`` to communicate errors to the user, but it may call
-system functions which set ``errno``. Users should not make any assumptions about
-the value of ``errno`` being preserved by library functions.
+{fmt} does not use ``errno`` to communicate errors to the user, but it may call
+system functions which set ``errno``. Users should not make any assumptions
+about the value of ``errno`` being preserved by library functions.
 
-.. doxygenclass:: fmt::system_error
-   :members:
+.. doxygenfunction:: fmt::system_error
 
 .. doxygenfunction:: fmt::format_system_error
 
-.. doxygenclass:: fmt::windows_error
-   :members:
-
 Custom Allocators
 -----------------
 
@@ -405,18 +397,37 @@ Using ``fmt::join``, you can separate tuple elements with a custom separator::
 Date and Time Formatting
 ========================
 
-The library supports `strftime
-<http://en.cppreference.com/w/cpp/chrono/c/strftime>`_-like date and time
-formatting::
+``fmt/chrono.h`` provides formatters for
+
+* `std::chrono::duration <https://en.cppreference.com/w/cpp/chrono/duration>`_
+* `std::chrono::time_point
+  <https://en.cppreference.com/w/cpp/chrono/time_point>`_
+* `std::tm <https://en.cppreference.com/w/cpp/chrono/c/tm>`_
+
+The format syntax is described in :ref:`chrono-specs`.
+
+**Example**::
 
   #include <fmt/chrono.h>
 
-  std::time_t t = std::time(nullptr);
-  // Prints "The date is 2016-04-29." (with the current date)
-  fmt::print("The date is {:%Y-%m-%d}.", fmt::localtime(t));
+  int main() {
+    std::time_t t = std::time(nullptr);
 
-The format string syntax is described in the documentation of
-`strftime <http://en.cppreference.com/w/cpp/chrono/c/strftime>`_.
+    // Prints "The date is 2020-11-07." (with the current date):
+    fmt::print("The date is {:%Y-%m-%d}.", fmt::localtime(t));
+
+    using namespace std::literals::chrono_literals;
+
+    // Prints "Default format: 42s 100ms":
+    fmt::print("Default format: {} {}\n", 42s, 100ms);
+
+    // Prints "strftime-like format: 03:15:30":
+    fmt::print("strftime-like format: {:%H:%M:%S}\n", 3h + 15min + 30s);
+  }
+
+.. doxygenfunction:: localtime(std::time_t time)
+
+.. doxygenfunction:: gmtime(std::time_t time)
 
 .. _compile-api:
 
@@ -424,13 +435,12 @@ Format string compilation
 =========================
 
 ``fmt/compile.h`` provides format string compilation support when using
-``FMT_COMPILE``. Format strings are parsed, checked and converted
-into efficient formatting code at compile-time.
-This supports arguments of built-in and string types as well as user-defined types
-with ``constexpr`` ``parse`` functions in their ``formatter`` specializations.
-Format string compilation can generate more binary code compared to the default
-API and is only recommended in places where formatting is a performance
-bottleneck.
+``FMT_COMPILE``. Format strings are parsed, checked and converted into efficient
+formatting code at compile-time. This supports arguments of built-in and string
+types as well as user-defined types with ``constexpr`` ``parse`` functions in
+their ``formatter`` specializations. Format string compilation can generate more
+binary code compared to the default API and is only recommended in places where
+formatting is a performance bottleneck.
 
 .. doxygendefine:: FMT_COMPILE
 
@@ -441,7 +451,22 @@ Terminal color and text style
 
 ``fmt/color.h`` provides support for terminal color and text style output.
 
-.. doxygenfunction:: print(const text_style&, const S&, const Args&...)
+.. doxygenfunction:: print(const text_style &ts, const S &format_str, const Args&... args)
+
+.. doxygenfunction:: fg(detail::color_type)
+
+.. doxygenfunction:: bg(detail::color_type)
+
+.. _os-api:
+
+System APIs
+===========
+
+.. doxygenclass:: fmt::ostream
+   :members:
+
+.. doxygenfunction:: fmt::windows_error
+   :members:
 
 .. _ostream-api:
 
@@ -449,7 +474,7 @@ Terminal color and text style
 ========================
 
 ``fmt/ostream.h`` provides ``std::ostream`` support including formatting of
-user-defined types that have overloaded ``operator<<``::
+user-defined types that have an overloaded insertion operator (``operator<<``)::
 
   #include <fmt/ostream.h>
 
@@ -466,7 +491,10 @@ user-defined types that have overloaded ``operator<<``::
   std::string s = fmt::format("The date is {}", date(2012, 12, 9));
   // s == "The date is 2012-12-9"
 
-.. doxygenfunction:: print(std::basic_ostream<Char>&, const S&, Args&&...)
+{fmt} only supports insertion operators that are defined in the same namespaces
+as the types they format and can be found with the argument-dependent lookup.
+
+.. doxygenfunction:: print(std::basic_ostream<Char> &os, const S &format_str, Args&&... args)
 
 .. _printf-api:
 
@@ -475,18 +503,32 @@ user-defined types that have overloaded ``operator<<``::
 
 The header ``fmt/printf.h`` provides ``printf``-like formatting functionality.
 The following functions use `printf format string syntax
-<http://pubs.opengroup.org/onlinepubs/009695399/functions/fprintf.html>`_ with
+<https://pubs.opengroup.org/onlinepubs/009695399/functions/fprintf.html>`_ with
 the POSIX extension for positional arguments. Unlike their standard
 counterparts, the ``fmt`` functions are type-safe and throw an exception if an
 argument type doesn't match its format specification.
 
-.. doxygenfunction:: printf(const S&, const Args&...)
+.. doxygenfunction:: printf(const S &format_str, const T&... args)
 
-.. doxygenfunction:: fprintf(std::FILE *, const S&, const Args&...)
+.. doxygenfunction:: fprintf(std::FILE *f, const S &fmt, const T&... args) -> int
 
-.. doxygenfunction:: fprintf(std::basic_ostream<Char>&, const S&, const Args&...)
+.. doxygenfunction:: sprintf(const S&, const T&...)
 
-.. doxygenfunction:: sprintf(const S&, const Args&...)
+.. _xchar-api:
+
+``wchar_t`` Support
+===================
+
+The optional header ``fmt/wchar_t.h`` provides support for ``wchar_t`` and
+exotic character types.
+
+.. doxygenstruct:: fmt::is_char
+
+.. doxygentypedef:: fmt::wstring_view
+
+.. doxygentypedef:: fmt::wformat_context
+
+.. doxygenfunction:: fmt::to_wstring(const T &value)
 
 Compatibility with C++20 ``std::format``
 ========================================
@@ -497,9 +539,6 @@ differences:
 
 * Names are defined in the ``fmt`` namespace instead of ``std`` to avoid
   collisions with standard library implementations.
-* The ``'L'`` format specifier cannot be combined with presentation specifiers
-  yet.
 * Width calculation doesn't use grapheme clusterization. The latter has been
   implemented in a separate branch but hasn't been integrated yet.
-* Chrono formatting doesn't support C++20 date types since they are not provided
-  by standard library implementations.
+* Most C++20 chrono types are not supported yet.

doc/build.py

@@ -1,52 +1,33 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 # Build the documentation.
 
-from __future__ import print_function
-import errno, os, shutil, sys, tempfile
-from subprocess import check_call, check_output, CalledProcessError, Popen, PIPE
-from distutils.version import LooseVersion
+import errno, os, re, sys
+from subprocess import check_call, CalledProcessError, Popen, PIPE, STDOUT
 
-versions = ['1.0.0', '1.1.0', '2.0.0', '3.0.2', '4.0.0', '4.1.0', '5.0.0', '5.1.0', '5.2.0', '5.2.1', '5.3.0', '6.0.0', '6.1.0', '6.1.1', '6.1.2', '6.2.0', '6.2.1', '7.0.0', '7.0.1', '7.0.2', '7.0.3', '7.1.0', '7.1.1']
+versions = ['1.0.0', '1.1.0', '2.0.0', '3.0.2', '4.0.0', '4.1.0', '5.0.0', '5.1.0', '5.2.0', '5.2.1', '5.3.0', '6.0.0', '6.1.0', '6.1.1', '6.1.2', '6.2.0', '6.2.1', '7.0.0', '7.0.1', '7.0.2', '7.0.3', '7.1.0', '7.1.1', '7.1.2', '7.1.3', '8.0.0']
 
-def pip_install(package, commit=None, **kwargs):
-  "Install package using pip."
-  if commit:
-    package = 'git+https://github.com/{0}.git@{1}'.format(package, commit)
-  print('Installing {0}'.format(package))
-  check_call(['pip', 'install', package])
+class Pip:
+  def __init__(self, venv_dir):
+    self.path = os.path.join(venv_dir, 'bin', 'pip')
 
-def create_build_env(dirname='virtualenv'):
+  def install(self, package, commit=None):
+    "Install package using pip."
+    if commit:
+      package = 'git+https://github.com/{0}.git@{1}'.format(package, commit)
+    print('Installing {0}'.format(package))
+    check_call([self.path, 'install', package])
+
+def create_build_env(venv_dir='virtualenv'):
   # Create virtualenv.
-  if not os.path.exists(dirname):
-    check_call(['virtualenv', dirname])
-  import sysconfig
-  scripts_dir = os.path.basename(sysconfig.get_path('scripts'))
-  activate_this_file = os.path.join(dirname, scripts_dir, 'activate_this.py')
-  with open(activate_this_file) as f:
-    exec(f.read(), dict(__file__=activate_this_file))
-  # Import get_distribution after activating virtualenv to get info about
-  # the correct packages.
-  from pkg_resources import get_distribution, DistributionNotFound
-  # Upgrade pip because installation of sphinx with pip 1.1 available on Travis
-  # is broken (see #207) and it doesn't support the show command.
-  pip_version = get_distribution('pip').version
-  if LooseVersion(pip_version) < LooseVersion('1.5.4'):
-    print("Updating pip")
-    check_call(['pip', 'install', '--upgrade', 'pip'])
-  # Upgrade distribute because installation of sphinx with distribute 0.6.24
-  # available on Travis is broken (see #207).
-  try:
-    distribute_version = get_distribution('distribute').version
-    if LooseVersion(distribute_version) <= LooseVersion('0.6.24'):
-      print("Updating distribute")
-      check_call(['pip', 'install', '--upgrade', 'distribute'])
-  except DistributionNotFound:
-    pass
+  if not os.path.exists(venv_dir):
+    check_call(['python3', '-m', 'venv', venv_dir])
   # Install Sphinx and Breathe. Require the exact version of Sphinx which is
   # compatible with Breathe.
-  pip_install('sphinx-doc/sphinx', '12b83372ac9316e8cbe86e7fed889296a4cc29ee')
-  pip_install('michaeljones/breathe',
-              '129222318f7c8f865d2631e7da7b033567e7f56a')
+  pip = Pip(venv_dir)
+  pip.install('wheel')
+  pip.install('six')
+  pip.install('sphinx-doc/sphinx', 'v3.3.0')
+  pip.install('michaeljones/breathe', 'v4.16.0')
 
 def build_docs(version='dev', **kwargs):
   doc_dir = kwargs.get('doc_dir', os.path.dirname(os.path.realpath(__file__)))
@@ -55,16 +36,17 @@ def build_docs(version='dev', **kwargs):
       'include_dir', os.path.join(os.path.dirname(doc_dir), 'include', 'fmt'))
   # Build docs.
   cmd = ['doxygen', '-']
-  p = Popen(cmd, stdin=PIPE)
+  p = Popen(cmd, stdin=PIPE, stdout=PIPE, stderr=STDOUT)
   doxyxml_dir = os.path.join(work_dir, 'doxyxml')
-  p.communicate(input=r'''
+  out, _ = p.communicate(input=r'''
       PROJECT_NAME      = fmt
       GENERATE_LATEX    = NO
       GENERATE_MAN      = NO
       GENERATE_RTF      = NO
       CASE_SENSE_NAMES  = NO
       INPUT             = {0}/chrono.h {0}/color.h {0}/core.h {0}/compile.h \
-                          {0}/format.h {0}/os.h {0}/ostream.h {0}/printf.h
+                          {0}/format.h {0}/os.h {0}/ostream.h {0}/printf.h \
+                          {0}/xchar.h
       QUIET             = YES
       JAVADOC_AUTOBRIEF = YES
       AUTOLINK_SUPPORT  = NO
@@ -75,6 +57,7 @@ def build_docs(version='dev', **kwargs):
       ALIASES          += "endrst=\endverbatim"
       MACRO_EXPANSION   = YES
       PREDEFINED        = _WIN32=1 \
+                          __linux__=1 \
                           FMT_USE_VARIADIC_TEMPLATES=1 \
                           FMT_USE_RVALUE_REFERENCES=1 \
                           FMT_USE_USER_DEFINED_LITERALS=1 \
@@ -83,21 +66,37 @@ def build_docs(version='dev', **kwargs):
                           "FMT_BEGIN_NAMESPACE=namespace fmt {{" \
                           "FMT_END_NAMESPACE=}}" \
                           "FMT_STRING_ALIAS=1" \
-                          "FMT_ENABLE_IF(B)="
+                          "FMT_DOC=1"
       EXCLUDE_SYMBOLS   = fmt::formatter fmt::printf_formatter fmt::arg_join \
                           fmt::basic_format_arg::handle
     '''.format(include_dir, doxyxml_dir).encode('UTF-8'))
+  out = out.decode('utf-8')
+  internal_symbols = [
+    'fmt::detail::.*',
+    'basic_data<>',
+    'fmt::type_identity',
+    'fmt::dynamic_formatter'
+  ]
+  noisy_warnings = [
+    'warning: (Compound|Member .* of class) (' + '|'.join(internal_symbols) + \
+      ') is not documented.',
+    'warning: Internal inconsistency: .* does not belong to any container!'
+  ]
+  for w in noisy_warnings:
+      out = re.sub('.*' + w + '\n', '', out)
+  print(out)
   if p.returncode != 0:
     raise CalledProcessError(p.returncode, cmd)
+
   html_dir = os.path.join(work_dir, 'html')
   main_versions = reversed(versions[-3:])
-  check_call(['sphinx-build',
+  check_call([os.path.join(work_dir, 'virtualenv', 'bin', 'sphinx-build'),
               '-Dbreathe_projects.format=' + os.path.abspath(doxyxml_dir),
               '-Dversion=' + version, '-Drelease=' + version,
               '-Aversion=' + version, '-Aversions=' + ','.join(main_versions),
               '-b', 'html', doc_dir, html_dir])
   try:
-    check_call(['lessc', '--clean-css',
+    check_call(['lessc', '--verbose', '--clean-css',
                 '--include-path=' + os.path.join(doc_dir, 'bootstrap'),
                 os.path.join(doc_dir, 'fmt.less'),
                 os.path.join(html_dir, '_static', 'fmt.css')])

doc/fmt.less

@@ -56,6 +56,11 @@ div.sphinxsidebar {
   padding: 0;
 }
 
+// Override center alignment in tables.
+td {
+  text-align: left;
+}
+
 p.rubric {
   margin-top: 10px;
 }

doc/index.rst

@@ -26,21 +26,23 @@ is safer, simpler and several times `faster
 <https://www.zverovich.net/2020/06/13/fast-int-to-string-revisited.html>`_
 than common standard library implementations.
 The `format string syntax <syntax.html>`_ is similar to the one used by
-`str.format <http://docs.python.org/3/library/stdtypes.html#str.format>`_ in
+`str.format <https://docs.python.org/3/library/stdtypes.html#str.format>`_ in
 Python:
 
 .. code:: c++
 
-  fmt::format("The answer is {}.", 42);
+  std::string s = fmt::format("The answer is {}.", 42);
   
 The ``fmt::format`` function returns a string "The answer is 42.". You can use
 ``fmt::memory_buffer`` to avoid constructing ``std::string``:
 
 .. code:: c++
 
-  fmt::memory_buffer out;
-  format_to(out, "For a moment, {} happened.", "nothing");
-  out.data(); // returns a pointer to the formatted data
+  auto out = fmt::memory_buffer();
+  format_to(std::back_inserter(out),
+            "For a moment, {} happened.", "nothing");
+  auto data = out.data(); // pointer to the formatted data
+  auto size = out.size(); // size of the formatted data
 
 The ``fmt::print`` function performs formatting and writes the result to a stream:
 
@@ -108,16 +110,10 @@ The following code
   fmt::format("Cyrillic letter {}", L'\x42e');
   
 produces a compile-time error because wide character ``L'\x42e'`` cannot be
-formatted into a narrow string. You can use a wide format string instead:
-
-.. code:: c++
-
-  fmt::format(L"Cyrillic letter {}", L'\x42e');
-
-For comparison, writing a wide character to ``std::ostream`` results in
-its numeric value being written to the stream (i.e. 1070 instead of letter 'ю'
-which is represented by ``L'\x42e'`` if we use Unicode) which is rarely
-desirable.
+formatted into a narrow string. For comparison, writing a wide character to
+``std::ostream`` results in its numeric value being written to the stream
+(i.e. 1070 instead of letter 'ю' which is represented by ``L'\x42e'`` if we
+use Unicode) which is rarely desirable.
 
 Compact Binary Code
 -------------------
@@ -166,7 +162,7 @@ The library is highly portable and relies only on a small set of C++11 features:
 * deleted functions
 * alias templates
 
-These are available in GCC 4.8, Clang 3.0, MSVC 19.0 (2015) and more recent
+These are available in GCC 4.8, Clang 3.4, MSVC 19.0 (2015) and more recent
 compiler version. For older compilers use {fmt} `version 4.x
 <https://github.com/fmtlib/fmt/releases/tag/4.1.0>`_ which is maintained and
 only requires C++98.
@@ -190,11 +186,13 @@ just three header files and no external dependencies.
 A permissive MIT `license <https://github.com/fmtlib/fmt#license>`_ allows
 using the library both in open-source and commercial projects.
 
+`Learn more... <contents.html>`_
+
 .. raw:: html
 
   <a class="btn btn-success" href="https://github.com/fmtlib/fmt">GitHub Repository</a>
 
   <div class="section footer">
-    <iframe src="http://ghbtns.com/github-btn.html?user=fmtlib&amp;repo=fmt&amp;type=watch&amp;count=true"
+    <iframe src="https://ghbtns.com/github-btn.html?user=fmtlib&amp;repo=fmt&amp;type=watch&amp;count=true"
             class="github-btn" width="100" height="20"></iframe>
   </div>

doc/syntax.rst

@@ -16,7 +16,7 @@ literal text, it can be escaped by doubling: ``{{`` and ``}}``.
 The grammar for a replacement field is as follows:
 
 .. productionlist:: sf
-   replacement_field: "{" [`arg_id`] [":" `format_spec`] "}"
+   replacement_field: "{" [`arg_id`] [":" (`format_spec` | `chrono_format_spec`)] "}"
    arg_id: `integer` | `identifier`
    integer: `digit`+
    digit: "0"..."9"
@@ -27,8 +27,8 @@ The grammar for a replacement field is as follows:
 In less formal terms, the replacement field can start with an *arg_id*
 that specifies the argument whose value is to be formatted and inserted into
 the output instead of the replacement field.
-The *arg_id* is optionally followed by a *format_spec*, which is preceded
-by a colon ``':'``.  These specify a non-default format for the replacement value.
+The *arg_id* is optionally followed by a *format_spec*, which is preceded by a
+colon ``':'``.  These specify a non-default format for the replacement value.
 
 See also the :ref:`formatspec` section.
 
@@ -75,14 +75,14 @@ although some of the formatting options are only supported by the numeric types.
 The general form of a *standard format specifier* is:
 
 .. productionlist:: sf
-   format_spec: [[`fill`]`align`][`sign`]["#"]["0"][`width`]["." `precision`][`type`]
+   format_spec: [[`fill`]`align`][`sign`]["#"]["0"][`width`]["." `precision`]["L"][`type`]
    fill: <a character other than '{' or '}'>
    align: "<" | ">" | "^"
    sign: "+" | "-" | " "
    width: `integer` | "{" [`arg_id`] "}"
    precision: `integer` | "{" [`arg_id`] "}"
-   type: `int_type` | "a" | "A" | "c" | "e" | "E" | "f" | "F" | "g" | "G" | "L" | "p" | "s"
-   int_type: "b" | "B" | "d" | "o" | "x" | "X"
+   type: "a" | "A" | "b" | "B" | "c" | "d" | "e" | "E" | "f" | "F" | "g" | "G" |
+       : "o" | "p" | "s" | "x" | "X"
 
 The *fill* character can be any Unicode code point other than ``'{'`` or
 ``'}'``. The presence of a fill character is signaled by the character following
@@ -163,6 +163,9 @@ indicates the maximum field size - in other words, how many characters will be
 used from the field content. The *precision* is not allowed for integer,
 character, Boolean, and pointer values.
 
+The ``'L'`` option uses the current locale setting to insert the appropriate
+number separator characters. This option is only valid for numeric types.
+
 Finally, the *type* determines how the data should be presented.
 
 The available string presentation types are:
@@ -200,6 +203,8 @@ The available integer presentation types are:
 |         | ``'#'`` option with this type adds the prefix ``"0B"``   |
 |         | to the output value.                                     |
 +---------+----------------------------------------------------------+
+| ``'c'`` | Character format. Outputs the number as a character.     |
++---------+----------------------------------------------------------+
 | ``'d'`` | Decimal integer. Outputs the number in base 10.          |
 +---------+----------------------------------------------------------+
 | ``'o'`` | Octal format. Outputs the number in base 8.              |
@@ -214,10 +219,6 @@ The available integer presentation types are:
 |         | ``'#'`` option with this type adds the prefix ``"0X"``   |
 |         | to the output value.                                     |
 +---------+----------------------------------------------------------+
-| ``'L'`` | Locale-specific format. This is the same as ``'d'``,     |
-|         | except that it uses the current locale setting to insert |
-|         | the appropriate number separator characters.             |
-+---------+----------------------------------------------------------+
 | none    | The same as ``'d'``.                                     |
 +---------+----------------------------------------------------------+
 
@@ -261,14 +262,8 @@ The available presentation types for floating-point values are:
 |         | ``'E'`` if the number gets too large. The                |
 |         | representations of infinity and NaN are uppercased, too. |
 +---------+----------------------------------------------------------+
-| ``'L'`` | Locale-specific format. This is the same as ``'g'``,     |
-|         | except that it uses the current locale setting to insert |
-|         | the appropriate number separator characters.             |
-+---------+----------------------------------------------------------+
-| none    | Similar to ``'g'``, except that fixed-point notation,    |
-|         | when used, has at least one digit past the decimal       |
-|         | point. The default precision is as high as needed to     |
-|         | represent the particular value.                          |
+| none    | Similar to ``'g'``, except that the default precision is |
+|         | as high as needed to represent the particular value.     |
 +---------+----------------------------------------------------------+
 
 .. ifconfig:: False
@@ -303,6 +298,59 @@ The available presentation types for pointers are:
 | none    | The same as ``'p'``.                                     |
 +---------+----------------------------------------------------------+
 
+.. _chrono-specs:
+
+Chrono Format Specifications
+============================
+
+Format specifications for chrono types have the following syntax:
+
+.. productionlist:: sf
+   chrono_format_spec: [[`fill`]`align`][`width`]["." `precision`][`chrono_specs`]
+   chrono_specs: [`chrono_specs`] `conversion_spec` | `chrono_specs` `literal_char`
+   conversion_spec: "%" [`modifier`] `chrono_type`
+   literal_char: <a character other than '{', '}' or '%'>
+   modifier: "E" | "O"
+   chrono_type: "a" | "A" | "b" | "B" | "c" | "C" | "d" | "D" | "e" | "F" |
+              : "g" | "G" | "h" | "H" | "I" | "j" | "m" | "M" | "n" | "p" |
+              : "q" | "Q" | "r" | "R" | "S" | "t" | "T" | "u" | "U" | "V" |
+              : "w" | "W" | "x" | "X" | "y" | "Y" | "z" | "Z" | "%"
+
+Literal chars are copied unchanged to the output. Precision is valid only for
+``std::chrono::duration`` types with a floating-point representation type.
+
+The available presentation types (*chrono_type*) for chrono durations and time
+points are:
+
++---------+--------------------------------------------------------------------+
+| Type    | Meaning                                                            |
++=========+====================================================================+
+| ``'H'`` | The hour (24-hour clock) as a decimal number. If the result is a   |
+|         | single digit, it is prefixed with 0. The modified command ``%OH``  |
+|         | produces the locale's alternative representation.                  |
++---------+--------------------------------------------------------------------+
+| ``'M'`` | The minute as a decimal number. If the result is a single digit,   |
+|         | it is prefixed with 0. The modified command ``%OM`` produces the   |
+|         | locale's alternative representation.                               |
++---------+--------------------------------------------------------------------+
+| ``'S'`` | Seconds as a decimal number. If the number of seconds is less than |
+|         | 10, the result is prefixed with 0. If the precision of the input   |
+|         | cannot be exactly represented with seconds, then the format is a   |
+|         | decimal floating-point number with a fixed format and a precision  |
+|         | matching that of the precision of the input (or to a microseconds  |
+|         | precision if the conversion to floating-point decimal seconds      |
+|         | cannot be made within 18 fractional digits). The character for the |
+|         | decimal point is localized according to the locale. The modified   |
+|         | command ``%OS`` produces the locale's alternative representation.  |
++---------+--------------------------------------------------------------------+
+
+Specifiers that have a calendaric component such as `'d'` (the day of month)
+are valid only for ``std::tm`` and not durations or time points.
+
+``std::tm`` uses the system's `strftime
+<https://en.cppreference.com/w/cpp/chrono/c/strftime>`_ so refer to its
+documentation for details on supported conversion specifiers. 
+
 .. _formatexamples:
 
 Format Examples
@@ -391,7 +439,7 @@ Using type-specific formatting::
 
    auto t = tm();
    t.tm_year = 2010 - 1900;
-   t.tm_mon = 6;
+   t.tm_mon = 7;
    t.tm_mday = 4;
    t.tm_hour = 12;
    t.tm_min = 15;

doc/usage.rst

@@ -15,7 +15,7 @@ Building the Library
 
 The included `CMake build script`__ can be used to build the fmt
 library on a wide range of platforms. CMake is freely available for
-download from http://www.cmake.org/download/.
+download from https://www.cmake.org/download/.
 
 __ https://github.com/fmtlib/fmt/blob/master/CMakeLists.txt
 
@@ -50,7 +50,7 @@ To build a `shared library`__ set the ``BUILD_SHARED_LIBS`` CMake variable to
 
   cmake -DBUILD_SHARED_LIBS=TRUE ...
 
-__ http://en.wikipedia.org/wiki/Library_%28computing%29#Shared_libraries
+__ https://en.wikipedia.org/wiki/Library_%28computing%29#Shared_libraries
 
 
 To build a `static library` with position independent code (required if the main
@@ -202,11 +202,11 @@ For an example of using fmt with Android NDK, see the
 `android-ndk-example <https://github.com/fmtlib/android-ndk-example>`_
 repository.
 
-__ https://github.com/fmtlib/fmt/blob/master/Android.mk
+__ https://github.com/fmtlib/fmt/blob/master/support/Android.mk
 
 Homebrew
 ========
 
-fmt can be installed on OS X using `Homebrew <http://brew.sh/>`_::
+fmt can be installed on OS X using `Homebrew <https://brew.sh/>`_::
 
   brew install fmt

include/fmt/args.h

@@ -0,0 +1,232 @@
+// Formatting library for C++ - dynamic format arguments
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_ARGS_H_
+#define FMT_ARGS_H_
+
+#include <functional>  // std::reference_wrapper
+#include <memory>      // std::unique_ptr
+#include <vector>
+
+#include "core.h"
+
+FMT_BEGIN_NAMESPACE
+
+namespace detail {
+
+template <typename T> struct is_reference_wrapper : std::false_type {};
+template <typename T>
+struct is_reference_wrapper<std::reference_wrapper<T>> : std::true_type {};
+
+template <typename T> const T& unwrap(const T& v) { return v; }
+template <typename T> const T& unwrap(const std::reference_wrapper<T>& v) {
+  return static_cast<const T&>(v);
+}
+
+class dynamic_arg_list {
+  // Workaround for clang's -Wweak-vtables. Unlike for regular classes, for
+  // templates it doesn't complain about inability to deduce single translation
+  // unit for placing vtable. So storage_node_base is made a fake template.
+  template <typename = void> struct node {
+    virtual ~node() = default;
+    std::unique_ptr<node<>> next;
+  };
+
+  template <typename T> struct typed_node : node<> {
+    T value;
+
+    template <typename Arg>
+    FMT_CONSTEXPR typed_node(const Arg& arg) : value(arg) {}
+
+    template <typename Char>
+    FMT_CONSTEXPR typed_node(const basic_string_view<Char>& arg)
+        : value(arg.data(), arg.size()) {}
+  };
+
+  std::unique_ptr<node<>> head_;
+
+ public:
+  template <typename T, typename Arg> const T& push(const Arg& arg) {
+    auto new_node = std::unique_ptr<typed_node<T>>(new typed_node<T>(arg));
+    auto& value = new_node->value;
+    new_node->next = std::move(head_);
+    head_ = std::move(new_node);
+    return value;
+  }
+};
+}  // namespace detail
+
+/**
+  \rst
+  A dynamic version of `fmt::format_arg_store`.
+  It's equipped with a storage to potentially temporary objects which lifetimes
+  could be shorter than the format arguments object.
+
+  It can be implicitly converted into `~fmt::basic_format_args` for passing
+  into type-erased formatting functions such as `~fmt::vformat`.
+  \endrst
+ */
+template <typename Context>
+class dynamic_format_arg_store
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+    // Workaround a GCC template argument substitution bug.
+    : public basic_format_args<Context>
+#endif
+{
+ private:
+  using char_type = typename Context::char_type;
+
+  template <typename T> struct need_copy {
+    static constexpr detail::type mapped_type =
+        detail::mapped_type_constant<T, Context>::value;
+
+    enum {
+      value = !(detail::is_reference_wrapper<T>::value ||
+                std::is_same<T, basic_string_view<char_type>>::value ||
+                std::is_same<T, detail::std_string_view<char_type>>::value ||
+                (mapped_type != detail::type::cstring_type &&
+                 mapped_type != detail::type::string_type &&
+                 mapped_type != detail::type::custom_type))
+    };
+  };
+
+  template <typename T>
+  using stored_type = conditional_t<detail::is_string<T>::value &&
+                                        !has_formatter<T, Context>::value &&
+                                        !detail::is_reference_wrapper<T>::value,
+                                    std::basic_string<char_type>, T>;
+
+  // Storage of basic_format_arg must be contiguous.
+  std::vector<basic_format_arg<Context>> data_;
+  std::vector<detail::named_arg_info<char_type>> named_info_;
+
+  // Storage of arguments not fitting into basic_format_arg must grow
+  // without relocation because items in data_ refer to it.
+  detail::dynamic_arg_list dynamic_args_;
+
+  friend class basic_format_args<Context>;
+
+  unsigned long long get_types() const {
+    return detail::is_unpacked_bit | data_.size() |
+           (named_info_.empty()
+                ? 0ULL
+                : static_cast<unsigned long long>(detail::has_named_args_bit));
+  }
+
+  const basic_format_arg<Context>* data() const {
+    return named_info_.empty() ? data_.data() : data_.data() + 1;
+  }
+
+  template <typename T> void emplace_arg(const T& arg) {
+    data_.emplace_back(detail::make_arg<Context>(arg));
+  }
+
+  template <typename T>
+  void emplace_arg(const detail::named_arg<char_type, T>& arg) {
+    if (named_info_.empty()) {
+      constexpr const detail::named_arg_info<char_type>* zero_ptr{nullptr};
+      data_.insert(data_.begin(), {zero_ptr, 0});
+    }
+    data_.emplace_back(detail::make_arg<Context>(detail::unwrap(arg.value)));
+    auto pop_one = [](std::vector<basic_format_arg<Context>>* data) {
+      data->pop_back();
+    };
+    std::unique_ptr<std::vector<basic_format_arg<Context>>, decltype(pop_one)>
+        guard{&data_, pop_one};
+    named_info_.push_back({arg.name, static_cast<int>(data_.size() - 2u)});
+    data_[0].value_.named_args = {named_info_.data(), named_info_.size()};
+    guard.release();
+  }
+
+ public:
+  /**
+    \rst
+    Adds an argument into the dynamic store for later passing to a formatting
+    function.
+
+    Note that custom types and string types (but not string views) are copied
+    into the store dynamically allocating memory if necessary.
+
+    **Example**::
+
+      fmt::dynamic_format_arg_store<fmt::format_context> store;
+      store.push_back(42);
+      store.push_back("abc");
+      store.push_back(1.5f);
+      std::string result = fmt::vformat("{} and {} and {}", store);
+    \endrst
+  */
+  template <typename T> void push_back(const T& arg) {
+    if (detail::const_check(need_copy<T>::value))
+      emplace_arg(dynamic_args_.push<stored_type<T>>(arg));
+    else
+      emplace_arg(detail::unwrap(arg));
+  }
+
+  /**
+    \rst
+    Adds a reference to the argument into the dynamic store for later passing to
+    a formatting function.
+
+    **Example**::
+
+      fmt::dynamic_format_arg_store<fmt::format_context> store;
+      char band[] = "Rolling Stones";
+      store.push_back(std::cref(band));
+      band[9] = 'c'; // Changing str affects the output.
+      std::string result = fmt::vformat("{}", store);
+      // result == "Rolling Scones"
+    \endrst
+  */
+  template <typename T> void push_back(std::reference_wrapper<T> arg) {
+    static_assert(
+        need_copy<T>::value,
+        "objects of built-in types and string views are always copied");
+    emplace_arg(arg.get());
+  }
+
+  /**
+    Adds named argument into the dynamic store for later passing to a formatting
+    function. ``std::reference_wrapper`` is supported to avoid copying of the
+    argument. The name is always copied into the store.
+  */
+  template <typename T>
+  void push_back(const detail::named_arg<char_type, T>& arg) {
+    const char_type* arg_name =
+        dynamic_args_.push<std::basic_string<char_type>>(arg.name).c_str();
+    if (detail::const_check(need_copy<T>::value)) {
+      emplace_arg(
+          fmt::arg(arg_name, dynamic_args_.push<stored_type<T>>(arg.value)));
+    } else {
+      emplace_arg(fmt::arg(arg_name, arg.value));
+    }
+  }
+
+  /** Erase all elements from the store */
+  void clear() {
+    data_.clear();
+    named_info_.clear();
+    dynamic_args_ = detail::dynamic_arg_list();
+  }
+
+  /**
+    \rst
+    Reserves space to store at least *new_cap* arguments including
+    *new_cap_named* named arguments.
+    \endrst
+  */
+  void reserve(size_t new_cap, size_t new_cap_named) {
+    FMT_ASSERT(new_cap >= new_cap_named,
+               "Set of arguments includes set of named arguments");
+    data_.reserve(new_cap);
+    named_info_.reserve(new_cap_named);
+  }
+};
+
+FMT_END_NAMESPACE
+
+#endif  // FMT_ARGS_H_

include/fmt/chrono.h

@@ -8,13 +8,13 @@
 #ifndef FMT_CHRONO_H_
 #define FMT_CHRONO_H_
 
+#include <algorithm>
 #include <chrono>
 #include <ctime>
 #include <locale>
 #include <sstream>
 
 #include "format.h"
-#include "locale.h"
 
 FMT_BEGIN_NAMESPACE
 
@@ -282,13 +282,89 @@ To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
 #define FMT_NOMACRO
 
 namespace detail {
+template <typename T = void> struct null {};
 inline null<> localtime_r FMT_NOMACRO(...) { return null<>(); }
 inline null<> localtime_s(...) { return null<>(); }
 inline null<> gmtime_r(...) { return null<>(); }
 inline null<> gmtime_s(...) { return null<>(); }
+
+inline auto do_write(const std::tm& time, const std::locale& loc, char format,
+                     char modifier) -> std::string {
+  auto&& os = std::ostringstream();
+  os.imbue(loc);
+  using iterator = std::ostreambuf_iterator<char>;
+  const auto& facet = std::use_facet<std::time_put<char, iterator>>(loc);
+  auto end = facet.put(os, os, ' ', &time, format, modifier);
+  if (end.failed()) FMT_THROW(format_error("failed to format time"));
+  auto str = os.str();
+  if (!detail::is_utf8() || loc == std::locale::classic()) return str;
+    // char16_t and char32_t codecvts are broken in MSVC (linkage errors) and
+    // gcc-4.
+#if FMT_MSC_VER != 0 || \
+    (defined(__GLIBCXX__) && !defined(_GLIBCXX_USE_DUAL_ABI))
+  // The _GLIBCXX_USE_DUAL_ABI macro is always defined in libstdc++ from gcc-5
+  // and newer.
+  using code_unit = wchar_t;
+#else
+  using code_unit = char32_t;
+#endif
+  auto& f = std::use_facet<std::codecvt<code_unit, char, std::mbstate_t>>(loc);
+  auto mb = std::mbstate_t();
+  const char* from_next = nullptr;
+  code_unit* to_next = nullptr;
+  constexpr size_t buf_size = 32;
+  code_unit buf[buf_size] = {};
+  auto result = f.in(mb, str.data(), str.data() + str.size(), from_next, buf,
+                     buf + buf_size, to_next);
+  if (result != std::codecvt_base::ok)
+    FMT_THROW(format_error("failed to format time"));
+  str.clear();
+  for (code_unit* p = buf; p != to_next; ++p) {
+    uint32_t c = static_cast<uint32_t>(*p);
+    if (sizeof(code_unit) == 2 && c >= 0xd800 && c <= 0xdfff) {
+      // surrogate pair
+      ++p;
+      if (p == to_next || (c & 0xfc00) != 0xd800 || (*p & 0xfc00) != 0xdc00) {
+        FMT_THROW(format_error("failed to format time"));
+      }
+      c = (c << 10) + static_cast<uint32_t>(*p) - 0x35fdc00;
+    }
+    if (c < 0x80) {
+      str.push_back(static_cast<char>(c));
+    } else if (c < 0x800) {
+      str.push_back(static_cast<char>(0xc0 | (c >> 6)));
+      str.push_back(static_cast<char>(0x80 | (c & 0x3f)));
+    } else if ((c >= 0x800 && c <= 0xd7ff) || (c >= 0xe000 && c <= 0xffff)) {
+      str.push_back(static_cast<char>(0xe0 | (c >> 12)));
+      str.push_back(static_cast<char>(0x80 | ((c & 0xfff) >> 6)));
+      str.push_back(static_cast<char>(0x80 | (c & 0x3f)));
+    } else if (c >= 0x10000 && c <= 0x10ffff) {
+      str.push_back(static_cast<char>(0xf0 | (c >> 18)));
+      str.push_back(static_cast<char>(0x80 | ((c & 0x3ffff) >> 12)));
+      str.push_back(static_cast<char>(0x80 | ((c & 0xfff) >> 6)));
+      str.push_back(static_cast<char>(0x80 | (c & 0x3f)));
+    } else {
+      FMT_THROW(format_error("failed to format time"));
+    }
+  }
+  return str;
+}
+
+template <typename OutputIt>
+auto write(OutputIt out, const std::tm& time, const std::locale& loc,
+           char format, char modifier = 0) -> OutputIt {
+  auto str = do_write(time, loc, format, modifier);
+  return std::copy(str.begin(), str.end(), out);
+}
 }  // namespace detail
 
-// Thread-safe replacement for std::localtime
+FMT_MODULE_EXPORT_BEGIN
+
+/**
+  Converts given time since epoch as ``std::time_t`` value into calendar time,
+  expressed in local time. Unlike ``std::localtime``, this function is
+  thread-safe on most platforms.
+ */
 inline std::tm localtime(std::time_t time) {
   struct dispatcher {
     std::time_t time_;
@@ -330,7 +406,11 @@ inline std::tm localtime(
   return localtime(std::chrono::system_clock::to_time_t(time_point));
 }
 
-// Thread-safe replacement for std::gmtime
+/**
+  Converts given time since epoch as ``std::time_t`` value into calendar time,
+  expressed in Coordinated Universal Time (UTC). Unlike ``std::gmtime``, this
+  function is thread-safe on most platforms.
+ */
 inline std::tm gmtime(std::time_t time) {
   struct dispatcher {
     std::time_t time_;
@@ -371,44 +451,84 @@ inline std::tm gmtime(
   return gmtime(std::chrono::system_clock::to_time_t(time_point));
 }
 
-namespace detail {
+FMT_BEGIN_DETAIL_NAMESPACE
+
 inline size_t strftime(char* str, size_t count, const char* format,
                        const std::tm* time) {
-  return std::strftime(str, count, format, time);
+  // Assign to a pointer to suppress GCCs -Wformat-nonliteral
+  // First assign the nullptr to suppress -Wsuggest-attribute=format
+  std::size_t (*strftime)(char*, std::size_t, const char*, const std::tm*) =
+      nullptr;
+  strftime = std::strftime;
+  return strftime(str, count, format, time);
 }
 
 inline size_t strftime(wchar_t* str, size_t count, const wchar_t* format,
                        const std::tm* time) {
-  return std::wcsftime(str, count, format, time);
+  // See above
+  std::size_t (*wcsftime)(wchar_t*, std::size_t, const wchar_t*,
+                          const std::tm*) = nullptr;
+  wcsftime = std::wcsftime;
+  return wcsftime(str, count, format, time);
 }
-}  // namespace detail
 
-template <typename Char>
-struct formatter<std::chrono::time_point<std::chrono::system_clock>, Char>
-    : formatter<std::tm, Char> {
+FMT_END_DETAIL_NAMESPACE
+
+template <typename Char, typename Duration>
+struct formatter<std::chrono::time_point<std::chrono::system_clock, Duration>,
+                 Char> : formatter<std::tm, Char> {
+  FMT_CONSTEXPR formatter() {
+    this->specs = {default_specs, sizeof(default_specs) / sizeof(Char)};
+  }
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    auto it = ctx.begin();
+    if (it != ctx.end() && *it == ':') ++it;
+    auto end = it;
+    while (end != ctx.end() && *end != '}') ++end;
+    if (end != it) this->specs = {it, detail::to_unsigned(end - it)};
+    return end;
+  }
+
   template <typename FormatContext>
   auto format(std::chrono::time_point<std::chrono::system_clock> val,
               FormatContext& ctx) -> decltype(ctx.out()) {
     std::tm time = localtime(val);
     return formatter<std::tm, Char>::format(time, ctx);
   }
+
+  static constexpr Char default_specs[] = {'%', 'Y', '-', '%', 'm', '-',
+                                           '%', 'd', ' ', '%', 'H', ':',
+                                           '%', 'M', ':', '%', 'S'};
 };
 
+template <typename Char, typename Duration>
+constexpr Char
+    formatter<std::chrono::time_point<std::chrono::system_clock, Duration>,
+              Char>::default_specs[];
+
 template <typename Char> struct formatter<std::tm, Char> {
   template <typename ParseContext>
-  auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
     auto it = ctx.begin();
     if (it != ctx.end() && *it == ':') ++it;
     auto end = it;
     while (end != ctx.end() && *end != '}') ++end;
-    tm_format.reserve(detail::to_unsigned(end - it + 1));
-    tm_format.append(it, end);
-    tm_format.push_back('\0');
+    specs = {it, detail::to_unsigned(end - it)};
     return end;
   }
 
   template <typename FormatContext>
-  auto format(const std::tm& tm, FormatContext& ctx) -> decltype(ctx.out()) {
+  auto format(const std::tm& tm, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    basic_memory_buffer<Char> tm_format;
+    tm_format.append(specs.begin(), specs.end());
+    // By appending an extra space we can distinguish an empty result that
+    // indicates insufficient buffer size from a guaranteed non-empty result
+    // https://github.com/fmtlib/fmt/issues/2238
+    tm_format.push_back(' ');
+    tm_format.push_back('\0');
     basic_memory_buffer<Char> buf;
     size_t start = buf.size();
     for (;;) {
@@ -418,49 +538,40 @@ template <typename Char> struct formatter<std::tm, Char> {
         buf.resize(start + count);
         break;
       }
-      if (size >= tm_format.size() * 256) {
-        // If the buffer is 256 times larger than the format string, assume
-        // that `strftime` gives an empty result. There doesn't seem to be a
-        // better way to distinguish the two cases:
-        // https://github.com/fmtlib/fmt/issues/367
-        break;
-      }
       const size_t MIN_GROWTH = 10;
       buf.reserve(buf.capacity() + (size > MIN_GROWTH ? size : MIN_GROWTH));
     }
-    return std::copy(buf.begin(), buf.end(), ctx.out());
+    // Remove the extra space.
+    return std::copy(buf.begin(), buf.end() - 1, ctx.out());
   }
 
-  basic_memory_buffer<Char> tm_format;
+  basic_string_view<Char> specs;
 };
 
-namespace detail {
-template <typename Period> FMT_CONSTEXPR const char* get_units() {
+FMT_BEGIN_DETAIL_NAMESPACE
+
+template <typename Period> FMT_CONSTEXPR inline const char* get_units() {
+  if (std::is_same<Period, std::atto>::value) return "as";
+  if (std::is_same<Period, std::femto>::value) return "fs";
+  if (std::is_same<Period, std::pico>::value) return "ps";
+  if (std::is_same<Period, std::nano>::value) return "ns";
+  if (std::is_same<Period, std::micro>::value) return "µs";
+  if (std::is_same<Period, std::milli>::value) return "ms";
+  if (std::is_same<Period, std::centi>::value) return "cs";
+  if (std::is_same<Period, std::deci>::value) return "ds";
+  if (std::is_same<Period, std::ratio<1>>::value) return "s";
+  if (std::is_same<Period, std::deca>::value) return "das";
+  if (std::is_same<Period, std::hecto>::value) return "hs";
+  if (std::is_same<Period, std::kilo>::value) return "ks";
+  if (std::is_same<Period, std::mega>::value) return "Ms";
+  if (std::is_same<Period, std::giga>::value) return "Gs";
+  if (std::is_same<Period, std::tera>::value) return "Ts";
+  if (std::is_same<Period, std::peta>::value) return "Ps";
+  if (std::is_same<Period, std::exa>::value) return "Es";
+  if (std::is_same<Period, std::ratio<60>>::value) return "m";
+  if (std::is_same<Period, std::ratio<3600>>::value) return "h";
   return nullptr;
 }
-template <> FMT_CONSTEXPR const char* get_units<std::atto>() { return "as"; }
-template <> FMT_CONSTEXPR const char* get_units<std::femto>() { return "fs"; }
-template <> FMT_CONSTEXPR const char* get_units<std::pico>() { return "ps"; }
-template <> FMT_CONSTEXPR const char* get_units<std::nano>() { return "ns"; }
-template <> FMT_CONSTEXPR const char* get_units<std::micro>() { return "µs"; }
-template <> FMT_CONSTEXPR const char* get_units<std::milli>() { return "ms"; }
-template <> FMT_CONSTEXPR const char* get_units<std::centi>() { return "cs"; }
-template <> FMT_CONSTEXPR const char* get_units<std::deci>() { return "ds"; }
-template <> FMT_CONSTEXPR const char* get_units<std::ratio<1>>() { return "s"; }
-template <> FMT_CONSTEXPR const char* get_units<std::deca>() { return "das"; }
-template <> FMT_CONSTEXPR const char* get_units<std::hecto>() { return "hs"; }
-template <> FMT_CONSTEXPR const char* get_units<std::kilo>() { return "ks"; }
-template <> FMT_CONSTEXPR const char* get_units<std::mega>() { return "Ms"; }
-template <> FMT_CONSTEXPR const char* get_units<std::giga>() { return "Gs"; }
-template <> FMT_CONSTEXPR const char* get_units<std::tera>() { return "Ts"; }
-template <> FMT_CONSTEXPR const char* get_units<std::peta>() { return "Ps"; }
-template <> FMT_CONSTEXPR const char* get_units<std::exa>() { return "Es"; }
-template <> FMT_CONSTEXPR const char* get_units<std::ratio<60>>() {
-  return "m";
-}
-template <> FMT_CONSTEXPR const char* get_units<std::ratio<3600>>() {
-  return "h";
-}
 
 enum class numeric_system {
   standard,
@@ -626,33 +737,50 @@ FMT_CONSTEXPR const Char* parse_chrono_format(const Char* begin,
   return ptr;
 }
 
-struct chrono_format_checker {
-  FMT_NORETURN void report_no_date() { FMT_THROW(format_error("no date")); }
+template <typename Derived> struct null_chrono_spec_handler {
+  FMT_CONSTEXPR void unsupported() {
+    static_cast<Derived*>(this)->unsupported();
+  }
+  FMT_CONSTEXPR void on_abbr_weekday() { unsupported(); }
+  FMT_CONSTEXPR void on_full_weekday() { unsupported(); }
+  FMT_CONSTEXPR void on_dec0_weekday(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_dec1_weekday(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_abbr_month() { unsupported(); }
+  FMT_CONSTEXPR void on_full_month() { unsupported(); }
+  FMT_CONSTEXPR void on_24_hour(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_12_hour(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_minute(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_second(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_datetime(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_loc_date(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_loc_time(numeric_system) { unsupported(); }
+  FMT_CONSTEXPR void on_us_date() { unsupported(); }
+  FMT_CONSTEXPR void on_iso_date() { unsupported(); }
+  FMT_CONSTEXPR void on_12_hour_time() { unsupported(); }
+  FMT_CONSTEXPR void on_24_hour_time() { unsupported(); }
+  FMT_CONSTEXPR void on_iso_time() { unsupported(); }
+  FMT_CONSTEXPR void on_am_pm() { unsupported(); }
+  FMT_CONSTEXPR void on_duration_value() { unsupported(); }
+  FMT_CONSTEXPR void on_duration_unit() { unsupported(); }
+  FMT_CONSTEXPR void on_utc_offset() { unsupported(); }
+  FMT_CONSTEXPR void on_tz_name() { unsupported(); }
+};
 
-  template <typename Char> void on_text(const Char*, const Char*) {}
-  FMT_NORETURN void on_abbr_weekday() { report_no_date(); }
-  FMT_NORETURN void on_full_weekday() { report_no_date(); }
-  FMT_NORETURN void on_dec0_weekday(numeric_system) { report_no_date(); }
-  FMT_NORETURN void on_dec1_weekday(numeric_system) { report_no_date(); }
-  FMT_NORETURN void on_abbr_month() { report_no_date(); }
-  FMT_NORETURN void on_full_month() { report_no_date(); }
-  void on_24_hour(numeric_system) {}
-  void on_12_hour(numeric_system) {}
-  void on_minute(numeric_system) {}
-  void on_second(numeric_system) {}
-  FMT_NORETURN void on_datetime(numeric_system) { report_no_date(); }
-  FMT_NORETURN void on_loc_date(numeric_system) { report_no_date(); }
-  FMT_NORETURN void on_loc_time(numeric_system) { report_no_date(); }
-  FMT_NORETURN void on_us_date() { report_no_date(); }
-  FMT_NORETURN void on_iso_date() { report_no_date(); }
-  void on_12_hour_time() {}
-  void on_24_hour_time() {}
-  void on_iso_time() {}
-  void on_am_pm() {}
-  void on_duration_value() {}
-  void on_duration_unit() {}
-  FMT_NORETURN void on_utc_offset() { report_no_date(); }
-  FMT_NORETURN void on_tz_name() { report_no_date(); }
+struct chrono_format_checker : null_chrono_spec_handler<chrono_format_checker> {
+  FMT_NORETURN void unsupported() { FMT_THROW(format_error("no date")); }
+
+  template <typename Char>
+  FMT_CONSTEXPR void on_text(const Char*, const Char*) {}
+  FMT_CONSTEXPR void on_24_hour(numeric_system) {}
+  FMT_CONSTEXPR void on_12_hour(numeric_system) {}
+  FMT_CONSTEXPR void on_minute(numeric_system) {}
+  FMT_CONSTEXPR void on_second(numeric_system) {}
+  FMT_CONSTEXPR void on_12_hour_time() {}
+  FMT_CONSTEXPR void on_24_hour_time() {}
+  FMT_CONSTEXPR void on_iso_time() {}
+  FMT_CONSTEXPR void on_am_pm() {}
+  FMT_CONSTEXPR void on_duration_value() {}
+  FMT_CONSTEXPR void on_duration_unit() {}
 };
 
 template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
@@ -676,7 +804,8 @@ inline bool isfinite(T value) {
 // Converts value to int and checks that it's in the range [0, upper).
 template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
 inline int to_nonnegative_int(T value, int upper) {
-  FMT_ASSERT(value >= 0 && value <= upper, "invalid value");
+  FMT_ASSERT(value >= 0 && to_unsigned(value) <= to_unsigned(upper),
+             "invalid value");
   (void)upper;
   return static_cast<int>(value);
 }
@@ -754,15 +883,21 @@ inline std::chrono::duration<Rep, std::milli> get_milliseconds(
   return std::chrono::duration<Rep, std::milli>(static_cast<Rep>(ms));
 }
 
-template <typename Char, typename Rep, typename OutputIt>
-OutputIt format_duration_value(OutputIt out, Rep val, int precision) {
-  const Char pr_f[] = {'{', ':', '.', '{', '}', 'f', '}', 0};
-  if (precision >= 0) return format_to(out, pr_f, val, precision);
-  const Char fp_f[] = {'{', ':', 'g', '}', 0};
-  const Char format[] = {'{', '}', 0};
-  return format_to(out, std::is_floating_point<Rep>::value ? fp_f : format,
-                   val);
+template <typename Char, typename Rep, typename OutputIt,
+          FMT_ENABLE_IF(std::is_integral<Rep>::value)>
+OutputIt format_duration_value(OutputIt out, Rep val, int) {
+  return write<Char>(out, val);
 }
+
+template <typename Char, typename Rep, typename OutputIt,
+          FMT_ENABLE_IF(std::is_floating_point<Rep>::value)>
+OutputIt format_duration_value(OutputIt out, Rep val, int precision) {
+  auto specs = basic_format_specs<Char>();
+  specs.precision = precision;
+  specs.type = precision > 0 ? 'f' : 'g';
+  return write<Char>(out, val, specs);
+}
+
 template <typename Char, typename OutputIt>
 OutputIt copy_unit(string_view unit, OutputIt out, Char) {
   return std::copy(unit.begin(), unit.end(), out);
@@ -780,10 +915,15 @@ template <typename Char, typename Period, typename OutputIt>
 OutputIt format_duration_unit(OutputIt out) {
   if (const char* unit = get_units<Period>())
     return copy_unit(string_view(unit), out, Char());
-  const Char num_f[] = {'[', '{', '}', ']', 's', 0};
-  if (const_check(Period::den == 1)) return format_to(out, num_f, Period::num);
-  const Char num_def_f[] = {'[', '{', '}', '/', '{', '}', ']', 's', 0};
-  return format_to(out, num_def_f, Period::num, Period::den);
+  *out++ = '[';
+  out = write<Char>(out, Period::num);
+  if (const_check(Period::den != 1)) {
+    *out++ = '/';
+    out = write<Char>(out, Period::den);
+  }
+  *out++ = ']';
+  *out++ = 's';
+  return out;
 }
 
 template <typename FormatContext, typename OutputIt, typename Rep,
@@ -792,6 +932,7 @@ struct chrono_formatter {
   FormatContext& context;
   OutputIt out;
   int precision;
+  bool localized = false;
   // rep is unsigned to avoid overflow.
   using rep =
       conditional_t<std::is_integral<Rep>::value && sizeof(Rep) < sizeof(int),
@@ -886,13 +1027,9 @@ struct chrono_formatter {
 
   void format_localized(const tm& time, char format, char modifier = 0) {
     if (isnan(val)) return write_nan();
-    auto locale = context.locale().template get<std::locale>();
-    auto& facet = std::use_facet<std::time_put<char_type>>(locale);
-    std::basic_ostringstream<char_type> os;
-    os.imbue(locale);
-    facet.put(os, os, ' ', &time, format, modifier);
-    auto str = os.str();
-    std::copy(str.begin(), str.end(), out);
+    const auto& loc = localized ? context.locale().template get<std::locale>()
+                                : std::locale::classic();
+    out = detail::write(out, time, loc, format, modifier);
   }
 
   void on_text(const char_type* begin, const char_type* end) {
@@ -1005,17 +1142,59 @@ struct chrono_formatter {
     out = format_duration_unit<char_type, Period>(out);
   }
 };
-}  // namespace detail
+
+FMT_END_DETAIL_NAMESPACE
+
+#if defined(__cpp_lib_chrono) && __cpp_lib_chrono >= 201907
+using weekday = std::chrono::weekday;
+#else
+// A fallback version of weekday.
+class weekday {
+ private:
+  unsigned char value;
+
+ public:
+  weekday() = default;
+  explicit constexpr weekday(unsigned wd) noexcept
+      : value(static_cast<unsigned char>(wd != 7 ? wd : 0)) {}
+  constexpr unsigned c_encoding() const noexcept { return value; }
+};
+#endif
+
+// A rudimentary weekday formatter.
+template <> struct formatter<weekday> {
+ private:
+  bool localized = false;
+
+ public:
+  FMT_CONSTEXPR auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
+    auto begin = ctx.begin(), end = ctx.end();
+    if (begin != end && *begin == 'L') {
+      ++begin;
+      localized = true;
+    }
+    return begin;
+  }
+
+  auto format(weekday wd, format_context& ctx) -> decltype(ctx.out()) {
+    auto time = std::tm();
+    time.tm_wday = static_cast<int>(wd.c_encoding());
+    const auto& loc = localized ? ctx.locale().template get<std::locale>()
+                                : std::locale::classic();
+    return detail::write(ctx.out(), time, loc, 'a');
+  }
+};
 
 template <typename Rep, typename Period, typename Char>
 struct formatter<std::chrono::duration<Rep, Period>, Char> {
  private:
   basic_format_specs<Char> specs;
-  int precision;
+  int precision = -1;
   using arg_ref_type = detail::arg_ref<Char>;
   arg_ref_type width_ref;
   arg_ref_type precision_ref;
-  mutable basic_string_view<Char> format_str;
+  bool localized = false;
+  basic_string_view<Char> format_str;
   using duration = std::chrono::duration<Rep, Period>;
 
   struct spec_handler {
@@ -1038,17 +1217,21 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
     }
 
     void on_error(const char* msg) { FMT_THROW(format_error(msg)); }
-    void on_fill(basic_string_view<Char> fill) { f.specs.fill = fill; }
-    void on_align(align_t align) { f.specs.align = align; }
-    void on_width(int width) { f.specs.width = width; }
-    void on_precision(int _precision) { f.precision = _precision; }
-    void end_precision() {}
+    FMT_CONSTEXPR void on_fill(basic_string_view<Char> fill) {
+      f.specs.fill = fill;
+    }
+    FMT_CONSTEXPR void on_align(align_t align) { f.specs.align = align; }
+    FMT_CONSTEXPR void on_width(int width) { f.specs.width = width; }
+    FMT_CONSTEXPR void on_precision(int _precision) {
+      f.precision = _precision;
+    }
+    FMT_CONSTEXPR void end_precision() {}
 
-    template <typename Id> void on_dynamic_width(Id arg_id) {
+    template <typename Id> FMT_CONSTEXPR void on_dynamic_width(Id arg_id) {
       f.width_ref = make_arg_ref(arg_id);
     }
 
-    template <typename Id> void on_dynamic_precision(Id arg_id) {
+    template <typename Id> FMT_CONSTEXPR void on_dynamic_precision(Id arg_id) {
       f.precision_ref = make_arg_ref(arg_id);
     }
   };
@@ -1073,13 +1256,15 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
       else
         handler.on_error("precision not allowed for this argument type");
     }
+    if (begin != end && *begin == 'L') {
+      ++begin;
+      localized = true;
+    }
     end = parse_chrono_format(begin, end, detail::chrono_format_checker());
     return {begin, end};
   }
 
  public:
-  formatter() : precision(-1) {}
-
   FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
       -> decltype(ctx.begin()) {
     auto range = do_parse(ctx);
@@ -1089,30 +1274,35 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
   }
 
   template <typename FormatContext>
-  auto format(const duration& d, FormatContext& ctx) -> decltype(ctx.out()) {
+  auto format(const duration& d, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto specs_copy = specs;
+    auto precision_copy = precision;
     auto begin = format_str.begin(), end = format_str.end();
     // As a possible future optimization, we could avoid extra copying if width
     // is not specified.
     basic_memory_buffer<Char> buf;
     auto out = std::back_inserter(buf);
-    detail::handle_dynamic_spec<detail::width_checker>(specs.width, width_ref,
-                                                       ctx);
-    detail::handle_dynamic_spec<detail::precision_checker>(precision,
+    detail::handle_dynamic_spec<detail::width_checker>(specs_copy.width,
+                                                       width_ref, ctx);
+    detail::handle_dynamic_spec<detail::precision_checker>(precision_copy,
                                                            precision_ref, ctx);
     if (begin == end || *begin == '}') {
-      out = detail::format_duration_value<Char>(out, d.count(), precision);
+      out = detail::format_duration_value<Char>(out, d.count(), precision_copy);
       detail::format_duration_unit<Char, Period>(out);
     } else {
       detail::chrono_formatter<FormatContext, decltype(out), Rep, Period> f(
           ctx, out, d);
-      f.precision = precision;
-      parse_chrono_format(begin, end, f);
+      f.precision = precision_copy;
+      f.localized = localized;
+      detail::parse_chrono_format(begin, end, f);
     }
     return detail::write(
-        ctx.out(), basic_string_view<Char>(buf.data(), buf.size()), specs);
+        ctx.out(), basic_string_view<Char>(buf.data(), buf.size()), specs_copy);
   }
 };
 
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_CHRONO_H_

include/fmt/color.h

@@ -10,7 +10,15 @@
 
 #include "format.h"
 
+// __declspec(deprecated) is broken in some MSVC versions.
+#if FMT_MSC_VER
+#  define FMT_DEPRECATED_NONMSVC
+#else
+#  define FMT_DEPRECATED_NONMSVC FMT_DEPRECATED
+#endif
+
 FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
 
 enum class color : uint32_t {
   alice_blue = 0xF0F8FF,               // rgb(240,248,255)
@@ -198,7 +206,7 @@ struct rgb {
   uint8_t b;
 };
 
-namespace detail {
+FMT_BEGIN_DETAIL_NAMESPACE
 
 // color is a struct of either a rgb color or a terminal color.
 struct color_type {
@@ -221,9 +229,10 @@ struct color_type {
     uint32_t rgb_color;
   } value;
 };
-}  // namespace detail
 
-// Experimental text formatting support.
+FMT_END_DETAIL_NAMESPACE
+
+/** A text style consisting of foreground and background colors and emphasis. */
 class text_style {
  public:
   FMT_CONSTEXPR text_style(emphasis em = emphasis()) FMT_NOEXCEPT
@@ -260,33 +269,14 @@ class text_style {
     return lhs |= rhs;
   }
 
-  FMT_CONSTEXPR text_style& operator&=(const text_style& rhs) {
-    if (!set_foreground_color) {
-      set_foreground_color = rhs.set_foreground_color;
-      foreground_color = rhs.foreground_color;
-    } else if (rhs.set_foreground_color) {
-      if (!foreground_color.is_rgb || !rhs.foreground_color.is_rgb)
-        FMT_THROW(format_error("can't AND a terminal color"));
-      foreground_color.value.rgb_color &= rhs.foreground_color.value.rgb_color;
-    }
-
-    if (!set_background_color) {
-      set_background_color = rhs.set_background_color;
-      background_color = rhs.background_color;
-    } else if (rhs.set_background_color) {
-      if (!background_color.is_rgb || !rhs.background_color.is_rgb)
-        FMT_THROW(format_error("can't AND a terminal color"));
-      background_color.value.rgb_color &= rhs.background_color.value.rgb_color;
-    }
-
-    ems = static_cast<emphasis>(static_cast<uint8_t>(ems) &
-                                static_cast<uint8_t>(rhs.ems));
-    return *this;
+  FMT_DEPRECATED_NONMSVC FMT_CONSTEXPR text_style& operator&=(
+      const text_style& rhs) {
+    return and_assign(rhs);
   }
 
-  friend FMT_CONSTEXPR text_style operator&(text_style lhs,
-                                            const text_style& rhs) {
-    return lhs &= rhs;
+  FMT_DEPRECATED_NONMSVC friend FMT_CONSTEXPR text_style
+  operator&(text_style lhs, const text_style& rhs) {
+    return lhs.and_assign(rhs);
   }
 
   FMT_CONSTEXPR bool has_foreground() const FMT_NOEXCEPT {
@@ -326,8 +316,34 @@ class text_style {
     }
   }
 
+  // DEPRECATED!
+  FMT_CONSTEXPR text_style& and_assign(const text_style& rhs) {
+    if (!set_foreground_color) {
+      set_foreground_color = rhs.set_foreground_color;
+      foreground_color = rhs.foreground_color;
+    } else if (rhs.set_foreground_color) {
+      if (!foreground_color.is_rgb || !rhs.foreground_color.is_rgb)
+        FMT_THROW(format_error("can't AND a terminal color"));
+      foreground_color.value.rgb_color &= rhs.foreground_color.value.rgb_color;
+    }
+
+    if (!set_background_color) {
+      set_background_color = rhs.set_background_color;
+      background_color = rhs.background_color;
+    } else if (rhs.set_background_color) {
+      if (!background_color.is_rgb || !rhs.background_color.is_rgb)
+        FMT_THROW(format_error("can't AND a terminal color"));
+      background_color.value.rgb_color &= rhs.background_color.value.rgb_color;
+    }
+
+    ems = static_cast<emphasis>(static_cast<uint8_t>(ems) &
+                                static_cast<uint8_t>(rhs.ems));
+    return *this;
+  }
+
   friend FMT_CONSTEXPR_DECL text_style fg(detail::color_type foreground)
       FMT_NOEXCEPT;
+
   friend FMT_CONSTEXPR_DECL text_style bg(detail::color_type background)
       FMT_NOEXCEPT;
 
@@ -338,19 +354,22 @@ class text_style {
   emphasis ems;
 };
 
-FMT_CONSTEXPR text_style fg(detail::color_type foreground) FMT_NOEXCEPT {
-  return text_style(/*is_foreground=*/true, foreground);
+/** Creates a text style from the foreground (text) color. */
+FMT_CONSTEXPR inline text_style fg(detail::color_type foreground) FMT_NOEXCEPT {
+  return text_style(true, foreground);
 }
 
-FMT_CONSTEXPR text_style bg(detail::color_type background) FMT_NOEXCEPT {
-  return text_style(/*is_foreground=*/false, background);
+/** Creates a text style from the background color. */
+FMT_CONSTEXPR inline text_style bg(detail::color_type background) FMT_NOEXCEPT {
+  return text_style(false, background);
 }
 
-FMT_CONSTEXPR text_style operator|(emphasis lhs, emphasis rhs) FMT_NOEXCEPT {
+FMT_CONSTEXPR inline text_style operator|(emphasis lhs,
+                                          emphasis rhs) FMT_NOEXCEPT {
   return text_style(lhs) | rhs;
 }
 
-namespace detail {
+FMT_BEGIN_DETAIL_NAMESPACE
 
 template <typename Char> struct ansi_color_escape {
   FMT_CONSTEXPR ansi_color_escape(detail::color_type text_color,
@@ -358,7 +377,7 @@ template <typename Char> struct ansi_color_escape {
     // If we have a terminal color, we need to output another escape code
     // sequence.
     if (!text_color.is_rgb) {
-      bool is_background = esc == detail::data::background_color;
+      bool is_background = esc == string_view("\x1b[48;2;");
       uint32_t value = text_color.value.term_color;
       // Background ASCII codes are the same as the foreground ones but with
       // 10 more.
@@ -411,7 +430,7 @@ template <typename Char> struct ansi_color_escape {
   FMT_CONSTEXPR operator const Char*() const FMT_NOEXCEPT { return buffer; }
 
   FMT_CONSTEXPR const Char* begin() const FMT_NOEXCEPT { return buffer; }
-  FMT_CONSTEXPR const Char* end() const FMT_NOEXCEPT {
+  FMT_CONSTEXPR_CHAR_TRAITS const Char* end() const FMT_NOEXCEPT {
     return buffer + std::char_traits<Char>::length(buffer);
   }
 
@@ -430,13 +449,13 @@ template <typename Char> struct ansi_color_escape {
 template <typename Char>
 FMT_CONSTEXPR ansi_color_escape<Char> make_foreground_color(
     detail::color_type foreground) FMT_NOEXCEPT {
-  return ansi_color_escape<Char>(foreground, detail::data::foreground_color);
+  return ansi_color_escape<Char>(foreground, "\x1b[38;2;");
 }
 
 template <typename Char>
 FMT_CONSTEXPR ansi_color_escape<Char> make_background_color(
     detail::color_type background) FMT_NOEXCEPT {
-  return ansi_color_escape<Char>(background, detail::data::background_color);
+  return ansi_color_escape<Char>(background, "\x1b[48;2;");
 }
 
 template <typename Char>
@@ -455,18 +474,17 @@ inline void fputs<wchar_t>(const wchar_t* chars, FILE* stream) FMT_NOEXCEPT {
 }
 
 template <typename Char> inline void reset_color(FILE* stream) FMT_NOEXCEPT {
-  fputs(detail::data::reset_color, stream);
+  fputs("\x1b[0m", stream);
 }
 
 template <> inline void reset_color<wchar_t>(FILE* stream) FMT_NOEXCEPT {
-  fputs(detail::data::wreset_color, stream);
+  fputs(L"\x1b[0m", stream);
 }
 
 template <typename Char>
 inline void reset_color(buffer<Char>& buffer) FMT_NOEXCEPT {
-  const char* begin = data::reset_color;
-  const char* end = begin + sizeof(data::reset_color) - 1;
-  buffer.append(begin, end);
+  auto reset_color = string_view("\x1b[0m");
+  buffer.append(reset_color.begin(), reset_color.end());
 }
 
 template <typename Char>
@@ -492,7 +510,8 @@ void vformat_to(buffer<Char>& buf, const text_style& ts,
   detail::vformat_to(buf, format_str, args);
   if (has_style) detail::reset_color<Char>(buf);
 }
-}  // namespace detail
+
+FMT_END_DETAIL_NAMESPACE
 
 template <typename S, typename Char = char_t<S>>
 void vprint(std::FILE* f, const text_style& ts, const S& format,
@@ -523,11 +542,15 @@ void print(std::FILE* f, const text_style& ts, const S& format_str,
 }
 
 /**
+  \rst
   Formats a string and prints it to stdout using ANSI escape sequences to
   specify text formatting.
-  Example:
+
+  **Example**::
+
     fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
                "Elapsed time: {0:.2f} seconds", 1.23);
+  \endrst
  */
 template <typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_string<S>::value)>
@@ -559,8 +582,8 @@ inline std::basic_string<Char> vformat(
 template <typename S, typename... Args, typename Char = char_t<S>>
 inline std::basic_string<Char> format(const text_style& ts, const S& format_str,
                                       const Args&... args) {
-  return vformat(ts, to_string_view(format_str),
-                 fmt::make_args_checked<Args...>(format_str, args...));
+  return fmt::vformat(ts, to_string_view(format_str),
+                      fmt::make_args_checked<Args...>(format_str, args...));
 }
 
 /**
@@ -571,7 +594,7 @@ template <typename OutputIt, typename Char,
 OutputIt vformat_to(
     OutputIt out, const text_style& ts, basic_string_view<Char> format_str,
     basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  decltype(detail::get_buffer<Char>(out)) buf(detail::get_buffer_init(out));
+  auto&& buf = detail::get_buffer<Char>(out);
   detail::vformat_to(buf, ts, format_str, args);
   return detail::get_iterator(buf);
 }
@@ -598,6 +621,7 @@ inline auto format_to(OutputIt out, const text_style& ts, const S& format_str,
                     fmt::make_args_checked<Args...>(format_str, args...));
 }
 
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_COLOR_H_

include/fmt/compile.h

@@ -8,13 +8,135 @@
 #ifndef FMT_COMPILE_H_
 #define FMT_COMPILE_H_
 
-#include <vector>
-
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
 namespace detail {
 
+// An output iterator that counts the number of objects written to it and
+// discards them.
+class counting_iterator {
+ private:
+  size_t count_;
+
+ public:
+  using iterator_category = std::output_iterator_tag;
+  using difference_type = std::ptrdiff_t;
+  using pointer = void;
+  using reference = void;
+  using _Unchecked_type = counting_iterator;  // Mark iterator as checked.
+
+  struct value_type {
+    template <typename T> void operator=(const T&) {}
+  };
+
+  counting_iterator() : count_(0) {}
+
+  size_t count() const { return count_; }
+
+  counting_iterator& operator++() {
+    ++count_;
+    return *this;
+  }
+  counting_iterator operator++(int) {
+    auto it = *this;
+    ++*this;
+    return it;
+  }
+
+  friend counting_iterator operator+(counting_iterator it, difference_type n) {
+    it.count_ += static_cast<size_t>(n);
+    return it;
+  }
+
+  value_type operator*() const { return {}; }
+};
+
+template <typename Char, typename InputIt>
+inline counting_iterator copy_str(InputIt begin, InputIt end,
+                                  counting_iterator it) {
+  return it + (end - begin);
+}
+
+template <typename OutputIt> class truncating_iterator_base {
+ protected:
+  OutputIt out_;
+  size_t limit_;
+  size_t count_ = 0;
+
+  truncating_iterator_base() : out_(), limit_(0) {}
+
+  truncating_iterator_base(OutputIt out, size_t limit)
+      : out_(out), limit_(limit) {}
+
+ public:
+  using iterator_category = std::output_iterator_tag;
+  using value_type = typename std::iterator_traits<OutputIt>::value_type;
+  using difference_type = std::ptrdiff_t;
+  using pointer = void;
+  using reference = void;
+  using _Unchecked_type =
+      truncating_iterator_base;  // Mark iterator as checked.
+
+  OutputIt base() const { return out_; }
+  size_t count() const { return count_; }
+};
+
+// An output iterator that truncates the output and counts the number of objects
+// written to it.
+template <typename OutputIt,
+          typename Enable = typename std::is_void<
+              typename std::iterator_traits<OutputIt>::value_type>::type>
+class truncating_iterator;
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::false_type>
+    : public truncating_iterator_base<OutputIt> {
+  mutable typename truncating_iterator_base<OutputIt>::value_type blackhole_;
+
+ public:
+  using value_type = typename truncating_iterator_base<OutputIt>::value_type;
+
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  truncating_iterator& operator++() {
+    if (this->count_++ < this->limit_) ++this->out_;
+    return *this;
+  }
+
+  truncating_iterator operator++(int) {
+    auto it = *this;
+    ++*this;
+    return it;
+  }
+
+  value_type& operator*() const {
+    return this->count_ < this->limit_ ? *this->out_ : blackhole_;
+  }
+};
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::true_type>
+    : public truncating_iterator_base<OutputIt> {
+ public:
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  template <typename T> truncating_iterator& operator=(T val) {
+    if (this->count_++ < this->limit_) *this->out_++ = val;
+    return *this;
+  }
+
+  truncating_iterator& operator++() { return *this; }
+  truncating_iterator& operator++(int) { return *this; }
+  truncating_iterator& operator*() { return *this; }
+};
+
 // A compile-time string which is compiled into fast formatting code.
 class compiled_string {};
 
@@ -34,335 +156,29 @@ struct is_compiled_string : std::is_base_of<compiled_string, S> {};
     std::string s = fmt::format(FMT_COMPILE("{}"), 42);
   \endrst
  */
-#define FMT_COMPILE(s) FMT_STRING_IMPL(s, fmt::detail::compiled_string)
+#ifdef __cpp_if_constexpr
+#  define FMT_COMPILE(s) \
+    FMT_STRING_IMPL(s, fmt::detail::compiled_string, explicit)
+#else
+#  define FMT_COMPILE(s) FMT_STRING(s)
+#endif
+
+#if FMT_USE_NONTYPE_TEMPLATE_PARAMETERS
+template <typename Char, size_t N,
+          fmt::detail_exported::fixed_string<Char, N> Str>
+struct udl_compiled_string : compiled_string {
+  using char_type = Char;
+  constexpr operator basic_string_view<char_type>() const {
+    return {Str.data, N - 1};
+  }
+};
+#endif
 
 template <typename T, typename... Tail>
 const T& first(const T& value, const Tail&...) {
   return value;
 }
 
-// Part of a compiled format string. It can be either literal text or a
-// replacement field.
-template <typename Char> struct format_part {
-  enum class kind { arg_index, arg_name, text, replacement };
-
-  struct replacement {
-    arg_ref<Char> arg_id;
-    dynamic_format_specs<Char> specs;
-  };
-
-  kind part_kind;
-  union value {
-    int arg_index;
-    basic_string_view<Char> str;
-    replacement repl;
-
-    FMT_CONSTEXPR value(int index = 0) : arg_index(index) {}
-    FMT_CONSTEXPR value(basic_string_view<Char> s) : str(s) {}
-    FMT_CONSTEXPR value(replacement r) : repl(r) {}
-  } val;
-  // Position past the end of the argument id.
-  const Char* arg_id_end = nullptr;
-
-  FMT_CONSTEXPR format_part(kind k = kind::arg_index, value v = {})
-      : part_kind(k), val(v) {}
-
-  static FMT_CONSTEXPR format_part make_arg_index(int index) {
-    return format_part(kind::arg_index, index);
-  }
-  static FMT_CONSTEXPR format_part make_arg_name(basic_string_view<Char> name) {
-    return format_part(kind::arg_name, name);
-  }
-  static FMT_CONSTEXPR format_part make_text(basic_string_view<Char> text) {
-    return format_part(kind::text, text);
-  }
-  static FMT_CONSTEXPR format_part make_replacement(replacement repl) {
-    return format_part(kind::replacement, repl);
-  }
-};
-
-template <typename Char> struct part_counter {
-  unsigned num_parts = 0;
-
-  FMT_CONSTEXPR void on_text(const Char* begin, const Char* end) {
-    if (begin != end) ++num_parts;
-  }
-
-  FMT_CONSTEXPR int on_arg_id() { return ++num_parts, 0; }
-  FMT_CONSTEXPR int on_arg_id(int) { return ++num_parts, 0; }
-  FMT_CONSTEXPR int on_arg_id(basic_string_view<Char>) {
-    return ++num_parts, 0;
-  }
-
-  FMT_CONSTEXPR void on_replacement_field(int, const Char*) {}
-
-  FMT_CONSTEXPR const Char* on_format_specs(int, const Char* begin,
-                                            const Char* end) {
-    // Find the matching brace.
-    unsigned brace_counter = 0;
-    for (; begin != end; ++begin) {
-      if (*begin == '{') {
-        ++brace_counter;
-      } else if (*begin == '}') {
-        if (brace_counter == 0u) break;
-        --brace_counter;
-      }
-    }
-    return begin;
-  }
-
-  FMT_CONSTEXPR void on_error(const char*) {}
-};
-
-// Counts the number of parts in a format string.
-template <typename Char>
-FMT_CONSTEXPR unsigned count_parts(basic_string_view<Char> format_str) {
-  part_counter<Char> counter;
-  parse_format_string<true>(format_str, counter);
-  return counter.num_parts;
-}
-
-template <typename Char, typename PartHandler>
-class format_string_compiler : public error_handler {
- private:
-  using part = format_part<Char>;
-
-  PartHandler handler_;
-  part part_;
-  basic_string_view<Char> format_str_;
-  basic_format_parse_context<Char> parse_context_;
-
- public:
-  FMT_CONSTEXPR format_string_compiler(basic_string_view<Char> format_str,
-                                       PartHandler handler)
-      : handler_(handler),
-        format_str_(format_str),
-        parse_context_(format_str) {}
-
-  FMT_CONSTEXPR void on_text(const Char* begin, const Char* end) {
-    if (begin != end)
-      handler_(part::make_text({begin, to_unsigned(end - begin)}));
-  }
-
-  FMT_CONSTEXPR int on_arg_id() {
-    part_ = part::make_arg_index(parse_context_.next_arg_id());
-    return 0;
-  }
-
-  FMT_CONSTEXPR int on_arg_id(int id) {
-    parse_context_.check_arg_id(id);
-    part_ = part::make_arg_index(id);
-    return 0;
-  }
-
-  FMT_CONSTEXPR int on_arg_id(basic_string_view<Char> id) {
-    part_ = part::make_arg_name(id);
-    return 0;
-  }
-
-  FMT_CONSTEXPR void on_replacement_field(int, const Char* ptr) {
-    part_.arg_id_end = ptr;
-    handler_(part_);
-  }
-
-  FMT_CONSTEXPR const Char* on_format_specs(int, const Char* begin,
-                                            const Char* end) {
-    auto repl = typename part::replacement();
-    dynamic_specs_handler<basic_format_parse_context<Char>> handler(
-        repl.specs, parse_context_);
-    auto it = parse_format_specs(begin, end, handler);
-    if (*it != '}') on_error("missing '}' in format string");
-    repl.arg_id = part_.part_kind == part::kind::arg_index
-                      ? arg_ref<Char>(part_.val.arg_index)
-                      : arg_ref<Char>(part_.val.str);
-    auto part = part::make_replacement(repl);
-    part.arg_id_end = begin;
-    handler_(part);
-    return it;
-  }
-};
-
-// Compiles a format string and invokes handler(part) for each parsed part.
-template <bool IS_CONSTEXPR, typename Char, typename PartHandler>
-FMT_CONSTEXPR void compile_format_string(basic_string_view<Char> format_str,
-                                         PartHandler handler) {
-  parse_format_string<IS_CONSTEXPR>(
-      format_str,
-      format_string_compiler<Char, PartHandler>(format_str, handler));
-}
-
-template <typename OutputIt, typename Context, typename Id>
-void format_arg(
-    basic_format_parse_context<typename Context::char_type>& parse_ctx,
-    Context& ctx, Id arg_id) {
-  ctx.advance_to(visit_format_arg(
-      arg_formatter<OutputIt, typename Context::char_type>(ctx, &parse_ctx),
-      ctx.arg(arg_id)));
-}
-
-// vformat_to is defined in a subnamespace to prevent ADL.
-namespace cf {
-template <typename Context, typename OutputIt, typename CompiledFormat>
-auto vformat_to(OutputIt out, CompiledFormat& cf,
-                basic_format_args<Context> args) -> typename Context::iterator {
-  using char_type = typename Context::char_type;
-  basic_format_parse_context<char_type> parse_ctx(
-      to_string_view(cf.format_str_));
-  Context ctx(out, args);
-
-  const auto& parts = cf.parts();
-  for (auto part_it = std::begin(parts); part_it != std::end(parts);
-       ++part_it) {
-    const auto& part = *part_it;
-    const auto& value = part.val;
-
-    using format_part_t = format_part<char_type>;
-    switch (part.part_kind) {
-    case format_part_t::kind::text: {
-      const auto text = value.str;
-      auto output = ctx.out();
-      auto&& it = reserve(output, text.size());
-      it = std::copy_n(text.begin(), text.size(), it);
-      ctx.advance_to(output);
-      break;
-    }
-
-    case format_part_t::kind::arg_index:
-      advance_to(parse_ctx, part.arg_id_end);
-      detail::format_arg<OutputIt>(parse_ctx, ctx, value.arg_index);
-      break;
-
-    case format_part_t::kind::arg_name:
-      advance_to(parse_ctx, part.arg_id_end);
-      detail::format_arg<OutputIt>(parse_ctx, ctx, value.str);
-      break;
-
-    case format_part_t::kind::replacement: {
-      const auto& arg_id_value = value.repl.arg_id.val;
-      const auto arg = value.repl.arg_id.kind == arg_id_kind::index
-                           ? ctx.arg(arg_id_value.index)
-                           : ctx.arg(arg_id_value.name);
-
-      auto specs = value.repl.specs;
-
-      handle_dynamic_spec<width_checker>(specs.width, specs.width_ref, ctx);
-      handle_dynamic_spec<precision_checker>(specs.precision,
-                                             specs.precision_ref, ctx);
-
-      error_handler h;
-      numeric_specs_checker<error_handler> checker(h, arg.type());
-      if (specs.align == align::numeric) checker.require_numeric_argument();
-      if (specs.sign != sign::none) checker.check_sign();
-      if (specs.alt) checker.require_numeric_argument();
-      if (specs.precision >= 0) checker.check_precision();
-
-      advance_to(parse_ctx, part.arg_id_end);
-      ctx.advance_to(
-          visit_format_arg(arg_formatter<OutputIt, typename Context::char_type>(
-                               ctx, nullptr, &specs),
-                           arg));
-      break;
-    }
-    }
-  }
-  return ctx.out();
-}
-}  // namespace cf
-
-struct basic_compiled_format {};
-
-template <typename S, typename = void>
-struct compiled_format_base : basic_compiled_format {
-  using char_type = char_t<S>;
-  using parts_container = std::vector<detail::format_part<char_type>>;
-
-  parts_container compiled_parts;
-
-  explicit compiled_format_base(basic_string_view<char_type> format_str) {
-    compile_format_string<false>(format_str,
-                                 [this](const format_part<char_type>& part) {
-                                   compiled_parts.push_back(part);
-                                 });
-  }
-
-  const parts_container& parts() const { return compiled_parts; }
-};
-
-template <typename Char, unsigned N> struct format_part_array {
-  format_part<Char> data[N] = {};
-  FMT_CONSTEXPR format_part_array() = default;
-};
-
-template <typename Char, unsigned N>
-FMT_CONSTEXPR format_part_array<Char, N> compile_to_parts(
-    basic_string_view<Char> format_str) {
-  format_part_array<Char, N> parts;
-  unsigned counter = 0;
-  // This is not a lambda for compatibility with older compilers.
-  struct {
-    format_part<Char>* parts;
-    unsigned* counter;
-    FMT_CONSTEXPR void operator()(const format_part<Char>& part) {
-      parts[(*counter)++] = part;
-    }
-  } collector{parts.data, &counter};
-  compile_format_string<true>(format_str, collector);
-  if (counter < N) {
-    parts.data[counter] =
-        format_part<Char>::make_text(basic_string_view<Char>());
-  }
-  return parts;
-}
-
-template <typename T> constexpr const T& constexpr_max(const T& a, const T& b) {
-  return (a < b) ? b : a;
-}
-
-template <typename S>
-struct compiled_format_base<S, enable_if_t<is_compile_string<S>::value>>
-    : basic_compiled_format {
-  using char_type = char_t<S>;
-
-  FMT_CONSTEXPR explicit compiled_format_base(basic_string_view<char_type>) {}
-
-// Workaround for old compilers. Format string compilation will not be
-// performed there anyway.
-#if FMT_USE_CONSTEXPR
-  static FMT_CONSTEXPR_DECL const unsigned num_format_parts =
-      constexpr_max(count_parts(to_string_view(S())), 1u);
-#else
-  static const unsigned num_format_parts = 1;
-#endif
-
-  using parts_container = format_part<char_type>[num_format_parts];
-
-  const parts_container& parts() const {
-    static FMT_CONSTEXPR_DECL const auto compiled_parts =
-        compile_to_parts<char_type, num_format_parts>(
-            detail::to_string_view(S()));
-    return compiled_parts.data;
-  }
-};
-
-template <typename S, typename... Args>
-class compiled_format : private compiled_format_base<S> {
- public:
-  using typename compiled_format_base<S>::char_type;
-
- private:
-  basic_string_view<char_type> format_str_;
-
-  template <typename Context, typename OutputIt, typename CompiledFormat>
-  friend auto cf::vformat_to(OutputIt out, CompiledFormat& cf,
-                             basic_format_args<Context> args) ->
-      typename Context::iterator;
-
- public:
-  compiled_format() = delete;
-  explicit constexpr compiled_format(basic_string_view<char_type> format_str)
-      : compiled_format_base<S>(format_str), format_str_(format_str) {}
-};
-
 #ifdef __cpp_if_constexpr
 template <typename... Args> struct type_list {};
 
@@ -377,6 +193,12 @@ constexpr const auto& get([[maybe_unused]] const T& first,
     return get<N - 1>(rest...);
 }
 
+template <typename Char, typename... Args>
+constexpr int get_arg_index_by_name(basic_string_view<Char> name,
+                                    type_list<Args...>) {
+  return get_arg_index_by_name<Args...>(name);
+}
+
 template <int N, typename> struct get_type_impl;
 
 template <int N, typename... Args> struct get_type_impl<N, type_list<Args...>> {
@@ -393,7 +215,7 @@ template <typename Char> struct text {
   using char_type = Char;
 
   template <typename OutputIt, typename... Args>
-  OutputIt format(OutputIt out, const Args&...) const {
+  constexpr OutputIt format(OutputIt out, const Args&...) const {
     return write<Char>(out, data);
   }
 };
@@ -412,11 +234,22 @@ template <typename Char> struct code_unit {
   using char_type = Char;
 
   template <typename OutputIt, typename... Args>
-  OutputIt format(OutputIt out, const Args&...) const {
+  constexpr OutputIt format(OutputIt out, const Args&...) const {
     return write<Char>(out, value);
   }
 };
 
+// This ensures that the argument type is convertible to `const T&`.
+template <typename T, int N, typename... Args>
+constexpr const T& get_arg_checked(const Args&... args) {
+  const auto& arg = get<N>(args...);
+  if constexpr (detail::is_named_arg<remove_cvref_t<decltype(arg)>>()) {
+    return arg.value;
+  } else {
+    return arg;
+  }
+}
+
 template <typename Char>
 struct is_compiled_format<code_unit<Char>> : std::true_type {};
 
@@ -425,29 +258,58 @@ template <typename Char, typename T, int N> struct field {
   using char_type = Char;
 
   template <typename OutputIt, typename... Args>
-  OutputIt format(OutputIt out, const Args&... args) const {
-    // This ensures that the argument type is convertile to `const T&`.
-    const T& arg = get<N>(args...);
-    return write<Char>(out, arg);
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+    return write<Char>(out, get_arg_checked<T, N>(args...));
   }
 };
 
 template <typename Char, typename T, int N>
 struct is_compiled_format<field<Char, T, N>> : std::true_type {};
 
+// A replacement field that refers to argument with name.
+template <typename Char> struct runtime_named_field {
+  using char_type = Char;
+  basic_string_view<Char> name;
+
+  template <typename OutputIt, typename T>
+  constexpr static bool try_format_argument(
+      OutputIt& out,
+      // [[maybe_unused]] due to unused-but-set-parameter warning in GCC 7,8,9
+      [[maybe_unused]] basic_string_view<Char> arg_name, const T& arg) {
+    if constexpr (is_named_arg<typename std::remove_cv<T>::type>::value) {
+      if (arg_name == arg.name) {
+        out = write<Char>(out, arg.value);
+        return true;
+      }
+    }
+    return false;
+  }
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+    bool found = (try_format_argument(out, name, args) || ...);
+    if (!found) {
+      throw format_error("argument with specified name is not found");
+    }
+    return out;
+  }
+};
+
+template <typename Char>
+struct is_compiled_format<runtime_named_field<Char>> : std::true_type {};
+
 // A replacement field that refers to argument N and has format specifiers.
 template <typename Char, typename T, int N> struct spec_field {
   using char_type = Char;
-  mutable formatter<T, Char> fmt;
+  formatter<T, Char> fmt;
 
   template <typename OutputIt, typename... Args>
-  OutputIt format(OutputIt out, const Args&... args) const {
-    // This ensures that the argument type is convertile to `const T&`.
-    const T& arg = get<N>(args...);
+  constexpr FMT_INLINE OutputIt format(OutputIt out,
+                                       const Args&... args) const {
     const auto& vargs =
-        make_format_args<basic_format_context<OutputIt, Char>>(args...);
+        fmt::make_format_args<basic_format_context<OutputIt, Char>>(args...);
     basic_format_context<OutputIt, Char> ctx(out, vargs);
-    return fmt.format(arg, ctx);
+    return fmt.format(get_arg_checked<T, N>(args...), ctx);
   }
 };
 
@@ -460,7 +322,7 @@ template <typename L, typename R> struct concat {
   using char_type = typename L::char_type;
 
   template <typename OutputIt, typename... Args>
-  OutputIt format(OutputIt out, const Args&... args) const {
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
     out = lhs.format(out, args...);
     return rhs.format(out, args...);
   }
@@ -508,14 +370,77 @@ template <typename T, typename Char> struct parse_specs_result {
   int next_arg_id;
 };
 
+constexpr int manual_indexing_id = -1;
+
 template <typename T, typename Char>
 constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,
-                                                  size_t pos, int arg_id) {
+                                                  size_t pos, int next_arg_id) {
   str.remove_prefix(pos);
-  auto ctx = basic_format_parse_context<Char>(str, {}, arg_id + 1);
+  auto ctx = basic_format_parse_context<Char>(str, {}, next_arg_id);
   auto f = formatter<T, Char>();
   auto end = f.parse(ctx);
-  return {f, pos + (end - str.data()) + 1, ctx.next_arg_id()};
+  return {f, pos + fmt::detail::to_unsigned(end - str.data()) + 1,
+          next_arg_id == 0 ? manual_indexing_id : ctx.next_arg_id()};
+}
+
+template <typename Char> struct arg_id_handler {
+  arg_ref<Char> arg_id;
+
+  constexpr int operator()() {
+    FMT_ASSERT(false, "handler cannot be used with automatic indexing");
+    return 0;
+  }
+  constexpr int operator()(int id) {
+    arg_id = arg_ref<Char>(id);
+    return 0;
+  }
+  constexpr int operator()(basic_string_view<Char> id) {
+    arg_id = arg_ref<Char>(id);
+    return 0;
+  }
+
+  constexpr void on_error(const char* message) { throw format_error(message); }
+};
+
+template <typename Char> struct parse_arg_id_result {
+  arg_ref<Char> arg_id;
+  const Char* arg_id_end;
+};
+
+template <int ID, typename Char>
+constexpr auto parse_arg_id(const Char* begin, const Char* end) {
+  auto handler = arg_id_handler<Char>{arg_ref<Char>{}};
+  auto arg_id_end = parse_arg_id(begin, end, handler);
+  return parse_arg_id_result<Char>{handler.arg_id, arg_id_end};
+}
+
+template <typename T, typename Enable = void> struct field_type {
+  using type = remove_cvref_t<T>;
+};
+
+template <typename T>
+struct field_type<T, enable_if_t<detail::is_named_arg<T>::value>> {
+  using type = remove_cvref_t<decltype(T::value)>;
+};
+
+template <typename T, typename Args, size_t END_POS, int ARG_INDEX, int NEXT_ID,
+          typename S>
+constexpr auto parse_replacement_field_then_tail(S format_str) {
+  using char_type = typename S::char_type;
+  constexpr auto str = basic_string_view<char_type>(format_str);
+  constexpr char_type c = END_POS != str.size() ? str[END_POS] : char_type();
+  if constexpr (c == '}') {
+    return parse_tail<Args, END_POS + 1, NEXT_ID>(
+        field<char_type, typename field_type<T>::type, ARG_INDEX>(),
+        format_str);
+  } else if constexpr (c == ':') {
+    constexpr auto result = parse_specs<typename field_type<T>::type>(
+        str, END_POS + 1, NEXT_ID == manual_indexing_id ? 0 : NEXT_ID);
+    return parse_tail<Args, result.end, result.next_arg_id>(
+        spec_field<char_type, typename field_type<T>::type, ARG_INDEX>{
+            result.fmt},
+        format_str);
+  }
 }
 
 // Compiles a non-empty format string and returns the compiled representation
@@ -523,26 +448,58 @@ constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,
 template <typename Args, size_t POS, int ID, typename S>
 constexpr auto compile_format_string(S format_str) {
   using char_type = typename S::char_type;
-  constexpr basic_string_view<char_type> str = format_str;
+  constexpr auto str = basic_string_view<char_type>(format_str);
   if constexpr (str[POS] == '{') {
-    if (POS + 1 == str.size())
+    if constexpr (POS + 1 == str.size())
       throw format_error("unmatched '{' in format string");
     if constexpr (str[POS + 1] == '{') {
       return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
-    } else if constexpr (str[POS + 1] == '}') {
-      using type = get_type<ID, Args>;
-      return parse_tail<Args, POS + 2, ID + 1>(field<char_type, type, ID>(),
-                                               format_str);
-    } else if constexpr (str[POS + 1] == ':') {
-      using type = get_type<ID, Args>;
-      constexpr auto result = parse_specs<type>(str, POS + 2, ID);
-      return parse_tail<Args, result.end, result.next_arg_id>(
-          spec_field<char_type, type, ID>{result.fmt}, format_str);
+    } else if constexpr (str[POS + 1] == '}' || str[POS + 1] == ':') {
+      static_assert(ID != manual_indexing_id,
+                    "cannot switch from manual to automatic argument indexing");
+      constexpr auto next_id =
+          ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
+      return parse_replacement_field_then_tail<get_type<ID, Args>, Args,
+                                               POS + 1, ID, next_id>(
+          format_str);
     } else {
-      return unknown_format();
+      constexpr auto arg_id_result =
+          parse_arg_id<ID>(str.data() + POS + 1, str.data() + str.size());
+      constexpr auto arg_id_end_pos = arg_id_result.arg_id_end - str.data();
+      constexpr char_type c =
+          arg_id_end_pos != str.size() ? str[arg_id_end_pos] : char_type();
+      static_assert(c == '}' || c == ':', "missing '}' in format string");
+      if constexpr (arg_id_result.arg_id.kind == arg_id_kind::index) {
+        static_assert(
+            ID == manual_indexing_id || ID == 0,
+            "cannot switch from automatic to manual argument indexing");
+        constexpr auto arg_index = arg_id_result.arg_id.val.index;
+        return parse_replacement_field_then_tail<get_type<arg_index, Args>,
+                                                 Args, arg_id_end_pos,
+                                                 arg_index, manual_indexing_id>(
+            format_str);
+      } else if constexpr (arg_id_result.arg_id.kind == arg_id_kind::name) {
+        constexpr auto arg_index =
+            get_arg_index_by_name(arg_id_result.arg_id.val.name, Args{});
+        if constexpr (arg_index != invalid_arg_index) {
+          constexpr auto next_id =
+              ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
+          return parse_replacement_field_then_tail<
+              decltype(get_type<arg_index, Args>::value), Args, arg_id_end_pos,
+              arg_index, next_id>(format_str);
+        } else {
+          if constexpr (c == '}') {
+            return parse_tail<Args, arg_id_end_pos + 1, ID>(
+                runtime_named_field<char_type>{arg_id_result.arg_id.val.name},
+                format_str);
+          } else if constexpr (c == ':') {
+            return unknown_format();  // no type info for specs parsing
+          }
+        }
+      }
     }
   } else if constexpr (str[POS] == '}') {
-    if (POS + 1 == str.size())
+    if constexpr (POS + 1 == str.size())
       throw format_error("unmatched '}' in format string");
     return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
   } else {
@@ -558,144 +515,125 @@ constexpr auto compile_format_string(S format_str) {
 }
 
 template <typename... Args, typename S,
-          FMT_ENABLE_IF(is_compile_string<S>::value ||
-                        detail::is_compiled_string<S>::value)>
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
 constexpr auto compile(S format_str) {
-  constexpr basic_string_view<typename S::char_type> str = format_str;
+  constexpr auto str = basic_string_view<typename S::char_type>(format_str);
   if constexpr (str.size() == 0) {
     return detail::make_text(str, 0, 0);
   } else {
     constexpr auto result =
         detail::compile_format_string<detail::type_list<Args...>, 0, 0>(
             format_str);
-    if constexpr (std::is_same<remove_cvref_t<decltype(result)>,
-                               detail::unknown_format>()) {
-      return detail::compiled_format<S, Args...>(to_string_view(format_str));
-    } else {
-      return result;
-    }
+    return result;
   }
 }
-#else
-template <typename... Args, typename S,
-          FMT_ENABLE_IF(is_compile_string<S>::value)>
-constexpr auto compile(S format_str) -> detail::compiled_format<S, Args...> {
-  return detail::compiled_format<S, Args...>(to_string_view(format_str));
-}
 #endif  // __cpp_if_constexpr
-
-// Compiles the format string which must be a string literal.
-template <typename... Args, typename Char, size_t N>
-auto compile(const Char (&format_str)[N])
-    -> detail::compiled_format<const Char*, Args...> {
-  return detail::compiled_format<const Char*, Args...>(
-      basic_string_view<Char>(format_str, N - 1));
-}
 }  // namespace detail
 
-// DEPRECATED! use FMT_COMPILE instead.
-template <typename... Args>
-FMT_DEPRECATED auto compile(const Args&... args)
-    -> decltype(detail::compile(args...)) {
-  return detail::compile(args...);
-}
+FMT_MODULE_EXPORT_BEGIN
 
-#if FMT_USE_CONSTEXPR
-#  ifdef __cpp_if_constexpr
+#ifdef __cpp_if_constexpr
 
 template <typename CompiledFormat, typename... Args,
           typename Char = typename CompiledFormat::char_type,
           FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
 FMT_INLINE std::basic_string<Char> format(const CompiledFormat& cf,
                                           const Args&... args) {
-  basic_memory_buffer<Char> buffer;
-  cf.format(detail::buffer_appender<Char>(buffer), args...);
-  return to_string(buffer);
+  auto s = std::basic_string<Char>();
+  cf.format(std::back_inserter(s), args...);
+  return s;
 }
 
 template <typename OutputIt, typename CompiledFormat, typename... Args,
           FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
-OutputIt format_to(OutputIt out, const CompiledFormat& cf,
-                   const Args&... args) {
+constexpr FMT_INLINE OutputIt format_to(OutputIt out, const CompiledFormat& cf,
+                                        const Args&... args) {
   return cf.format(out, args...);
 }
-#  endif  // __cpp_if_constexpr
-#endif    // FMT_USE_CONSTEXPR
-
-template <typename CompiledFormat, typename... Args,
-          typename Char = typename CompiledFormat::char_type,
-          FMT_ENABLE_IF(std::is_base_of<detail::basic_compiled_format,
-                                        CompiledFormat>::value)>
-std::basic_string<Char> format(const CompiledFormat& cf, const Args&... args) {
-  basic_memory_buffer<Char> buffer;
-  using context = buffer_context<Char>;
-  detail::cf::vformat_to<context>(detail::buffer_appender<Char>(buffer), cf,
-                                  make_format_args<context>(args...));
-  return to_string(buffer);
-}
 
 template <typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
 FMT_INLINE std::basic_string<typename S::char_type> format(const S&,
                                                            Args&&... args) {
-#ifdef __cpp_if_constexpr
   if constexpr (std::is_same<typename S::char_type, char>::value) {
-    constexpr basic_string_view<typename S::char_type> str = S();
-    if (str.size() == 2 && str[0] == '{' && str[1] == '}')
-      return fmt::to_string(detail::first(args...));
+    constexpr auto str = basic_string_view<typename S::char_type>(S());
+    if constexpr (str.size() == 2 && str[0] == '{' && str[1] == '}') {
+      const auto& first = detail::first(args...);
+      if constexpr (detail::is_named_arg<
+                        remove_cvref_t<decltype(first)>>::value) {
+        return fmt::to_string(first.value);
+      } else {
+        return fmt::to_string(first);
+      }
+    }
   }
+  constexpr auto compiled = detail::compile<Args...>(S());
+  if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
+                             detail::unknown_format>()) {
+    return format(static_cast<basic_string_view<typename S::char_type>>(S()),
+                  std::forward<Args>(args)...);
+  } else {
+    return format(compiled, std::forward<Args>(args)...);
+  }
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+FMT_CONSTEXPR OutputIt format_to(OutputIt out, const S&, Args&&... args) {
+  constexpr auto compiled = detail::compile<Args...>(S());
+  if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
+                             detail::unknown_format>()) {
+    return format_to(out,
+                     static_cast<basic_string_view<typename S::char_type>>(S()),
+                     std::forward<Args>(args)...);
+  } else {
+    return format_to(out, compiled, std::forward<Args>(args)...);
+  }
+}
 #endif
-  constexpr auto compiled = detail::compile<Args...>(S());
-  return format(compiled, std::forward<Args>(args)...);
-}
-
-template <typename OutputIt, typename CompiledFormat, typename... Args,
-          FMT_ENABLE_IF(std::is_base_of<detail::basic_compiled_format,
-                                        CompiledFormat>::value)>
-OutputIt format_to(OutputIt out, const CompiledFormat& cf,
-                   const Args&... args) {
-  using char_type = typename CompiledFormat::char_type;
-  using context = format_context_t<OutputIt, char_type>;
-  return detail::cf::vformat_to<context>(out, cf,
-                                         make_format_args<context>(args...));
-}
 
 template <typename OutputIt, typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
-OutputIt format_to(OutputIt out, const S&, const Args&... args) {
-  constexpr auto compiled = detail::compile<Args...>(S());
-  return format_to(out, compiled, args...);
-}
-
-template <typename OutputIt, typename CompiledFormat, typename... Args>
-auto format_to_n(OutputIt out, size_t n, const CompiledFormat& cf,
-                 const Args&... args) ->
-    typename std::enable_if<
-        detail::is_output_iterator<OutputIt,
-                                   typename CompiledFormat::char_type>::value &&
-            std::is_base_of<detail::basic_compiled_format,
-                            CompiledFormat>::value,
-        format_to_n_result<OutputIt>>::type {
-  auto it =
-      format_to(detail::truncating_iterator<OutputIt>(out, n), cf, args...);
+format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n,
+                                         const S& format_str, Args&&... args) {
+  auto it = format_to(detail::truncating_iterator<OutputIt>(out, n), format_str,
+                      std::forward<Args>(args)...);
   return {it.base(), it.count()};
 }
 
-template <typename OutputIt, typename S, typename... Args,
+template <typename S, typename... Args,
           FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
-format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n, const S&,
-                                         const Args&... args) {
-  constexpr auto compiled = detail::compile<Args...>(S());
-  auto it = format_to(detail::truncating_iterator<OutputIt>(out, n), compiled,
-                      args...);
-  return {it.base(), it.count()};
+size_t formatted_size(const S& format_str, const Args&... args) {
+  return format_to(detail::counting_iterator(), format_str, args...).count();
 }
 
-template <typename CompiledFormat, typename... Args>
-size_t formatted_size(const CompiledFormat& cf, const Args&... args) {
-  return format_to(detail::counting_iterator(), cf, args...).count();
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(std::FILE* f, const S& format_str, const Args&... args) {
+  memory_buffer buffer;
+  format_to(std::back_inserter(buffer), format_str, args...);
+  detail::print(f, {buffer.data(), buffer.size()});
 }
 
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+void print(const S& format_str, const Args&... args) {
+  print(stdout, format_str, args...);
+}
+
+#if FMT_USE_NONTYPE_TEMPLATE_PARAMETERS
+inline namespace literals {
+template <detail_exported::fixed_string Str>
+constexpr detail::udl_compiled_string<
+    remove_cvref_t<decltype(Str.data[0])>,
+    sizeof(Str.data) / sizeof(decltype(Str.data[0])), Str>
+operator""_cf() {
+  return {};
+}
+}  // namespace literals
+#endif
+
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_COMPILE_H_

include/fmt/locale.h

@@ -1,64 +1,2 @@
-// Formatting library for C++ - std::locale support
-//
-// Copyright (c) 2012 - present, Victor Zverovich
-// All rights reserved.
-//
-// For the license information refer to format.h.
-
-#ifndef FMT_LOCALE_H_
-#define FMT_LOCALE_H_
-
-#include <locale>
-
-#include "format.h"
-
-FMT_BEGIN_NAMESPACE
-
-namespace detail {
-template <typename Char>
-std::basic_string<Char> vformat(
-    const std::locale& loc, basic_string_view<Char> format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  basic_memory_buffer<Char> buffer;
-  detail::vformat_to(buffer, format_str, args, detail::locale_ref(loc));
-  return fmt::to_string(buffer);
-}
-}  // namespace detail
-
-template <typename S, typename Char = char_t<S>>
-inline std::basic_string<Char> vformat(
-    const std::locale& loc, const S& format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  return detail::vformat(loc, to_string_view(format_str), args);
-}
-
-template <typename S, typename... Args, typename Char = char_t<S>>
-inline std::basic_string<Char> format(const std::locale& loc,
-                                      const S& format_str, Args&&... args) {
-  return detail::vformat(loc, to_string_view(format_str),
-                         fmt::make_args_checked<Args...>(format_str, args...));
-}
-
-template <typename S, typename OutputIt, typename... Args,
-          typename Char = char_t<S>,
-          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value)>
-inline OutputIt vformat_to(
-    OutputIt out, const std::locale& loc, const S& format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  decltype(detail::get_buffer<Char>(out)) buf(detail::get_buffer_init(out));
-  vformat_to(buf, to_string_view(format_str), args, detail::locale_ref(loc));
-  return detail::get_iterator(buf);
-}
-
-template <typename OutputIt, typename S, typename... Args,
-          bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value>
-inline auto format_to(OutputIt out, const std::locale& loc,
-                      const S& format_str, Args&&... args) ->
-    typename std::enable_if<enable, OutputIt>::type {
-  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
-  return vformat_to(out, loc, to_string_view(format_str), vargs);
-}
-
-FMT_END_NAMESPACE
-
-#endif  // FMT_LOCALE_H_
+#include "xchar.h"
+#warning fmt/locale.h is deprecated, include fmt/format.h or fmt/xchar.h instead

include/fmt/os.h

@@ -8,16 +8,12 @@
 #ifndef FMT_OS_H_
 #define FMT_OS_H_
 
-#if defined(__MINGW32__) || defined(__CYGWIN__)
-// Workaround MinGW bug https://sourceforge.net/p/mingw/bugs/2024/.
-#  undef __STRICT_ANSI__
-#endif
-
 #include <cerrno>
-#include <clocale>  // for locale_t
+#include <clocale>  // locale_t
 #include <cstddef>
 #include <cstdio>
-#include <cstdlib>  // for strtod_l
+#include <cstdlib>       // strtod_l
+#include <system_error>  // std::system_error
 
 #if defined __APPLE__ || defined(__FreeBSD__)
 #  include <xlocale.h>  // for LC_NUMERIC_MASK on OS X
@@ -74,6 +70,7 @@
 #define FMT_RETRY(result, expression) FMT_RETRY_VAL(result, expression, -1)
 
 FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
 
 /**
   \rst
@@ -122,19 +119,28 @@ template <typename Char> class basic_cstring_view {
 using cstring_view = basic_cstring_view<char>;
 using wcstring_view = basic_cstring_view<wchar_t>;
 
-// An error code.
-class error_code {
- private:
-  int value_;
+template <typename Char> struct formatter<std::error_code, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
 
- public:
-  explicit error_code(int value = 0) FMT_NOEXCEPT : value_(value) {}
-
-  int get() const FMT_NOEXCEPT { return value_; }
+  template <typename FormatContext>
+  FMT_CONSTEXPR auto format(const std::error_code& ec, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    out = detail::write_bytes(out, ec.category().name(),
+                              basic_format_specs<Char>());
+    out = detail::write<Char>(out, Char(':'));
+    out = detail::write<Char>(out, ec.value());
+    return out;
+  }
 };
 
 #ifdef _WIN32
-namespace detail {
+FMT_API const std::error_category& system_category() FMT_NOEXCEPT;
+
+FMT_BEGIN_DETAIL_NAMESPACE
 // A converter from UTF-16 to UTF-8.
 // It is only provided for Windows since other systems support UTF-8 natively.
 class utf16_to_utf8 {
@@ -143,7 +149,7 @@ class utf16_to_utf8 {
 
  public:
   utf16_to_utf8() {}
-  FMT_API explicit utf16_to_utf8(wstring_view s);
+  FMT_API explicit utf16_to_utf8(basic_string_view<wchar_t> s);
   operator string_view() const { return string_view(&buffer_[0], size()); }
   size_t size() const { return buffer_.size() - 1; }
   const char* c_str() const { return &buffer_[0]; }
@@ -152,59 +158,68 @@ class utf16_to_utf8 {
   // Performs conversion returning a system error code instead of
   // throwing exception on conversion error. This method may still throw
   // in case of memory allocation error.
-  FMT_API int convert(wstring_view s);
+  FMT_API int convert(basic_string_view<wchar_t> s);
 };
 
 FMT_API void format_windows_error(buffer<char>& out, int error_code,
-                                  string_view message) FMT_NOEXCEPT;
-}  // namespace detail
+                                  const char* message) FMT_NOEXCEPT;
+FMT_END_DETAIL_NAMESPACE
 
-/** A Windows error. */
-class windows_error : public system_error {
- private:
-  FMT_API void init(int error_code, string_view format_str, format_args args);
+FMT_API std::system_error vwindows_error(int error_code, string_view format_str,
+                                         format_args args);
 
- public:
-  /**
-   \rst
-   Constructs a :class:`fmt::windows_error` object with the description
-   of the form
+/**
+ \rst
+ Constructs a :class:`std::system_error` object with the description
+ of the form
 
-   .. parsed-literal::
-     *<message>*: *<system-message>*
+ .. parsed-literal::
+   *<message>*: *<system-message>*
 
-   where *<message>* is the formatted message and *<system-message>* is the
-   system message corresponding to the error code.
-   *error_code* is a Windows error code as given by ``GetLastError``.
-   If *error_code* is not a valid error code such as -1, the system message
-   will look like "error -1".
+ where *<message>* is the formatted message and *<system-message>* is the
+ system message corresponding to the error code.
+ *error_code* is a Windows error code as given by ``GetLastError``.
+ If *error_code* is not a valid error code such as -1, the system message
+ will look like "error -1".
 
-   **Example**::
+ **Example**::
 
-     // This throws a windows_error with the description
-     //   cannot open file 'madeup': The system cannot find the file specified.
-     // or similar (system message may vary).
-     const char *filename = "madeup";
-     LPOFSTRUCT of = LPOFSTRUCT();
-     HFILE file = OpenFile(filename, &of, OF_READ);
-     if (file == HFILE_ERROR) {
-       throw fmt::windows_error(GetLastError(),
-                                "cannot open file '{}'", filename);
-     }
-   \endrst
-  */
-  template <typename... Args>
-  windows_error(int error_code, string_view message, const Args&... args) {
-    init(error_code, message, make_format_args(args...));
-  }
-};
+   // This throws a system_error with the description
+   //   cannot open file 'madeup': The system cannot find the file specified.
+   // or similar (system message may vary).
+   const char *filename = "madeup";
+   LPOFSTRUCT of = LPOFSTRUCT();
+   HFILE file = OpenFile(filename, &of, OF_READ);
+   if (file == HFILE_ERROR) {
+     throw fmt::windows_error(GetLastError(),
+                              "cannot open file '{}'", filename);
+   }
+ \endrst
+*/
+template <typename... Args>
+std::system_error windows_error(int error_code, string_view message,
+                                const Args&... args) {
+  return vwindows_error(error_code, message, fmt::make_format_args(args...));
+}
 
 // Reports a Windows error without throwing an exception.
 // Can be used to report errors from destructors.
 FMT_API void report_windows_error(int error_code,
-                                  string_view message) FMT_NOEXCEPT;
+                                  const char* message) FMT_NOEXCEPT;
+#else
+inline const std::error_category& system_category() FMT_NOEXCEPT {
+  return std::system_category();
+}
 #endif  // _WIN32
 
+// std::system is not available on some platforms such as iOS (#2248).
+#ifdef __OSX__
+template <typename S, typename... Args, typename Char = char_t<S>>
+void say(const S& format_str, Args&&... args) {
+  std::system(format("say \"{}\"", format(format_str, args...)).c_str());
+}
+#endif
+
 // A buffered file.
 class buffered_file {
  private:
@@ -255,7 +270,7 @@ class buffered_file {
 
   template <typename... Args>
   inline void print(string_view format_str, const Args&... args) {
-    vprint(format_str, make_format_args(args...));
+    vprint(format_str, fmt::make_format_args(args...));
   }
 };
 
@@ -280,7 +295,8 @@ class file {
     WRONLY = FMT_POSIX(O_WRONLY),  // Open for writing only.
     RDWR = FMT_POSIX(O_RDWR),      // Open for reading and writing.
     CREATE = FMT_POSIX(O_CREAT),   // Create if the file doesn't exist.
-    APPEND = FMT_POSIX(O_APPEND)   // Open in append mode.
+    APPEND = FMT_POSIX(O_APPEND),  // Open in append mode.
+    TRUNC = FMT_POSIX(O_TRUNC)     // Truncate the content of the file.
   };
 
   // Constructs a file object which doesn't represent any file.
@@ -295,7 +311,8 @@ class file {
 
   file(file&& other) FMT_NOEXCEPT : fd_(other.fd_) { other.fd_ = -1; }
 
-  file& operator=(file&& other) FMT_NOEXCEPT {
+  // Move assignment is not noexcept because close may throw.
+  file& operator=(file&& other) {
     close();
     fd_ = other.fd_;
     other.fd_ = -1;
@@ -331,7 +348,7 @@ class file {
 
   // Makes fd be the copy of this file descriptor, closing fd first if
   // necessary.
-  FMT_API void dup2(int fd, error_code& ec) FMT_NOEXCEPT;
+  FMT_API void dup2(int fd, std::error_code& ec) FMT_NOEXCEPT;
 
   // Creates a pipe setting up read_end and write_end file objects for reading
   // and writing respectively.
@@ -345,9 +362,10 @@ class file {
 // Returns the memory page size.
 long getpagesize();
 
-namespace detail {
+FMT_BEGIN_DETAIL_NAMESPACE
 
 struct buffer_size {
+  buffer_size() = default;
   size_t value = 0;
   buffer_size operator=(size_t val) const {
     auto bs = buffer_size();
@@ -357,14 +375,14 @@ struct buffer_size {
 };
 
 struct ostream_params {
-  int oflag = file::WRONLY | file::CREATE;
+  int oflag = file::WRONLY | file::CREATE | file::TRUNC;
   size_t buffer_size = BUFSIZ > 32768 ? BUFSIZ : 32768;
 
   ostream_params() {}
 
   template <typename... T>
-  ostream_params(T... params, int oflag) : ostream_params(params...) {
-    this->oflag = oflag;
+  ostream_params(T... params, int new_oflag) : ostream_params(params...) {
+    oflag = new_oflag;
   }
 
   template <typename... T>
@@ -373,12 +391,13 @@ struct ostream_params {
     this->buffer_size = bs.value;
   }
 };
-}  // namespace detail
+
+FMT_END_DETAIL_NAMESPACE
 
 static constexpr detail::buffer_size buffer_size;
 
-// A fast output stream which is not thread-safe.
-class ostream final : private detail::buffer<char> {
+/** A fast output stream which is not thread-safe. */
+class FMT_API ostream final : private detail::buffer<char> {
  private:
   file file_;
 
@@ -388,7 +407,7 @@ class ostream final : private detail::buffer<char> {
     clear();
   }
 
-  void grow(size_t) final;
+  void grow(size_t) override;
 
   ostream(cstring_view path, const detail::ostream_params& params)
       : file_(path, params.oflag) {
@@ -399,6 +418,7 @@ class ostream final : private detail::buffer<char> {
   ostream(ostream&& other)
       : detail::buffer<char>(other.data(), other.size(), other.capacity()),
         file_(std::move(other.file_)) {
+    other.clear();
     other.set(nullptr, 0);
   }
   ~ostream() {
@@ -414,16 +434,30 @@ class ostream final : private detail::buffer<char> {
     file_.close();
   }
 
-  template <typename S, typename... Args>
-  void print(const S& format_str, const Args&... args) {
-    format_to(detail::buffer_appender<char>(*this), format_str, args...);
+  /**
+    Formats ``args`` according to specifications in ``fmt`` and writes the
+    output to the file.
+   */
+  template <typename... T> void print(format_string<T...> fmt, T&&... args) {
+    vformat_to(detail::buffer_appender<char>(*this), fmt,
+               fmt::make_format_args(args...));
   }
 };
 
 /**
-  Opens a file for writing. Supported parameters passed in `params`:
-  * ``<integer>``: Output flags (``file::WRONLY | file::CREATE`` by default)
+  \rst
+  Opens a file for writing. Supported parameters passed in *params*:
+
+  * ``<integer>``: Flags passed to `open
+    <https://pubs.opengroup.org/onlinepubs/007904875/functions/open.html>`_
+    (``file::WRONLY | file::CREATE`` by default)
   * ``buffer_size=<integer>``: Output buffer size
+
+  **Example**::
+
+    auto out = fmt::output_file("guide.txt");
+    out.print("Don't {}", "Panic");
+  \endrst
  */
 template <typename... T>
 inline ostream output_file(cstring_view path, T... params) {
@@ -475,6 +509,7 @@ class locale {
 };
 using Locale FMT_DEPRECATED_ALIAS = locale;
 #endif  // FMT_LOCALE
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_OS_H_

include/fmt/ostream.h

@@ -85,6 +85,8 @@ template <typename T, typename Char> class is_streamable {
   using result = decltype(test<T>(0));
 
  public:
+  is_streamable() = default;
+
   static const bool value = result::value;
 };
 
@@ -149,6 +151,7 @@ struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
 };
 }  // namespace detail
 
+FMT_MODULE_EXPORT
 template <typename Char>
 void vprint(std::basic_ostream<Char>& os, basic_string_view<Char> format_str,
             basic_format_args<buffer_context<type_identity_t<Char>>> args) {
@@ -166,6 +169,7 @@ void vprint(std::basic_ostream<Char>& os, basic_string_view<Char> format_str,
     fmt::print(cerr, "Don't {}!", "panic");
   \endrst
  */
+FMT_MODULE_EXPORT
 template <typename S, typename... Args,
           typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
 void print(std::basic_ostream<Char>& os, const S& format_str, Args&&... args) {

include/fmt/posix.h

@@ -1,2 +0,0 @@
-#include "os.h"
-#warning "fmt/posix.h is deprecated; use fmt/os.h instead"

include/fmt/printf.h

@@ -10,11 +10,54 @@
 
 #include <algorithm>  // std::max
 #include <limits>     // std::numeric_limits
+#include <ostream>
 
-#include "ostream.h"
+#include "format.h"
 
 FMT_BEGIN_NAMESPACE
-namespace detail {
+FMT_MODULE_EXPORT_BEGIN
+
+template <typename T> struct printf_formatter { printf_formatter() = delete; };
+
+template <typename Char>
+class basic_printf_parse_context : public basic_format_parse_context<Char> {
+  using basic_format_parse_context<Char>::basic_format_parse_context;
+};
+
+template <typename OutputIt, typename Char> class basic_printf_context {
+ private:
+  OutputIt out_;
+  basic_format_args<basic_printf_context> args_;
+
+ public:
+  using char_type = Char;
+  using format_arg = basic_format_arg<basic_printf_context>;
+  using parse_context_type = basic_printf_parse_context<Char>;
+  template <typename T> using formatter_type = printf_formatter<T>;
+
+  /**
+    \rst
+    Constructs a ``printf_context`` object. References to the arguments are
+    stored in the context object so make sure they have appropriate lifetimes.
+    \endrst
+   */
+  basic_printf_context(OutputIt out,
+                       basic_format_args<basic_printf_context> args)
+      : out_(out), args_(args) {}
+
+  OutputIt out() { return out_; }
+  void advance_to(OutputIt it) { out_ = it; }
+
+  detail::locale_ref locale() { return {}; }
+
+  format_arg arg(int id) const { return args_.get(id); }
+
+  FMT_CONSTEXPR void on_error(const char* message) {
+    detail::error_handler().on_error(message);
+  }
+};
+
+FMT_BEGIN_DETAIL_NAMESPACE
 
 // Checks if a value fits in int - used to avoid warnings about comparing
 // signed and unsigned integers.
@@ -178,79 +221,34 @@ template <typename Char> class printf_width_handler {
   }
 };
 
-template <typename Char, typename Context>
-void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
-             basic_format_args<Context> args) {
-  Context(buffer_appender<Char>(buf), format, args).format();
-}
-}  // namespace detail
-
-// For printing into memory_buffer.
-template <typename Char, typename Context>
-FMT_DEPRECATED void printf(detail::buffer<Char>& buf,
-                           basic_string_view<Char> format,
-                           basic_format_args<Context> args) {
-  return detail::vprintf(buf, format, args);
-}
-using detail::vprintf;
-
-template <typename Char>
-class basic_printf_parse_context : public basic_format_parse_context<Char> {
-  using basic_format_parse_context<Char>::basic_format_parse_context;
-};
-template <typename OutputIt, typename Char> class basic_printf_context;
-
-/**
-  \rst
-  The ``printf`` argument formatter.
-  \endrst
- */
+// The ``printf`` argument formatter.
 template <typename OutputIt, typename Char>
-class printf_arg_formatter : public detail::arg_formatter_base<OutputIt, Char> {
- public:
-  using iterator = OutputIt;
-
+class printf_arg_formatter : public arg_formatter<Char> {
  private:
-  using char_type = Char;
-  using base = detail::arg_formatter_base<OutputIt, Char>;
+  using base = arg_formatter<Char>;
   using context_type = basic_printf_context<OutputIt, Char>;
+  using format_specs = basic_format_specs<Char>;
 
   context_type& context_;
 
-  void write_null_pointer(char) {
-    this->specs()->type = 0;
-    this->write("(nil)");
-  }
-
-  void write_null_pointer(wchar_t) {
-    this->specs()->type = 0;
-    this->write(L"(nil)");
+  OutputIt write_null_pointer(bool is_string = false) {
+    auto s = this->specs;
+    s.type = 0;
+    return write_bytes(this->out, is_string ? "(null)" : "(nil)", s);
   }
 
  public:
-  using format_specs = typename base::format_specs;
+  printf_arg_formatter(OutputIt iter, format_specs& s, context_type& ctx)
+      : base{iter, s, locale_ref()}, context_(ctx) {}
 
-  /**
-    \rst
-    Constructs an argument formatter object.
-    *buffer* is a reference to the output buffer and *specs* contains format
-    specifier information for standard argument types.
-    \endrst
-   */
-  printf_arg_formatter(iterator iter, format_specs& specs, context_type& ctx)
-      : base(iter, &specs, detail::locale_ref()), context_(ctx) {}
+  OutputIt operator()(monostate value) { return base::operator()(value); }
 
-  template <typename T, FMT_ENABLE_IF(fmt::detail::is_integral<T>::value)>
-  iterator operator()(T value) {
-    // MSVC2013 fails to compile separate overloads for bool and char_type so
-    // use std::is_same instead.
-    if (std::is_same<T, bool>::value) {
-      format_specs& fmt_specs = *this->specs();
-      if (fmt_specs.type != 's') return base::operator()(value ? 1 : 0);
-      fmt_specs.type = 0;
-      this->write(value != 0);
-    } else if (std::is_same<T, char_type>::value) {
-      format_specs& fmt_specs = *this->specs();
+  template <typename T, FMT_ENABLE_IF(detail::is_integral<T>::value)>
+  OutputIt operator()(T value) {
+    // MSVC2013 fails to compile separate overloads for bool and Char so use
+    // std::is_same instead.
+    if (std::is_same<T, Char>::value) {
+      format_specs fmt_specs = this->specs;
       if (fmt_specs.type && fmt_specs.type != 'c')
         return (*this)(static_cast<int>(value));
       fmt_specs.sign = sign::none;
@@ -260,138 +258,49 @@ class printf_arg_formatter : public detail::arg_formatter_base<OutputIt, Char> {
       // ignored for non-numeric types
       if (fmt_specs.align == align::none || fmt_specs.align == align::numeric)
         fmt_specs.align = align::right;
-      return base::operator()(value);
-    } else {
-      return base::operator()(value);
+      return write<Char>(this->out, static_cast<Char>(value), fmt_specs);
     }
-    return this->out();
+    return base::operator()(value);
   }
 
   template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
-  iterator operator()(T value) {
+  OutputIt operator()(T value) {
     return base::operator()(value);
   }
 
   /** Formats a null-terminated C string. */
-  iterator operator()(const char* value) {
-    if (value)
-      base::operator()(value);
-    else if (this->specs()->type == 'p')
-      write_null_pointer(char_type());
-    else
-      this->write("(null)");
-    return this->out();
+  OutputIt operator()(const char* value) {
+    if (value) return base::operator()(value);
+    return write_null_pointer(this->specs.type != 'p');
   }
 
   /** Formats a null-terminated wide C string. */
-  iterator operator()(const wchar_t* value) {
-    if (value)
-      base::operator()(value);
-    else if (this->specs()->type == 'p')
-      write_null_pointer(char_type());
-    else
-      this->write(L"(null)");
-    return this->out();
+  OutputIt operator()(const wchar_t* value) {
+    if (value) return base::operator()(value);
+    return write_null_pointer(this->specs.type != 'p');
   }
 
-  iterator operator()(basic_string_view<char_type> value) {
+  OutputIt operator()(basic_string_view<Char> value) {
     return base::operator()(value);
   }
 
-  iterator operator()(monostate value) { return base::operator()(value); }
-
   /** Formats a pointer. */
-  iterator operator()(const void* value) {
-    if (value) return base::operator()(value);
-    this->specs()->type = 0;
-    write_null_pointer(char_type());
-    return this->out();
+  OutputIt operator()(const void* value) {
+    return value ? base::operator()(value) : write_null_pointer();
   }
 
   /** Formats an argument of a custom (user-defined) type. */
-  iterator operator()(typename basic_format_arg<context_type>::handle handle) {
-    handle.format(context_.parse_context(), context_);
-    return this->out();
+  OutputIt operator()(typename basic_format_arg<context_type>::handle handle) {
+    auto parse_ctx =
+        basic_printf_parse_context<Char>(basic_string_view<Char>());
+    handle.format(parse_ctx, context_);
+    return this->out;
   }
 };
 
-template <typename T> struct printf_formatter {
-  printf_formatter() = delete;
-
-  template <typename ParseContext>
-  auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    return ctx.begin();
-  }
-
-  template <typename FormatContext>
-  auto format(const T& value, FormatContext& ctx) -> decltype(ctx.out()) {
-    detail::format_value(detail::get_container(ctx.out()), value);
-    return ctx.out();
-  }
-};
-
-/**
- This template formats data and writes the output through an output iterator.
- */
-template <typename OutputIt, typename Char> class basic_printf_context {
- public:
-  /** The character type for the output. */
-  using char_type = Char;
-  using iterator = OutputIt;
-  using format_arg = basic_format_arg<basic_printf_context>;
-  using parse_context_type = basic_printf_parse_context<Char>;
-  template <typename T> using formatter_type = printf_formatter<T>;
-
- private:
-  using format_specs = basic_format_specs<char_type>;
-
-  OutputIt out_;
-  basic_format_args<basic_printf_context> args_;
-  parse_context_type parse_ctx_;
-
-  static void parse_flags(format_specs& specs, const Char*& it,
-                          const Char* end);
-
-  // Returns the argument with specified index or, if arg_index is -1, the next
-  // argument.
-  format_arg get_arg(int arg_index = -1);
-
-  // Parses argument index, flags and width and returns the argument index.
-  int parse_header(const Char*& it, const Char* end, format_specs& specs);
-
- public:
-  /**
-   \rst
-   Constructs a ``printf_context`` object. References to the arguments are
-   stored in the context object so make sure they have appropriate lifetimes.
-   \endrst
-   */
-  basic_printf_context(OutputIt out, basic_string_view<char_type> format_str,
-                       basic_format_args<basic_printf_context> args)
-      : out_(out), args_(args), parse_ctx_(format_str) {}
-
-  OutputIt out() { return out_; }
-  void advance_to(OutputIt it) { out_ = it; }
-
-  detail::locale_ref locale() { return {}; }
-
-  format_arg arg(int id) const { return args_.get(id); }
-
-  parse_context_type& parse_context() { return parse_ctx_; }
-
-  FMT_CONSTEXPR void on_error(const char* message) {
-    parse_ctx_.on_error(message);
-  }
-
-  /** Formats stored arguments and writes the output to the range. */
-  template <typename ArgFormatter = printf_arg_formatter<OutputIt, Char>>
-  OutputIt format();
-};
-
-template <typename OutputIt, typename Char>
-void basic_printf_context<OutputIt, Char>::parse_flags(format_specs& specs,
-                                                       const Char*& it,
-                                                       const Char* end) {
+template <typename Char>
+void parse_flags(basic_format_specs<Char>& specs, const Char*& it,
+                 const Char* end) {
   for (; it != end; ++it) {
     switch (*it) {
     case '-':
@@ -417,35 +326,24 @@ void basic_printf_context<OutputIt, Char>::parse_flags(format_specs& specs,
   }
 }
 
-template <typename OutputIt, typename Char>
-typename basic_printf_context<OutputIt, Char>::format_arg
-basic_printf_context<OutputIt, Char>::get_arg(int arg_index) {
-  if (arg_index < 0)
-    arg_index = parse_ctx_.next_arg_id();
-  else
-    parse_ctx_.check_arg_id(--arg_index);
-  return detail::get_arg(*this, arg_index);
-}
-
-template <typename OutputIt, typename Char>
-int basic_printf_context<OutputIt, Char>::parse_header(const Char*& it,
-                                                       const Char* end,
-                                                       format_specs& specs) {
+template <typename Char, typename GetArg>
+int parse_header(const Char*& it, const Char* end,
+                 basic_format_specs<Char>& specs, GetArg get_arg) {
   int arg_index = -1;
-  char_type c = *it;
+  Char c = *it;
   if (c >= '0' && c <= '9') {
     // Parse an argument index (if followed by '$') or a width possibly
     // preceded with '0' flag(s).
-    detail::error_handler eh;
-    int value = parse_nonnegative_int(it, end, eh);
+    int value = parse_nonnegative_int(it, end, -1);
     if (it != end && *it == '$') {  // value is an argument index
       ++it;
-      arg_index = value;
+      arg_index = value != -1 ? value : max_value<int>();
     } else {
       if (c == '0') specs.fill[0] = '0';
       if (value != 0) {
         // Nonzero value means that we parsed width and don't need to
         // parse it or flags again, so return now.
+        if (value == -1) FMT_THROW(format_error("number is too big"));
         specs.width = value;
         return arg_index;
       }
@@ -455,58 +353,76 @@ int basic_printf_context<OutputIt, Char>::parse_header(const Char*& it,
   // Parse width.
   if (it != end) {
     if (*it >= '0' && *it <= '9') {
-      detail::error_handler eh;
-      specs.width = parse_nonnegative_int(it, end, eh);
+      specs.width = parse_nonnegative_int(it, end, -1);
+      if (specs.width == -1) FMT_THROW(format_error("number is too big"));
     } else if (*it == '*') {
       ++it;
       specs.width = static_cast<int>(visit_format_arg(
-          detail::printf_width_handler<char_type>(specs), get_arg()));
+          detail::printf_width_handler<Char>(specs), get_arg(-1)));
     }
   }
   return arg_index;
 }
 
-template <typename OutputIt, typename Char>
-template <typename ArgFormatter>
-OutputIt basic_printf_context<OutputIt, Char>::format() {
-  auto out = this->out();
-  const Char* start = parse_ctx_.begin();
-  const Char* end = parse_ctx_.end();
+template <typename Char, typename Context>
+void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
+             basic_format_args<Context> args) {
+  using OutputIt = buffer_appender<Char>;
+  auto out = OutputIt(buf);
+  auto context = basic_printf_context<OutputIt, Char>(out, args);
+  auto parse_ctx = basic_printf_parse_context<Char>(format);
+
+  // Returns the argument with specified index or, if arg_index is -1, the next
+  // argument.
+  auto get_arg = [&](int arg_index) {
+    if (arg_index < 0)
+      arg_index = parse_ctx.next_arg_id();
+    else
+      parse_ctx.check_arg_id(--arg_index);
+    return detail::get_arg(context, arg_index);
+  };
+
+  const Char* start = parse_ctx.begin();
+  const Char* end = parse_ctx.end();
   auto it = start;
   while (it != end) {
-    char_type c = *it++;
-    if (c != '%') continue;
+    if (!detail::find<false, Char>(it, end, '%', it)) {
+      it = end;  // detail::find leaves it == nullptr if it doesn't find '%'
+      break;
+    }
+    Char c = *it++;
     if (it != end && *it == c) {
-      out = std::copy(start, it, out);
+      out = detail::write(
+          out, basic_string_view<Char>(start, detail::to_unsigned(it - start)));
       start = ++it;
       continue;
     }
-    out = std::copy(start, it - 1, out);
+    out = detail::write(out, basic_string_view<Char>(
+                                 start, detail::to_unsigned(it - 1 - start)));
 
-    format_specs specs;
+    basic_format_specs<Char> specs;
     specs.align = align::right;
 
     // Parse argument index, flags and width.
-    int arg_index = parse_header(it, end, specs);
-    if (arg_index == 0) on_error("argument not found");
+    int arg_index = parse_header(it, end, specs, get_arg);
+    if (arg_index == 0) parse_ctx.on_error("argument not found");
 
     // Parse precision.
     if (it != end && *it == '.') {
       ++it;
       c = it != end ? *it : 0;
       if ('0' <= c && c <= '9') {
-        detail::error_handler eh;
-        specs.precision = parse_nonnegative_int(it, end, eh);
+        specs.precision = parse_nonnegative_int(it, end, 0);
       } else if (c == '*') {
         ++it;
         specs.precision = static_cast<int>(
-            visit_format_arg(detail::printf_precision_handler(), get_arg()));
+            visit_format_arg(detail::printf_precision_handler(), get_arg(-1)));
       } else {
         specs.precision = 0;
       }
     }
 
-    format_arg arg = get_arg(arg_index);
+    auto arg = get_arg(arg_index);
     // For d, i, o, u, x, and X conversion specifiers, if a precision is
     // specified, the '0' flag is ignored
     if (specs.precision >= 0 && arg.is_integral())
@@ -516,9 +432,10 @@ OutputIt basic_printf_context<OutputIt, Char>::format() {
       auto str = visit_format_arg(detail::get_cstring<Char>(), arg);
       auto str_end = str + specs.precision;
       auto nul = std::find(str, str_end, Char());
-      arg = detail::make_arg<basic_printf_context>(basic_string_view<Char>(
-          str,
-          detail::to_unsigned(nul != str_end ? nul - str : specs.precision)));
+      arg = detail::make_arg<basic_printf_context<OutputIt, Char>>(
+          basic_string_view<Char>(
+              str, detail::to_unsigned(nul != str_end ? nul - str
+                                                      : specs.precision)));
     }
     if (specs.alt && visit_format_arg(detail::is_zero_int(), arg))
       specs.alt = false;
@@ -532,7 +449,7 @@ OutputIt basic_printf_context<OutputIt, Char>::format() {
 
     // Parse length and convert the argument to the required type.
     c = it != end ? *it++ : 0;
-    char_type t = it != end ? *it : 0;
+    Char t = it != end ? *it : 0;
     using detail::convert_arg;
     switch (c) {
     case 'h':
@@ -582,8 +499,9 @@ OutputIt basic_printf_context<OutputIt, Char>::format() {
         specs.type = 'd';
         break;
       case 'c':
-        visit_format_arg(detail::char_converter<basic_printf_context>(arg),
-                         arg);
+        visit_format_arg(
+            detail::char_converter<basic_printf_context<OutputIt, Char>>(arg),
+            arg);
         break;
       }
     }
@@ -591,10 +509,12 @@ OutputIt basic_printf_context<OutputIt, Char>::format() {
     start = it;
 
     // Format argument.
-    out = visit_format_arg(ArgFormatter(out, specs, *this), arg);
+    out = visit_format_arg(
+        detail::printf_arg_formatter<OutputIt, Char>(out, specs, context), arg);
   }
-  return std::copy(start, it, out);
+  detail::write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
 }
+FMT_END_DETAIL_NAMESPACE
 
 template <typename Char>
 using basic_printf_context_t =
@@ -612,9 +532,9 @@ using wprintf_args = basic_format_args<wprintf_context>;
   arguments and can be implicitly converted to `~fmt::printf_args`.
   \endrst
  */
-template <typename... Args>
-inline format_arg_store<printf_context, Args...> make_printf_args(
-    const Args&... args) {
+template <typename... T>
+inline auto make_printf_args(const T&... args)
+    -> format_arg_store<printf_context, T...> {
   return {args...};
 }
 
@@ -624,18 +544,19 @@ inline format_arg_store<printf_context, Args...> make_printf_args(
   arguments and can be implicitly converted to `~fmt::wprintf_args`.
   \endrst
  */
-template <typename... Args>
-inline format_arg_store<wprintf_context, Args...> make_wprintf_args(
-    const Args&... args) {
+template <typename... T>
+inline auto make_wprintf_args(const T&... args)
+    -> format_arg_store<wprintf_context, T...> {
   return {args...};
 }
 
 template <typename S, typename Char = char_t<S>>
-inline std::basic_string<Char> vsprintf(
-    const S& format,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
+inline auto vsprintf(
+    const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
   basic_memory_buffer<Char> buffer;
-  vprintf(buffer, to_string_view(format), args);
+  vprintf(buffer, to_string_view(fmt), args);
   return to_string(buffer);
 }
 
@@ -648,19 +569,20 @@ inline std::basic_string<Char> vsprintf(
     std::string message = fmt::sprintf("The answer is %d", 42);
   \endrst
 */
-template <typename S, typename... Args,
+template <typename S, typename... T,
           typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
-inline std::basic_string<Char> sprintf(const S& format, const Args&... args) {
+inline auto sprintf(const S& fmt, const T&... args) -> std::basic_string<Char> {
   using context = basic_printf_context_t<Char>;
-  return vsprintf(to_string_view(format), make_format_args<context>(args...));
+  return vsprintf(to_string_view(fmt), fmt::make_format_args<context>(args...));
 }
 
 template <typename S, typename Char = char_t<S>>
-inline int vfprintf(
-    std::FILE* f, const S& format,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
+inline auto vfprintf(
+    std::FILE* f, const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
   basic_memory_buffer<Char> buffer;
-  vprintf(buffer, to_string_view(format), args);
+  vprintf(buffer, to_string_view(fmt), args);
   size_t size = buffer.size();
   return std::fwrite(buffer.data(), sizeof(Char), size, f) < size
              ? -1
@@ -676,19 +598,19 @@ inline int vfprintf(
     fmt::fprintf(stderr, "Don't %s!", "panic");
   \endrst
  */
-template <typename S, typename... Args,
-          typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
-inline int fprintf(std::FILE* f, const S& format, const Args&... args) {
+template <typename S, typename... T, typename Char = char_t<S>>
+inline auto fprintf(std::FILE* f, const S& fmt, const T&... args) -> int {
   using context = basic_printf_context_t<Char>;
-  return vfprintf(f, to_string_view(format),
-                  make_format_args<context>(args...));
+  return vfprintf(f, to_string_view(fmt),
+                  fmt::make_format_args<context>(args...));
 }
 
 template <typename S, typename Char = char_t<S>>
-inline int vprintf(
-    const S& format,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
-  return vfprintf(stdout, to_string_view(format), args);
+inline auto vprintf(
+    const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
+  return vfprintf(stdout, to_string_view(fmt), args);
 }
 
 /**
@@ -700,52 +622,31 @@ inline int vprintf(
     fmt::printf("Elapsed time: %.2f seconds", 1.23);
   \endrst
  */
-template <typename S, typename... Args,
-          FMT_ENABLE_IF(detail::is_string<S>::value)>
-inline int printf(const S& format_str, const Args&... args) {
-  using context = basic_printf_context_t<char_t<S>>;
-  return vprintf(to_string_view(format_str),
-                 make_format_args<context>(args...));
+template <typename S, typename... T, FMT_ENABLE_IF(detail::is_string<S>::value)>
+inline auto printf(const S& fmt, const T&... args) -> int {
+  return vprintf(
+      to_string_view(fmt),
+      fmt::make_format_args<basic_printf_context_t<char_t<S>>>(args...));
 }
 
 template <typename S, typename Char = char_t<S>>
-inline int vfprintf(
-    std::basic_ostream<Char>& os, const S& format,
-    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
+FMT_DEPRECATED auto vfprintf(
+    std::basic_ostream<Char>& os, const S& fmt,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args)
+    -> int {
   basic_memory_buffer<Char> buffer;
-  vprintf(buffer, to_string_view(format), args);
-  detail::write_buffer(os, buffer);
+  vprintf(buffer, to_string_view(fmt), args);
+  os.write(buffer.data(), static_cast<std::streamsize>(buffer.size()));
   return static_cast<int>(buffer.size());
 }
-
-/** Formats arguments and writes the output to the range. */
-template <typename ArgFormatter, typename Char,
-          typename Context =
-              basic_printf_context<typename ArgFormatter::iterator, Char>>
-typename ArgFormatter::iterator vprintf(
-    detail::buffer<Char>& out, basic_string_view<Char> format_str,
-    basic_format_args<type_identity_t<Context>> args) {
-  typename ArgFormatter::iterator iter(out);
-  Context(iter, format_str, args).template format<ArgFormatter>();
-  return iter;
+template <typename S, typename... T, typename Char = char_t<S>>
+FMT_DEPRECATED auto fprintf(std::basic_ostream<Char>& os, const S& fmt,
+                            const T&... args) -> int {
+  return vfprintf(os, to_string_view(fmt),
+                  fmt::make_format_args<basic_printf_context_t<Char>>(args...));
 }
 
-/**
-  \rst
-  Prints formatted data to the stream *os*.
-
-  **Example**::
-
-    fmt::fprintf(cerr, "Don't %s!", "panic");
-  \endrst
- */
-template <typename S, typename... Args, typename Char = char_t<S>>
-inline int fprintf(std::basic_ostream<Char>& os, const S& format_str,
-                   const Args&... args) {
-  using context = basic_printf_context_t<Char>;
-  return vfprintf(os, to_string_view(format_str),
-                  make_format_args<context>(args...));
-}
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_PRINTF_H_

include/fmt/ranges.h

@@ -17,41 +17,31 @@
 
 #include "format.h"
 
-// output only up to N items from the range.
-#ifndef FMT_RANGE_OUTPUT_LENGTH_LIMIT
-#  define FMT_RANGE_OUTPUT_LENGTH_LIMIT 256
-#endif
-
 FMT_BEGIN_NAMESPACE
 
-template <typename Char> struct formatting_base {
+template <typename Char, typename Enable = void> struct formatting_range {
+#ifdef FMT_DEPRECATED_BRACED_RANGES
+  Char prefix = '{';
+  Char postfix = '}';
+#else
+  Char prefix = '[';
+  Char postfix = ']';
+#endif
+
   template <typename ParseContext>
   FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
 };
 
-template <typename Char, typename Enable = void>
-struct formatting_range : formatting_base<Char> {
-  static FMT_CONSTEXPR_DECL const size_t range_length_limit =
-      FMT_RANGE_OUTPUT_LENGTH_LIMIT;  // output only up to N items from the
-                                      // range.
-  Char prefix;
-  Char delimiter;
-  Char postfix;
-  formatting_range() : prefix('{'), delimiter(','), postfix('}') {}
-  static FMT_CONSTEXPR_DECL const bool add_delimiter_spaces = true;
-  static FMT_CONSTEXPR_DECL const bool add_prepostfix_space = false;
-};
+template <typename Char, typename Enable = void> struct formatting_tuple {
+  Char prefix = '(';
+  Char postfix = ')';
 
-template <typename Char, typename Enable = void>
-struct formatting_tuple : formatting_base<Char> {
-  Char prefix;
-  Char delimiter;
-  Char postfix;
-  formatting_tuple() : prefix('('), delimiter(','), postfix(')') {}
-  static FMT_CONSTEXPR_DECL const bool add_delimiter_spaces = true;
-  static FMT_CONSTEXPR_DECL const bool add_prepostfix_space = false;
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
 };
 
 namespace detail {
@@ -75,8 +65,14 @@ OutputIterator copy(char ch, OutputIterator out) {
   return out;
 }
 
+template <typename OutputIterator>
+OutputIterator copy(wchar_t ch, OutputIterator out) {
+  *out++ = ch;
+  return out;
+}
+
 /// Return true value if T has std::string interface, like std::string_view.
-template <typename T> class is_like_std_string {
+template <typename T> class is_std_string_like {
   template <typename U>
   static auto check(U* p)
       -> decltype((void)p->find('a'), p->length(), (void)p->data(), int());
@@ -88,19 +84,107 @@ template <typename T> class is_like_std_string {
 };
 
 template <typename Char>
-struct is_like_std_string<fmt::basic_string_view<Char>> : std::true_type {};
+struct is_std_string_like<fmt::basic_string_view<Char>> : std::true_type {};
 
 template <typename... Ts> struct conditional_helper {};
 
 template <typename T, typename _ = void> struct is_range_ : std::false_type {};
 
 #if !FMT_MSC_VER || FMT_MSC_VER > 1800
+
+#  define FMT_DECLTYPE_RETURN(val)  \
+    ->decltype(val) { return val; } \
+    static_assert(                  \
+        true, "")  // This makes it so that a semicolon is required after the
+                   // macro, which helps clang-format handle the formatting.
+
+// C array overload
+template <typename T, std::size_t N>
+auto range_begin(const T (&arr)[N]) -> const T* {
+  return arr;
+}
+template <typename T, std::size_t N>
+auto range_end(const T (&arr)[N]) -> const T* {
+  return arr + N;
+}
+
+template <typename T, typename Enable = void>
+struct has_member_fn_begin_end_t : std::false_type {};
+
 template <typename T>
-struct is_range_<
-    T, conditional_t<false,
-                     conditional_helper<decltype(std::declval<T>().begin()),
-                                        decltype(std::declval<T>().end())>,
-                     void>> : std::true_type {};
+struct has_member_fn_begin_end_t<T, void_t<decltype(std::declval<T>().begin()),
+                                           decltype(std::declval<T>().end())>>
+    : std::true_type {};
+
+// Member function overload
+template <typename T>
+auto range_begin(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).begin());
+template <typename T>
+auto range_end(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).end());
+
+// ADL overload. Only participates in overload resolution if member functions
+// are not found.
+template <typename T>
+auto range_begin(T&& rng)
+    -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
+                   decltype(begin(static_cast<T&&>(rng)))> {
+  return begin(static_cast<T&&>(rng));
+}
+template <typename T>
+auto range_end(T&& rng) -> enable_if_t<!has_member_fn_begin_end_t<T&&>::value,
+                                       decltype(end(static_cast<T&&>(rng)))> {
+  return end(static_cast<T&&>(rng));
+}
+
+template <typename T, typename Enable = void>
+struct has_const_begin_end : std::false_type {};
+template <typename T, typename Enable = void>
+struct has_mutable_begin_end : std::false_type {};
+
+template <typename T>
+struct has_const_begin_end<
+    T, void_t<decltype(detail::range_begin(
+                  std::declval<const remove_cvref_t<T>&>())),
+              decltype(detail::range_begin(
+                  std::declval<const remove_cvref_t<T>&>()))>>
+    : std::true_type {};
+
+template <typename T>
+struct has_mutable_begin_end<
+    T, void_t<decltype(detail::range_begin(std::declval<T>())),
+              decltype(detail::range_begin(std::declval<T>())),
+              enable_if_t<std::is_copy_constructible<T>::value>>>
+    : std::true_type {};
+
+template <typename T>
+struct is_range_<T, void>
+    : std::integral_constant<bool, (has_const_begin_end<T>::value ||
+                                    has_mutable_begin_end<T>::value)> {};
+
+template <typename T, typename Enable = void> struct range_to_view;
+template <typename T>
+struct range_to_view<T, enable_if_t<has_const_begin_end<T>::value>> {
+  struct view_t {
+    const T* m_range_ptr;
+
+    auto begin() const FMT_DECLTYPE_RETURN(detail::range_begin(*m_range_ptr));
+    auto end() const FMT_DECLTYPE_RETURN(detail::range_end(*m_range_ptr));
+  };
+  static auto view(const T& range) -> view_t { return {&range}; }
+};
+
+template <typename T>
+struct range_to_view<T, enable_if_t<!has_const_begin_end<T>::value &&
+                                    has_mutable_begin_end<T>::value>> {
+  struct view_t {
+    T m_range_copy;
+
+    auto begin() FMT_DECLTYPE_RETURN(detail::range_begin(m_range_copy));
+    auto end() FMT_DECLTYPE_RETURN(detail::range_end(m_range_copy));
+  };
+  static auto view(const T& range) -> view_t { return {range}; }
+};
+#  undef FMT_DECLTYPE_RETURN
 #endif
 
 /// tuple_size and tuple_element check.
@@ -158,33 +242,42 @@ template <class Tuple, class F> void for_each(Tuple&& tup, F&& f) {
 }
 
 template <typename Range>
-using value_type = remove_cvref_t<decltype(*std::declval<Range>().begin())>;
+using value_type =
+    remove_cvref_t<decltype(*detail::range_begin(std::declval<Range>()))>;
 
-template <typename Arg, FMT_ENABLE_IF(!is_like_std_string<
-                                      typename std::decay<Arg>::type>::value)>
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const Arg&) {
-  return add_space ? " {}" : "{}";
+template <typename OutputIt> OutputIt write_delimiter(OutputIt out) {
+  *out++ = ',';
+  *out++ = ' ';
+  return out;
 }
 
-template <typename Arg, FMT_ENABLE_IF(is_like_std_string<
-                                      typename std::decay<Arg>::type>::value)>
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const Arg&) {
-  return add_space ? " \"{}\"" : "\"{}\"";
+template <
+    typename Char, typename OutputIt, typename Arg,
+    FMT_ENABLE_IF(is_std_string_like<typename std::decay<Arg>::type>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg& v) {
+  *out++ = '"';
+  out = write<Char>(out, v);
+  *out++ = '"';
+  return out;
 }
 
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const char*) {
-  return add_space ? " \"{}\"" : "\"{}\"";
-}
-FMT_CONSTEXPR const wchar_t* format_str_quoted(bool add_space, const wchar_t*) {
-  return add_space ? L" \"{}\"" : L"\"{}\"";
+template <typename Char, typename OutputIt, typename Arg,
+          FMT_ENABLE_IF(std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg v) {
+  *out++ = '\'';
+  *out++ = v;
+  *out++ = '\'';
+  return out;
 }
 
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const char) {
-  return add_space ? " '{}'" : "'{}'";
-}
-FMT_CONSTEXPR const wchar_t* format_str_quoted(bool add_space, const wchar_t) {
-  return add_space ? L" '{}'" : L"'{}'";
+template <
+    typename Char, typename OutputIt, typename Arg,
+    FMT_ENABLE_IF(!is_std_string_like<typename std::decay<Arg>::type>::value &&
+                  !std::is_same<Arg, Char>::value)>
+OutputIt write_range_entry(OutputIt out, const Arg& v) {
+  return write<Char>(out, v);
 }
+
 }  // namespace detail
 
 template <typename T> struct is_tuple_like {
@@ -198,23 +291,14 @@ struct formatter<TupleT, Char, enable_if_t<fmt::is_tuple_like<TupleT>::value>> {
   // C++11 generic lambda for format()
   template <typename FormatContext> struct format_each {
     template <typename T> void operator()(const T& v) {
-      if (i > 0) {
-        if (formatting.add_prepostfix_space) {
-          *out++ = ' ';
-        }
-        out = detail::copy(formatting.delimiter, out);
-      }
-      out = format_to(out,
-                      detail::format_str_quoted(
-                          (formatting.add_delimiter_spaces && i > 0), v),
-                      v);
+      if (i > 0) out = detail::write_delimiter(out);
+      out = detail::write_range_entry<Char>(out, v);
       ++i;
     }
-
     formatting_tuple<Char>& formatting;
     size_t& i;
-    typename std::add_lvalue_reference<decltype(
-        std::declval<FormatContext>().out())>::type out;
+    typename std::add_lvalue_reference<
+        decltype(std::declval<FormatContext>().out())>::type out;
   };
 
  public:
@@ -229,12 +313,9 @@ struct formatter<TupleT, Char, enable_if_t<fmt::is_tuple_like<TupleT>::value>> {
   auto format(const TupleT& values, FormatContext& ctx) -> decltype(ctx.out()) {
     auto out = ctx.out();
     size_t i = 0;
-    detail::copy(formatting.prefix, out);
 
+    detail::copy(formatting.prefix, out);
     detail::for_each(values, format_each<FormatContext>{formatting, i, out});
-    if (formatting.add_prepostfix_space) {
-      *out++ = ' ';
-    }
     detail::copy(formatting.postfix, out);
 
     return ctx.out();
@@ -243,7 +324,7 @@ struct formatter<TupleT, Char, enable_if_t<fmt::is_tuple_like<TupleT>::value>> {
 
 template <typename T, typename Char> struct is_range {
   static FMT_CONSTEXPR_DECL const bool value =
-      detail::is_range_<T>::value && !detail::is_like_std_string<T>::value &&
+      detail::is_range_<T>::value && !detail::is_std_string_like<T>::value &&
       !std::is_convertible<T, std::basic_string<Char>>::value &&
       !std::is_constructible<detail::std_string_view<Char>, T>::value;
 };
@@ -251,12 +332,14 @@ template <typename T, typename Char> struct is_range {
 template <typename T, typename Char>
 struct formatter<
     T, Char,
-    enable_if_t<fmt::is_range<T, Char>::value
+    enable_if_t<
+        fmt::is_range<T, Char>::value
 // Workaround a bug in MSVC 2017 and earlier.
 #if !FMT_MSC_VER || FMT_MSC_VER >= 1927
-                && has_formatter<detail::value_type<T>, format_context>::value
+        && (has_formatter<detail::value_type<T>, format_context>::value ||
+            detail::has_fallback_formatter<detail::value_type<T>, Char>::value)
 #endif
-                >> {
+        >> {
   formatting_range<Char> formatting;
 
   template <typename ParseContext>
@@ -268,71 +351,64 @@ struct formatter<
   typename FormatContext::iterator format(const T& values, FormatContext& ctx) {
     auto out = detail::copy(formatting.prefix, ctx.out());
     size_t i = 0;
-    auto it = values.begin();
-    auto end = values.end();
+    auto view = detail::range_to_view<T>::view(values);
+    auto it = view.begin();
+    auto end = view.end();
     for (; it != end; ++it) {
-      if (i > 0) {
-        if (formatting.add_prepostfix_space) *out++ = ' ';
-        out = detail::copy(formatting.delimiter, out);
-      }
-      out = format_to(out,
-                      detail::format_str_quoted(
-                          (formatting.add_delimiter_spaces && i > 0), *it),
-                      *it);
-      if (++i > formatting.range_length_limit) {
-        out = format_to(out, " ... <other elements>");
-        break;
-      }
+      if (i > 0) out = detail::write_delimiter(out);
+      out = detail::write_range_entry<Char>(out, *it);
+      ++i;
     }
-    if (formatting.add_prepostfix_space) *out++ = ' ';
     return detail::copy(formatting.postfix, out);
   }
 };
 
-template <typename Char, typename... T> struct tuple_arg_join : detail::view {
+template <typename Char, typename... T> struct tuple_join_view : detail::view {
   const std::tuple<T...>& tuple;
   basic_string_view<Char> sep;
 
-  tuple_arg_join(const std::tuple<T...>& t, basic_string_view<Char> s)
-      : tuple{t}, sep{s} {}
+  tuple_join_view(const std::tuple<T...>& t, basic_string_view<Char> s)
+      : tuple(t), sep{s} {}
 };
 
 template <typename Char, typename... T>
-struct formatter<tuple_arg_join<Char, T...>, Char> {
+using tuple_arg_join = tuple_join_view<Char, T...>;
+
+template <typename Char, typename... T>
+struct formatter<tuple_join_view<Char, T...>, Char> {
   template <typename ParseContext>
   FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
 
   template <typename FormatContext>
-  typename FormatContext::iterator format(
-      const tuple_arg_join<Char, T...>& value, FormatContext& ctx) {
+  auto format(const tuple_join_view<Char, T...>& value, FormatContext& ctx) ->
+      typename FormatContext::iterator {
     return format(value, ctx, detail::make_index_sequence<sizeof...(T)>{});
   }
 
  private:
   template <typename FormatContext, size_t... N>
-  typename FormatContext::iterator format(
-      const tuple_arg_join<Char, T...>& value, FormatContext& ctx,
-      detail::index_sequence<N...>) {
+  auto format(const tuple_join_view<Char, T...>& value, FormatContext& ctx,
+              detail::index_sequence<N...>) ->
+      typename FormatContext::iterator {
     return format_args(value, ctx, std::get<N>(value.tuple)...);
   }
 
   template <typename FormatContext>
-  typename FormatContext::iterator format_args(
-      const tuple_arg_join<Char, T...>&, FormatContext& ctx) {
+  auto format_args(const tuple_join_view<Char, T...>&, FormatContext& ctx) ->
+      typename FormatContext::iterator {
     // NOTE: for compilers that support C++17, this empty function instantiation
     // can be replaced with a constexpr branch in the variadic overload.
     return ctx.out();
   }
 
   template <typename FormatContext, typename Arg, typename... Args>
-  typename FormatContext::iterator format_args(
-      const tuple_arg_join<Char, T...>& value, FormatContext& ctx,
-      const Arg& arg, const Args&... args) {
+  auto format_args(const tuple_join_view<Char, T...>& value, FormatContext& ctx,
+                   const Arg& arg, const Args&... args) ->
+      typename FormatContext::iterator {
     using base = formatter<typename std::decay<Arg>::type, Char>;
-    auto out = ctx.out();
-    out = base{}.format(arg, ctx);
+    auto out = base().format(arg, ctx);
     if (sizeof...(Args) > 0) {
       out = std::copy(value.sep.begin(), value.sep.end(), out);
       ctx.advance_to(out);
@@ -342,6 +418,8 @@ struct formatter<tuple_arg_join<Char, T...>, Char> {
   }
 };
 
+FMT_MODULE_EXPORT_BEGIN
+
 /**
   \rst
   Returns an object that formats `tuple` with elements separated by `sep`.
@@ -354,14 +432,15 @@ struct formatter<tuple_arg_join<Char, T...>, Char> {
   \endrst
  */
 template <typename... T>
-FMT_CONSTEXPR tuple_arg_join<char, T...> join(const std::tuple<T...>& tuple,
-                                              string_view sep) {
+FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple, string_view sep)
+    -> tuple_join_view<char, T...> {
   return {tuple, sep};
 }
 
 template <typename... T>
-FMT_CONSTEXPR tuple_arg_join<wchar_t, T...> join(const std::tuple<T...>& tuple,
-                                                 wstring_view sep) {
+FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple,
+                        basic_string_view<wchar_t> sep)
+    -> tuple_join_view<wchar_t, T...> {
   return {tuple, sep};
 }
 
@@ -377,17 +456,12 @@ FMT_CONSTEXPR tuple_arg_join<wchar_t, T...> join(const std::tuple<T...>& tuple,
   \endrst
  */
 template <typename T>
-arg_join<const T*, const T*, char> join(std::initializer_list<T> list,
-                                        string_view sep) {
-  return join(std::begin(list), std::end(list), sep);
-}
-
-template <typename T>
-arg_join<const T*, const T*, wchar_t> join(std::initializer_list<T> list,
-                                           wstring_view sep) {
+auto join(std::initializer_list<T> list, string_view sep)
+    -> join_view<const T*, const T*> {
   return join(std::begin(list), std::end(list), sep);
 }
 
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_RANGES_H_

include/fmt/xchar.h

@@ -0,0 +1,236 @@
+// Formatting library for C++ - optional wchar_t and exotic character support
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_WCHAR_H_
+#define FMT_WCHAR_H_
+
+#include <cwchar>
+#include <tuple>
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+template <typename T>
+using is_exotic_char = bool_constant<!std::is_same<T, char>::value>;
+}
+
+FMT_MODULE_EXPORT_BEGIN
+
+using wstring_view = basic_string_view<wchar_t>;
+using wformat_parse_context = basic_format_parse_context<wchar_t>;
+using wformat_context = buffer_context<wchar_t>;
+using wformat_args = basic_format_args<wformat_context>;
+using wmemory_buffer = basic_memory_buffer<wchar_t>;
+
+#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+// Workaround broken conversion on older gcc.
+template <typename... Args> using wformat_string = wstring_view;
+#else
+template <typename... Args>
+using wformat_string = basic_format_string<wchar_t, type_identity_t<Args>...>;
+#endif
+
+template <> struct is_char<wchar_t> : std::true_type {};
+template <> struct is_char<detail::char8_type> : std::true_type {};
+template <> struct is_char<char16_t> : std::true_type {};
+template <> struct is_char<char32_t> : std::true_type {};
+
+template <typename... Args>
+constexpr format_arg_store<wformat_context, Args...> make_wformat_args(
+    const Args&... args) {
+  return {args...};
+}
+
+inline namespace literals {
+constexpr auto operator"" _format(const wchar_t* s, size_t n)
+    -> detail::udl_formatter<wchar_t> {
+  return {{s, n}};
+}
+
+#if FMT_USE_USER_DEFINED_LITERALS && !FMT_USE_NONTYPE_TEMPLATE_PARAMETERS
+constexpr detail::udl_arg<wchar_t> operator"" _a(const wchar_t* s, size_t) {
+  return {s};
+}
+#endif
+}  // namespace literals
+
+template <typename It, typename Sentinel>
+auto join(It begin, Sentinel end, wstring_view sep)
+    -> join_view<It, Sentinel, wchar_t> {
+  return {begin, end, sep};
+}
+
+template <typename Range>
+auto join(Range&& range, wstring_view sep)
+    -> join_view<detail::iterator_t<Range>, detail::sentinel_t<Range>,
+                 wchar_t> {
+  return join(std::begin(range), std::end(range), sep);
+}
+
+template <typename T>
+auto join(std::initializer_list<T> list, wstring_view sep)
+    -> join_view<const T*, const T*, wchar_t> {
+  return join(std::begin(list), std::end(list), sep);
+}
+
+template <typename Char, FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
+auto vformat(basic_string_view<Char> format_str,
+             basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  basic_memory_buffer<Char> buffer;
+  detail::vformat_to(buffer, format_str, args);
+  return to_string(buffer);
+}
+
+// Pass char_t as a default template parameter instead of using
+// std::basic_string<char_t<S>> to reduce the symbol size.
+template <typename S, typename... Args, typename Char = char_t<S>,
+          FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
+auto format(const S& format_str, Args&&... args) -> std::basic_string<Char> {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  return vformat(to_string_view(format_str), vargs);
+}
+
+template <typename Locale, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto vformat(
+    const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> std::basic_string<Char> {
+  return detail::vformat(loc, to_string_view(format_str), args);
+}
+
+template <typename Locale, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format(const Locale& loc, const S& format_str, Args&&... args)
+    -> std::basic_string<Char> {
+  return detail::vformat(loc, to_string_view(format_str),
+                         fmt::make_args_checked<Args...>(format_str, args...));
+}
+
+template <typename OutputIt, typename S, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+auto vformat_to(OutputIt out, const S& format_str,
+                basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> OutputIt {
+  auto&& buf = detail::get_buffer<Char>(out);
+  detail::vformat_to(buf, to_string_view(format_str), args);
+  return detail::get_iterator(buf);
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format_to(OutputIt out, const S& fmt, Args&&... args) -> OutputIt {
+  const auto& vargs = fmt::make_args_checked<Args...>(fmt, args...);
+  return vformat_to(out, to_string_view(fmt), vargs);
+}
+
+template <typename S, typename... Args, typename Char, size_t SIZE,
+          typename Allocator, FMT_ENABLE_IF(detail::is_string<S>::value)>
+FMT_DEPRECATED auto format_to(basic_memory_buffer<Char, SIZE, Allocator>& buf,
+                              const S& format_str, Args&&... args) ->
+    typename buffer_context<Char>::iterator {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  detail::vformat_to(buf, to_string_view(format_str), vargs);
+  return detail::buffer_appender<Char>(buf);
+}
+
+template <typename Locale, typename S, typename OutputIt, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_locale<Locale>::value&&
+                                detail::is_exotic_char<Char>::value)>
+inline auto vformat_to(
+    OutputIt out, const Locale& loc, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) -> OutputIt {
+  auto&& buf = detail::get_buffer<Char>(out);
+  vformat_to(buf, to_string_view(format_str), args, detail::locale_ref(loc));
+  return detail::get_iterator(buf);
+}
+
+template <
+    typename OutputIt, typename Locale, typename S, typename... Args,
+    typename Char = char_t<S>,
+    bool enable = detail::is_output_iterator<OutputIt, Char>::value&&
+        detail::is_locale<Locale>::value&& detail::is_exotic_char<Char>::value>
+inline auto format_to(OutputIt out, const Locale& loc, const S& format_str,
+                      Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  const auto& vargs = fmt::make_args_checked<Args...>(format_str, args...);
+  return vformat_to(out, loc, to_string_view(format_str), vargs);
+}
+
+template <typename OutputIt, typename Char, typename... Args,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto vformat_to_n(
+    OutputIt out, size_t n, basic_string_view<Char> format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+    -> format_to_n_result<OutputIt> {
+  detail::iterator_buffer<OutputIt, Char, detail::fixed_buffer_traits> buf(out,
+                                                                           n);
+  detail::vformat_to(buf, format_str, args);
+  return {buf.out(), buf.count()};
+}
+
+template <typename OutputIt, typename S, typename... Args,
+          typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+                            detail::is_exotic_char<Char>::value)>
+inline auto format_to_n(OutputIt out, size_t n, const S& fmt,
+                        const Args&... args) -> format_to_n_result<OutputIt> {
+  const auto& vargs = fmt::make_args_checked<Args...>(fmt, args...);
+  return vformat_to_n(out, n, to_string_view(fmt), vargs);
+}
+
+template <typename S, typename... Args, typename Char = char_t<S>,
+          FMT_ENABLE_IF(detail::is_exotic_char<Char>::value)>
+inline auto formatted_size(const S& fmt, Args&&... args) -> size_t {
+  detail::counting_buffer<Char> buf;
+  const auto& vargs = fmt::make_args_checked<Args...>(fmt, args...);
+  detail::vformat_to(buf, to_string_view(fmt), vargs);
+  return buf.count();
+}
+
+inline void vprint(std::FILE* f, wstring_view fmt, wformat_args args) {
+  wmemory_buffer buffer;
+  detail::vformat_to(buffer, fmt, args);
+  buffer.push_back(L'\0');
+  if (std::fputws(buffer.data(), f) == -1)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+inline void vprint(wstring_view fmt, wformat_args args) {
+  vprint(stdout, fmt, args);
+}
+
+template <typename... T>
+void print(std::FILE* f, wformat_string<T...> fmt, T&&... args) {
+  return vprint(f, wstring_view(fmt), make_wformat_args(args...));
+}
+
+template <typename... T> void print(wformat_string<T...> fmt, T&&... args) {
+  return vprint(wstring_view(fmt), make_wformat_args(args...));
+}
+
+/**
+  Converts *value* to ``std::wstring`` using the default format for type *T*.
+ */
+template <typename T> inline auto to_wstring(const T& value) -> std::wstring {
+  return format(FMT_STRING(L"{}"), value);
+}
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_WCHAR_H_

pull_request_template.md

@@ -1,6 +0,0 @@
-<!-- Please read the contribution guidelines before submitting a pull request. -->
-<!-- By submitting this pull request, you agree that your contributions are licensed under the {fmt} license,
-     and agree to future changes to the licensing. -->
-<!-- If you're a first-time contributor, please acknowledge it by leaving the statement below. -->
-
-I agree that my contributions are licensed under the {fmt} license, and agree to future changes to the licensing.

src/fmt.cc

@@ -0,0 +1,100 @@
+module;
+#ifndef __cpp_modules
+#  error Module not supported.
+#endif
+
+// put all implementation-provided headers into the global module fragment
+// to prevent attachment to this module
+#if !defined(_CRT_SECURE_NO_WARNINGS) && defined(_MSC_VER)
+#  define _CRT_SECURE_NO_WARNINGS
+#endif
+#if !defined(WIN32_LEAN_AND_MEAN) && defined(_WIN32)
+#  define WIN32_LEAN_AND_MEAN
+#endif
+
+#include <algorithm>
+#include <cctype>
+#include <cerrno>
+#include <chrono>
+#include <climits>
+#include <clocale>
+#include <cmath>
+#include <cstdarg>
+#include <cstddef>
+#include <cstdint>
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <ctime>
+#include <cwchar>
+#include <exception>
+#include <functional>
+#include <iterator>
+#include <limits>
+#include <locale>
+#include <memory>
+#include <ostream>
+#include <sstream>
+#include <stdexcept>
+#include <string>
+#include <string_view>
+#include <system_error>
+#include <type_traits>
+#include <utility>
+#include <vector>
+
+#if _MSC_VER
+#  include <intrin.h>
+#endif
+#if defined __APPLE__ || defined(__FreeBSD__)
+#  include <xlocale.h>
+#endif
+#if __has_include(<winapifamily.h>)
+#  include <winapifamily.h>
+#endif
+#if (__has_include(<fcntl.h>) || defined(__APPLE__) || \
+     defined(__linux__)) &&                            \
+    (!defined(WINAPI_FAMILY) || (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
+#  include <fcntl.h>
+#  include <sys/stat.h>
+#  include <sys/types.h>
+#  ifndef _WIN32
+#    include <unistd.h>
+#  else
+#    include <io.h>
+#  endif
+#endif
+#ifdef _WIN32
+#  include <windows.h>
+#endif
+
+export module fmt;
+
+#define FMT_MODULE_EXPORT export
+#define FMT_MODULE_EXPORT_BEGIN export {
+#define FMT_MODULE_EXPORT_END }
+#define FMT_BEGIN_DETAIL_NAMESPACE \
+  }                                \
+  namespace detail {
+#define FMT_END_DETAIL_NAMESPACE \
+  }                              \
+  export {
+
+// all library-provided declarations and definitions
+// must be in the module purview to be exported
+#include "fmt/args.h"
+#include "fmt/chrono.h"
+#include "fmt/color.h"
+#include "fmt/compile.h"
+#include "fmt/format.h"
+#include "fmt/os.h"
+#include "fmt/printf.h"
+#include "fmt/xchar.h"
+
+// gcc doesn't yet implement private module fragments
+#if !FMT_GCC_VERSION
+module : private;
+#endif
+
+#include "format.cc"
+#include "os.cc"

src/format.cc

@@ -24,39 +24,12 @@ int format_float(char* buf, std::size_t size, const char* format, int precision,
                        : snprintf_ptr(buf, size, format, precision, value);
 }
 
-template dragonbox::decimal_fp<float> dragonbox::to_decimal(float x)
+template FMT_API dragonbox::decimal_fp<float> dragonbox::to_decimal(float x)
     FMT_NOEXCEPT;
-template dragonbox::decimal_fp<double> dragonbox::to_decimal(double x)
+template FMT_API dragonbox::decimal_fp<double> dragonbox::to_decimal(double x)
     FMT_NOEXCEPT;
-
-// DEPRECATED! This function exists for ABI compatibility.
-template <typename Char>
-typename basic_format_context<std::back_insert_iterator<buffer<Char>>,
-                              Char>::iterator
-vformat_to(buffer<Char>& buf, basic_string_view<Char> format_str,
-           basic_format_args<basic_format_context<
-               std::back_insert_iterator<buffer<type_identity_t<Char>>>,
-               type_identity_t<Char>>>
-               args) {
-  using iterator = std::back_insert_iterator<buffer<char>>;
-  using context = basic_format_context<
-      std::back_insert_iterator<buffer<type_identity_t<Char>>>,
-      type_identity_t<Char>>;
-  auto out = iterator(buf);
-  format_handler<iterator, Char, context> h(out, format_str, args, {});
-  parse_format_string<false>(format_str, h);
-  return out;
-}
-template basic_format_context<std::back_insert_iterator<buffer<char>>,
-                              char>::iterator
-vformat_to(buffer<char>&, string_view,
-           basic_format_args<basic_format_context<
-               std::back_insert_iterator<buffer<type_identity_t<char>>>,
-               type_identity_t<char>>>);
 }  // namespace detail
 
-template struct FMT_INSTANTIATION_DEF_API detail::basic_data<void>;
-
 // Workaround a bug in MSVC2013 that prevents instantiation of format_float.
 int (*instantiate_format_float)(double, int, detail::float_specs,
                                 detail::buffer<char>&) = detail::format_float;
@@ -68,8 +41,8 @@ template FMT_API std::locale detail::locale_ref::get<std::locale>() const;
 
 // Explicit instantiations for char.
 
-template FMT_API std::string detail::grouping_impl<char>(locale_ref);
-template FMT_API char detail::thousands_sep_impl(locale_ref);
+template FMT_API auto detail::thousands_sep_impl(locale_ref)
+    -> thousands_sep_result<char>;
 template FMT_API char detail::decimal_point_impl(locale_ref);
 
 template FMT_API void detail::buffer<char>::append(const char*, const char*);
@@ -90,10 +63,13 @@ template FMT_API int detail::format_float(long double, int, detail::float_specs,
 
 // Explicit instantiations for wchar_t.
 
-template FMT_API std::string detail::grouping_impl<wchar_t>(locale_ref);
-template FMT_API wchar_t detail::thousands_sep_impl(locale_ref);
+template FMT_API auto detail::thousands_sep_impl(locale_ref)
+    -> thousands_sep_result<wchar_t>;
 template FMT_API wchar_t detail::decimal_point_impl(locale_ref);
 
 template FMT_API void detail::buffer<wchar_t>::append(const wchar_t*,
                                                       const wchar_t*);
+
+template struct detail::basic_data<void>;
+
 FMT_END_NAMESPACE

src/os.cc

@@ -25,7 +25,6 @@
 #      define WIN32_LEAN_AND_MEAN
 #    endif
 #    include <io.h>
-#    include <windows.h>
 
 #    define O_CREAT _O_CREAT
 #    define O_TRUNC _O_TRUNC
@@ -55,7 +54,7 @@
 namespace {
 #ifdef _WIN32
 // Return type of read and write functions.
-using RWResult = int;
+using rwresult = int;
 
 // On Windows the count argument to read and write is unsigned, so convert
 // it from size_t preventing integer overflow.
@@ -64,7 +63,7 @@ inline unsigned convert_rwcount(std::size_t count) {
 }
 #elif FMT_USE_FCNTL
 // Return type of read and write functions.
-using RWResult = ssize_t;
+using rwresult = ssize_t;
 
 inline std::size_t convert_rwcount(std::size_t count) { return count; }
 #endif
@@ -73,14 +72,14 @@ inline std::size_t convert_rwcount(std::size_t count) { return count; }
 FMT_BEGIN_NAMESPACE
 
 #ifdef _WIN32
-detail::utf16_to_utf8::utf16_to_utf8(wstring_view s) {
+detail::utf16_to_utf8::utf16_to_utf8(basic_string_view<wchar_t> s) {
   if (int error_code = convert(s)) {
     FMT_THROW(windows_error(error_code,
                             "cannot convert string from UTF-16 to UTF-8"));
   }
 }
 
-int detail::utf16_to_utf8::convert(wstring_view s) {
+int detail::utf16_to_utf8::convert(basic_string_view<wchar_t> s) {
   if (s.size() > INT_MAX) return ERROR_INVALID_PARAMETER;
   int s_size = static_cast<int>(s.size());
   if (s_size == 0) {
@@ -101,46 +100,85 @@ int detail::utf16_to_utf8::convert(wstring_view s) {
   return 0;
 }
 
-void windows_error::init(int err_code, string_view format_str,
-                         format_args args) {
-  error_code_ = err_code;
-  memory_buffer buffer;
-  detail::format_windows_error(buffer, err_code, vformat(format_str, args));
-  std::runtime_error& base = *this;
-  base = std::runtime_error(to_string(buffer));
+namespace detail {
+
+class system_message {
+  system_message(const system_message&) = delete;
+  void operator=(const system_message&) = delete;
+
+  unsigned long result_;
+  wchar_t* message_;
+
+  static bool is_whitespace(wchar_t c) FMT_NOEXCEPT {
+    return c == L' ' || c == L'\n' || c == L'\r' || c == L'\t' || c == L'\0';
+  }
+
+ public:
+  explicit system_message(unsigned long error_code)
+      : result_(0), message_(nullptr) {
+    result_ = FormatMessageW(
+        FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
+            FORMAT_MESSAGE_IGNORE_INSERTS,
+        nullptr, error_code, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+        reinterpret_cast<wchar_t*>(&message_), 0, nullptr);
+    if (result_ != 0) {
+      while (result_ != 0 && is_whitespace(message_[result_ - 1])) {
+        --result_;
+      }
+    }
+  }
+  ~system_message() { LocalFree(message_); }
+  explicit operator bool() const FMT_NOEXCEPT { return result_ != 0; }
+  operator basic_string_view<wchar_t>() const FMT_NOEXCEPT {
+    return basic_string_view<wchar_t>(message_, result_);
+  }
+};
+
+class utf8_system_category final : public std::error_category {
+ public:
+  const char* name() const FMT_NOEXCEPT override { return "system"; }
+  std::string message(int error_code) const override {
+    system_message msg(error_code);
+    if (msg) {
+      utf16_to_utf8 utf8_message;
+      if (utf8_message.convert(msg) == ERROR_SUCCESS) {
+        return utf8_message.str();
+      }
+    }
+    return "unknown error";
+  }
+};
+
+}  // namespace detail
+
+FMT_API const std::error_category& system_category() FMT_NOEXCEPT {
+  static const detail::utf8_system_category category;
+  return category;
+}
+
+std::system_error vwindows_error(int err_code, string_view format_str,
+                                 format_args args) {
+  auto ec = std::error_code(err_code, system_category());
+  return std::system_error(ec, vformat(format_str, args));
 }
 
 void detail::format_windows_error(detail::buffer<char>& out, int error_code,
-                                  string_view message) FMT_NOEXCEPT {
+                                  const char* message) FMT_NOEXCEPT {
   FMT_TRY {
-    wmemory_buffer buf;
-    buf.resize(inline_buffer_size);
-    for (;;) {
-      wchar_t* system_message = &buf[0];
-      int result = FormatMessageW(
-          FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, nullptr,
-          error_code, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), system_message,
-          static_cast<uint32_t>(buf.size()), nullptr);
-      if (result != 0) {
-        utf16_to_utf8 utf8_message;
-        if (utf8_message.convert(system_message) == ERROR_SUCCESS) {
-          format_to(buffer_appender<char>(out), "{}: {}", message,
-                    utf8_message);
-          return;
-        }
-        break;
+    system_message msg(error_code);
+    if (msg) {
+      utf16_to_utf8 utf8_message;
+      if (utf8_message.convert(msg) == ERROR_SUCCESS) {
+        format_to(buffer_appender<char>(out), "{}: {}", message, utf8_message);
+        return;
       }
-      if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
-        break;  // Can't get error message, report error code instead.
-      buf.resize(buf.size() * 2);
     }
   }
   FMT_CATCH(...) {}
   format_error_code(out, error_code, message);
 }
 
-void report_windows_error(int error_code,
-                          fmt::string_view message) FMT_NOEXCEPT {
+void report_windows_error(int error_code, const char* message) FMT_NOEXCEPT {
   report_error(detail::format_windows_error, error_code, message);
 }
 #endif  // _WIN32
@@ -229,14 +267,14 @@ long long file::size() const {
 }
 
 std::size_t file::read(void* buffer, std::size_t count) {
-  RWResult result = 0;
+  rwresult result = 0;
   FMT_RETRY(result, FMT_POSIX_CALL(read(fd_, buffer, convert_rwcount(count))));
   if (result < 0) FMT_THROW(system_error(errno, "cannot read from file"));
   return detail::to_unsigned(result);
 }
 
 std::size_t file::write(const void* buffer, std::size_t count) {
-  RWResult result = 0;
+  rwresult result = 0;
   FMT_RETRY(result, FMT_POSIX_CALL(write(fd_, buffer, convert_rwcount(count))));
   if (result < 0) FMT_THROW(system_error(errno, "cannot write to file"));
   return detail::to_unsigned(result);
@@ -260,10 +298,10 @@ void file::dup2(int fd) {
   }
 }
 
-void file::dup2(int fd, error_code& ec) FMT_NOEXCEPT {
+void file::dup2(int fd, std::error_code& ec) FMT_NOEXCEPT {
   int result = 0;
   FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
-  if (result == -1) ec = error_code(errno);
+  if (result == -1) ec = std::error_code(errno, std::generic_category());
 }
 
 void file::pipe(file& read_end, file& write_end) {
@@ -315,7 +353,7 @@ long getpagesize() {
 #  endif
 }
 
-void ostream::grow(size_t) {
+FMT_API void ostream::grow(size_t) {
   if (this->size() == this->capacity()) flush();
 }
 #endif  // FMT_USE_FCNTL

support/appveyor.yml

@@ -6,11 +6,8 @@ clone_depth: 1
 
 image:
   - Visual Studio 2015
-  - Visual Studio 2019
-  - Visual Studio 2017
 
 platform:
-  - Win32
   - x64
 
 environment:
@@ -18,13 +15,6 @@ environment:
   MSVC_DEFAULT_OPTIONS: ON
   BUILD: msvc
 
-matrix:
-  exclude:
-    - image: Visual Studio 2015
-      platform: Win32
-    - image: Visual Studio 2019
-      platform: Win32
-
 before_build:
  - mkdir build
  - cd build

support/build-docs.py

@@ -0,0 +1,58 @@
+#!/usr/bin/env python
+# Build the documentation in CI.
+
+from __future__ import print_function
+import errno, os, shutil, subprocess, sys, urllib
+from subprocess import call, check_call, Popen, PIPE, STDOUT
+
+def rmtree_if_exists(dir):
+    try:
+        shutil.rmtree(dir)
+    except OSError as e:
+        if e.errno == errno.ENOENT:
+            pass
+
+# Build the docs.
+fmt_dir = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
+sys.path.insert(0, os.path.join(fmt_dir, 'doc'))
+import build
+build.create_build_env()
+html_dir = build.build_docs()
+
+repo = 'fmtlib.github.io'
+branch = os.environ['GITHUB_REF']
+is_ci = 'CI' in os.environ
+if is_ci and branch != 'refs/heads/master':
+    print('Branch: ' + branch)
+    exit(0) # Ignore non-master branches
+if is_ci and 'KEY' not in os.environ:
+    # Don't update the repo if building in CI from an account that doesn't have
+    # push access.
+    print('Skipping update of ' + repo)
+    exit(0)
+
+# Clone the fmtlib.github.io repo.
+rmtree_if_exists(repo)
+git_url = 'https://github.com/' if is_ci else 'git@github.com:'
+check_call(['git', 'clone', git_url + 'fmtlib/{}.git'.format(repo)])
+
+# Copy docs to the repo.
+target_dir = os.path.join(repo, 'dev')
+rmtree_if_exists(target_dir)
+shutil.copytree(html_dir, target_dir, ignore=shutil.ignore_patterns('.*'))
+if is_ci:
+    check_call(['git', 'config', '--global', 'user.name', 'fmtbot'])
+    check_call(['git', 'config', '--global', 'user.email', 'viz@fmt.dev'])
+
+# Push docs to GitHub pages.
+check_call(['git', 'add', '--all'], cwd=repo)
+if call(['git', 'diff-index', '--quiet', 'HEAD'], cwd=repo):
+    check_call(['git', 'commit', '-m', 'Update documentation'], cwd=repo)
+    cmd = 'git push'
+    if is_ci:
+        cmd += ' https://$KEY@github.com/fmtlib/fmtlib.github.io.git master'
+    p = Popen(cmd, shell=True, stdout=PIPE, stderr=STDOUT, cwd=repo)
+    # Print the output without the key.
+    print(p.communicate()[0].decode('utf-8').replace(os.environ['KEY'], '$KEY'))
+    if p.returncode != 0:
+        raise subprocess.CalledProcessError(p.returncode, cmd)

support/build.gradle

@@ -1,3 +1,4 @@
+import java.nio.file.Paths
 
 // General gradle arguments for root project
 buildscript {    
@@ -7,24 +8,25 @@ buildscript {
     }
     dependencies {
         //
-        // https://developer.android.com/studio/releases/gradle-plugin
+        // https://developer.android.com/studio/releases/gradle-plugin#updating-gradle
         //
-        // Notice that 3.3.0 here is the version of [Android Gradle Plugin]
-        // Accroding to URL above you will need Gradle 5.0 or higher
+        // Notice that 4.0.0 here is the version of [Android Gradle Plugin]
+        // Accroding to URL above you will need Gradle 6.1 or higher
         //
-        // If you are using Android Studio, and it is using Gradle's lower 
-        // version, Use the plugin version 3.1.3 ~ 3.2.0 for Gradle 4.4 ~ 4.10
-        classpath 'com.android.tools.build:gradle:3.3.0'
+        classpath "com.android.tools.build:gradle:4.1.1"
     }
 }
 repositories {
     google()
     jcenter()
 }
-    
-// Output: Shared library (.so) for Android 
-apply plugin: 'com.android.library'
 
+// Project's root where CMakeLists.txt exists: rootDir/support/.cxx -> rootDir
+def rootDir = Paths.get(project.buildDir.getParent()).getParent()
+println("rootDir: ${rootDir}")
+
+// Output: Shared library (.so) for Android 
+apply plugin: "com.android.library"
 android {
     compileSdkVersion 25    // Android 7.0
 
@@ -41,13 +43,13 @@ android {
             include  "arm64-v8a", "armeabi-v7a", "x86_64"
         }
     }
+    ndkVersion "21.3.6528147" // ANDROID_NDK_HOME is deprecated. Be explicit
 
     defaultConfig {
         minSdkVersion 21    // Android 5.0+
         targetSdkVersion 25 // Follow Compile SDK
-        versionCode 21      // Follow release count
-        versionName "5.3.0" // Follow Official version
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        versionCode 34      // Follow release count
+        versionName "7.1.2" // Follow Official version
         
         externalNativeBuild {
             cmake {
@@ -56,9 +58,9 @@ android {
                 arguments "-DFMT_TEST=false"            // Skip test
                 arguments "-DFMT_DOC=false"             // Skip document
                 cppFlags  "-std=c++17"
+                targets   "fmt"
             }
         }
-        println("Gradle CMake Plugin: ")
         println(externalNativeBuild.cmake.cppFlags)
         println(externalNativeBuild.cmake.arguments)
     }
@@ -69,16 +71,27 @@ android {
     //    neighbor of the top level cmake
     externalNativeBuild {
         cmake {
-            path "../CMakeLists.txt"
+            version "3.10.0+"
+            path "${rootDir}/CMakeLists.txt"
             // buildStagingDirectory "./build"  // Custom path for cmake output
         }
-        //println(cmake.path)
     }
     
     sourceSets{
         // Android Manifest for Gradle
         main {
-            manifest.srcFile 'AndroidManifest.xml'
+            manifest.srcFile "AndroidManifest.xml"
+        }
+    }
+
+    // https://developer.android.com/studio/build/native-dependencies#build_system_configuration
+    buildFeatures {
+        prefab true
+        prefabPublishing true
+    }
+    prefab {
+        fmt {
+            headers "${rootDir}/include"
         }
     }
 }
@@ -88,20 +101,32 @@ assemble.doLast
     // Instead of `ninja install`, Gradle will deploy the files.
     // We are doing this since FMT is dependent to the ANDROID_STL after build
     copy {
-        from 'build/intermediates/cmake'
-        into '../libs'
+        from "build/intermediates/cmake"
+        into "${rootDir}/libs"
     }
     // Copy debug binaries
     copy {
-        from '../libs/debug/obj'
-        into '../libs/debug'
+        from "${rootDir}/libs/debug/obj"
+        into "${rootDir}/libs/debug"
     }
     // Copy Release binaries
     copy {
-        from '../libs/release/obj'
-        into '../libs/release'
+        from "${rootDir}/libs/release/obj"
+        into "${rootDir}/libs/release"
     }
     // Remove empty directory
-    delete '../libs/debug/obj'
-    delete '../libs/release/obj'
+    delete "${rootDir}/libs/debug/obj"
+    delete "${rootDir}/libs/release/obj"
+
+    // Copy AAR files. Notice that the aar is named after the folder of this script.
+    copy {
+        from "build/outputs/aar/support-release.aar"
+        into "${rootDir}/libs"
+        rename "support-release.aar", "fmt-release.aar"
+    }
+    copy {
+        from "build/outputs/aar/support-debug.aar"
+        into "${rootDir}/libs"
+        rename "support-debug.aar", "fmt-debug.aar"
+    }
 }

support/rst2md.py

@@ -65,7 +65,7 @@ class Translator(nodes.NodeVisitor):
         self.write('\n\n')
 
     def visit_paragraph(self, node):
-        pass
+        self.write('\n\n')
 
     def depart_paragraph(self, node):
         pass

support/travis-build.py

@@ -1,119 +0,0 @@
-#!/usr/bin/env python
-# Build the project on Travis CI.
-
-from __future__ import print_function
-import errno, os, shutil, subprocess, sys, urllib
-from subprocess import call, check_call, Popen, PIPE, STDOUT
-
-def rmtree_if_exists(dir):
-    try:
-        shutil.rmtree(dir)
-    except OSError as e:
-        if e.errno == errno.ENOENT:
-            pass
-
-def makedirs_if_not_exist(dir):
-    try:
-        os.makedirs(dir)
-    except OSError as e:
-        if e.errno != errno.EEXIST:
-            raise
-
-def install_dependencies():
-    branch = os.environ['TRAVIS_BRANCH']
-    if branch != 'master':
-        print('Branch: ' + branch)
-        exit(0) # Ignore non-master branches
-    check_call('curl -s https://deb.nodesource.com/gpgkey/nodesource.gpg.key ' +
-               '| sudo apt-key add -', shell=True)
-    check_call('echo "deb https://deb.nodesource.com/node_0.10 precise main" ' +
-               '| sudo tee /etc/apt/sources.list.d/nodesource.list', shell=True)
-    check_call(['sudo', 'apt-get', 'update'])
-    check_call(['sudo', 'apt-get', 'install', 'python-virtualenv', 'nodejs'])
-    check_call(['sudo', 'npm', 'install', '-g', 'less@2.6.1', 'less-plugin-clean-css'])
-    deb_file = 'doxygen_1.8.6-2_amd64.deb'
-    urllib.urlretrieve('http://mirrors.kernel.org/ubuntu/pool/main/d/doxygen/' +
-                       deb_file, deb_file)
-    check_call(['sudo', 'dpkg', '-i', deb_file])
-
-fmt_dir = os.path.dirname(os.path.dirname(os.path.realpath(__file__)))
-
-build = os.environ['BUILD']
-if build == 'Doc':
-    travis = 'TRAVIS' in os.environ
-    if travis:
-        install_dependencies()
-    sys.path.insert(0, os.path.join(fmt_dir, 'doc'))
-    import build
-    build.create_build_env()
-    html_dir = build.build_docs()
-    repo = 'fmtlib.github.io'
-    if travis and 'KEY' not in os.environ:
-        # Don't update the repo if building on Travis from an account that
-        # doesn't have push access.
-        print('Skipping update of ' + repo)
-        exit(0)
-    # Clone the fmtlib.github.io repo.
-    rmtree_if_exists(repo)
-    git_url = 'https://github.com/' if travis else 'git@github.com:'
-    check_call(['git', 'clone', git_url + 'fmtlib/{}.git'.format(repo)])
-    # Copy docs to the repo.
-    target_dir = os.path.join(repo, 'dev')
-    rmtree_if_exists(target_dir)
-    shutil.copytree(html_dir, target_dir, ignore=shutil.ignore_patterns('.*'))
-    if travis:
-        check_call(['git', 'config', '--global', 'user.name', 'amplbot'])
-        check_call(['git', 'config', '--global', 'user.email', 'viz@ampl.com'])
-    # Push docs to GitHub pages.
-    check_call(['git', 'add', '--all'], cwd=repo)
-    if call(['git', 'diff-index', '--quiet', 'HEAD'], cwd=repo):
-        check_call(['git', 'commit', '-m', 'Update documentation'], cwd=repo)
-        cmd = 'git push'
-        if travis:
-            cmd += ' https://$KEY@github.com/fmtlib/fmtlib.github.io.git master'
-        p = Popen(cmd, shell=True, stdout=PIPE, stderr=STDOUT, cwd=repo)
-        # Print the output without the key.
-        print(p.communicate()[0].replace(os.environ['KEY'], '$KEY'))
-        if p.returncode != 0:
-            raise subprocess.CalledProcessError(p.returncode, cmd)
-    exit(0)
-
-standard = os.environ['STANDARD']
-install_dir    = os.path.join(fmt_dir, "_install")
-build_dir      = os.path.join(fmt_dir, "_build")
-test_build_dir = os.path.join(fmt_dir, "_build_test")
-
-# Configure the library.
-makedirs_if_not_exist(build_dir)
-cmake_flags = [
-    '-DCMAKE_INSTALL_PREFIX=' + install_dir, '-DCMAKE_BUILD_TYPE=' + build,
-    '-DCMAKE_CXX_STANDARD=' + standard
-]
-
-# Make sure the fuzzers still compile.
-main_cmake_flags = list(cmake_flags)
-if 'ENABLE_FUZZING' in os.environ:
-    main_cmake_flags += ['-DFMT_FUZZ=ON', '-DFMT_FUZZ_LINKMAIN=On']
-
-check_call(['cmake', '-DFMT_DOC=OFF', '-DFMT_PEDANTIC=ON', '-DFMT_WERROR=ON', fmt_dir] +
-           main_cmake_flags, cwd=build_dir)
-
-# Build the library.
-check_call(['cmake', '--build','.'], cwd=build_dir)
-
-# Test the library.
-env = os.environ.copy()
-env['CTEST_OUTPUT_ON_FAILURE'] = '1'
-if call(['make', 'test'], env=env, cwd=build_dir):
-    with open(os.path.join(build_dir, 'Testing', 'Temporary', 'LastTest.log'), 'r') as f:
-        print(f.read())
-    sys.exit(-1)
-
-# Install the library.
-check_call(['make', 'install'], cwd=build_dir)
-
-# Test installation.
-makedirs_if_not_exist(test_build_dir)
-check_call(['cmake', os.path.join(fmt_dir, "test", "find-package-test")] +
-            cmake_flags, cwd=test_build_dir)
-check_call(['make', '-j4'], cwd=test_build_dir)

test/CMakeLists.txt

@@ -1,52 +1,10 @@
-#------------------------------------------------------------------------------
-# Build the google test library
-
-# We compile Google Test ourselves instead of using pre-compiled libraries.
-# See the Google Test FAQ "Why is it not recommended to install a
-# pre-compiled copy of Google Test (for example, into /usr/local)?"
-# at http://code.google.com/p/googletest/wiki/FAQ for more details.
-add_library(gmock STATIC
-  gmock-gtest-all.cc gmock/gmock.h gtest/gtest.h gtest/gtest-spi.h)
-target_compile_definitions(gmock PUBLIC GTEST_HAS_STD_WSTRING=1)
-target_include_directories(gmock SYSTEM PUBLIC . gmock gtest)
-
-find_package(Threads)
-if (Threads_FOUND)
-  target_link_libraries(gmock ${CMAKE_THREAD_LIBS_INIT})
-else ()
-  target_compile_definitions(gmock PUBLIC GTEST_HAS_PTHREAD=0)
-endif ()
-
-target_compile_definitions(gmock PUBLIC GTEST_LANG_CXX11=0)
-
-if (MSVC)
-  # Workaround a bug in implementation of variadic templates in MSVC11.
-  target_compile_definitions(gmock PUBLIC _VARIADIC_MAX=10)
-  
-  # Disable MSVC warnings of _CRT_INSECURE_DEPRECATE functions.
-  target_compile_definitions(gmock PRIVATE _CRT_SECURE_NO_WARNINGS)
-  if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-    # Disable MSVC warnings of POSIX functions.
-    target_compile_options(gmock PUBLIC -Wno-deprecated-declarations)
-  endif ()
-endif ()
-
-# GTest doesn't detect <tuple> with clang.
-if (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
-  target_compile_definitions(gmock PUBLIC GTEST_USE_OWN_TR1_TUPLE=1)
-endif ()
-
-# Silence MSVC tr1 deprecation warning in gmock.
-target_compile_definitions(gmock
-  PUBLIC _SILENCE_TR1_NAMESPACE_DEPRECATION_WARNING=1)
-
-#------------------------------------------------------------------------------
-# Build the actual library tests
+add_subdirectory(gtest)
 
 set(TEST_MAIN_SRC test-main.cc gtest-extra.cc gtest-extra.h util.cc)
 add_library(test-main STATIC ${TEST_MAIN_SRC})
-target_include_directories(test-main SYSTEM PUBLIC gtest gmock)
-target_link_libraries(test-main gmock fmt)
+target_include_directories(test-main PUBLIC
+  $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>)
+target_link_libraries(test-main gtest)
 
 include(CheckCXXCompilerFlag)
 
@@ -73,8 +31,23 @@ endfunction()
 # Adds a test.
 # Usage: add_fmt_test(name srcs...)
 function(add_fmt_test name)
-  add_fmt_executable(${name} ${name}.cc ${ARGN})
-  target_link_libraries(${name} test-main)
+  cmake_parse_arguments(ADD_FMT_TEST "HEADER_ONLY;MODULE" "" "" ${ARGN})
+
+  set(sources ${name}.cc ${ADD_FMT_TEST_UNPARSED_ARGUMENTS})
+  if (ADD_FMT_TEST_HEADER_ONLY)
+    set(sources ${sources} ${TEST_MAIN_SRC} ../src/os.cc)
+    set(libs gtest fmt-header-only)
+    if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+      set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS} -Wno-weak-vtables)
+    endif ()
+  elseif (ADD_FMT_TEST_MODULE)
+    set(libs test-main test-module)
+    set_source_files_properties(${name}.cc PROPERTIES OBJECT_DEPENDS test-module)
+  else ()
+    set(libs test-main fmt)
+  endif ()
+  add_fmt_executable(${name} ${sources})
+  target_link_libraries(${name} ${libs})
 
   # Define if certain C++ features can be used.
   if (FMT_PEDANTIC)
@@ -83,10 +56,10 @@ function(add_fmt_test name)
   if (FMT_WERROR)
     target_compile_options(${name} PRIVATE ${WERROR_FLAG})
   endif ()
-  target_include_directories(${name} SYSTEM PUBLIC gtest gmock)
   add_test(NAME ${name} COMMAND ${name})
 endfunction()
 
+add_fmt_test(args-test)
 add_fmt_test(assert-test)
 add_fmt_test(chrono-test)
 add_fmt_test(color-test)
@@ -97,14 +70,39 @@ if (MSVC)
   target_compile_options(format-test PRIVATE /bigobj)
 endif ()
 if (NOT (MSVC AND BUILD_SHARED_LIBS))
-  add_fmt_test(format-impl-test)
+  add_fmt_test(format-impl-test HEADER_ONLY header-only-test.cc)
 endif ()
-add_fmt_test(locale-test)
 add_fmt_test(ostream-test)
 add_fmt_test(compile-test)
 add_fmt_test(printf-test)
 add_fmt_test(ranges-test)
 add_fmt_test(scan-test)
+add_fmt_test(unicode-test HEADER_ONLY)
+if (MSVC)
+  target_compile_options(unicode-test PRIVATE /utf-8)
+endif ()
+add_fmt_test(xchar-test)
+add_fmt_test(enforce-checks-test)
+target_compile_definitions(enforce-checks-test PRIVATE
+                           -DFMT_ENFORCE_COMPILE_STRING)
+
+if (FMT_CAN_MODULE)
+  # The tests need {fmt} to be compiled as traditional library
+  # because of visibility of implementation details.
+  # If module support is present the module tests require a
+  # test-only module to be built from {fmt}
+  add_library(test-module OBJECT ${CMAKE_SOURCE_DIR}/src/fmt.cc)
+  target_compile_features(test-module PUBLIC ${FMT_REQUIRED_FEATURES})
+  target_include_directories(test-module PUBLIC
+    $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>)
+  enable_module(test-module)
+
+  add_fmt_test(module-test MODULE)
+  if (MSVC)
+    target_compile_options(test-module PRIVATE /utf-8)
+    target_compile_options(module-test PRIVATE /utf-8)
+  endif ()
+endif ()
 
 if (NOT DEFINED MSVC_STATIC_RUNTIME AND MSVC)
   foreach (flag_var
@@ -122,8 +120,7 @@ if (NOT MSVC_STATIC_RUNTIME)
     posix-mock-test.cc ../src/format.cc ${TEST_MAIN_SRC})
   target_include_directories(
     posix-mock-test PRIVATE ${PROJECT_SOURCE_DIR}/include)
-  target_link_libraries(posix-mock-test gmock)
-  target_include_directories(posix-mock-test SYSTEM PUBLIC gtest gmock)
+  target_link_libraries(posix-mock-test gtest)
   if (FMT_PEDANTIC)
     target_compile_options(posix-mock-test PRIVATE ${PEDANTIC_COMPILE_FLAGS})
   endif ()
@@ -134,21 +131,9 @@ if (NOT MSVC_STATIC_RUNTIME)
   add_fmt_test(os-test)
 endif ()
 
-add_fmt_executable(header-only-test
-  header-only-test.cc header-only-test2.cc test-main.cc)
-target_link_libraries(header-only-test gmock)
-target_include_directories(header-only-test SYSTEM PUBLIC gtest gmock)
-if (TARGET fmt-header-only)
-  target_link_libraries(header-only-test fmt-header-only)
-else ()
-  target_include_directories(
-    header-only-test PRIVATE ${PROJECT_SOURCE_DIR}/include)
-  target_compile_definitions(header-only-test PRIVATE FMT_HEADER_ONLY=1)
-endif ()
-
 message(STATUS "FMT_PEDANTIC: ${FMT_PEDANTIC}")
 
-if (FMT_PEDANTIC)
+if (FMT_PEDANTIC AND CXX_STANDARD LESS 20)
   # MSVC fails to compile GMock when C++17 is enabled.
   if (FMT_HAS_VARIANT AND NOT MSVC)
     add_fmt_test(std-format-test)
@@ -203,6 +188,7 @@ if (FMT_PEDANTIC AND NOT WIN32)
     --build-makeprogram ${CMAKE_MAKE_PROGRAM}
     --build-options
     "-DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}"
+    "-DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}"
     "-DCMAKE_CXX_STANDARD=${CMAKE_CXX_STANDARD}"
     "-DFMT_DIR=${PROJECT_BINARY_DIR}"
     "-DPEDANTIC_COMPILE_FLAGS=${PEDANTIC_COMPILE_FLAGS}"
@@ -223,6 +209,21 @@ if (FMT_PEDANTIC AND NOT WIN32)
     "-DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}")
 endif ()
 
+# This test are disabled on Windows because it is only *NIX issue.
+if (FMT_PEDANTIC AND NOT WIN32)
+  add_test(static-export-test ${CMAKE_CTEST_COMMAND}
+    -C ${CMAKE_BUILD_TYPE}
+    --build-and-test
+    "${CMAKE_CURRENT_SOURCE_DIR}/static-export-test"
+    "${CMAKE_CURRENT_BINARY_DIR}/static-export-test"
+    --build-generator ${CMAKE_GENERATOR}
+    --build-makeprogram ${CMAKE_MAKE_PROGRAM}
+    --build-options
+    "-DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}"
+    "-DCMAKE_CXX_STANDARD=${CMAKE_CXX_STANDARD}"
+    "-DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}")
+endif ()
+
 # Activate optional CUDA tests if CUDA is found. For version selection see
 # https://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html#cpp14-language-features
 if (FMT_CUDA_TEST)

test/add-subdirectory-test/CMakeLists.txt

@@ -1,17 +1,17 @@
 cmake_minimum_required(VERSION 3.1...3.18)
 
-project(fmt-test)
+project(fmt-test CXX)
 
 add_subdirectory(../.. fmt)
 
-add_executable(library-test "main.cc")
-target_link_libraries(library-test fmt::fmt)
-target_compile_options(library-test PRIVATE ${PEDANTIC_COMPILE_FLAGS})
+add_executable(library-test main.cc)
 target_include_directories(library-test PUBLIC SYSTEM .)
+target_compile_options(library-test PRIVATE ${PEDANTIC_COMPILE_FLAGS})
+target_link_libraries(library-test fmt::fmt)
 
 if (TARGET fmt::fmt-header-only)
-  add_executable(header-only-test "main.cc")
-  target_link_libraries(header-only-test fmt::fmt-header-only)
-  target_compile_options(header-only-test PRIVATE ${PEDANTIC_COMPILE_FLAGS})
+  add_executable(header-only-test main.cc)
   target_include_directories(header-only-test PUBLIC SYSTEM .)
+  target_compile_options(header-only-test PRIVATE ${PEDANTIC_COMPILE_FLAGS})
+  target_link_libraries(header-only-test fmt::fmt-header-only)
 endif ()

test/add-subdirectory-test/main.cc

@@ -1,6 +1,5 @@
-#include "fmt/format.h"
+#include "fmt/core.h"
 
 int main(int argc, char** argv) {
-  for(int i = 0; i < argc; ++i)
-    fmt::print("{}: {}\n", i, argv[i]);
+  for (int i = 0; i < argc; ++i) fmt::print("{}: {}\n", i, argv[i]);
 }

test/args-test.cc

@@ -0,0 +1,173 @@
+// Formatting library for C++ - dynamic argument store tests
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#include "fmt/args.h"
+
+#include "gtest/gtest.h"
+
+TEST(args_test, basic) {
+  auto store = fmt::dynamic_format_arg_store<fmt::format_context>();
+  store.push_back(42);
+  store.push_back("abc1");
+  store.push_back(1.5f);
+  EXPECT_EQ("42 and abc1 and 1.5", fmt::vformat("{} and {} and {}", store));
+}
+
+TEST(args_test, strings_and_refs) {
+  // Unfortunately the tests are compiled with old ABI so strings use COW.
+  auto store = fmt::dynamic_format_arg_store<fmt::format_context>();
+  char str[] = "1234567890";
+  store.push_back(str);
+  store.push_back(std::cref(str));
+  store.push_back(fmt::string_view{str});
+  str[0] = 'X';
+
+  auto result = fmt::vformat("{} and {} and {}", store);
+  EXPECT_EQ("1234567890 and X234567890 and X234567890", result);
+}
+
+struct custom_type {
+  int i = 0;
+};
+
+FMT_BEGIN_NAMESPACE
+template <> struct formatter<custom_type> {
+  auto parse(format_parse_context& ctx) const -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  auto format(const custom_type& p, FormatContext& ctx) -> decltype(ctx.out()) {
+    return format_to(ctx.out(), "cust={}", p.i);
+  }
+};
+FMT_END_NAMESPACE
+
+TEST(args_test, custom_format) {
+  auto store = fmt::dynamic_format_arg_store<fmt::format_context>();
+  auto c = custom_type();
+  store.push_back(c);
+  ++c.i;
+  store.push_back(c);
+  ++c.i;
+  store.push_back(std::cref(c));
+  ++c.i;
+  auto result = fmt::vformat("{} and {} and {}", store);
+  EXPECT_EQ("cust=0 and cust=1 and cust=3", result);
+}
+
+struct to_stringable {
+  friend fmt::string_view to_string_view(to_stringable) { return {}; }
+};
+
+FMT_BEGIN_NAMESPACE
+template <> struct formatter<to_stringable> {
+  auto parse(format_parse_context& ctx) const -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  auto format(to_stringable, format_context& ctx) -> decltype(ctx.out()) {
+    return ctx.out();
+  }
+};
+FMT_END_NAMESPACE
+
+TEST(args_test, to_string_and_formatter) {
+  auto store = fmt::dynamic_format_arg_store<fmt::format_context>();
+  auto s = to_stringable();
+  store.push_back(s);
+  store.push_back(std::cref(s));
+  fmt::vformat("", store);
+}
+
+TEST(args_test, named_int) {
+  auto store = fmt::dynamic_format_arg_store<fmt::format_context>();
+  store.push_back(fmt::arg("a1", 42));
+  EXPECT_EQ("42", fmt::vformat("{a1}", store));
+}
+
+TEST(args_test, named_strings) {
+  auto store = fmt::dynamic_format_arg_store<fmt::format_context>();
+  char str[] = "1234567890";
+  store.push_back(fmt::arg("a1", str));
+  store.push_back(fmt::arg("a2", std::cref(str)));
+  str[0] = 'X';
+  EXPECT_EQ("1234567890 and X234567890", fmt::vformat("{a1} and {a2}", store));
+}
+
+TEST(args_test, named_arg_by_ref) {
+  auto store = fmt::dynamic_format_arg_store<fmt::format_context>();
+  char band[] = "Rolling Stones";
+  store.push_back(fmt::arg("band", std::cref(band)));
+  band[9] = 'c';  // Changing band affects the output.
+  EXPECT_EQ(fmt::vformat("{band}", store), "Rolling Scones");
+}
+
+TEST(args_test, named_custom_format) {
+  auto store = fmt::dynamic_format_arg_store<fmt::format_context>();
+  auto c = custom_type();
+  store.push_back(fmt::arg("c1", c));
+  ++c.i;
+  store.push_back(fmt::arg("c2", c));
+  ++c.i;
+  store.push_back(fmt::arg("c_ref", std::cref(c)));
+  ++c.i;
+  auto result = fmt::vformat("{c1} and {c2} and {c_ref}", store);
+  EXPECT_EQ("cust=0 and cust=1 and cust=3", result);
+}
+
+TEST(args_test, clear) {
+  auto store = fmt::dynamic_format_arg_store<fmt::format_context>();
+  store.push_back(42);
+
+  auto result = fmt::vformat("{}", store);
+  EXPECT_EQ("42", result);
+
+  store.push_back(43);
+  result = fmt::vformat("{} and {}", store);
+  EXPECT_EQ("42 and 43", result);
+
+  store.clear();
+  store.push_back(44);
+  result = fmt::vformat("{}", store);
+  EXPECT_EQ("44", result);
+}
+
+TEST(args_test, reserve) {
+  auto store = fmt::dynamic_format_arg_store<fmt::format_context>();
+  store.reserve(2, 1);
+  store.push_back(1.5f);
+  store.push_back(fmt::arg("a1", 42));
+  auto result = fmt::vformat("{a1} and {}", store);
+  EXPECT_EQ("42 and 1.5", result);
+}
+
+struct copy_throwable {
+  copy_throwable() {}
+  copy_throwable(const copy_throwable&) { throw "deal with it"; }
+};
+
+FMT_BEGIN_NAMESPACE
+template <> struct formatter<copy_throwable> {
+  auto parse(format_parse_context& ctx) const -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+  auto format(copy_throwable, format_context& ctx) -> decltype(ctx.out()) {
+    return ctx.out();
+  }
+};
+FMT_END_NAMESPACE
+
+TEST(args_test, throw_on_copy) {
+  auto store = fmt::dynamic_format_arg_store<fmt::format_context>();
+  store.push_back(std::string("foo"));
+  try {
+    store.push_back(copy_throwable());
+  } catch (...) {
+  }
+  EXPECT_EQ(fmt::vformat("{}", store), "foo");
+}

test/assert-test.cc

@@ -10,9 +10,9 @@
 // For the license information refer to format.h.
 
 #include "fmt/core.h"
-#include "gtest.h"
+#include "gtest/gtest.h"
 
-TEST(AssertTest, Fail) {
+TEST(assert_test, fail) {
 #if GTEST_HAS_DEATH_TEST
   EXPECT_DEBUG_DEATH(FMT_ASSERT(false, "don't panic!"), "don't panic!");
 #else
@@ -20,9 +20,8 @@ TEST(AssertTest, Fail) {
 #endif
 }
 
-bool test_condition = false;
-
-TEST(AssertTest, DanglingElse) {
+TEST(assert_test, dangling_else) {
+  bool test_condition = false;
   bool executed_else = false;
   if (test_condition)
     FMT_ASSERT(true, "");

test/chrono-test.cc

@@ -5,77 +5,70 @@
 //
 // For the license information refer to format.h.
 
-#ifdef WIN32
-#  define _CRT_SECURE_NO_WARNINGS
-#endif
-
 #include "fmt/chrono.h"
 
-#include <iomanip>
+#include "gtest-extra.h"  // EXPECT_THROW_MSG
+#include "util.h"         // get_locale
 
-#include "gtest-extra.h"
+using fmt::runtime;
 
-std::tm make_tm() {
+using testing::Contains;
+
+auto make_tm() -> std::tm {
   auto time = std::tm();
   time.tm_mday = 1;
   return time;
 }
 
-std::tm make_hour(int h) {
+auto make_hour(int h) -> std::tm {
   auto time = make_tm();
   time.tm_hour = h;
   return time;
 }
 
-std::tm make_minute(int m) {
+auto make_minute(int m) -> std::tm {
   auto time = make_tm();
   time.tm_min = m;
   return time;
 }
 
-std::tm make_second(int s) {
+auto make_second(int s) -> std::tm {
   auto time = make_tm();
   time.tm_sec = s;
   return time;
 }
 
-std::string format_tm(const std::tm& time, const char* spec,
-                      const std::locale& loc) {
-  auto& facet = std::use_facet<std::time_put<char>>(loc);
-  std::ostringstream os;
-  os.imbue(loc);
-  facet.put(os, os, ' ', &time, spec, spec + std::strlen(spec));
-  return os.str();
-}
-
-TEST(TimeTest, Format) {
-  std::tm tm = std::tm();
+TEST(chrono_test, format_tm) {
+  auto tm = std::tm();
   tm.tm_year = 116;
   tm.tm_mon = 3;
   tm.tm_mday = 25;
-  EXPECT_EQ("The date is 2016-04-25.",
-            fmt::format("The date is {:%Y-%m-%d}.", tm));
+  tm.tm_hour = 11;
+  tm.tm_min = 22;
+  tm.tm_sec = 33;
+  EXPECT_EQ(fmt::format("The date is {:%Y-%m-%d %H:%M:%S}.", tm),
+            "The date is 2016-04-25 11:22:33.");
 }
 
-TEST(TimeTest, GrowBuffer) {
-  std::string s = "{:";
+TEST(chrono_test, grow_buffer) {
+  auto s = std::string("{:");
   for (int i = 0; i < 30; ++i) s += "%c";
   s += "}\n";
-  std::time_t t = std::time(nullptr);
-  fmt::format(s, *std::localtime(&t));
+  auto t = std::time(nullptr);
+  fmt::format(fmt::runtime(s), *std::localtime(&t));
 }
 
-TEST(TimeTest, FormatToEmptyContainer) {
-  std::string s;
+TEST(chrono_test, format_to_empty_container) {
   auto time = std::tm();
   time.tm_sec = 42;
+  auto s = std::string();
   fmt::format_to(std::back_inserter(s), "{:%S}", time);
   EXPECT_EQ(s, "42");
 }
 
-TEST(TimeTest, EmptyResult) { EXPECT_EQ("", fmt::format("{}", std::tm())); }
+TEST(chrono_test, empty_result) { EXPECT_EQ(fmt::format("{}", std::tm()), ""); }
 
-static bool EqualTime(const std::tm& lhs, const std::tm& rhs) {
+auto equal(const std::tm& lhs, const std::tm& rhs) -> bool {
   return lhs.tm_sec == rhs.tm_sec && lhs.tm_min == rhs.tm_min &&
          lhs.tm_hour == rhs.tm_hour && lhs.tm_mday == rhs.tm_mday &&
          lhs.tm_mon == rhs.tm_mon && lhs.tm_year == rhs.tm_year &&
@@ -83,39 +76,39 @@ static bool EqualTime(const std::tm& lhs, const std::tm& rhs) {
          lhs.tm_isdst == rhs.tm_isdst;
 }
 
-TEST(TimeTest, LocalTime) {
-  std::time_t t = std::time(nullptr);
-  std::tm tm = *std::localtime(&t);
-  EXPECT_TRUE(EqualTime(tm, fmt::localtime(t)));
+TEST(chrono_test, localtime) {
+  auto t = std::time(nullptr);
+  auto tm = *std::localtime(&t);
+  EXPECT_TRUE(equal(tm, fmt::localtime(t)));
 }
 
-TEST(TimeTest, GMTime) {
-  std::time_t t = std::time(nullptr);
-  std::tm tm = *std::gmtime(&t);
-  EXPECT_TRUE(EqualTime(tm, fmt::gmtime(t)));
+TEST(chrono_test, gmtime) {
+  auto t = std::time(nullptr);
+  auto tm = *std::gmtime(&t);
+  EXPECT_TRUE(equal(tm, fmt::gmtime(t)));
 }
 
-TEST(TimeTest, TimePoint) {
-  std::chrono::system_clock::time_point point = std::chrono::system_clock::now();
-
-  std::time_t t = std::chrono::system_clock::to_time_t(point);
-  std::tm tm = *std::localtime(&t);
-  char strftime_output[256];
-  std::strftime(strftime_output, sizeof(strftime_output), "It is %Y-%m-%d %H:%M:%S", &tm);
-
-  EXPECT_EQ(strftime_output, fmt::format("It is {:%Y-%m-%d %H:%M:%S}", point));
+template <typename TimePoint> auto strftime(TimePoint tp) -> std::string {
+  auto t = std::chrono::system_clock::to_time_t(tp);
+  auto tm = *std::localtime(&t);
+  char output[256] = {};
+  std::strftime(output, sizeof(output), "%Y-%m-%d %H:%M:%S", &tm);
+  return output;
 }
 
-#define EXPECT_TIME(spec, time, duration)                 \
-  {                                                       \
-    std::locale loc("ja_JP.utf8");                        \
-    EXPECT_EQ(format_tm(time, spec, loc),                 \
-              fmt::format(loc, "{:" spec "}", duration)); \
-  }
+TEST(chrono_test, time_point) {
+  auto t1 = std::chrono::system_clock::now();
+  EXPECT_EQ(strftime(t1), fmt::format("{:%Y-%m-%d %H:%M:%S}", t1));
+  EXPECT_EQ(strftime(t1), fmt::format("{}", t1));
+  using time_point =
+      std::chrono::time_point<std::chrono::system_clock, std::chrono::seconds>;
+  auto t2 = time_point(std::chrono::seconds(42));
+  EXPECT_EQ(strftime(t2), fmt::format("{:%Y-%m-%d %H:%M:%S}", t2));
+}
 
 #ifndef FMT_STATIC_THOUSANDS_SEPARATOR
 
-TEST(ChronoTest, FormatDefault) {
+TEST(chrono_test, format_default) {
   EXPECT_EQ("42s", fmt::format("{}", std::chrono::seconds(42)));
   EXPECT_EQ("42as",
             fmt::format("{}", std::chrono::duration<int, std::atto>(42)));
@@ -157,49 +150,7 @@ TEST(ChronoTest, FormatDefault) {
       fmt::format("{}", std::chrono::duration<int, std::ratio<15, 4>>(42)));
 }
 
-TEST(ChronoTest, FormatWide) {
-  EXPECT_EQ(L"42s", fmt::format(L"{}", std::chrono::seconds(42)));
-  EXPECT_EQ(L"42as",
-            fmt::format(L"{}", std::chrono::duration<int, std::atto>(42)));
-  EXPECT_EQ(L"42fs",
-            fmt::format(L"{}", std::chrono::duration<int, std::femto>(42)));
-  EXPECT_EQ(L"42ps",
-            fmt::format(L"{}", std::chrono::duration<int, std::pico>(42)));
-  EXPECT_EQ(L"42ns", fmt::format(L"{}", std::chrono::nanoseconds(42)));
-  EXPECT_EQ(L"42\u00B5s", fmt::format(L"{}", std::chrono::microseconds(42)));
-  EXPECT_EQ(L"42ms", fmt::format(L"{}", std::chrono::milliseconds(42)));
-  EXPECT_EQ(L"42cs",
-            fmt::format(L"{}", std::chrono::duration<int, std::centi>(42)));
-  EXPECT_EQ(L"42ds",
-            fmt::format(L"{}", std::chrono::duration<int, std::deci>(42)));
-  EXPECT_EQ(L"42s", fmt::format(L"{}", std::chrono::seconds(42)));
-  EXPECT_EQ(L"42das",
-            fmt::format(L"{}", std::chrono::duration<int, std::deca>(42)));
-  EXPECT_EQ(L"42hs",
-            fmt::format(L"{}", std::chrono::duration<int, std::hecto>(42)));
-  EXPECT_EQ(L"42ks",
-            fmt::format(L"{}", std::chrono::duration<int, std::kilo>(42)));
-  EXPECT_EQ(L"42Ms",
-            fmt::format(L"{}", std::chrono::duration<int, std::mega>(42)));
-  EXPECT_EQ(L"42Gs",
-            fmt::format(L"{}", std::chrono::duration<int, std::giga>(42)));
-  EXPECT_EQ(L"42Ts",
-            fmt::format(L"{}", std::chrono::duration<int, std::tera>(42)));
-  EXPECT_EQ(L"42Ps",
-            fmt::format(L"{}", std::chrono::duration<int, std::peta>(42)));
-  EXPECT_EQ(L"42Es",
-            fmt::format(L"{}", std::chrono::duration<int, std::exa>(42)));
-  EXPECT_EQ(L"42m", fmt::format(L"{}", std::chrono::minutes(42)));
-  EXPECT_EQ(L"42h", fmt::format(L"{}", std::chrono::hours(42)));
-  EXPECT_EQ(
-      L"42[15]s",
-      fmt::format(L"{}", std::chrono::duration<int, std::ratio<15, 1>>(42)));
-  EXPECT_EQ(
-      L"42[15/4]s",
-      fmt::format(L"{}", std::chrono::duration<int, std::ratio<15, 4>>(42)));
-}
-
-TEST(ChronoTest, Align) {
+TEST(chrono_test, align) {
   auto s = std::chrono::seconds(42);
   EXPECT_EQ("42s  ", fmt::format("{:5}", s));
   EXPECT_EQ("42s  ", fmt::format("{:{}}", s, 5));
@@ -215,7 +166,7 @@ TEST(ChronoTest, Align) {
             fmt::format("{:{}%H:%M:%S}", std::chrono::seconds(12345), 12));
 }
 
-TEST(ChronoTest, FormatSpecs) {
+TEST(chrono_test, format_specs) {
   EXPECT_EQ("%", fmt::format("{:%%}", std::chrono::seconds(0)));
   EXPECT_EQ("\n", fmt::format("{:%n}", std::chrono::seconds(0)));
   EXPECT_EQ("\t", fmt::format("{:%t}", std::chrono::seconds(0)));
@@ -244,43 +195,64 @@ TEST(ChronoTest, FormatSpecs) {
   EXPECT_EQ("s", fmt::format("{:%q}", std::chrono::seconds(12345)));
 }
 
-TEST(ChronoTest, InvalidSpecs) {
+TEST(chrono_test, invalid_specs) {
   auto sec = std::chrono::seconds(0);
-  EXPECT_THROW_MSG(fmt::format("{:%a}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%A}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%c}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%x}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%Ex}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%X}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%EX}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%D}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%F}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%Ec}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%w}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%u}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%b}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%B}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%z}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%Z}", sec), fmt::format_error, "no date");
-  EXPECT_THROW_MSG(fmt::format("{:%Eq}", sec), fmt::format_error,
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%a}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%A}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%c}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%x}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%Ex}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%X}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%EX}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%D}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%F}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%Ec}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%w}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%u}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%b}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%B}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%z}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%Z}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%Eq}"), sec), fmt::format_error,
                    "invalid format");
-  EXPECT_THROW_MSG(fmt::format("{:%Oq}", sec), fmt::format_error,
+  EXPECT_THROW_MSG(fmt::format(runtime("{:%Oq}"), sec), fmt::format_error,
                    "invalid format");
 }
 
-TEST(ChronoTest, Locale) {
-  const char* loc_name = "ja_JP.utf8";
-  bool has_locale = false;
-  std::locale loc;
-  try {
-    loc = std::locale(loc_name);
-    has_locale = true;
-  } catch (const std::runtime_error&) {
-  }
-  if (!has_locale) {
-    fmt::print("{} locale is missing.\n", loc_name);
-    return;
-  }
+auto format_tm(const std::tm& time, fmt::string_view spec,
+               const std::locale& loc) -> std::string {
+  auto& facet = std::use_facet<std::time_put<char>>(loc);
+  std::ostringstream os;
+  os.imbue(loc);
+  facet.put(os, os, ' ', &time, spec.begin(), spec.end());
+  return os.str();
+}
+
+TEST(chrono_test, locale) {
+  auto loc = get_locale("ja_JP.utf8");
+  if (loc == std::locale::classic()) return;
+#  define EXPECT_TIME(spec, time, duration)                     \
+    {                                                           \
+      auto jp_loc = std::locale("ja_JP.utf8");                  \
+      EXPECT_EQ(format_tm(time, spec, jp_loc),                  \
+                fmt::format(jp_loc, "{:L" spec "}", duration)); \
+    }
   EXPECT_TIME("%OH", make_hour(14), std::chrono::hours(14));
   EXPECT_TIME("%OI", make_hour(14), std::chrono::hours(14));
   EXPECT_TIME("%OM", make_minute(42), std::chrono::minutes(42));
@@ -294,9 +266,9 @@ TEST(ChronoTest, Locale) {
   EXPECT_TIME("%p", time, sec);
 }
 
-typedef std::chrono::duration<double, std::milli> dms;
+using dms = std::chrono::duration<double, std::milli>;
 
-TEST(ChronoTest, FormatDefaultFP) {
+TEST(chrono_test, format_default_fp) {
   typedef std::chrono::duration<float> fs;
   EXPECT_EQ("1.234s", fmt::format("{}", fs(1.234)));
   typedef std::chrono::duration<float, std::milli> fms;
@@ -306,15 +278,15 @@ TEST(ChronoTest, FormatDefaultFP) {
   EXPECT_EQ("1.234ms", fmt::format("{}", dms(1.234)));
 }
 
-TEST(ChronoTest, FormatPrecision) {
-  EXPECT_THROW_MSG(fmt::format("{:.2}", std::chrono::seconds(42)),
+TEST(chrono_test, format_precision) {
+  EXPECT_THROW_MSG(fmt::format(runtime("{:.2}"), std::chrono::seconds(42)),
                    fmt::format_error,
                    "precision not allowed for this argument type");
   EXPECT_EQ("1.2ms", fmt::format("{:.1}", dms(1.234)));
   EXPECT_EQ("1.23ms", fmt::format("{:.{}}", dms(1.234), 2));
 }
 
-TEST(ChronoTest, FormatFullSpecs) {
+TEST(chrono_test, format_full_specs) {
   EXPECT_EQ("1.2ms ", fmt::format("{:6.1}", dms(1.234)));
   EXPECT_EQ("  1.23ms", fmt::format("{:>8.{}}", dms(1.234), 2));
   EXPECT_EQ(" 1.2ms ", fmt::format("{:^{}.{}}", dms(1.234), 7, 1));
@@ -323,7 +295,7 @@ TEST(ChronoTest, FormatFullSpecs) {
   EXPECT_EQ("*1.2340ms*", fmt::format("{:*^10.4}", dms(1.234)));
 }
 
-TEST(ChronoTest, FormatSimpleQq) {
+TEST(chrono_test, format_simple_q) {
   typedef std::chrono::duration<float> fs;
   EXPECT_EQ("1.234 s", fmt::format("{:%Q %q}", fs(1.234)));
   typedef std::chrono::duration<float, std::milli> fms;
@@ -333,15 +305,15 @@ TEST(ChronoTest, FormatSimpleQq) {
   EXPECT_EQ("1.234 ms", fmt::format("{:%Q %q}", dms(1.234)));
 }
 
-TEST(ChronoTest, FormatPrecisionQq) {
-  EXPECT_THROW_MSG(fmt::format("{:.2%Q %q}", std::chrono::seconds(42)),
+TEST(chrono_test, format_precision_q) {
+  EXPECT_THROW_MSG(fmt::format(runtime("{:.2%Q %q}"), std::chrono::seconds(42)),
                    fmt::format_error,
                    "precision not allowed for this argument type");
   EXPECT_EQ("1.2 ms", fmt::format("{:.1%Q %q}", dms(1.234)));
   EXPECT_EQ("1.23 ms", fmt::format("{:.{}%Q %q}", dms(1.234), 2));
 }
 
-TEST(ChronoTest, FormatFullSpecsQq) {
+TEST(chrono_test, format_full_specs_q) {
   EXPECT_EQ("1.2 ms ", fmt::format("{:7.1%Q %q}", dms(1.234)));
   EXPECT_EQ(" 1.23 ms", fmt::format("{:>8.{}%Q %q}", dms(1.234), 2));
   EXPECT_EQ(" 1.2 ms ", fmt::format("{:^{}.{}%Q %q}", dms(1.234), 8, 1));
@@ -350,17 +322,17 @@ TEST(ChronoTest, FormatFullSpecsQq) {
   EXPECT_EQ("*1.2340 ms*", fmt::format("{:*^11.4%Q %q}", dms(1.234)));
 }
 
-TEST(ChronoTest, InvalidWidthId) {
-  EXPECT_THROW(fmt::format("{:{o}", std::chrono::seconds(0)),
+TEST(chrono_test, invalid_width_id) {
+  EXPECT_THROW(fmt::format(runtime("{:{o}"), std::chrono::seconds(0)),
                fmt::format_error);
 }
 
-TEST(ChronoTest, InvalidColons) {
-  EXPECT_THROW(fmt::format("{0}=:{0::", std::chrono::seconds(0)),
+TEST(chrono_test, invalid_colons) {
+  EXPECT_THROW(fmt::format(runtime("{0}=:{0::"), std::chrono::seconds(0)),
                fmt::format_error);
 }
 
-TEST(ChronoTest, NegativeDurations) {
+TEST(chrono_test, negative_durations) {
   EXPECT_EQ("-12345", fmt::format("{:%Q}", std::chrono::seconds(-12345)));
   EXPECT_EQ("-03:25:45",
             fmt::format("{:%H:%M:%S}", std::chrono::seconds(-12345)));
@@ -375,7 +347,7 @@ TEST(ChronoTest, NegativeDurations) {
             fmt::format("{:%Q}", std::chrono::duration<int>(min)));
 }
 
-TEST(ChronoTest, SpecialDurations) {
+TEST(chrono_test, special_durations) {
   EXPECT_EQ(
       "40.",
       fmt::format("{:%S}", std::chrono::duration<double>(1e20)).substr(0, 3));
@@ -395,4 +367,19 @@ TEST(ChronoTest, SpecialDurations) {
             "03:33:20");
 }
 
+TEST(chrono_test, unsigned_duration) {
+  EXPECT_EQ("42s", fmt::format("{}", std::chrono::duration<unsigned>(42)));
+}
+
+TEST(chrono_test, weekday) {
+  auto loc = get_locale("ru_RU.UTF-8");
+  std::locale::global(loc);
+  auto mon = fmt::weekday(1);
+  EXPECT_EQ(fmt::format("{}", mon), "Mon");
+  if (loc != std::locale::classic()) {
+    EXPECT_THAT((std::vector<std::string>{"пн", "Пн", "пнд", "Пнд"}),
+                Contains(fmt::format(loc, "{:L}", mon)));
+  }
+}
+
 #endif  // FMT_STATIC_THOUSANDS_SEPARATOR

test/color-test.cc

@@ -7,56 +7,13 @@
 
 #include "fmt/color.h"
 
-#include <iterator>
-#include <string>
-#include <utility>
+#include <iterator>  // std::back_inserter
 
-#include "gtest-extra.h"
+#include "gtest-extra.h"  // EXPECT_WRITE
 
-TEST(ColorsTest, ColorsPrint) {
-  EXPECT_WRITE(stdout, fmt::print(fg(fmt::rgb(255, 20, 30)), "rgb(255,20,30)"),
-               "\x1b[38;2;255;020;030mrgb(255,20,30)\x1b[0m");
-  EXPECT_WRITE(stdout, fmt::print(fg(fmt::color::blue), "blue"),
-               "\x1b[38;2;000;000;255mblue\x1b[0m");
-  EXPECT_WRITE(
-      stdout,
-      fmt::print(fg(fmt::color::blue) | bg(fmt::color::red), "two color"),
-      "\x1b[38;2;000;000;255m\x1b[48;2;255;000;000mtwo color\x1b[0m");
-  EXPECT_WRITE(stdout, fmt::print(fmt::emphasis::bold, "bold"),
-               "\x1b[1mbold\x1b[0m");
-  EXPECT_WRITE(stdout, fmt::print(fmt::emphasis::italic, "italic"),
-               "\x1b[3mitalic\x1b[0m");
-  EXPECT_WRITE(stdout, fmt::print(fmt::emphasis::underline, "underline"),
-               "\x1b[4munderline\x1b[0m");
-  EXPECT_WRITE(stdout,
-               fmt::print(fmt::emphasis::strikethrough, "strikethrough"),
-               "\x1b[9mstrikethrough\x1b[0m");
-  EXPECT_WRITE(
-      stdout,
-      fmt::print(fg(fmt::color::blue) | fmt::emphasis::bold, "blue/bold"),
-      "\x1b[1m\x1b[38;2;000;000;255mblue/bold\x1b[0m");
-  EXPECT_WRITE(stderr, fmt::print(stderr, fmt::emphasis::bold, "bold error"),
-               "\x1b[1mbold error\x1b[0m");
-  EXPECT_WRITE(stderr, fmt::print(stderr, fg(fmt::color::blue), "blue log"),
-               "\x1b[38;2;000;000;255mblue log\x1b[0m");
-  EXPECT_WRITE(stdout, fmt::print(fmt::text_style(), "hi"), "hi");
-  EXPECT_WRITE(stdout, fmt::print(fg(fmt::terminal_color::red), "tred"),
-               "\x1b[31mtred\x1b[0m");
-  EXPECT_WRITE(stdout, fmt::print(bg(fmt::terminal_color::cyan), "tcyan"),
-               "\x1b[46mtcyan\x1b[0m");
-  EXPECT_WRITE(stdout,
-               fmt::print(fg(fmt::terminal_color::bright_green), "tbgreen"),
-               "\x1b[92mtbgreen\x1b[0m");
-  EXPECT_WRITE(stdout,
-               fmt::print(bg(fmt::terminal_color::bright_magenta), "tbmagenta"),
-               "\x1b[105mtbmagenta\x1b[0m");
-}
-
-TEST(ColorsTest, Format) {
+TEST(color_test, format) {
   EXPECT_EQ(fmt::format(fg(fmt::rgb(255, 20, 30)), "rgb(255,20,30)"),
             "\x1b[38;2;255;020;030mrgb(255,20,30)\x1b[0m");
-  EXPECT_EQ(fmt::format(fg(fmt::rgb(255, 20, 30)), L"rgb(255,20,30) wide"),
-            L"\x1b[38;2;255;020;030mrgb(255,20,30) wide\x1b[0m");
   EXPECT_EQ(fmt::format(fg(fmt::color::blue), "blue"),
             "\x1b[38;2;000;000;255mblue\x1b[0m");
   EXPECT_EQ(
@@ -89,11 +46,15 @@ TEST(ColorsTest, Format) {
             "\x1b[31mfoo\x1b[0m");
 }
 
-TEST(ColorsTest, FormatToOutAcceptsTextStyle) {
-  fmt::text_style ts = fg(fmt::rgb(255, 20, 30));
-  std::string out;
-  fmt::format_to(std::back_inserter(out), ts, "rgb(255,20,30){}{}{}", 1, 2, 3);
-
+TEST(color_test, format_to) {
+  auto out = std::string();
+  fmt::format_to(std::back_inserter(out), fg(fmt::rgb(255, 20, 30)),
+                 "rgb(255,20,30){}{}{}", 1, 2, 3);
   EXPECT_EQ(fmt::to_string(out),
             "\x1b[38;2;255;020;030mrgb(255,20,30)123\x1b[0m");
 }
+
+TEST(color_test, print) {
+  EXPECT_WRITE(stdout, fmt::print(fg(fmt::rgb(255, 20, 30)), "rgb(255,20,30)"),
+               "\x1b[38;2;255;020;030mrgb(255,20,30)\x1b[0m");
+}

test/compile-test.cc

@@ -5,121 +5,83 @@
 //
 // For the license information refer to format.h.
 
-#include <string>
+#include "fmt/compile.h"
+
 #include <type_traits>
 
-// Check that fmt/compile.h compiles with windows.h included before it.
-#ifdef _WIN32
-#  include <windows.h>
-#endif
-
-#include "fmt/compile.h"
-#include "gmock.h"
+#include "fmt/chrono.h"
+#include "gmock/gmock.h"
 #include "gtest-extra.h"
-#include "util.h"
 
-// compiletime_prepared_parts_type_provider is useful only with relaxed
-// constexpr.
-#if FMT_USE_CONSTEXPR
-template <unsigned EXPECTED_PARTS_COUNT, typename Format>
-void check_prepared_parts_type(Format format) {
-  typedef fmt::detail::compiled_format_base<decltype(format)> provider;
-  typedef fmt::detail::format_part<char>
-      expected_parts_type[EXPECTED_PARTS_COUNT];
-  static_assert(std::is_same<typename provider::parts_container,
-                             expected_parts_type>::value,
-                "CompileTimePreparedPartsTypeProvider test failed");
+TEST(iterator_test, counting_iterator) {
+  auto it = fmt::detail::counting_iterator();
+  auto prev = it++;
+  EXPECT_EQ(prev.count(), 0);
+  EXPECT_EQ(it.count(), 1);
+  EXPECT_EQ((it + 41).count(), 42);
 }
 
-TEST(CompileTest, CompileTimePreparedPartsTypeProvider) {
-  check_prepared_parts_type<1u>(FMT_STRING("text"));
-  check_prepared_parts_type<1u>(FMT_STRING("{}"));
-  check_prepared_parts_type<2u>(FMT_STRING("text{}"));
-  check_prepared_parts_type<2u>(FMT_STRING("{}text"));
-  check_prepared_parts_type<3u>(FMT_STRING("text{}text"));
-  check_prepared_parts_type<3u>(FMT_STRING("{:{}.{}} {:{}}"));
+TEST(iterator_test, truncating_iterator) {
+  char* p = nullptr;
+  auto it = fmt::detail::truncating_iterator<char*>(p, 3);
+  auto prev = it++;
+  EXPECT_EQ(prev.base(), p);
+  EXPECT_EQ(it.base(), p + 1);
+}
 
-  check_prepared_parts_type<3u>(FMT_STRING("{{{}}}"));   // '{', 'argument', '}'
-  check_prepared_parts_type<2u>(FMT_STRING("text{{"));   // 'text', '{'
-  check_prepared_parts_type<3u>(FMT_STRING("text{{ "));  // 'text', '{', ' '
-  check_prepared_parts_type<2u>(FMT_STRING("}}text"));   // '}', text
-  check_prepared_parts_type<2u>(FMT_STRING("text}}text"));  // 'text}', 'text'
-  check_prepared_parts_type<4u>(
-      FMT_STRING("text{{}}text"));  // 'text', '{', '}', 'text'
+TEST(iterator_test, truncating_iterator_default_construct) {
+  auto it = fmt::detail::truncating_iterator<char*>();
+  EXPECT_EQ(nullptr, it.base());
+  EXPECT_EQ(std::size_t{0}, it.count());
+}
+
+#ifdef __cpp_lib_ranges
+TEST(iterator_test, truncating_iterator_is_output_iterator) {
+  static_assert(
+      std::output_iterator<fmt::detail::truncating_iterator<char*>, char>);
 }
 #endif
 
-TEST(CompileTest, PassStringLiteralFormat) {
-  const auto prepared = fmt::detail::compile<int>("test {}");
-  EXPECT_EQ("test 42", fmt::format(prepared, 42));
-  const auto wprepared = fmt::detail::compile<int>(L"test {}");
-  EXPECT_EQ(L"test 42", fmt::format(wprepared, 42));
+TEST(iterator_test, truncating_back_inserter) {
+  auto buffer = std::string();
+  auto bi = std::back_inserter(buffer);
+  auto it = fmt::detail::truncating_iterator<decltype(bi)>(bi, 2);
+  *it++ = '4';
+  *it++ = '2';
+  *it++ = '1';
+  EXPECT_EQ(buffer.size(), 2);
+  EXPECT_EQ(buffer, "42");
 }
 
-TEST(CompileTest, FormatToArrayOfChars) {
-  char buffer[32] = {0};
-  const auto prepared = fmt::detail::compile<int>("4{}");
-  fmt::format_to(fmt::detail::make_checked(buffer, 32), prepared, 2);
-  EXPECT_EQ(std::string("42"), buffer);
-  wchar_t wbuffer[32] = {0};
-  const auto wprepared = fmt::detail::compile<int>(L"4{}");
-  fmt::format_to(fmt::detail::make_checked(wbuffer, 32), wprepared, 2);
-  EXPECT_EQ(std::wstring(L"42"), wbuffer);
-}
-
-TEST(CompileTest, FormatToIterator) {
-  std::string s(2, ' ');
-  const auto prepared = fmt::detail::compile<int>("4{}");
-  fmt::format_to(s.begin(), prepared, 2);
-  EXPECT_EQ("42", s);
-  std::wstring ws(2, L' ');
-  const auto wprepared = fmt::detail::compile<int>(L"4{}");
-  fmt::format_to(ws.begin(), wprepared, 2);
-  EXPECT_EQ(L"42", ws);
-}
-
-TEST(CompileTest, FormatToN) {
-  char buf[5];
-  auto f = fmt::detail::compile<int>("{:10}");
-  auto result = fmt::format_to_n(buf, 5, f, 42);
-  EXPECT_EQ(result.size, 10);
-  EXPECT_EQ(result.out, buf + 5);
-  EXPECT_EQ(fmt::string_view(buf, 5), "     ");
-}
-
-TEST(CompileTest, FormattedSize) {
-  auto f = fmt::detail::compile<int>("{:10}");
-  EXPECT_EQ(fmt::formatted_size(f, 42), 10);
-}
-
-TEST(CompileTest, MultipleTypes) {
-  auto f = fmt::detail::compile<int, int>("{} {}");
-  EXPECT_EQ(fmt::format(f, 42, 42), "42 42");
+TEST(compile_test, compile_fallback) {
+  // FMT_COMPILE should fallback on runtime formatting when `if constexpr` is
+  // not available.
+  EXPECT_EQ("42", fmt::format(FMT_COMPILE("{}"), 42));
 }
 
+#ifdef __cpp_if_constexpr
 struct test_formattable {};
 
 FMT_BEGIN_NAMESPACE
 template <> struct formatter<test_formattable> : formatter<const char*> {
+  char word_spec = 'f';
+  constexpr auto parse(format_parse_context& ctx) {
+    auto it = ctx.begin(), end = ctx.end();
+    if (it == end || *it == '}') return it;
+    if (it != end && (*it == 'f' || *it == 'b')) word_spec = *it++;
+    if (it != end && *it != '}') throw format_error("invalid format");
+    return it;
+  }
   template <typename FormatContext>
-  auto format(test_formattable, FormatContext& ctx) -> decltype(ctx.out()) {
-    return formatter<const char*>::format("foo", ctx);
+  constexpr auto format(test_formattable, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    return formatter<const char*>::format(word_spec == 'f' ? "foo" : "bar",
+                                          ctx);
   }
 };
 FMT_END_NAMESPACE
 
-TEST(CompileTest, FormatUserDefinedType) {
-  auto f = fmt::detail::compile<test_formattable>("{}");
-  EXPECT_EQ(fmt::format(f, test_formattable()), "foo");
-}
-
-TEST(CompileTest, EmptyFormatString) {
-  auto f = fmt::detail::compile<>("");
-  EXPECT_EQ(fmt::format(f), "");
-}
-
-#ifdef __cpp_if_constexpr
-TEST(CompileTest, FormatDefault) {
+TEST(compile_test, format_default) {
   EXPECT_EQ("42", fmt::format(FMT_COMPILE("{}"), 42));
   EXPECT_EQ("42", fmt::format(FMT_COMPILE("{}"), 42u));
   EXPECT_EQ("42", fmt::format(FMT_COMPILE("{}"), 42ll));
@@ -130,22 +92,99 @@ TEST(CompileTest, FormatDefault) {
   EXPECT_EQ("foo", fmt::format(FMT_COMPILE("{}"), "foo"));
   EXPECT_EQ("foo", fmt::format(FMT_COMPILE("{}"), std::string("foo")));
   EXPECT_EQ("foo", fmt::format(FMT_COMPILE("{}"), test_formattable()));
+  auto t = std::chrono::system_clock::now();
+  EXPECT_EQ(fmt::format("{}", t), fmt::format(FMT_COMPILE("{}"), t));
+#  ifdef __cpp_lib_byte
+  EXPECT_EQ("42", fmt::format(FMT_COMPILE("{}"), std::byte{42}));
+#  endif
 }
 
-TEST(CompileTest, FormatWideString) {
+TEST(compile_test, format_wide_string) {
   EXPECT_EQ(L"42", fmt::format(FMT_COMPILE(L"{}"), 42));
 }
 
-TEST(CompileTest, FormatSpecs) {
+TEST(compile_test, format_specs) {
   EXPECT_EQ("42", fmt::format(FMT_COMPILE("{:x}"), 0x42));
+  EXPECT_EQ("1.2 ms ",
+            fmt::format(FMT_COMPILE("{:7.1%Q %q}"),
+                        std::chrono::duration<double, std::milli>(1.234)));
 }
 
-TEST(CompileTest, DynamicWidth) {
-  EXPECT_EQ("  42foo  ",
-            fmt::format(FMT_COMPILE("{:{}}{:{}}"), 42, 4, "foo", 5));
+TEST(compile_test, dynamic_format_specs) {
+  EXPECT_EQ("foo  ", fmt::format(FMT_COMPILE("{:{}}"), "foo", 5));
+  EXPECT_EQ("  3.14", fmt::format(FMT_COMPILE("{:{}.{}f}"), 3.141592, 6, 2));
+  EXPECT_EQ(
+      "=1.234ms=",
+      fmt::format(FMT_COMPILE("{:=^{}.{}}"),
+                  std::chrono::duration<double, std::milli>(1.234), 9, 3));
 }
 
-TEST(CompileTest, FormatTo) {
+TEST(compile_test, manual_ordering) {
+  EXPECT_EQ("42", fmt::format(FMT_COMPILE("{0}"), 42));
+  EXPECT_EQ(" -42", fmt::format(FMT_COMPILE("{0:4}"), -42));
+  EXPECT_EQ("41 43", fmt::format(FMT_COMPILE("{0} {1}"), 41, 43));
+  EXPECT_EQ("41 43", fmt::format(FMT_COMPILE("{1} {0}"), 43, 41));
+  EXPECT_EQ("41 43", fmt::format(FMT_COMPILE("{0} {2}"), 41, 42, 43));
+  EXPECT_EQ("  41   43", fmt::format(FMT_COMPILE("{1:{2}} {0:4}"), 43, 41, 4));
+  EXPECT_EQ("42 1.2 ms ",
+            fmt::format(FMT_COMPILE("{0} {1:7.1%Q %q}"), 42,
+                        std::chrono::duration<double, std::milli>(1.234)));
+  EXPECT_EQ(
+      "true 42 42 foo 0x1234 foo",
+      fmt::format(FMT_COMPILE("{0} {1} {2} {3} {4} {5}"), true, 42, 42.0f,
+                  "foo", reinterpret_cast<void*>(0x1234), test_formattable()));
+  EXPECT_EQ(L"42", fmt::format(FMT_COMPILE(L"{0}"), 42));
+}
+
+TEST(compile_test, named) {
+  auto runtime_named_field_compiled =
+      fmt::detail::compile<decltype(fmt::arg("arg", 42))>(FMT_COMPILE("{arg}"));
+  static_assert(std::is_same_v<decltype(runtime_named_field_compiled),
+                               fmt::detail::runtime_named_field<char>>);
+
+  EXPECT_EQ("42", fmt::format(FMT_COMPILE("{}"), fmt::arg("arg", 42)));
+  EXPECT_EQ("41 43", fmt::format(FMT_COMPILE("{} {}"), fmt::arg("arg", 41),
+                                 fmt::arg("arg", 43)));
+
+  EXPECT_EQ("foobar",
+            fmt::format(FMT_COMPILE("{a0}{a1}"), fmt::arg("a0", "foo"),
+                        fmt::arg("a1", "bar")));
+  EXPECT_EQ("foobar", fmt::format(FMT_COMPILE("{}{a1}"), fmt::arg("a0", "foo"),
+                                  fmt::arg("a1", "bar")));
+  EXPECT_EQ("foofoo", fmt::format(FMT_COMPILE("{a0}{}"), fmt::arg("a0", "foo"),
+                                  fmt::arg("a1", "bar")));
+  EXPECT_EQ("foobar", fmt::format(FMT_COMPILE("{0}{a1}"), fmt::arg("a0", "foo"),
+                                  fmt::arg("a1", "bar")));
+  EXPECT_EQ("foobar", fmt::format(FMT_COMPILE("{a0}{1}"), fmt::arg("a0", "foo"),
+                                  fmt::arg("a1", "bar")));
+
+  EXPECT_EQ("foobar",
+            fmt::format(FMT_COMPILE("{}{a1}"), "foo", fmt::arg("a1", "bar")));
+  EXPECT_EQ("foobar",
+            fmt::format(FMT_COMPILE("{a0}{a1}"), fmt::arg("a1", "bar"),
+                        fmt::arg("a2", "baz"), fmt::arg("a0", "foo")));
+  EXPECT_EQ(" bar foo ",
+            fmt::format(FMT_COMPILE(" {foo} {bar} "), fmt::arg("foo", "bar"),
+                        fmt::arg("bar", "foo")));
+
+  EXPECT_THROW(fmt::format(FMT_COMPILE("{invalid}"), fmt::arg("valid", 42)),
+               fmt::format_error);
+
+#  if FMT_USE_NONTYPE_TEMPLATE_PARAMETERS
+  using namespace fmt::literals;
+  auto statically_named_field_compiled =
+      fmt::detail::compile<decltype("arg"_a = 42)>(FMT_COMPILE("{arg}"));
+  static_assert(std::is_same_v<decltype(statically_named_field_compiled),
+                               fmt::detail::field<char, int, 0>>);
+
+  EXPECT_EQ("41 43",
+            fmt::format(FMT_COMPILE("{a0} {a1}"), "a0"_a = 41, "a1"_a = 43));
+  EXPECT_EQ("41 43",
+            fmt::format(FMT_COMPILE("{a1} {a0}"), "a0"_a = 43, "a1"_a = 41));
+#  endif
+}
+
+TEST(compile_test, format_to) {
   char buf[8];
   auto end = fmt::format_to(buf, FMT_COMPILE("{}"), 42);
   *end = '\0';
@@ -155,7 +194,7 @@ TEST(CompileTest, FormatTo) {
   EXPECT_STREQ("2a", buf);
 }
 
-TEST(CompileTest, FormatToNWithCompileMacro) {
+TEST(compile_test, format_to_n) {
   constexpr auto buffer_size = 8;
   char buffer[buffer_size];
   auto res = fmt::format_to_n(buffer, buffer_size, FMT_COMPILE("{}"), 42);
@@ -166,8 +205,155 @@ TEST(CompileTest, FormatToNWithCompileMacro) {
   EXPECT_STREQ("2a", buffer);
 }
 
-TEST(CompileTest, TextAndArg) {
+TEST(compile_test, formatted_size) {
+  EXPECT_EQ(2, fmt::formatted_size(FMT_COMPILE("{0}"), 42));
+  EXPECT_EQ(5, fmt::formatted_size(FMT_COMPILE("{0:<4.2f}"), 42.0));
+}
+
+TEST(compile_test, text_and_arg) {
   EXPECT_EQ(">>>42<<<", fmt::format(FMT_COMPILE(">>>{}<<<"), 42));
   EXPECT_EQ("42!", fmt::format(FMT_COMPILE("{}!"), 42));
 }
+
+TEST(compile_test, unknown_format_fallback) {
+  EXPECT_EQ(" 42 ",
+            fmt::format(FMT_COMPILE("{name:^4}"), fmt::arg("name", 42)));
+
+  std::vector<char> v;
+  fmt::format_to(std::back_inserter(v), FMT_COMPILE("{name:^4}"),
+                 fmt::arg("name", 42));
+  EXPECT_EQ(" 42 ", fmt::string_view(v.data(), v.size()));
+
+  char buffer[4];
+  auto result = fmt::format_to_n(buffer, 4, FMT_COMPILE("{name:^5}"),
+                                 fmt::arg("name", 42));
+  EXPECT_EQ(5u, result.size);
+  EXPECT_EQ(buffer + 4, result.out);
+  EXPECT_EQ(" 42 ", fmt::string_view(buffer, 4));
+}
+
+TEST(compile_test, empty) { EXPECT_EQ("", fmt::format(FMT_COMPILE(""))); }
+
+struct to_stringable {
+  friend fmt::string_view to_string_view(to_stringable) { return {}; }
+};
+
+FMT_BEGIN_NAMESPACE
+template <> struct formatter<to_stringable> {
+  auto parse(format_parse_context& ctx) const -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  auto format(const to_stringable&, FormatContext& ctx) -> decltype(ctx.out()) {
+    return ctx.out();
+  }
+};
+FMT_END_NAMESPACE
+
+TEST(compile_test, to_string_and_formatter) {
+  fmt::format(FMT_COMPILE("{}"), to_stringable());
+}
+
+TEST(compile_test, print) {
+  EXPECT_WRITE(stdout, fmt::print(FMT_COMPILE("Don't {}!"), "panic"),
+               "Don't panic!");
+  EXPECT_WRITE(stderr, fmt::print(stderr, FMT_COMPILE("Don't {}!"), "panic"),
+               "Don't panic!");
+}
+#endif
+
+#if FMT_USE_NONTYPE_TEMPLATE_PARAMETERS
+TEST(compile_test, compile_format_string_literal) {
+  using namespace fmt::literals;
+  EXPECT_EQ("", fmt::format(""_cf));
+  EXPECT_EQ("42", fmt::format("{}"_cf, 42));
+  EXPECT_EQ(L"42", fmt::format(L"{}"_cf, 42));
+}
+#endif
+
+#if __cplusplus >= 202002L || \
+    (__cplusplus >= 201709L && FMT_GCC_VERSION >= 1002)
+template <size_t max_string_length, typename Char = char> struct test_string {
+  template <typename T> constexpr bool operator==(const T& rhs) const noexcept {
+    return fmt::basic_string_view<Char>(rhs).compare(buffer) == 0;
+  }
+  Char buffer[max_string_length]{};
+};
+
+template <size_t max_string_length, typename Char = char, typename... Args>
+consteval auto test_format(auto format, const Args&... args) {
+  test_string<max_string_length, Char> string{};
+  fmt::format_to(string.buffer, format, args...);
+  return string;
+}
+
+TEST(compile_time_formatting_test, bool) {
+  EXPECT_EQ("true", test_format<5>(FMT_COMPILE("{}"), true));
+  EXPECT_EQ("false", test_format<6>(FMT_COMPILE("{}"), false));
+  EXPECT_EQ("true ", test_format<6>(FMT_COMPILE("{:5}"), true));
+  EXPECT_EQ("1", test_format<2>(FMT_COMPILE("{:d}"), true));
+}
+
+TEST(compile_time_formatting_test, integer) {
+  EXPECT_EQ("42", test_format<3>(FMT_COMPILE("{}"), 42));
+  EXPECT_EQ("420", test_format<4>(FMT_COMPILE("{}"), 420));
+  EXPECT_EQ("42 42", test_format<6>(FMT_COMPILE("{} {}"), 42, 42));
+  EXPECT_EQ("42 42",
+            test_format<6>(FMT_COMPILE("{} {}"), uint32_t{42}, uint64_t{42}));
+
+  EXPECT_EQ("+42", test_format<4>(FMT_COMPILE("{:+}"), 42));
+  EXPECT_EQ("42", test_format<3>(FMT_COMPILE("{:-}"), 42));
+  EXPECT_EQ(" 42", test_format<4>(FMT_COMPILE("{: }"), 42));
+
+  EXPECT_EQ("-0042", test_format<6>(FMT_COMPILE("{:05}"), -42));
+
+  EXPECT_EQ("101010", test_format<7>(FMT_COMPILE("{:b}"), 42));
+  EXPECT_EQ("0b101010", test_format<9>(FMT_COMPILE("{:#b}"), 42));
+  EXPECT_EQ("0B101010", test_format<9>(FMT_COMPILE("{:#B}"), 42));
+  EXPECT_EQ("042", test_format<4>(FMT_COMPILE("{:#o}"), 042));
+  EXPECT_EQ("0x4a", test_format<5>(FMT_COMPILE("{:#x}"), 0x4a));
+  EXPECT_EQ("0X4A", test_format<5>(FMT_COMPILE("{:#X}"), 0x4a));
+
+  EXPECT_EQ("   42", test_format<6>(FMT_COMPILE("{:5}"), 42));
+  EXPECT_EQ("   42", test_format<6>(FMT_COMPILE("{:5}"), 42ll));
+  EXPECT_EQ("   42", test_format<6>(FMT_COMPILE("{:5}"), 42ull));
+
+  EXPECT_EQ("42  ", test_format<5>(FMT_COMPILE("{:<4}"), 42));
+  EXPECT_EQ("  42", test_format<5>(FMT_COMPILE("{:>4}"), 42));
+  EXPECT_EQ(" 42 ", test_format<5>(FMT_COMPILE("{:^4}"), 42));
+  EXPECT_EQ("**-42", test_format<6>(FMT_COMPILE("{:*>5}"), -42));
+}
+
+TEST(compile_time_formatting_test, char) {
+  EXPECT_EQ("c", test_format<2>(FMT_COMPILE("{}"), 'c'));
+
+  EXPECT_EQ("c  ", test_format<4>(FMT_COMPILE("{:3}"), 'c'));
+  EXPECT_EQ("99", test_format<3>(FMT_COMPILE("{:d}"), 'c'));
+}
+
+TEST(compile_time_formatting_test, string) {
+  EXPECT_EQ("42", test_format<3>(FMT_COMPILE("{}"), "42"));
+  EXPECT_EQ("The answer is 42",
+            test_format<17>(FMT_COMPILE("{} is {}"), "The answer", "42"));
+
+  EXPECT_EQ("abc**", test_format<6>(FMT_COMPILE("{:*<5}"), "abc"));
+  EXPECT_EQ("**🤡**", test_format<9>(FMT_COMPILE("{:*^6}"), "🤡"));
+}
+
+TEST(compile_time_formatting_test, combination) {
+  EXPECT_EQ("420, true, answer",
+            test_format<18>(FMT_COMPILE("{}, {}, {}"), 420, true, "answer"));
+
+  EXPECT_EQ(" -42", test_format<5>(FMT_COMPILE("{:{}}"), -42, 4));
+}
+
+TEST(compile_time_formatting_test, custom_type) {
+  EXPECT_EQ("foo", test_format<4>(FMT_COMPILE("{}"), test_formattable()));
+  EXPECT_EQ("bar", test_format<4>(FMT_COMPILE("{:b}"), test_formattable()));
+}
+
+TEST(compile_time_formatting_test, multibyte_fill) {
+  EXPECT_EQ("жж42", test_format<8>(FMT_COMPILE("{:ж>4}"), 42));
+}
 #endif

test/enforce-checks-test.cc

@@ -0,0 +1,62 @@
+// Formatting library for C++ - formatting library tests
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#include <iterator>
+#include <vector>
+
+#include "fmt/chrono.h"
+#include "fmt/color.h"
+#include "fmt/format.h"
+#include "fmt/ostream.h"
+#include "fmt/ranges.h"
+#include "fmt/xchar.h"
+
+// Exercise the API to verify that everything we expect to can compile.
+void test_format_api() {
+  fmt::format(FMT_STRING("{}"), 42);
+  fmt::format(FMT_STRING(L"{}"), 42);
+  fmt::format(FMT_STRING("noop"));
+
+  fmt::to_string(42);
+  fmt::to_wstring(42);
+
+  std::vector<char> out;
+  fmt::format_to(std::back_inserter(out), FMT_STRING("{}"), 42);
+
+  char buffer[4];
+  fmt::format_to_n(buffer, 3, FMT_STRING("{}"), 12345);
+
+  wchar_t wbuffer[4];
+  fmt::format_to_n(wbuffer, 3, FMT_STRING(L"{}"), 12345);
+}
+
+void test_chrono() {
+  fmt::format(FMT_STRING("{}"), std::chrono::seconds(42));
+  fmt::format(FMT_STRING(L"{}"), std::chrono::seconds(42));
+}
+
+void test_text_style() {
+  fmt::print(fg(fmt::rgb(255, 20, 30)), FMT_STRING("{}"), "rgb(255,20,30)");
+  fmt::format(fg(fmt::rgb(255, 20, 30)), FMT_STRING("{}"), "rgb(255,20,30)");
+
+  fmt::text_style ts = fg(fmt::rgb(255, 20, 30));
+  std::string out;
+  fmt::format_to(std::back_inserter(out), ts,
+                 FMT_STRING("rgb(255,20,30){}{}{}"), 1, 2, 3);
+}
+
+void test_range() {
+  std::vector<char> hello = {'h', 'e', 'l', 'l', 'o'};
+  fmt::format(FMT_STRING("{}"), hello);
+}
+
+int main() {
+  test_format_api();
+  test_chrono();
+  test_text_style();
+  test_range();
+}

test/format

@@ -8,6 +8,7 @@
 #ifndef FMT_FORMAT_
 #define FMT_FORMAT_
 
+#include <algorithm>
 #include <cassert>
 #include <variant>
 #include "fmt/format.h"

test/format-impl-test.cc

@@ -5,24 +5,16 @@
 //
 // For the license information refer to format.h.
 
-#define FMT_NOEXCEPT
-#undef FMT_SHARED
-#include "test-assert.h"
-
-// Include format.cc instead of format.h to test implementation.
 #include <algorithm>
 #include <cstring>
 
-#include "../src/format.cc"
-#include "fmt/printf.h"
-#include "gmock.h"
-#include "gtest-extra.h"
-#include "util.h"
+// clang-format off
+#include "test-assert.h"
+// clang-format on
 
-#ifdef _WIN32
-#  include <windows.h>
-#  undef max
-#endif
+#include "fmt/format.h"
+#include "gmock/gmock.h"
+#include "util.h"
 
 using fmt::detail::bigint;
 using fmt::detail::fp;
@@ -31,13 +23,13 @@ using fmt::detail::max_value;
 static_assert(!std::is_copy_constructible<bigint>::value, "");
 static_assert(!std::is_copy_assignable<bigint>::value, "");
 
-TEST(BigIntTest, Construct) {
+TEST(bigint_test, construct) {
   EXPECT_EQ("", fmt::format("{}", bigint()));
   EXPECT_EQ("42", fmt::format("{}", bigint(0x42)));
   EXPECT_EQ("123456789abcedf0", fmt::format("{}", bigint(0x123456789abcedf0)));
 }
 
-TEST(BigIntTest, Compare) {
+TEST(bigint_test, compare) {
   bigint n1(42);
   bigint n2(42);
   EXPECT_EQ(compare(n1, n2), 0);
@@ -51,7 +43,7 @@ TEST(BigIntTest, Compare) {
   EXPECT_GT(compare(n4, n2), 0);
 }
 
-TEST(BigIntTest, AddCompare) {
+TEST(bigint_test, add_compare) {
   EXPECT_LT(
       add_compare(bigint(0xffffffff), bigint(0xffffffff), bigint(1) <<= 64), 0);
   EXPECT_LT(add_compare(bigint(1) <<= 32, bigint(1), bigint(1) <<= 96), 0);
@@ -77,7 +69,7 @@ TEST(BigIntTest, AddCompare) {
             0);
 }
 
-TEST(BigIntTest, ShiftLeft) {
+TEST(bigint_test, shift_left) {
   bigint n(0x42);
   n <<= 0;
   EXPECT_EQ("42", fmt::format("{}", n));
@@ -87,7 +79,7 @@ TEST(BigIntTest, ShiftLeft) {
   EXPECT_EQ("108000000", fmt::format("{}", n));
 }
 
-TEST(BigIntTest, Multiply) {
+TEST(bigint_test, multiply) {
   bigint n(0x42);
   EXPECT_THROW(n *= 0, assertion_failure);
   n *= 1;
@@ -104,7 +96,7 @@ TEST(BigIntTest, Multiply) {
   EXPECT_EQ("fffffffffffffffe0000000000000001", fmt::format("{}", bigmax));
 }
 
-TEST(BigIntTest, Accumulator) {
+TEST(bigint_test, accumulator) {
   fmt::detail::accumulator acc;
   EXPECT_EQ(acc.lower, 0);
   EXPECT_EQ(acc.upper, 0);
@@ -113,7 +105,7 @@ TEST(BigIntTest, Accumulator) {
   EXPECT_EQ(static_cast<uint32_t>(acc), 34);
   acc += 56;
   EXPECT_EQ(acc.lower, 90);
-  acc += fmt::detail::max_value<uint64_t>();
+  acc += max_value<uint64_t>();
   EXPECT_EQ(acc.upper, 13);
   EXPECT_EQ(acc.lower, 89);
   acc >>= 32;
@@ -121,7 +113,7 @@ TEST(BigIntTest, Accumulator) {
   EXPECT_EQ(acc.lower, 13 * 0x100000000);
 }
 
-TEST(BigIntTest, Square) {
+TEST(bigint_test, square) {
   bigint n0(0);
   n0.square();
   EXPECT_EQ("0", fmt::format("{}", n0));
@@ -139,18 +131,18 @@ TEST(BigIntTest, Square) {
   EXPECT_EQ("2540be400", fmt::format("{}", n4));
 }
 
-TEST(BigIntTest, DivModAssignZeroDivisor) {
+TEST(bigint_test, divmod_assign_zero_divisor) {
   bigint zero(0);
   EXPECT_THROW(bigint(0).divmod_assign(zero), assertion_failure);
   EXPECT_THROW(bigint(42).divmod_assign(zero), assertion_failure);
 }
 
-TEST(BigIntTest, DivModAssignSelf) {
+TEST(bigint_test, divmod_assign_self) {
   bigint n(100);
   EXPECT_THROW(n.divmod_assign(n), assertion_failure);
 }
 
-TEST(BigIntTest, DivModAssignUnaligned) {
+TEST(bigint_test, divmod_assign_unaligned) {
   // (42 << 340) / pow(10, 100):
   bigint n1(42);
   n1 <<= 340;
@@ -162,7 +154,7 @@ TEST(BigIntTest, DivModAssignUnaligned) {
             fmt::format("{}", n1));
 }
 
-TEST(BigIntTest, DivModAssign) {
+TEST(bigint_test, divmod_assign) {
   // 100 / 10:
   bigint n1(100);
   int result = n1.divmod_assign(bigint(10));
@@ -191,18 +183,18 @@ template <> void run_double_tests<true>() {
   EXPECT_EQ(fp(1.23), fp(0x13ae147ae147aeu, -52));
 }
 
-TEST(FPTest, DoubleTests) {
+TEST(fp_test, double_tests) {
   run_double_tests<std::numeric_limits<double>::is_iec559>();
 }
 
-TEST(FPTest, Normalize) {
+TEST(fp_test, normalize) {
   const auto v = fp(0xbeef, 42);
   auto normalized = normalize(v);
   EXPECT_EQ(0xbeef000000000000, normalized.f);
   EXPECT_EQ(-6, normalized.e);
 }
 
-TEST(FPTest, Multiply) {
+TEST(fp_test, multiply) {
   auto v = fp(123ULL << 32, 4) * fp(56ULL << 32, 7);
   EXPECT_EQ(v.f, 123u * 56u);
   EXPECT_EQ(v.e, 4 + 7 + 64);
@@ -211,7 +203,7 @@ TEST(FPTest, Multiply) {
   EXPECT_EQ(v.e, 4 + 8 + 64);
 }
 
-TEST(FPTest, GetCachedPower) {
+TEST(fp_test, get_cached_power) {
   using limits = std::numeric_limits<double>;
   for (auto exp = limits::min_exponent; exp <= limits::max_exponent; ++exp) {
     int dec_exp = 0;
@@ -248,7 +240,7 @@ TEST(FPTest, GetCachedPower) {
   }
 }
 
-TEST(FPTest, DragonboxMaxK) {
+TEST(fp_test, dragonbox_max_k) {
   using fmt::detail::dragonbox::floor_log10_pow2;
   using float_info = fmt::detail::dragonbox::float_info<float>;
   EXPECT_EQ(fmt::detail::const_check(float_info::max_k),
@@ -261,7 +253,7 @@ TEST(FPTest, DragonboxMaxK) {
                                             double_info::significand_bits));
 }
 
-TEST(FPTest, GetRoundDirection) {
+TEST(fp_test, get_round_direction) {
   using fmt::detail::get_round_direction;
   using fmt::detail::round_direction;
   EXPECT_EQ(round_direction::down, get_round_direction(100, 50, 0));
@@ -285,7 +277,7 @@ TEST(FPTest, GetRoundDirection) {
   EXPECT_EQ(round_direction::up, get_round_direction(max, max - 1, 1));
 }
 
-TEST(FPTest, FixedHandler) {
+TEST(fp_test, fixed_handler) {
   struct handler : fmt::detail::fixed_handler {
     char buffer[10];
     handler(int prec = 0) : fmt::detail::fixed_handler() {
@@ -307,86 +299,23 @@ TEST(FPTest, FixedHandler) {
             digits::error);
 }
 
-TEST(FPTest, GrisuFormatCompilesWithNonIEEEDouble) {
+TEST(fp_test, grisu_format_compiles_with_on_ieee_double) {
   fmt::memory_buffer buf;
   format_float(0.42, -1, fmt::detail::float_specs(), buf);
 }
 
-template <typename T> struct value_extractor {
-  T operator()(T value) { return value; }
-
-  template <typename U> FMT_NORETURN T operator()(U) {
-    throw std::runtime_error(fmt::format("invalid type {}", typeid(U).name()));
-  }
-
-#if FMT_USE_INT128
-  // Apple Clang does not define typeid for __int128_t and __uint128_t.
-  FMT_NORETURN T operator()(fmt::detail::int128_t) {
-    throw std::runtime_error("invalid type __int128_t");
-  }
-
-  FMT_NORETURN T operator()(fmt::detail::uint128_t) {
-    throw std::runtime_error("invalid type __uint128_t");
-  }
-#endif
-};
-
-TEST(FormatTest, ArgConverter) {
-  long long value = max_value<long long>();
-  auto arg = fmt::detail::make_arg<fmt::format_context>(value);
-  fmt::visit_format_arg(
-      fmt::detail::arg_converter<long long, fmt::format_context>(arg, 'd'),
-      arg);
-  EXPECT_EQ(value, fmt::visit_format_arg(value_extractor<long long>(), arg));
-}
-
-TEST(FormatTest, StrError) {
-  char* message = nullptr;
-  char buffer[BUFFER_SIZE];
-  EXPECT_ASSERT(fmt::detail::safe_strerror(EDOM, message = nullptr, 0),
-                "invalid buffer");
-  EXPECT_ASSERT(fmt::detail::safe_strerror(EDOM, message = buffer, 0),
-                "invalid buffer");
-  buffer[0] = 'x';
-#if defined(_GNU_SOURCE) && !defined(__COVERITY__)
-  // Use invalid error code to make sure that safe_strerror returns an error
-  // message in the buffer rather than a pointer to a static string.
-  int error_code = -1;
-#else
-  int error_code = EDOM;
-#endif
-
-  int result =
-      fmt::detail::safe_strerror(error_code, message = buffer, BUFFER_SIZE);
-  EXPECT_EQ(result, 0);
-  size_t message_size = std::strlen(message);
-  EXPECT_GE(BUFFER_SIZE - 1u, message_size);
-  EXPECT_EQ(get_system_error(error_code), message);
-
-  // safe_strerror never uses buffer on MinGW.
-#if !defined(__MINGW32__) && !defined(__sun)
-  result =
-      fmt::detail::safe_strerror(error_code, message = buffer, message_size);
-  EXPECT_EQ(ERANGE, result);
-  result = fmt::detail::safe_strerror(error_code, message = buffer, 1);
-  EXPECT_EQ(buffer, message);  // Message should point to buffer.
-  EXPECT_EQ(ERANGE, result);
-  EXPECT_STREQ("", message);
-#endif
-}
-
-TEST(FormatTest, FormatErrorCode) {
+TEST(format_impl_test, format_error_code) {
   std::string msg = "error 42", sep = ": ";
   {
     fmt::memory_buffer buffer;
-    format_to(buffer, "garbage");
+    format_to(fmt::appender(buffer), "garbage");
     fmt::detail::format_error_code(buffer, 42, "test");
     EXPECT_EQ("test: " + msg, to_string(buffer));
   }
   {
     fmt::memory_buffer buffer;
-    std::string prefix(fmt::inline_buffer_size - msg.size() - sep.size() + 1,
-                       'x');
+    auto prefix =
+        std::string(fmt::inline_buffer_size - msg.size() - sep.size() + 1, 'x');
     fmt::detail::format_error_code(buffer, 42, prefix);
     EXPECT_EQ(msg, to_string(buffer));
   }
@@ -395,7 +324,8 @@ TEST(FormatTest, FormatErrorCode) {
     // Test maximum buffer size.
     msg = fmt::format("error {}", codes[i]);
     fmt::memory_buffer buffer;
-    std::string prefix(fmt::inline_buffer_size - msg.size() - sep.size(), 'x');
+    auto prefix =
+        std::string(fmt::inline_buffer_size - msg.size() - sep.size(), 'x');
     fmt::detail::format_error_code(buffer, codes[i], prefix);
     EXPECT_EQ(prefix + sep + msg, to_string(buffer));
     size_t size = fmt::inline_buffer_size;
@@ -408,9 +338,9 @@ TEST(FormatTest, FormatErrorCode) {
   }
 }
 
-TEST(FormatTest, CountCodePoints) {
+TEST(format_impl_test, compute_width) {
   EXPECT_EQ(4,
-            fmt::detail::count_code_points(
+            fmt::detail::compute_width(
                 fmt::basic_string_view<fmt::detail::char8_type>(
                     reinterpret_cast<const fmt::detail::char8_type*>("ёжик"))));
 }
@@ -425,12 +355,12 @@ template <typename Int> void test_count_digits() {
   }
 }
 
-TEST(UtilTest, CountDigits) {
+TEST(format_impl_test, count_digits) {
   test_count_digits<uint32_t>();
   test_count_digits<uint64_t>();
 }
 
-TEST(UtilTest, WriteFallbackUIntPtr) {
+TEST(format_impl_test, write_fallback_uintptr) {
   std::string s;
   fmt::detail::write_ptr<char>(
       std::back_inserter(s),
@@ -439,7 +369,11 @@ TEST(UtilTest, WriteFallbackUIntPtr) {
 }
 
 #ifdef _WIN32
-TEST(UtilTest, WriteConsoleSignature) {
+#  include <windows.h>
+#endif
+
+#ifdef _WIN32
+TEST(format_impl_test, write_console_signature) {
   decltype(WriteConsoleW)* p = fmt::detail::WriteConsoleW;
   (void)p;
 }

test/fuzzing/float.cc

@@ -9,26 +9,31 @@
 
 #include "fuzzer-common.h"
 
-extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  if (size <= sizeof(double) || !std::numeric_limits<double>::is_iec559)
-    return 0;
-
-  auto value = assign_from_buf<double>(data);
+void check_round_trip(fmt::string_view format_str, double value) {
   auto buffer = fmt::memory_buffer();
-  fmt::format_to(buffer, "{}", value);
+  fmt::format_to(buffer, format_str, value);
 
-  // Check a round trip.
   if (std::isnan(value)) {
     auto nan = std::signbit(value) ? "-nan" : "nan";
     if (fmt::string_view(buffer.data(), buffer.size()) != nan)
       throw std::runtime_error("round trip failure");
-    return 0;
+    return;
   }
+
   buffer.push_back('\0');
   char* ptr = nullptr;
   if (std::strtod(buffer.data(), &ptr) != value)
     throw std::runtime_error("round trip failure");
   if (ptr + 1 != buffer.end())
     throw std::runtime_error("unparsed output");
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  if (size <= sizeof(double) || !std::numeric_limits<double>::is_iec559)
+    return 0;
+  check_round_trip("{}", assign_from_buf<double>(data));
+  // A larger than necessary precision is used to trigger the fallback
+  // formatter.
+  check_round_trip("{:.50g}", assign_from_buf<double>(data));
   return 0;
 }

test/gtest-extra-test.cc

@@ -9,31 +9,18 @@
 
 #include <gtest/gtest-spi.h>
 
-#include <algorithm>
 #include <cstring>
 #include <memory>
 #include <stdexcept>
 
-#if defined(_WIN32) && !defined(__MINGW32__)
-#  include <crtdbg.h>  // for _CrtSetReportMode
-#endif                 // _WIN32
-
+#include "fmt/os.h"
 #include "util.h"
 
-namespace {
-
-// This is used to suppress coverity warnings about untrusted values.
-std::string sanitize(const std::string& s) {
-  std::string result;
-  for (std::string::const_iterator i = s.begin(), end = s.end(); i != end; ++i)
-    result.push_back(static_cast<char>(*i & 0xff));
-  return result;
-}
-
 // Tests that assertion macros evaluate their arguments exactly once.
-class SingleEvaluationTest : public ::testing::Test {
+namespace {
+class single_evaluation_test : public ::testing::Test {
  protected:
-  SingleEvaluationTest() {
+  single_evaluation_test() {
     p_ = s_;
     a_ = 0;
     b_ = 0;
@@ -45,11 +32,12 @@ class SingleEvaluationTest : public ::testing::Test {
   static int a_;
   static int b_;
 };
+}  // namespace
 
-const char* const SingleEvaluationTest::s_ = "01234";
-const char* SingleEvaluationTest::p_;
-int SingleEvaluationTest::a_;
-int SingleEvaluationTest::b_;
+const char* const single_evaluation_test::s_ = "01234";
+const char* single_evaluation_test::p_;
+int single_evaluation_test::a_;
+int single_evaluation_test::b_;
 
 void do_nothing() {}
 
@@ -61,7 +49,7 @@ FMT_NORETURN void throw_system_error() {
 
 // Tests that when EXPECT_THROW_MSG fails, it evaluates its message argument
 // exactly once.
-TEST_F(SingleEvaluationTest, FailedEXPECT_THROW_MSG) {
+TEST_F(single_evaluation_test, failed_expect_throw_msg) {
   EXPECT_NONFATAL_FAILURE(
       EXPECT_THROW_MSG(throw_exception(), std::exception, p_++), "01234");
   EXPECT_EQ(s_ + 1, p_);
@@ -69,14 +57,14 @@ TEST_F(SingleEvaluationTest, FailedEXPECT_THROW_MSG) {
 
 // Tests that when EXPECT_SYSTEM_ERROR fails, it evaluates its message argument
 // exactly once.
-TEST_F(SingleEvaluationTest, FailedEXPECT_SYSTEM_ERROR) {
+TEST_F(single_evaluation_test, failed_expect_system_error) {
   EXPECT_NONFATAL_FAILURE(EXPECT_SYSTEM_ERROR(throw_system_error(), EDOM, p_++),
                           "01234");
   EXPECT_EQ(s_ + 1, p_);
 }
 
 // Tests that assertion arguments are evaluated exactly once.
-TEST_F(SingleEvaluationTest, ExceptionTests) {
+TEST_F(single_evaluation_test, exception_tests) {
   // successful EXPECT_THROW_MSG
   EXPECT_THROW_MSG(
       {  // NOLINT
@@ -116,7 +104,7 @@ TEST_F(SingleEvaluationTest, ExceptionTests) {
   EXPECT_EQ(4, b_);
 }
 
-TEST_F(SingleEvaluationTest, SystemErrorTests) {
+TEST_F(single_evaluation_test, system_error_tests) {
   // successful EXPECT_SYSTEM_ERROR
   EXPECT_SYSTEM_ERROR(
       {  // NOLINT
@@ -159,14 +147,14 @@ TEST_F(SingleEvaluationTest, SystemErrorTests) {
 #if FMT_USE_FCNTL
 // Tests that when EXPECT_WRITE fails, it evaluates its message argument
 // exactly once.
-TEST_F(SingleEvaluationTest, FailedEXPECT_WRITE) {
+TEST_F(single_evaluation_test, failed_expect_write) {
   EXPECT_NONFATAL_FAILURE(EXPECT_WRITE(stdout, std::printf("test"), p_++),
                           "01234");
   EXPECT_EQ(s_ + 1, p_);
 }
 
 // Tests that assertion arguments are evaluated exactly once.
-TEST_F(SingleEvaluationTest, WriteTests) {
+TEST_F(single_evaluation_test, write_tests) {
   // successful EXPECT_WRITE
   EXPECT_WRITE(
       stdout,
@@ -192,7 +180,7 @@ TEST_F(SingleEvaluationTest, WriteTests) {
 }
 
 // Tests EXPECT_WRITE.
-TEST(ExpectTest, EXPECT_WRITE) {
+TEST(gtest_extra_test, expect_write) {
   EXPECT_WRITE(stdout, do_nothing(), "");
   EXPECT_WRITE(stdout, std::printf("test"), "test");
   EXPECT_WRITE(stderr, std::fprintf(stderr, "test"), "test");
@@ -201,7 +189,7 @@ TEST(ExpectTest, EXPECT_WRITE) {
                           "  Actual: that");
 }
 
-TEST(StreamingAssertionsTest, EXPECT_WRITE) {
+TEST(gtest_extra_test, expect_write_streaming) {
   EXPECT_WRITE(stdout, std::printf("test"), "test") << "unexpected failure";
   EXPECT_NONFATAL_FAILURE(EXPECT_WRITE(stdout, std::printf("test"), "other")
                               << "expected failure",
@@ -211,7 +199,7 @@ TEST(StreamingAssertionsTest, EXPECT_WRITE) {
 
 // Tests that the compiler will not complain about unreachable code in the
 // EXPECT_THROW_MSG macro.
-TEST(ExpectThrowTest, DoesNotGenerateUnreachableCodeWarning) {
+TEST(gtest_extra_test, expect_throw_no_unreachable_code_warning) {
   int n = 0;
   using std::runtime_error;
   EXPECT_THROW_MSG(throw runtime_error(""), runtime_error, "");
@@ -223,7 +211,7 @@ TEST(ExpectThrowTest, DoesNotGenerateUnreachableCodeWarning) {
 
 // Tests that the compiler will not complain about unreachable code in the
 // EXPECT_SYSTEM_ERROR macro.
-TEST(ExpectSystemErrorTest, DoesNotGenerateUnreachableCodeWarning) {
+TEST(gtest_extra_test, expect_system_error_no_unreachable_code_warning) {
   int n = 0;
   EXPECT_SYSTEM_ERROR(throw fmt::system_error(EDOM, "test"), EDOM, "test");
   EXPECT_NONFATAL_FAILURE(EXPECT_SYSTEM_ERROR(n++, EDOM, ""), "");
@@ -233,7 +221,7 @@ TEST(ExpectSystemErrorTest, DoesNotGenerateUnreachableCodeWarning) {
       "");
 }
 
-TEST(AssertionSyntaxTest, ExceptionAssertionBehavesLikeSingleStatement) {
+TEST(gtest_extra_test, expect_throw_behaves_like_single_statement) {
   if (::testing::internal::AlwaysFalse())
     EXPECT_THROW_MSG(do_nothing(), std::exception, "");
 
@@ -243,7 +231,7 @@ TEST(AssertionSyntaxTest, ExceptionAssertionBehavesLikeSingleStatement) {
     do_nothing();
 }
 
-TEST(AssertionSyntaxTest, SystemErrorAssertionBehavesLikeSingleStatement) {
+TEST(gtest_extra_test, expect_system_error_behaves_like_single_statement) {
   if (::testing::internal::AlwaysFalse())
     EXPECT_SYSTEM_ERROR(do_nothing(), EDOM, "");
 
@@ -253,7 +241,7 @@ TEST(AssertionSyntaxTest, SystemErrorAssertionBehavesLikeSingleStatement) {
     do_nothing();
 }
 
-TEST(AssertionSyntaxTest, WriteAssertionBehavesLikeSingleStatement) {
+TEST(gtest_extra_test, expect_write_behaves_like_single_statement) {
   if (::testing::internal::AlwaysFalse())
     EXPECT_WRITE(stdout, std::printf("x"), "x");
 
@@ -264,7 +252,7 @@ TEST(AssertionSyntaxTest, WriteAssertionBehavesLikeSingleStatement) {
 }
 
 // Tests EXPECT_THROW_MSG.
-TEST(ExpectTest, EXPECT_THROW_MSG) {
+TEST(gtest_extra_test, expect_throw_msg) {
   EXPECT_THROW_MSG(throw_exception(), std::exception, "test");
   EXPECT_NONFATAL_FAILURE(
       EXPECT_THROW_MSG(throw_exception(), std::logic_error, "test"),
@@ -282,15 +270,15 @@ TEST(ExpectTest, EXPECT_THROW_MSG) {
 }
 
 // Tests EXPECT_SYSTEM_ERROR.
-TEST(ExpectTest, EXPECT_SYSTEM_ERROR) {
+TEST(gtest_extra_test, expect_system_error) {
   EXPECT_SYSTEM_ERROR(throw_system_error(), EDOM, "test");
   EXPECT_NONFATAL_FAILURE(
       EXPECT_SYSTEM_ERROR(throw_exception(), EDOM, "test"),
       "Expected: throw_exception() throws an exception of "
-      "type fmt::system_error.\n  Actual: it throws a different type.");
+      "type std::system_error.\n  Actual: it throws a different type.");
   EXPECT_NONFATAL_FAILURE(
       EXPECT_SYSTEM_ERROR(do_nothing(), EDOM, "test"),
-      "Expected: do_nothing() throws an exception of type fmt::system_error.\n"
+      "Expected: do_nothing() throws an exception of type std::system_error.\n"
       "  Actual: it throws nothing.");
   EXPECT_NONFATAL_FAILURE(
       EXPECT_SYSTEM_ERROR(throw_system_error(), EDOM, "other"),
@@ -298,11 +286,11 @@ TEST(ExpectTest, EXPECT_SYSTEM_ERROR) {
           "throw_system_error() throws an exception with a different message.\n"
           "Expected: {}\n"
           "  Actual: {}",
-          format_system_error(EDOM, "other"),
-          format_system_error(EDOM, "test")));
+          system_error_message(EDOM, "other"),
+          system_error_message(EDOM, "test")));
 }
 
-TEST(StreamingAssertionsTest, EXPECT_THROW_MSG) {
+TEST(gtest_extra_test, expect_throw_msg_streaming) {
   EXPECT_THROW_MSG(throw_exception(), std::exception, "test")
       << "unexpected failure";
   EXPECT_NONFATAL_FAILURE(
@@ -311,7 +299,7 @@ TEST(StreamingAssertionsTest, EXPECT_THROW_MSG) {
       "expected failure");
 }
 
-TEST(StreamingAssertionsTest, EXPECT_SYSTEM_ERROR) {
+TEST(gtest_extra_test, expect_system_error_streaming) {
   EXPECT_SYSTEM_ERROR(throw_system_error(), EDOM, "test")
       << "unexpected failure";
   EXPECT_NONFATAL_FAILURE(
@@ -320,31 +308,19 @@ TEST(StreamingAssertionsTest, EXPECT_SYSTEM_ERROR) {
       "expected failure");
 }
 
-TEST(UtilTest, FormatSystemError) {
-  fmt::memory_buffer out;
-  fmt::format_system_error(out, EDOM, "test message");
-  EXPECT_EQ(to_string(out), format_system_error(EDOM, "test message"));
-}
-
 #if FMT_USE_FCNTL
 
 using fmt::buffered_file;
-using fmt::error_code;
 using fmt::file;
 
-TEST(ErrorCodeTest, Ctor) {
-  EXPECT_EQ(error_code().get(), 0);
-  EXPECT_EQ(error_code(42).get(), 42);
-}
-
-TEST(OutputRedirectTest, ScopedRedirect) {
+TEST(output_redirect_test, scoped_redirect) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   {
     buffered_file file(write_end.fdopen("w"));
     std::fprintf(file.get(), "[[[");
     {
-      OutputRedirect redir(file.get());
+      output_redirect redir(file.get());
       std::fprintf(file.get(), "censored");
     }
     std::fprintf(file.get(), "]]]");
@@ -352,8 +328,8 @@ TEST(OutputRedirectTest, ScopedRedirect) {
   EXPECT_READ(read_end, "[[[]]]");
 }
 
-// Test that OutputRedirect handles errors in flush correctly.
-TEST(OutputRedirectTest, FlushErrorInCtor) {
+// Test that output_redirect handles errors in flush correctly.
+TEST(output_redirect_test, flush_error_in_ctor) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   int write_fd = write_end.descriptor();
@@ -362,47 +338,47 @@ TEST(OutputRedirectTest, FlushErrorInCtor) {
   // Put a character in a file buffer.
   EXPECT_EQ('x', fputc('x', f.get()));
   FMT_POSIX(close(write_fd));
-  std::unique_ptr<OutputRedirect> redir{nullptr};
-  EXPECT_SYSTEM_ERROR_NOASSERT(redir.reset(new OutputRedirect(f.get())), EBADF,
+  std::unique_ptr<output_redirect> redir{nullptr};
+  EXPECT_SYSTEM_ERROR_NOASSERT(redir.reset(new output_redirect(f.get())), EBADF,
                                "cannot flush stream");
   redir.reset(nullptr);
   write_copy.dup2(write_fd);  // "undo" close or dtor will fail
 }
 
-TEST(OutputRedirectTest, DupErrorInCtor) {
+TEST(output_redirect_test, dup_error_in_ctor) {
   buffered_file f = open_buffered_file();
   int fd = (f.fileno)();
   file copy = file::dup(fd);
   FMT_POSIX(close(fd));
-  std::unique_ptr<OutputRedirect> redir{nullptr};
+  std::unique_ptr<output_redirect> redir{nullptr};
   EXPECT_SYSTEM_ERROR_NOASSERT(
-      redir.reset(new OutputRedirect(f.get())), EBADF,
+      redir.reset(new output_redirect(f.get())), EBADF,
       fmt::format("cannot duplicate file descriptor {}", fd));
   copy.dup2(fd);  // "undo" close or dtor will fail
 }
 
-TEST(OutputRedirectTest, RestoreAndRead) {
+TEST(output_redirect_test, restore_and_read) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   buffered_file file(write_end.fdopen("w"));
   std::fprintf(file.get(), "[[[");
-  OutputRedirect redir(file.get());
+  output_redirect redir(file.get());
   std::fprintf(file.get(), "censored");
-  EXPECT_EQ("censored", sanitize(redir.restore_and_read()));
-  EXPECT_EQ("", sanitize(redir.restore_and_read()));
+  EXPECT_EQ("censored", redir.restore_and_read());
+  EXPECT_EQ("", redir.restore_and_read());
   std::fprintf(file.get(), "]]]");
   file = buffered_file();
   EXPECT_READ(read_end, "[[[]]]");
 }
 
 // Test that OutputRedirect handles errors in flush correctly.
-TEST(OutputRedirectTest, FlushErrorInRestoreAndRead) {
+TEST(output_redirect_test, flush_error_in_restore_and_read) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   int write_fd = write_end.descriptor();
   file write_copy = write_end.dup(write_fd);
   buffered_file f = write_end.fdopen("w");
-  OutputRedirect redir(f.get());
+  output_redirect redir(f.get());
   // Put a character in a file buffer.
   EXPECT_EQ('x', fputc('x', f.get()));
   FMT_POSIX(close(write_fd));
@@ -411,13 +387,13 @@ TEST(OutputRedirectTest, FlushErrorInRestoreAndRead) {
   write_copy.dup2(write_fd);  // "undo" close or dtor will fail
 }
 
-TEST(OutputRedirectTest, ErrorInDtor) {
+TEST(output_redirect_test, error_in_dtor) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   int write_fd = write_end.descriptor();
   file write_copy = write_end.dup(write_fd);
   buffered_file f = write_end.fdopen("w");
-  std::unique_ptr<OutputRedirect> redir(new OutputRedirect(f.get()));
+  std::unique_ptr<output_redirect> redir(new output_redirect(f.get()));
   // Put a character in a file buffer.
   EXPECT_EQ('x', fputc('x', f.get()));
   EXPECT_WRITE(
@@ -430,10 +406,8 @@ TEST(OutputRedirectTest, ErrorInDtor) {
         FMT_POSIX(close(write_fd));
         SUPPRESS_ASSERT(redir.reset(nullptr));
       },
-      format_system_error(EBADF, "cannot flush stream"));
+      system_error_message(EBADF, "cannot flush stream"));
   write_copy.dup2(write_fd);  // "undo" close or dtor of buffered_file will fail
 }
 
-#endif  // FMT_USE_FILE_DESCRIPTORS
-
-}  // namespace
+#endif  // FMT_USE_FCNTL

test/gtest-extra.cc

@@ -11,24 +11,7 @@
 
 using fmt::file;
 
-void OutputRedirect::flush() {
-#  if EOF != -1
-#    error "FMT_RETRY assumes return value of -1 indicating failure"
-#  endif
-  int result = 0;
-  FMT_RETRY(result, fflush(file_));
-  if (result != 0) throw fmt::system_error(errno, "cannot flush stream");
-}
-
-void OutputRedirect::restore() {
-  if (original_.descriptor() == -1) return;  // Already restored.
-  flush();
-  // Restore the original file.
-  original_.dup2(FMT_POSIX(fileno(file_)));
-  original_.close();
-}
-
-OutputRedirect::OutputRedirect(FILE* f) : file_(f) {
+output_redirect::output_redirect(FILE* f) : file_(f) {
   flush();
   int fd = FMT_POSIX(fileno(f));
   // Create a file object referring to the original file.
@@ -40,7 +23,7 @@ OutputRedirect::OutputRedirect(FILE* f) : file_(f) {
   write_end.dup2(fd);
 }
 
-OutputRedirect::~OutputRedirect() FMT_NOEXCEPT {
+output_redirect::~output_redirect() FMT_NOEXCEPT {
   try {
     restore();
   } catch (const std::exception& e) {
@@ -48,7 +31,24 @@ OutputRedirect::~OutputRedirect() FMT_NOEXCEPT {
   }
 }
 
-std::string OutputRedirect::restore_and_read() {
+void output_redirect::flush() {
+#  if EOF != -1
+#    error "FMT_RETRY assumes return value of -1 indicating failure"
+#  endif
+  int result = 0;
+  FMT_RETRY(result, fflush(file_));
+  if (result != 0) throw fmt::system_error(errno, "cannot flush stream");
+}
+
+void output_redirect::restore() {
+  if (original_.descriptor() == -1) return;  // Already restored.
+  flush();
+  // Restore the original file.
+  original_.dup2(FMT_POSIX(fileno(file_)));
+  original_.close();
+}
+
+std::string output_redirect::restore_and_read() {
   // Restore output.
   restore();
 
@@ -79,9 +79,3 @@ std::string read(file& f, size_t count) {
 }
 
 #endif  // FMT_USE_FCNTL
-
-std::string format_system_error(int error_code, fmt::string_view message) {
-  fmt::memory_buffer out;
-  format_system_error(out, error_code, message);
-  return to_string(out);
-}

test/gtest-extra.h

@@ -8,10 +8,12 @@
 #ifndef FMT_GTEST_EXTRA_H_
 #define FMT_GTEST_EXTRA_H_
 
+#include <stdlib.h>  // _invalid_parameter_handler
+
 #include <string>
 
 #include "fmt/os.h"
-#include "gmock.h"
+#include "gmock/gmock.h"
 
 #define FMT_TEST_THROW_(statement, expected_exception, expected_message, fail) \
   GTEST_AMBIGUOUS_ELSE_BLOCKER_                                                \
@@ -51,30 +53,35 @@
   FMT_TEST_THROW_(statement, expected_exception, expected_message,        \
                   GTEST_NONFATAL_FAILURE_)
 
-std::string format_system_error(int error_code, fmt::string_view message);
+inline std::string system_error_message(int error_code,
+                                        const std::string& message) {
+  auto ec = std::error_code(error_code, std::generic_category());
+  return std::system_error(ec, message).what();
+}
 
 #define EXPECT_SYSTEM_ERROR(statement, error_code, message) \
-  EXPECT_THROW_MSG(statement, fmt::system_error,            \
-                   format_system_error(error_code, message))
+  EXPECT_THROW_MSG(statement, std::system_error,            \
+                   system_error_message(error_code, message))
 
 #if FMT_USE_FCNTL
 
 // Captures file output by redirecting it to a pipe.
 // The output it can handle is limited by the pipe capacity.
-class OutputRedirect {
+class output_redirect {
  private:
   FILE* file_;
   fmt::file original_;  // Original file passed to redirector.
   fmt::file read_end_;  // Read end of the pipe where the output is redirected.
 
-  GTEST_DISALLOW_COPY_AND_ASSIGN_(OutputRedirect);
-
   void flush();
   void restore();
 
  public:
-  explicit OutputRedirect(FILE* file);
-  ~OutputRedirect() FMT_NOEXCEPT;
+  explicit output_redirect(FILE* file);
+  ~output_redirect() FMT_NOEXCEPT;
+
+  output_redirect(const output_redirect&) = delete;
+  void operator=(const output_redirect&) = delete;
 
   // Restores the original file, reads output from the pipe into a string
   // and returns it.
@@ -85,7 +92,7 @@ class OutputRedirect {
     GTEST_AMBIGUOUS_ELSE_BLOCKER_                                              \
     if (::testing::AssertionResult gtest_ar = ::testing::AssertionSuccess()) { \
       std::string gtest_expected_output = expected_output;                     \
-      OutputRedirect gtest_redir(file);                                        \
+      output_redirect gtest_redir(file);                                       \
       GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_(statement);               \
       std::string gtest_output = gtest_redir.restore_and_read();               \
       if (gtest_output != gtest_expected_output) {                             \
@@ -106,7 +113,7 @@ class OutputRedirect {
 
 // Suppresses Windows assertions on invalid file descriptors, making
 // POSIX functions return proper error codes instead of crashing on Windows.
-class SuppressAssert {
+class suppress_assert {
  private:
   _invalid_parameter_handler original_handler_;
   int original_report_mode_;
@@ -115,11 +122,11 @@ class SuppressAssert {
                                        const wchar_t*, unsigned, uintptr_t) {}
 
  public:
-  SuppressAssert()
+  suppress_assert()
       : original_handler_(
             _set_invalid_parameter_handler(handle_invalid_parameter)),
         original_report_mode_(_CrtSetReportMode(_CRT_ASSERT, 0)) {}
-  ~SuppressAssert() {
+  ~suppress_assert() {
     _set_invalid_parameter_handler(original_handler_);
     _CrtSetReportMode(_CRT_ASSERT, original_report_mode_);
   }
@@ -127,7 +134,7 @@ class SuppressAssert {
 
 #    define SUPPRESS_ASSERT(statement) \
       {                                \
-        SuppressAssert sa;             \
+        suppress_assert sa;            \
         statement;                     \
       }
 #  else
@@ -141,7 +148,7 @@ class SuppressAssert {
 std::string read(fmt::file& f, size_t count);
 
 #  define EXPECT_READ(file, expected_content) \
-    EXPECT_EQ(expected_content, \
+    EXPECT_EQ(expected_content,               \
               read(file, fmt::string_view(expected_content).size()))
 
 #else
@@ -154,9 +161,4 @@ std::string read(fmt::file& f, size_t count);
     } while (false)
 #endif  // FMT_USE_FCNTL
 
-template <typename Mock> struct ScopedMock : testing::StrictMock<Mock> {
-  ScopedMock() { Mock::instance = this; }
-  ~ScopedMock() { Mock::instance = nullptr; }
-};
-
 #endif  // FMT_GTEST_EXTRA_H_

test/gtest/.clang-format

@@ -0,0 +1,3 @@
+# Disable clang-format here
+DisableFormat: true
+SortIncludes: Never

test/gtest/CMakeLists.txt

@@ -0,0 +1,31 @@
+#------------------------------------------------------------------------------
+# Build the google test library
+
+# We compile Google Test ourselves instead of using pre-compiled libraries.
+# See the Google Test FAQ "Why is it not recommended to install a
+# pre-compiled copy of Google Test (for example, into /usr/local)?"
+# at http://code.google.com/p/googletest/wiki/FAQ for more details.
+add_library(gtest STATIC
+  gmock-gtest-all.cc gmock/gmock.h gtest/gtest.h gtest/gtest-spi.h)
+target_compile_definitions(gtest PUBLIC GTEST_HAS_STD_WSTRING=1)
+target_include_directories(gtest SYSTEM PUBLIC .)
+
+find_package(Threads)
+if (Threads_FOUND)
+  target_link_libraries(gtest ${CMAKE_THREAD_LIBS_INIT})
+else ()
+  target_compile_definitions(gtest PUBLIC GTEST_HAS_PTHREAD=0)
+endif ()
+
+if (MSVC)
+  # Disable MSVC warnings of _CRT_INSECURE_DEPRECATE functions.
+  target_compile_definitions(gtest PRIVATE _CRT_SECURE_NO_WARNINGS)
+  if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
+    # Disable MSVC warnings of POSIX functions.
+    target_compile_options(gtest PUBLIC -Wno-deprecated-declarations)
+  endif ()
+endif ()
+
+# Silence MSVC tr1 deprecation warning in gmock.
+target_compile_definitions(gtest
+  PUBLIC _SILENCE_TR1_NAMESPACE_DEPRECATION_WARNING=1)

test/gtest/gtest/gtest-spi.h

@@ -26,17 +26,21 @@
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
-//
-// Author: wan@google.com (Zhanyong Wan)
+
 //
 // Utilities for testing Google Test itself and code that uses Google Test
 // (e.g. frameworks built on top of Google Test).
 
-#ifndef GTEST_INCLUDE_GTEST_GTEST_SPI_H_
-#define GTEST_INCLUDE_GTEST_GTEST_SPI_H_
+// GOOGLETEST_CM0004 DO NOT DELETE
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_SPI_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_SPI_H_
 
 #include "gtest/gtest.h"
 
+GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
+/* class A needs to have dll-interface to be used by clients of class B */)
+
 namespace testing {
 
 // This helper class can be used to mock out Google Test failure reporting
@@ -68,14 +72,15 @@ class GTEST_API_ ScopedFakeTestPartResultReporter
                                    TestPartResultArray* result);
 
   // The d'tor restores the previous test part result reporter.
-  virtual ~ScopedFakeTestPartResultReporter();
+  ~ScopedFakeTestPartResultReporter() override;
 
   // Appends the TestPartResult object to the TestPartResultArray
   // received in the constructor.
   //
   // This method is from the TestPartResultReporterInterface
   // interface.
-  virtual void ReportTestPartResult(const TestPartResult& result);
+  void ReportTestPartResult(const TestPartResult& result) override;
+
  private:
   void Init();
 
@@ -97,13 +102,12 @@ class GTEST_API_ SingleFailureChecker {
  public:
   // The constructor remembers the arguments.
   SingleFailureChecker(const TestPartResultArray* results,
-                       TestPartResult::Type type,
-                       const string& substr);
+                       TestPartResult::Type type, const std::string& substr);
   ~SingleFailureChecker();
  private:
   const TestPartResultArray* const results_;
   const TestPartResult::Type type_;
-  const string substr_;
+  const std::string substr_;
 
   GTEST_DISALLOW_COPY_AND_ASSIGN_(SingleFailureChecker);
 };
@@ -112,6 +116,8 @@ class GTEST_API_ SingleFailureChecker {
 
 }  // namespace testing
 
+GTEST_DISABLE_MSC_WARNINGS_POP_()  //  4251
+
 // A set of macros for testing Google Test assertions or code that's expected
 // to generate Google Test fatal failures.  It verifies that the given
 // statement will cause exactly one fatal Google Test failure with 'substr'
@@ -229,4 +235,4 @@ class GTEST_API_ SingleFailureChecker {
     }\
   } while (::testing::internal::AlwaysFalse())
 
-#endif  // GTEST_INCLUDE_GTEST_GTEST_SPI_H_
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_SPI_H_

test/header-only-test.cc

@@ -1,3 +1,7 @@
 // Header-only configuration test
 
 #include "fmt/core.h"
+
+#ifndef FMT_HEADER_ONLY
+#  error "Not in the header-only mode."
+#endif

test/header-only-test2.cc

@@ -1,3 +0,0 @@
-// Additional translation unit for the header-only configuration test
-
-#include "fmt/core.h"

test/locale-test.cc

@@ -1,160 +0,0 @@
-// Formatting library for C++ - locale tests
-//
-// Copyright (c) 2012 - present, Victor Zverovich
-// All rights reserved.
-//
-// For the license information refer to format.h.
-
-#include "fmt/locale.h"
-
-#include <complex>
-
-#include "gmock.h"
-
-using fmt::detail::max_value;
-
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
-template <typename Char> struct numpunct : std::numpunct<Char> {
- protected:
-  Char do_decimal_point() const FMT_OVERRIDE { return '?'; }
-  std::string do_grouping() const FMT_OVERRIDE { return "\03"; }
-  Char do_thousands_sep() const FMT_OVERRIDE { return '~'; }
-};
-
-template <typename Char> struct no_grouping : std::numpunct<Char> {
- protected:
-  Char do_decimal_point() const FMT_OVERRIDE { return '.'; }
-  std::string do_grouping() const FMT_OVERRIDE { return ""; }
-  Char do_thousands_sep() const FMT_OVERRIDE { return ','; }
-};
-
-template <typename Char> struct special_grouping : std::numpunct<Char> {
- protected:
-  Char do_decimal_point() const FMT_OVERRIDE { return '.'; }
-  std::string do_grouping() const FMT_OVERRIDE { return "\03\02"; }
-  Char do_thousands_sep() const FMT_OVERRIDE { return ','; }
-};
-
-template <typename Char> struct small_grouping : std::numpunct<Char> {
- protected:
-  Char do_decimal_point() const FMT_OVERRIDE { return '.'; }
-  std::string do_grouping() const FMT_OVERRIDE { return "\01"; }
-  Char do_thousands_sep() const FMT_OVERRIDE { return ','; }
-};
-
-TEST(LocaleTest, DoubleDecimalPoint) {
-  std::locale loc(std::locale(), new numpunct<char>());
-  EXPECT_EQ("1?23", fmt::format(loc, "{:L}", 1.23));
-}
-
-TEST(LocaleTest, Format) {
-  std::locale loc(std::locale(), new numpunct<char>());
-  EXPECT_EQ("1234567", fmt::format(std::locale(), "{:L}", 1234567));
-  EXPECT_EQ("1~234~567", fmt::format(loc, "{:L}", 1234567));
-  EXPECT_EQ("-1~234~567", fmt::format(loc, "{:L}", -1234567));
-  EXPECT_EQ("-256", fmt::format(loc, "{:L}", -256));
-  fmt::format_arg_store<fmt::format_context, int> as{1234567};
-  EXPECT_EQ("1~234~567", fmt::vformat(loc, "{:L}", fmt::format_args(as)));
-  std::string s;
-  fmt::format_to(std::back_inserter(s), loc, "{:L}", 1234567);
-  EXPECT_EQ("1~234~567", s);
-
-  std::locale no_grouping_loc(std::locale(), new no_grouping<char>());
-  EXPECT_EQ("1234567", fmt::format(no_grouping_loc, "{:L}", 1234567));
-
-  std::locale special_grouping_loc(std::locale(), new special_grouping<char>());
-  EXPECT_EQ("1,23,45,678", fmt::format(special_grouping_loc, "{:L}", 12345678));
-  EXPECT_EQ("12,345", fmt::format(special_grouping_loc, "{:L}", 12345));
-
-  std::locale small_grouping_loc(std::locale(), new small_grouping<char>());
-  EXPECT_EQ("4,2,9,4,9,6,7,2,9,5",
-            fmt::format(small_grouping_loc, "{:L}", max_value<uint32_t>()));
-}
-
-TEST(LocaleTest, FormatDetaultAlign) {
-  std::locale special_grouping_loc(std::locale(), new special_grouping<char>());
-  EXPECT_EQ("  12,345", fmt::format(special_grouping_loc, "{:8L}", 12345));
-}
-
-TEST(LocaleTest, WFormat) {
-  std::locale loc(std::locale(), new numpunct<wchar_t>());
-  EXPECT_EQ(L"1234567", fmt::format(std::locale(), L"{:L}", 1234567));
-  EXPECT_EQ(L"1~234~567", fmt::format(loc, L"{:L}", 1234567));
-  fmt::format_arg_store<fmt::wformat_context, int> as{1234567};
-  EXPECT_EQ(L"1~234~567", fmt::vformat(loc, L"{:L}", fmt::wformat_args(as)));
-  EXPECT_EQ(L"1234567", fmt::format(std::locale("C"), L"{:L}", 1234567));
-
-  std::locale no_grouping_loc(std::locale(), new no_grouping<wchar_t>());
-  EXPECT_EQ(L"1234567", fmt::format(no_grouping_loc, L"{:L}", 1234567));
-
-  std::locale special_grouping_loc(std::locale(),
-                                   new special_grouping<wchar_t>());
-  EXPECT_EQ(L"1,23,45,678",
-            fmt::format(special_grouping_loc, L"{:L}", 12345678));
-
-  std::locale small_grouping_loc(std::locale(), new small_grouping<wchar_t>());
-  EXPECT_EQ(L"4,2,9,4,9,6,7,2,9,5",
-            fmt::format(small_grouping_loc, L"{:L}", max_value<uint32_t>()));
-}
-
-TEST(LocaleTest, DoubleFormatter) {
-  auto loc = std::locale(std::locale(), new special_grouping<char>());
-  auto f = fmt::formatter<int>();
-  auto parse_ctx = fmt::format_parse_context("L");
-  f.parse(parse_ctx);
-  char buf[10] = {};
-  fmt::basic_format_context<char*, char> format_ctx(
-      buf, {}, fmt::detail::locale_ref(loc));
-  *f.format(12345, format_ctx) = 0;
-  EXPECT_STREQ("12,345", buf);
-}
-
-FMT_BEGIN_NAMESPACE
-template <class charT> struct formatter<std::complex<double>, charT> {
- private:
-  detail::dynamic_format_specs<char> specs_;
-
- public:
-  typename basic_format_parse_context<charT>::iterator parse(
-      basic_format_parse_context<charT>& ctx) {
-    using handler_type =
-        detail::dynamic_specs_handler<basic_format_parse_context<charT>>;
-    detail::specs_checker<handler_type> handler(handler_type(specs_, ctx),
-                                                detail::type::string_type);
-    auto it = parse_format_specs(ctx.begin(), ctx.end(), handler);
-    detail::parse_float_type_spec(specs_, ctx.error_handler());
-    return it;
-  }
-
-  template <class FormatContext>
-  typename FormatContext::iterator format(const std::complex<double>& c,
-                                          FormatContext& ctx) {
-    detail::handle_dynamic_spec<detail::precision_checker>(
-        specs_.precision, specs_.precision_ref, ctx);
-    auto format_specs = std::string();
-    if (specs_.precision > 0)
-      format_specs = fmt::format(".{}", specs_.precision);
-    if (specs_.type)
-      format_specs += specs_.type;
-    auto real = fmt::format(ctx.locale().template get<std::locale>(),
-                            "{:" + format_specs + "}", c.real());
-    auto imag = fmt::format(ctx.locale().template get<std::locale>(),
-                            "{:" + format_specs + "}", c.imag());
-    auto fill_align_width = std::string();
-    if (specs_.width > 0)
-      fill_align_width = fmt::format(">{}", specs_.width);
-    return format_to(
-        ctx.out(), "{:" + fill_align_width + "}",
-        fmt::format(c.real() != 0 ? "({0}+{1}i)" : "{1}i", real, imag));
-  }
-};
-FMT_END_NAMESPACE
-
-TEST(FormatTest, Complex) {
-  std::string s = fmt::format("{}", std::complex<double>(1, 2));
-  EXPECT_EQ(s, "(1+2i)");
-  EXPECT_EQ(fmt::format("{:.2f}", std::complex<double>(1, 2)), "(1.00+2.00i)");
-  EXPECT_EQ(fmt::format("{:8}", std::complex<double>(1, 2)), "  (1+2i)");
-}
-
-#endif  // FMT_STATIC_THOUSANDS_SEPARATOR

test/mock-allocator.h

@@ -8,14 +8,18 @@
 #ifndef FMT_MOCK_ALLOCATOR_H_
 #define FMT_MOCK_ALLOCATOR_H_
 
-#include "fmt/format.h"
-#include "gmock.h"
+#include <assert.h>  // assert
+#include <stddef.h>  // size_t
+
+#include <memory>  // std::allocator_traits
+
+#include "gmock/gmock.h"
 
 template <typename T> class mock_allocator {
  public:
   mock_allocator() {}
   mock_allocator(const mock_allocator&) {}
-  typedef T value_type;
+  using value_type = T;
   MOCK_METHOD1_T(allocate, T*(size_t n));
   MOCK_METHOD2_T(deallocate, void(T* p, size_t n));
 };
@@ -30,7 +34,7 @@ template <typename Allocator> class allocator_ref {
   }
 
  public:
-  typedef typename Allocator::value_type value_type;
+  using value_type = typename Allocator::value_type;
 
   explicit allocator_ref(Allocator* alloc = nullptr) : alloc_(alloc) {}
 

test/module-test.cc

@@ -0,0 +1,565 @@
+// Formatting library for C++ - module tests
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+//
+// Copyright (c) 2021 - present, Daniela Engert
+// All Rights Reserved
+// {fmt} module.
+
+#ifdef _MSC_FULL_VER
+// hide some implementation bugs in msvc
+// that are not essential to users of the module.
+#  define FMT_HIDE_MODULE_BUGS
+#endif
+
+#include <bit>
+#include <chrono>
+#include <exception>
+#include <iterator>
+#include <locale>
+#include <memory>
+#include <ostream>
+#include <string>
+#include <string_view>
+#include <system_error>
+
+#if (__has_include(<fcntl.h>) || defined(__APPLE__) || \
+     defined(__linux__)) &&                              \
+    (!defined(WINAPI_FAMILY) || (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
+#  include <fcntl.h>
+#  define FMT_USE_FCNTL 1
+#else
+#  define FMT_USE_FCNTL 0
+#endif
+#define FMT_NOEXCEPT noexcept
+
+import fmt;
+
+// check for macros leaking from BMI
+static bool macro_leaked =
+#if defined(FMT_CORE_H_) || defined(FMT_FORMAT_H)
+    true;
+#else
+    false;
+#endif
+
+#include "gtest-extra.h"
+
+// an implicitly exported namespace must be visible [module.interface]/2.2
+TEST(module_test, namespace) {
+  using namespace fmt;
+  using namespace fmt::literals;
+  ASSERT_TRUE(true);
+}
+
+namespace detail {
+bool oops_detail_namespace_is_visible;
+}
+
+namespace fmt {
+bool namespace_detail_invisible() {
+#if defined(FMT_HIDE_MODULE_BUGS) && defined(_MSC_FULL_VER) && \
+    _MSC_FULL_VER <= 192930129
+  // bug in msvc up to 16.11-pre1:
+  // the namespace is visible even when it is neither
+  // implicitly nor explicitly exported
+  return true;
+#else
+  using namespace detail;
+  // this fails to compile if fmt::detail is visible
+  return !oops_detail_namespace_is_visible;
+#endif
+}
+}  // namespace fmt
+
+// the non-exported namespace 'detail' must be invisible [module.interface]/2
+TEST(module_test, detail_namespace) {
+  EXPECT_TRUE(fmt::namespace_detail_invisible());
+}
+
+// macros must not be imported from a *named* module  [cpp.import]/5.1
+TEST(module_test, macros) {
+#if defined(FMT_HIDE_MODULE_BUGS) && defined(_MSC_FULL_VER) && \
+    _MSC_FULL_VER <= 192930129
+  // bug in msvc up to 16.11-pre1:
+  // include-guard macros leak from BMI
+  // and even worse: they cannot be #undef-ined
+  macro_leaked = false;
+#endif
+  EXPECT_FALSE(macro_leaked);
+}
+
+// The following is less about functional testing (that's done elsewhere)
+// but rather visibility of all client-facing overloads, reachability of
+// non-exported entities, name lookup and overload resolution within
+// template instantitions.
+// Excercise all exported entities of the API at least once.
+// Instantiate as many code paths as possible.
+
+TEST(module_test, to_string) {
+  EXPECT_EQ("42", fmt::to_string(42));
+  EXPECT_EQ("42", fmt::to_string(42.0));
+
+  EXPECT_EQ(L"42", fmt::to_wstring(42));
+  EXPECT_EQ(L"42", fmt::to_wstring(42.0));
+}
+
+TEST(module_test, format) {
+  EXPECT_EQ("42", fmt::format("{:}", 42));
+  EXPECT_EQ("-42", fmt::format("{0}", -42.0));
+
+  EXPECT_EQ(L"42", fmt::format(L"{:}", 42));
+  EXPECT_EQ(L"-42", fmt::format(L"{0}", -42.0));
+}
+
+TEST(module_test, format_to) {
+  std::string s;
+  fmt::format_to(std::back_inserter(s), "{}", 42);
+  EXPECT_EQ("42", s);
+
+  char buffer[4] = {0};
+  fmt::format_to(buffer, "{}", 42);
+  EXPECT_EQ("42", std::string_view(buffer));
+
+  fmt::memory_buffer mb;
+  fmt::format_to(mb, "{}", 42);
+  EXPECT_EQ("42", std::string_view(buffer));
+
+  std::wstring w;
+  fmt::format_to(std::back_inserter(w), L"{}", 42);
+  EXPECT_EQ(L"42", w);
+
+  wchar_t wbuffer[4] = {0};
+  fmt::format_to(wbuffer, L"{}", 42);
+  EXPECT_EQ(L"42", std::wstring_view(wbuffer));
+
+  fmt::wmemory_buffer wb;
+  fmt::format_to(wb, L"{}", 42);
+  EXPECT_EQ(L"42", std::wstring_view(wbuffer));
+}
+
+TEST(module_test, formatted_size) {
+  EXPECT_EQ(2u, fmt::formatted_size("{}", 42));
+  EXPECT_EQ(2u, fmt::formatted_size(L"{}", 42));
+}
+
+TEST(module_test, format_to_n) {
+  std::string s;
+  auto result = fmt::format_to_n(std::back_inserter(s), 1, "{}", 42);
+  EXPECT_EQ(2u, result.size);
+  char buffer[4] = {0};
+  fmt::format_to_n(buffer, 3, "{}", 12345);
+
+  std::wstring w;
+  auto wresult = fmt::format_to_n(std::back_inserter(w), 1, L"{}", 42);
+  EXPECT_EQ(2u, wresult.size);
+  wchar_t wbuffer[4] = {0};
+  fmt::format_to_n(wbuffer, 3, L"{}", 12345);
+}
+
+TEST(module_test, format_args) {
+  auto no_args = fmt::format_args();
+  EXPECT_FALSE(no_args.get(1));
+
+  fmt::basic_format_args args = fmt::make_format_args(42);
+  EXPECT_TRUE(args.max_size() > 0);
+  auto arg0 = args.get(0);
+  EXPECT_TRUE(arg0);
+  decltype(arg0) arg_none;
+  EXPECT_FALSE(arg_none);
+  EXPECT_TRUE(arg0.type() != arg_none.type());
+}
+
+TEST(module_test, wformat_args) {
+  auto no_args = fmt::wformat_args();
+  EXPECT_FALSE(no_args.get(1));
+  fmt::basic_format_args args = fmt::make_wformat_args(42);
+  EXPECT_TRUE(args.get(0));
+}
+
+TEST(module_test, checked_format_args) {
+  fmt::basic_format_args args = fmt::make_args_checked<int>("{}", 42);
+  EXPECT_TRUE(args.get(0));
+  fmt::basic_format_args wargs = fmt::make_args_checked<int>(L"{}", 42);
+  EXPECT_TRUE(wargs.get(0));
+}
+
+TEST(module_test, dynamic_format_args) {
+  fmt::dynamic_format_arg_store<fmt::format_context> dyn_store;
+  dyn_store.push_back(fmt::arg("a42", 42));
+  fmt::basic_format_args args = dyn_store;
+  EXPECT_FALSE(args.get(3));
+  EXPECT_TRUE(args.get(fmt::string_view("a42")));
+
+  fmt::dynamic_format_arg_store<fmt::wformat_context> wdyn_store;
+  wdyn_store.push_back(fmt::arg(L"a42", 42));
+  fmt::basic_format_args wargs = wdyn_store;
+  EXPECT_FALSE(wargs.get(3));
+  EXPECT_TRUE(wargs.get(fmt::wstring_view(L"a42")));
+}
+
+TEST(module_test, vformat) {
+  EXPECT_EQ("42", fmt::vformat("{}", fmt::make_format_args(42)));
+  EXPECT_EQ(L"42", fmt::vformat(fmt::to_string_view(L"{}"),
+                                fmt::make_wformat_args(42)));
+}
+
+TEST(module_test, vformat_to) {
+  auto store = fmt::make_format_args(42);
+  std::string s;
+  fmt::vformat_to(std::back_inserter(s), "{}", store);
+  EXPECT_EQ("42", s);
+
+  char buffer[4] = {0};
+  fmt::vformat_to(buffer, "{:}", store);
+  EXPECT_EQ("42", std::string_view(buffer));
+
+  auto wstore = fmt::make_wformat_args(42);
+  std::wstring w;
+  fmt::vformat_to(std::back_inserter(w), L"{}", wstore);
+  EXPECT_EQ(L"42", w);
+
+  wchar_t wbuffer[4] = {0};
+  fmt::vformat_to(wbuffer, L"{:}", wstore);
+  EXPECT_EQ(L"42", std::wstring_view(wbuffer));
+}
+
+TEST(module_test, vformat_to_n) {
+  auto store = fmt::make_format_args(12345);
+  std::string s;
+  auto result = fmt::vformat_to_n(std::back_inserter(s), 1, "{}", store);
+  char buffer[4] = {0};
+  fmt::vformat_to_n(buffer, 3, "{:}", store);
+
+  auto wstore = fmt::make_wformat_args(12345);
+  std::wstring w;
+  auto wresult = fmt::vformat_to_n(std::back_inserter(w), 1,
+                                   fmt::to_string_view(L"{}"), wstore);
+  wchar_t wbuffer[4] = {0};
+  fmt::vformat_to_n(wbuffer, 3, fmt::to_string_view(L"{:}"), wstore);
+}
+
+std::string as_string(std::wstring_view text) {
+  return {reinterpret_cast<const char*>(text.data()),
+          text.size() * sizeof(text[0])};
+}
+
+TEST(module_test, print) {
+  EXPECT_WRITE(stdout, fmt::print("{}µ", 42), "42µ");
+  EXPECT_WRITE(stderr, fmt::print(stderr, "{}µ", 4.2), "4.2µ");
+  if (false) {
+    EXPECT_WRITE(stdout, fmt::print(L"{}µ", 42), as_string(L"42µ"));
+    EXPECT_WRITE(stderr, fmt::print(stderr, L"{}µ", 4.2), as_string(L"4.2µ"));
+  }
+}
+
+TEST(module_test, vprint) {
+  EXPECT_WRITE(stdout, fmt::vprint("{:}µ", fmt::make_format_args(42)), "42µ");
+  EXPECT_WRITE(stderr, fmt::vprint(stderr, "{}", fmt::make_format_args(4.2)),
+               "4.2");
+  if (false) {
+    EXPECT_WRITE(stdout, fmt::vprint(L"{:}µ", fmt::make_wformat_args(42)),
+                 as_string(L"42µ"));
+    EXPECT_WRITE(stderr, fmt::vprint(stderr, L"{}", fmt::make_wformat_args(42)),
+                 as_string(L"42"));
+  }
+}
+
+TEST(module_test, named_args) {
+  EXPECT_EQ("42", fmt::format("{answer}", fmt::arg("answer", 42)));
+  EXPECT_EQ(L"42", fmt::format(L"{answer}", fmt::arg(L"answer", 42)));
+}
+
+TEST(module_test, literals) {
+  using namespace fmt::literals;
+  EXPECT_EQ("42", fmt::format("{answer}", "answer"_a = 42));
+  EXPECT_EQ("42", "{}"_format(42));
+  EXPECT_EQ(L"42", fmt::format(L"{answer}", L"answer"_a = 42));
+  EXPECT_EQ(L"42", L"{}"_format(42));
+}
+
+TEST(module_test, locale) {
+  auto store = fmt::make_format_args(4.2);
+  const auto classic = std::locale::classic();
+  EXPECT_EQ("4.2", fmt::format(classic, "{:L}", 4.2));
+  EXPECT_EQ("4.2", fmt::vformat(classic, "{:L}", store));
+  std::string s;
+  fmt::vformat_to(std::back_inserter(s), classic, "{:L}", store);
+  EXPECT_EQ("4.2", s);
+  EXPECT_EQ("4.2", fmt::format("{:L}", 4.2));
+
+  auto wstore = fmt::make_wformat_args(4.2);
+  EXPECT_EQ(L"4.2", fmt::format(classic, L"{:L}", 4.2));
+  EXPECT_EQ(L"4.2", fmt::vformat(classic, L"{:L}", wstore));
+  std::wstring w;
+  fmt::vformat_to(std::back_inserter(w), classic, L"{:L}", wstore);
+  EXPECT_EQ(L"4.2", w);
+  EXPECT_EQ(L"4.2", fmt::format(L"{:L}", 4.2));
+}
+
+TEST(module_test, string_view) {
+  fmt::string_view nsv("fmt");
+  EXPECT_EQ("fmt", nsv);
+  EXPECT_TRUE(fmt::string_view("fmt") == nsv);
+
+  fmt::wstring_view wsv(L"fmt");
+  EXPECT_EQ(L"fmt", wsv);
+  EXPECT_TRUE(fmt::wstring_view(L"fmt") == wsv);
+}
+
+TEST(module_test, memory_buffer) {
+  fmt::basic_memory_buffer<char, fmt::inline_buffer_size> buffer;
+  fmt::format_to(buffer, "{}", "42");
+  EXPECT_EQ("42", to_string(buffer));
+  fmt::memory_buffer nbuffer(std::move(buffer));
+  EXPECT_EQ("42", to_string(nbuffer));
+  buffer = std::move(nbuffer);
+  EXPECT_EQ("42", to_string(buffer));
+  nbuffer.clear();
+  EXPECT_EQ(0u, to_string(nbuffer).size());
+
+  fmt::wmemory_buffer wbuffer;
+  EXPECT_EQ(0u, to_string(wbuffer).size());
+}
+
+TEST(module_test, is_char) {
+  EXPECT_TRUE(fmt::is_char<char>());
+  EXPECT_TRUE(fmt::is_char<wchar_t>());
+  EXPECT_TRUE(fmt::is_char<char8_t>());
+  EXPECT_TRUE(fmt::is_char<char16_t>());
+  EXPECT_TRUE(fmt::is_char<char32_t>());
+  EXPECT_FALSE(fmt::is_char<signed char>());
+}
+
+TEST(module_test, ptr) {
+  uintptr_t answer = 42;
+  auto p = std::bit_cast<int*>(answer);
+  EXPECT_EQ("0x2a", fmt::to_string(fmt::ptr(p)));
+  std::unique_ptr<int> up(p);
+  EXPECT_EQ("0x2a", fmt::to_string(fmt::ptr(up)));
+  up.release();
+  auto sp = std::make_shared<int>(0);
+  p = sp.get();
+  EXPECT_EQ(fmt::to_string(fmt::ptr(p)), fmt::to_string(fmt::ptr(sp)));
+}
+
+TEST(module_test, errors) {
+  auto store = fmt::make_format_args(42);
+  EXPECT_THROW(throw fmt::format_error("oops"), std::exception);
+  EXPECT_THROW(throw fmt::vsystem_error(0, "{}", store), std::system_error);
+  EXPECT_THROW(throw fmt::system_error(0, "{}", 42), std::system_error);
+
+  fmt::memory_buffer buffer;
+  fmt::format_system_error(buffer, 0, "oops");
+  auto oops = to_string(buffer);
+  EXPECT_TRUE(oops.size() > 0);
+  EXPECT_WRITE(stderr, fmt::report_system_error(0, "oops"), oops + '\n');
+
+#ifdef _WIN32
+  EXPECT_THROW(throw fmt::vwindows_error(0, "{}", store), std::system_error);
+  EXPECT_THROW(throw fmt::windows_error(0, "{}", 42), std::system_error);
+  output_redirect redirect(stderr);
+  fmt::report_windows_error(0, "oops");
+  EXPECT_TRUE(redirect.restore_and_read().size() > 0);
+#endif
+}
+
+TEST(module_test, error_code) {
+  EXPECT_EQ("generic:42",
+            fmt::format("{0}", std::error_code(42, std::generic_category())));
+  EXPECT_EQ("system:42",
+            fmt::format("{0}", std::error_code(42, fmt::system_category())));
+  EXPECT_EQ(L"generic:42",
+            fmt::format(L"{0}", std::error_code(42, std::generic_category())));
+}
+
+TEST(module_test, format_int) {
+  fmt::format_int sanswer(42);
+  EXPECT_EQ("42", fmt::string_view(sanswer.data(), sanswer.size()));
+  fmt::format_int uanswer(42u);
+  EXPECT_EQ("42", fmt::string_view(uanswer.data(), uanswer.size()));
+}
+
+struct test_formatter : fmt::formatter<char> {
+  bool check() { return true; }
+};
+
+struct test_dynamic_formatter : fmt::dynamic_formatter<> {
+  bool check() { return true; }
+};
+
+TEST(module_test, formatter) {
+  EXPECT_TRUE(test_formatter{}.check());
+  EXPECT_TRUE(test_dynamic_formatter{}.check());
+}
+
+TEST(module_test, join) {
+  int arr[3] = {1, 2, 3};
+  std::vector<double> vec{1.0, 2.0, 3.0};
+  std::initializer_list<int> il{1, 2, 3};
+  auto sep = fmt::to_string_view(", ");
+  EXPECT_EQ("1, 2, 3", to_string(fmt::join(arr + 0, arr + 3, sep)));
+  EXPECT_EQ("1, 2, 3", to_string(fmt::join(arr, sep)));
+  EXPECT_EQ("1, 2, 3", to_string(fmt::join(vec.begin(), vec.end(), sep)));
+  EXPECT_EQ("1, 2, 3", to_string(fmt::join(vec, sep)));
+  EXPECT_EQ("1, 2, 3", to_string(fmt::join(il, sep)));
+
+  auto wsep = fmt::to_string_view(L", ");
+  EXPECT_EQ(L"1, 2, 3", fmt::format(L"{}", fmt::join(arr + 0, arr + 3, wsep)));
+  EXPECT_EQ(L"1, 2, 3", fmt::format(L"{}", fmt::join(arr, wsep)));
+  EXPECT_EQ(L"1, 2, 3", fmt::format(L"{}", fmt::join(il, wsep)));
+}
+
+TEST(module_test, time) {
+  auto time_now = std::time(nullptr);
+  EXPECT_TRUE(fmt::localtime(time_now).tm_year > 120);
+  EXPECT_TRUE(fmt::gmtime(time_now).tm_year > 120);
+  auto chrono_now = std::chrono::system_clock::now();
+  EXPECT_TRUE(fmt::localtime(chrono_now).tm_year > 120);
+  EXPECT_TRUE(fmt::gmtime(chrono_now).tm_year > 120);
+}
+
+TEST(module_test, time_point) {
+  auto now = std::chrono::system_clock::now();
+  std::string_view past("2021-05-20 10:30:15");
+  EXPECT_TRUE(past < fmt::format("{:%Y-%m-%d %H:%M:%S}", now));
+  std::wstring_view wpast(L"2021-05-20 10:30:15");
+  EXPECT_TRUE(wpast < fmt::format(L"{:%Y-%m-%d %H:%M:%S}", now));
+}
+
+TEST(module_test, time_duration) {
+  using us = std::chrono::duration<double, std::micro>;
+  EXPECT_EQ("42s", fmt::format("{}", std::chrono::seconds{42}));
+  EXPECT_EQ("4.2µs", fmt::format("{:3.1}", us{4.234}));
+  EXPECT_EQ("4.2µs", fmt::format(std::locale::classic(), "{:L}", us{4.2}));
+
+  EXPECT_EQ(L"42s", fmt::format(L"{}", std::chrono::seconds{42}));
+  EXPECT_EQ(L"4.2µs", fmt::format(L"{:3.1}", us{4.234}));
+  EXPECT_EQ(L"4.2µs", fmt::format(std::locale::classic(), L"{:L}", us{4.2}));
+}
+
+TEST(module_test, weekday) {
+  EXPECT_EQ("Monday",
+            std::format(std::locale::classic(), "{:%A}", fmt::weekday(1)));
+}
+
+TEST(module_test, to_string_view) {
+  using fmt::to_string_view;
+  fmt::string_view nsv{to_string_view("42")};
+  EXPECT_EQ("42", nsv);
+  fmt::wstring_view wsv{to_string_view(L"42")};
+  EXPECT_EQ(L"42", wsv);
+}
+
+TEST(module_test, printf) {
+  EXPECT_WRITE(stdout, fmt::printf("%f", 42.123456), "42.123456");
+  EXPECT_WRITE(stdout, fmt::printf("%d", 42), "42");
+  if (false) {
+    EXPECT_WRITE(stdout, fmt::printf(L"%f", 42.123456),
+                 as_string(L"42.123456"));
+    EXPECT_WRITE(stdout, fmt::printf(L"%d", 42), as_string(L"42"));
+  }
+}
+
+TEST(module_test, fprintf) {
+  EXPECT_WRITE(stderr, fmt::fprintf(stderr, "%d", 42), "42");
+  std::ostringstream os;
+  fmt::fprintf(os, "%s", "bla");
+  EXPECT_EQ("bla", os.str());
+
+  EXPECT_WRITE(stderr, fmt::fprintf(stderr, L"%d", 42), as_string(L"42"));
+  std::wostringstream ws;
+  fmt::fprintf(ws, L"%s", L"bla");
+  EXPECT_EQ(L"bla", ws.str());
+}
+
+TEST(module_test, sprintf) {
+  EXPECT_EQ("42", fmt::sprintf("%d", 42));
+  EXPECT_EQ(L"42", fmt::sprintf(L"%d", 42));
+}
+
+TEST(module_test, vprintf) {
+  EXPECT_WRITE(stdout, fmt::vprintf("%d", fmt::make_printf_args(42)), "42");
+  if (false) {
+    EXPECT_WRITE(stdout, fmt::vprintf(L"%d", fmt::make_wprintf_args(42)),
+                 as_string(L"42"));
+  }
+}
+
+TEST(module_test, vfprintf) {
+  auto args = fmt::make_printf_args(42);
+  EXPECT_WRITE(stderr, fmt::vfprintf(stderr, "%d", args), "42");
+  std::ostringstream os;
+  fmt::vfprintf(os, "%d", args);
+  EXPECT_EQ("42", os.str());
+  auto wargs = fmt::make_wprintf_args(42);
+  if (false) {
+    EXPECT_WRITE(stderr, fmt::vfprintf(stderr, L"%d", wargs), as_string(L"42"));
+  }
+  std::wostringstream ws;
+  fmt::vfprintf(ws, L"%d", wargs);
+  EXPECT_EQ(L"42", ws.str());
+}
+
+TEST(module_test, vsprintf) {
+  EXPECT_EQ("42", fmt::vsprintf("%d", fmt::make_printf_args(42)));
+  EXPECT_EQ(L"42", fmt::vsprintf(L"%d", fmt::make_wprintf_args(42)));
+}
+
+TEST(module_test, color) {
+  auto fg_check = fg(fmt::rgb(255, 200, 30));
+  auto bg_check = bg(fmt::color::dark_slate_gray) | fmt::emphasis::italic;
+  auto emphasis_check = fmt::emphasis::underline | fmt::emphasis::bold;
+  EXPECT_EQ("\x1B[30m42\x1B[0m",
+            fmt::format(fg(fmt::terminal_color::black), "{}", 42));
+  EXPECT_EQ(L"\x1B[30m42\x1B[0m",
+            fmt::format(fg(fmt::terminal_color::black), L"{}", 42));
+}
+
+TEST(module_test, cstring_view) {
+  auto s = "fmt";
+  EXPECT_EQ(s, fmt::cstring_view(s).c_str());
+  auto w = L"fmt";
+  EXPECT_EQ(w, fmt::wcstring_view(w).c_str());
+}
+
+TEST(module_test, buffered_file) {
+  EXPECT_TRUE(fmt::buffered_file{}.get() == nullptr);
+}
+
+TEST(module_test, output_file) {
+  fmt::ostream out = fmt::output_file("module-test", fmt::buffer_size = 1);
+  out.close();
+}
+
+struct custom_context {
+  using char_type = char;
+  using parse_context_type = fmt::format_parse_context;
+};
+
+TEST(module_test, custom_context) {
+  fmt::basic_format_arg<custom_context> custom_arg;
+  EXPECT_TRUE(!custom_arg);
+}
+
+struct disabled_formatter {};
+
+TEST(module_test, has_formatter) {
+  EXPECT_FALSE(
+      (fmt::has_formatter<disabled_formatter, fmt::format_context>::value));
+}
+
+TEST(module_test, is_formattable) {
+  EXPECT_FALSE(fmt::is_formattable<disabled_formatter>::value);
+}
+
+TEST(module_test, compile_format_string) {
+  using namespace fmt::literals;
+  EXPECT_EQ("42", fmt::format("{0:x}"_cf, 0x42));
+  EXPECT_EQ(L"42", fmt::format(L"{:}"_cf, 42));
+  EXPECT_EQ("4.2", fmt::format("{arg:3.1f}"_cf, "arg"_a = 4.2));
+  EXPECT_EQ(L" 42", fmt::format(L"{arg:>3}"_cf, L"arg"_a = L"42"));
+}

test/os-test.cc

@@ -19,20 +19,21 @@
 #endif
 
 using fmt::buffered_file;
-using fmt::error_code;
+using testing::HasSubstr;
+using wstring_view = fmt::basic_string_view<wchar_t>;
 
 #ifdef _WIN32
 
 #  include <windows.h>
 
-TEST(UtilTest, UTF16ToUTF8) {
-  std::string s = "ёжик";
+TEST(util_test, utf16_to_utf8) {
+  auto s = std::string("ёжик");
   fmt::detail::utf16_to_utf8 u(L"\x0451\x0436\x0438\x043A");
   EXPECT_EQ(s, u.str());
   EXPECT_EQ(s.size(), u.size());
 }
 
-TEST(UtilTest, UTF16ToUTF8EmptyString) {
+TEST(util_test, utf16_to_utf8_empty_string) {
   std::string s = "";
   fmt::detail::utf16_to_utf8 u(L"");
   EXPECT_EQ(s, u.str());
@@ -45,65 +46,73 @@ void check_utf_conversion_error(
     fmt::basic_string_view<Char> str = fmt::basic_string_view<Char>(0, 1)) {
   fmt::memory_buffer out;
   fmt::detail::format_windows_error(out, ERROR_INVALID_PARAMETER, message);
-  fmt::system_error error(0, "");
+  auto error = std::system_error(std::error_code());
   try {
     (Converter)(str);
-  } catch (const fmt::system_error& e) {
+  } catch (const std::system_error& e) {
     error = e;
   }
-  EXPECT_EQ(ERROR_INVALID_PARAMETER, error.error_code());
-  EXPECT_EQ(fmt::to_string(out), error.what());
+  EXPECT_EQ(ERROR_INVALID_PARAMETER, error.code().value());
+  EXPECT_THAT(error.what(), HasSubstr(fmt::to_string(out)));
 }
 
-TEST(UtilTest, UTF16ToUTF8Error) {
+TEST(util_test, utf16_to_utf8_error) {
   check_utf_conversion_error<fmt::detail::utf16_to_utf8, wchar_t>(
       "cannot convert string from UTF-16 to UTF-8");
 }
 
-TEST(UtilTest, UTF16ToUTF8Convert) {
+TEST(util_test, utf16_to_utf8_convert) {
   fmt::detail::utf16_to_utf8 u;
-  EXPECT_EQ(ERROR_INVALID_PARAMETER, u.convert(fmt::wstring_view(0, 1)));
+  EXPECT_EQ(ERROR_INVALID_PARAMETER, u.convert(wstring_view(0, 1)));
   EXPECT_EQ(ERROR_INVALID_PARAMETER,
-            u.convert(fmt::wstring_view(L"foo", INT_MAX + 1u)));
+            u.convert(wstring_view(L"foo", INT_MAX + 1u)));
 }
 
-TEST(UtilTest, FormatWindowsError) {
+TEST(os_test, format_std_error_code) {
+  EXPECT_EQ("generic:42",
+            fmt::format(FMT_STRING("{0}"),
+                        std::error_code(42, std::generic_category())));
+  EXPECT_EQ("system:42",
+            fmt::format(FMT_STRING("{0}"),
+                        std::error_code(42, fmt::system_category())));
+  EXPECT_EQ("system:-42",
+            fmt::format(FMT_STRING("{0}"),
+                        std::error_code(-42, fmt::system_category())));
+}
+
+TEST(os_test, format_windows_error) {
   LPWSTR message = 0;
-  FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
-                     FORMAT_MESSAGE_IGNORE_INSERTS,
-                 0, ERROR_FILE_EXISTS,
-                 MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-                 reinterpret_cast<LPWSTR>(&message), 0, 0);
-  fmt::detail::utf16_to_utf8 utf8_message(message);
+  auto result = FormatMessageW(
+      FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
+          FORMAT_MESSAGE_IGNORE_INSERTS,
+      0, ERROR_FILE_EXISTS, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+      reinterpret_cast<LPWSTR>(&message), 0, 0);
+  fmt::detail::utf16_to_utf8 utf8_message(wstring_view(message, result - 2));
   LocalFree(message);
   fmt::memory_buffer actual_message;
   fmt::detail::format_windows_error(actual_message, ERROR_FILE_EXISTS, "test");
   EXPECT_EQ(fmt::format("test: {}", utf8_message.str()),
             fmt::to_string(actual_message));
   actual_message.resize(0);
-  auto max_size = fmt::detail::max_value<size_t>() / 2;
-  fmt::detail::format_windows_error(actual_message, ERROR_FILE_EXISTS,
-                                    fmt::string_view(nullptr, max_size));
-  EXPECT_EQ(fmt::format("error {}", ERROR_FILE_EXISTS),
-            fmt::to_string(actual_message));
 }
 
-TEST(UtilTest, FormatLongWindowsError) {
+TEST(os_test, format_long_windows_error) {
   LPWSTR message = 0;
   // this error code is not available on all Windows platforms and
   // Windows SDKs, so do not fail the test if the error string cannot
   // be retrieved.
-  const int provisioning_not_allowed =
-      0x80284013L /*TBS_E_PROVISIONING_NOT_ALLOWED*/;
-  if (FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
-                         FORMAT_MESSAGE_FROM_SYSTEM |
-                         FORMAT_MESSAGE_IGNORE_INSERTS,
-                     0, static_cast<DWORD>(provisioning_not_allowed),
-                     MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-                     reinterpret_cast<LPWSTR>(&message), 0, 0) == 0) {
+  int provisioning_not_allowed = 0x80284013L;  // TBS_E_PROVISIONING_NOT_ALLOWED
+  auto result = FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+                                   FORMAT_MESSAGE_FROM_SYSTEM |
+                                   FORMAT_MESSAGE_IGNORE_INSERTS,
+                               0, static_cast<DWORD>(provisioning_not_allowed),
+                               MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                               reinterpret_cast<LPWSTR>(&message), 0, 0);
+  if (result == 0) {
+    LocalFree(message);
     return;
   }
-  fmt::detail::utf16_to_utf8 utf8_message(message);
+  fmt::detail::utf16_to_utf8 utf8_message(wstring_view(message, result - 2));
   LocalFree(message);
   fmt::memory_buffer actual_message;
   fmt::detail::format_windows_error(actual_message, provisioning_not_allowed,
@@ -112,20 +121,20 @@ TEST(UtilTest, FormatLongWindowsError) {
             fmt::to_string(actual_message));
 }
 
-TEST(UtilTest, WindowsError) {
-  fmt::system_error error(0, "");
+TEST(os_test, windows_error) {
+  auto error = std::system_error(std::error_code());
   try {
     throw fmt::windows_error(ERROR_FILE_EXISTS, "test {}", "error");
-  } catch (const fmt::system_error& e) {
+  } catch (const std::system_error& e) {
     error = e;
   }
   fmt::memory_buffer message;
   fmt::detail::format_windows_error(message, ERROR_FILE_EXISTS, "test error");
-  EXPECT_EQ(to_string(message), error.what());
-  EXPECT_EQ(ERROR_FILE_EXISTS, error.error_code());
+  EXPECT_THAT(error.what(), HasSubstr(to_string(message)));
+  EXPECT_EQ(ERROR_FILE_EXISTS, error.code().value());
 }
 
-TEST(UtilTest, ReportWindowsError) {
+TEST(os_test, report_windows_error) {
   fmt::memory_buffer out;
   fmt::detail::format_windows_error(out, ERROR_FILE_EXISTS, "test error");
   out.push_back('\n');
@@ -140,30 +149,24 @@ TEST(UtilTest, ReportWindowsError) {
 
 using fmt::file;
 
-// Checks if the file is open by reading one character from it.
-static bool isopen(int fd) {
+bool isclosed(int fd) {
   char buffer;
-  return FMT_POSIX(read(fd, &buffer, 1)) == 1;
-}
-
-static bool isclosed(int fd) {
-  char buffer;
-  std::streamsize result = 0;
+  auto result = std::streamsize();
   SUPPRESS_ASSERT(result = FMT_POSIX(read(fd, &buffer, 1)));
   return result == -1 && errno == EBADF;
 }
 
 // Opens a file for reading.
-static file open_file() {
+file open_file() {
   file read_end, write_end;
   file::pipe(read_end, write_end);
-  write_end.write(FILE_CONTENT, std::strlen(FILE_CONTENT));
+  write_end.write(file_content, std::strlen(file_content));
   write_end.close();
   return read_end;
 }
 
 // Attempts to write a string to a file.
-static void write(file& f, fmt::string_view s) {
+void write(file& f, fmt::string_view s) {
   size_t num_chars_left = s.size();
   const char* ptr = s.data();
   do {
@@ -175,12 +178,12 @@ static void write(file& f, fmt::string_view s) {
   } while (num_chars_left != 0);
 }
 
-TEST(BufferedFileTest, DefaultCtor) {
-  buffered_file f;
+TEST(buffered_file_test, default_ctor) {
+  auto f = buffered_file();
   EXPECT_TRUE(f.get() == nullptr);
 }
 
-TEST(BufferedFileTest, MoveCtor) {
+TEST(buffered_file_test, move_ctor) {
   buffered_file bf = open_buffered_file();
   FILE* fp = bf.get();
   EXPECT_TRUE(fp != nullptr);
@@ -189,7 +192,7 @@ TEST(BufferedFileTest, MoveCtor) {
   EXPECT_TRUE(bf.get() == nullptr);
 }
 
-TEST(BufferedFileTest, MoveAssignment) {
+TEST(buffered_file_test, move_assignment) {
   buffered_file bf = open_buffered_file();
   FILE* fp = bf.get();
   EXPECT_TRUE(fp != nullptr);
@@ -199,7 +202,7 @@ TEST(BufferedFileTest, MoveAssignment) {
   EXPECT_TRUE(bf.get() == nullptr);
 }
 
-TEST(BufferedFileTest, MoveAssignmentClosesFile) {
+TEST(buffered_file_test, move_assignment_closes_file) {
   buffered_file bf = open_buffered_file();
   buffered_file bf2 = open_buffered_file();
   int old_fd = bf2.fileno();
@@ -207,27 +210,27 @@ TEST(BufferedFileTest, MoveAssignmentClosesFile) {
   EXPECT_TRUE(isclosed(old_fd));
 }
 
-TEST(BufferedFileTest, MoveFromTemporaryInCtor) {
+TEST(buffered_file_test, move_from_temporary_in_ctor) {
   FILE* fp = nullptr;
-  buffered_file f(open_buffered_file(&fp));
+  buffered_file f = open_buffered_file(&fp);
   EXPECT_EQ(fp, f.get());
 }
 
-TEST(BufferedFileTest, MoveFromTemporaryInAssignment) {
+TEST(buffered_file_test, move_from_temporary_in_assignment) {
   FILE* fp = nullptr;
-  buffered_file f;
+  auto f = buffered_file();
   f = open_buffered_file(&fp);
   EXPECT_EQ(fp, f.get());
 }
 
-TEST(BufferedFileTest, MoveFromTemporaryInAssignmentClosesFile) {
+TEST(buffered_file_test, move_from_temporary_in_assignment_closes_file) {
   buffered_file f = open_buffered_file();
   int old_fd = f.fileno();
   f = open_buffered_file();
   EXPECT_TRUE(isclosed(old_fd));
 }
 
-TEST(BufferedFileTest, CloseFileInDtor) {
+TEST(buffered_file_test, close_file_in_dtor) {
   int fd = 0;
   {
     buffered_file f = open_buffered_file();
@@ -236,8 +239,9 @@ TEST(BufferedFileTest, CloseFileInDtor) {
   EXPECT_TRUE(isclosed(fd));
 }
 
-TEST(BufferedFileTest, CloseErrorInDtor) {
-  std::unique_ptr<buffered_file> f(new buffered_file(open_buffered_file()));
+TEST(buffered_file_test, close_error_in_dtor) {
+  auto f =
+      std::unique_ptr<buffered_file>(new buffered_file(open_buffered_file()));
   EXPECT_WRITE(
       stderr,
       {
@@ -248,10 +252,10 @@ TEST(BufferedFileTest, CloseErrorInDtor) {
         FMT_POSIX(close(f->fileno()));
         SUPPRESS_ASSERT(f.reset(nullptr));
       },
-      format_system_error(EBADF, "cannot close file") + "\n");
+      system_error_message(EBADF, "cannot close file") + "\n");
 }
 
-TEST(BufferedFileTest, Close) {
+TEST(buffered_file_test, close) {
   buffered_file f = open_buffered_file();
   int fd = f.fileno();
   f.close();
@@ -259,49 +263,49 @@ TEST(BufferedFileTest, Close) {
   EXPECT_TRUE(isclosed(fd));
 }
 
-TEST(BufferedFileTest, CloseError) {
+TEST(buffered_file_test, close_error) {
   buffered_file f = open_buffered_file();
   FMT_POSIX(close(f.fileno()));
   EXPECT_SYSTEM_ERROR_NOASSERT(f.close(), EBADF, "cannot close file");
   EXPECT_TRUE(f.get() == nullptr);
 }
 
-TEST(BufferedFileTest, Fileno) {
-  buffered_file f;
-#  ifndef __COVERITY__
-  // fileno on a null FILE pointer either crashes or returns an error.
-  // Disable Coverity because this is intentional.
-  EXPECT_DEATH_IF_SUPPORTED(
-      {
-        try {
-          f.fileno();
-        } catch (const fmt::system_error&) {
-          std::exit(1);
-        }
-      },
-      "");
-#  endif
-  f = open_buffered_file();
+TEST(buffered_file_test, fileno) {
+  auto f = open_buffered_file();
   EXPECT_TRUE(f.fileno() != -1);
   file copy = file::dup(f.fileno());
-  EXPECT_READ(copy, FILE_CONTENT);
+  EXPECT_READ(copy, file_content);
 }
 
-TEST(OStreamTest, Move) {
+TEST(ostream_test, move) {
   fmt::ostream out = fmt::output_file("test-file");
   fmt::ostream moved(std::move(out));
   moved.print("hello");
 }
 
-TEST(OStreamTest, Print) {
+TEST(ostream_test, move_while_holding_data) {
+  {
+    fmt::ostream out = fmt::output_file("test-file");
+    out.print("Hello, ");
+    fmt::ostream moved(std::move(out));
+    moved.print("world!\n");
+  }
+  {
+    file in("test-file", file::RDONLY);
+    EXPECT_READ(in, "Hello, world!\n");
+  }
+}
+
+TEST(ostream_test, print) {
   fmt::ostream out = fmt::output_file("test-file");
-  out.print("The answer is {}.\n", 42);
+  out.print("The answer is {}.\n",
+            fmt::join(std::initializer_list<int>{42}, ", "));
   out.close();
   file in("test-file", file::RDONLY);
   EXPECT_READ(in, "The answer is 42.\n");
 }
 
-TEST(OStreamTest, BufferBoundary) {
+TEST(ostream_test, buffer_boundary) {
   auto str = std::string(4096, 'x');
   fmt::ostream out = fmt::output_file("test-file");
   out.print("{}", str);
@@ -311,33 +315,49 @@ TEST(OStreamTest, BufferBoundary) {
   EXPECT_READ(in, str + str);
 }
 
-TEST(OStreamTest, BufferSize) {
-  fmt::ostream out = fmt::output_file("test-file", fmt::buffer_size=1);
+TEST(ostream_test, buffer_size) {
+  fmt::ostream out = fmt::output_file("test-file", fmt::buffer_size = 1);
   out.print("{}", "foo");
   out.close();
   file in("test-file", file::RDONLY);
   EXPECT_READ(in, "foo");
 }
 
-TEST(FileTest, DefaultCtor) {
+TEST(ostream_test, truncate) {
+  {
+    fmt::ostream out = fmt::output_file("test-file");
+    out.print("0123456789");
+  }
+  {
+    fmt::ostream out = fmt::output_file("test-file");
+    out.print("foo");
+  }
+  file in("test-file", file::RDONLY);
+  EXPECT_EQ("foo", read(in, 4));
+}
+
+TEST(file_test, default_ctor) {
   file f;
   EXPECT_EQ(-1, f.descriptor());
 }
 
-TEST(FileTest, OpenBufferedFileInCtor) {
+TEST(file_test, open_buffered_file_in_ctor) {
   FILE* fp = safe_fopen("test-file", "w");
-  std::fputs(FILE_CONTENT, fp);
+  std::fputs(file_content, fp);
   std::fclose(fp);
   file f("test-file", file::RDONLY);
-  ASSERT_TRUE(isopen(f.descriptor()));
+  // Check if the file is open by reading one character from it.
+  char buffer;
+  bool isopen = FMT_POSIX(read(f.descriptor(), &buffer, 1)) == 1;
+  ASSERT_TRUE(isopen);
 }
 
-TEST(FileTest, OpenBufferedFileError) {
+TEST(file_test, open_buffered_file_error) {
   EXPECT_SYSTEM_ERROR(file("nonexistent", file::RDONLY), ENOENT,
                       "cannot open file nonexistent");
 }
 
-TEST(FileTest, MoveCtor) {
+TEST(file_test, move_ctor) {
   file f = open_file();
   int fd = f.descriptor();
   EXPECT_NE(-1, fd);
@@ -346,7 +366,7 @@ TEST(FileTest, MoveCtor) {
   EXPECT_EQ(-1, f.descriptor());
 }
 
-TEST(FileTest, MoveAssignment) {
+TEST(file_test, move_assignment) {
   file f = open_file();
   int fd = f.descriptor();
   EXPECT_NE(-1, fd);
@@ -356,7 +376,7 @@ TEST(FileTest, MoveAssignment) {
   EXPECT_EQ(-1, f.descriptor());
 }
 
-TEST(FileTest, MoveAssignmentClosesFile) {
+TEST(file_test, move_assignment_closes_file) {
   file f = open_file();
   file f2 = open_file();
   int old_fd = f2.descriptor();
@@ -364,34 +384,34 @@ TEST(FileTest, MoveAssignmentClosesFile) {
   EXPECT_TRUE(isclosed(old_fd));
 }
 
-static file OpenBufferedFile(int& fd) {
+file open_buffered_file(int& fd) {
   file f = open_file();
   fd = f.descriptor();
   return f;
 }
 
-TEST(FileTest, MoveFromTemporaryInCtor) {
+TEST(file_test, move_from_temporary_in_ctor) {
   int fd = 0xdead;
-  file f(OpenBufferedFile(fd));
+  file f(open_buffered_file(fd));
   EXPECT_EQ(fd, f.descriptor());
 }
 
-TEST(FileTest, MoveFromTemporaryInAssignment) {
+TEST(file_test, move_from_temporary_in_assignment) {
   int fd = 0xdead;
   file f;
-  f = OpenBufferedFile(fd);
+  f = open_buffered_file(fd);
   EXPECT_EQ(fd, f.descriptor());
 }
 
-TEST(FileTest, MoveFromTemporaryInAssignmentClosesFile) {
+TEST(file_test, move_from_temporary_in_assignment_closes_file) {
   int fd = 0xdead;
   file f = open_file();
   int old_fd = f.descriptor();
-  f = OpenBufferedFile(fd);
+  f = open_buffered_file(fd);
   EXPECT_TRUE(isclosed(old_fd));
 }
 
-TEST(FileTest, CloseFileInDtor) {
+TEST(file_test, close_file_in_dtor) {
   int fd = 0;
   {
     file f = open_file();
@@ -400,7 +420,7 @@ TEST(FileTest, CloseFileInDtor) {
   EXPECT_TRUE(isclosed(fd));
 }
 
-TEST(FileTest, CloseErrorInDtor) {
+TEST(file_test, close_error_in_dtor) {
   std::unique_ptr<file> f(new file(open_file()));
   EXPECT_WRITE(
       stderr,
@@ -412,10 +432,10 @@ TEST(FileTest, CloseErrorInDtor) {
         FMT_POSIX(close(f->descriptor()));
         SUPPRESS_ASSERT(f.reset(nullptr));
       },
-      format_system_error(EBADF, "cannot close file") + "\n");
+      system_error_message(EBADF, "cannot close file") + "\n");
 }
 
-TEST(FileTest, Close) {
+TEST(file_test, close) {
   file f = open_file();
   int fd = f.descriptor();
   f.close();
@@ -423,19 +443,19 @@ TEST(FileTest, Close) {
   EXPECT_TRUE(isclosed(fd));
 }
 
-TEST(FileTest, CloseError) {
+TEST(file_test, close_error) {
   file f = open_file();
   FMT_POSIX(close(f.descriptor()));
   EXPECT_SYSTEM_ERROR_NOASSERT(f.close(), EBADF, "cannot close file");
   EXPECT_EQ(-1, f.descriptor());
 }
 
-TEST(FileTest, Read) {
+TEST(file_test, read) {
   file f = open_file();
-  EXPECT_READ(f, FILE_CONTENT);
+  EXPECT_READ(f, file_content);
 }
 
-TEST(FileTest, ReadError) {
+TEST(file_test, read_error) {
   file f("test-file", file::WRONLY);
   char buf;
   // We intentionally read from a file opened in the write-only mode to
@@ -443,7 +463,7 @@ TEST(FileTest, ReadError) {
   EXPECT_SYSTEM_ERROR(f.read(&buf, 1), EBADF, "cannot read from file");
 }
 
-TEST(FileTest, Write) {
+TEST(file_test, write) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   write(write_end, "test");
@@ -451,61 +471,61 @@ TEST(FileTest, Write) {
   EXPECT_READ(read_end, "test");
 }
 
-TEST(FileTest, WriteError) {
+TEST(file_test, write_error) {
   file f("test-file", file::RDONLY);
   // We intentionally write to a file opened in the read-only mode to
   // cause error.
   EXPECT_SYSTEM_ERROR(f.write(" ", 1), EBADF, "cannot write to file");
 }
 
-TEST(FileTest, Dup) {
+TEST(file_test, dup) {
   file f = open_file();
   file copy = file::dup(f.descriptor());
   EXPECT_NE(f.descriptor(), copy.descriptor());
-  EXPECT_EQ(FILE_CONTENT, read(copy, std::strlen(FILE_CONTENT)));
+  EXPECT_EQ(file_content, read(copy, std::strlen(file_content)));
 }
 
 #  ifndef __COVERITY__
-TEST(FileTest, DupError) {
+TEST(file_test, dup_error) {
   int value = -1;
   EXPECT_SYSTEM_ERROR_NOASSERT(file::dup(value), EBADF,
                                "cannot duplicate file descriptor -1");
 }
 #  endif
 
-TEST(FileTest, Dup2) {
+TEST(file_test, dup2) {
   file f = open_file();
   file copy = open_file();
   f.dup2(copy.descriptor());
   EXPECT_NE(f.descriptor(), copy.descriptor());
-  EXPECT_READ(copy, FILE_CONTENT);
+  EXPECT_READ(copy, file_content);
 }
 
-TEST(FileTest, Dup2Error) {
+TEST(file_test, dup2_error) {
   file f = open_file();
   EXPECT_SYSTEM_ERROR_NOASSERT(
       f.dup2(-1), EBADF,
       fmt::format("cannot duplicate file descriptor {} to -1", f.descriptor()));
 }
 
-TEST(FileTest, Dup2NoExcept) {
+TEST(file_test, dup2_noexcept) {
   file f = open_file();
   file copy = open_file();
-  error_code ec;
+  std::error_code ec;
   f.dup2(copy.descriptor(), ec);
-  EXPECT_EQ(ec.get(), 0);
+  EXPECT_EQ(ec.value(), 0);
   EXPECT_NE(f.descriptor(), copy.descriptor());
-  EXPECT_READ(copy, FILE_CONTENT);
+  EXPECT_READ(copy, file_content);
 }
 
-TEST(FileTest, Dup2NoExceptError) {
+TEST(file_test, dup2_noexcept_error) {
   file f = open_file();
-  error_code ec;
+  std::error_code ec;
   SUPPRESS_ASSERT(f.dup2(-1, ec));
-  EXPECT_EQ(EBADF, ec.get());
+  EXPECT_EQ(EBADF, ec.value());
 }
 
-TEST(FileTest, Pipe) {
+TEST(file_test, pipe) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   EXPECT_NE(-1, read_end.descriptor());
@@ -514,7 +534,7 @@ TEST(FileTest, Pipe) {
   EXPECT_READ(read_end, "test");
 }
 
-TEST(FileTest, Fdopen) {
+TEST(file_test, fdopen) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   int read_fd = read_end.descriptor();
@@ -522,7 +542,7 @@ TEST(FileTest, Fdopen) {
 }
 
 #  ifdef FMT_LOCALE
-TEST(LocaleTest, Strtod) {
+TEST(locale_test, strtod) {
   fmt::locale loc;
   const char *start = "4.2", *ptr = start;
   EXPECT_EQ(4.2, loc.strtod(ptr));

test/ostream-test.cc

@@ -5,17 +5,17 @@
 //
 // For the license information refer to format.h.
 
-#define FMT_STRING_ALIAS 1
 #include "fmt/format.h"
 
+using fmt::runtime;
+
 struct test {};
 
 // Test that there is no issues with specializations when fmt/ostream.h is
 // included after fmt/format.h.
 namespace fmt {
 template <> struct formatter<test> : formatter<int> {
-  template <typename FormatContext>
-  typename FormatContext::iterator format(const test&, FormatContext& ctx) {
+  auto format(const test&, format_context& ctx) -> decltype(ctx.out()) {
     return formatter<int>::format(42, ctx);
   }
 };
@@ -24,19 +24,17 @@ template <> struct formatter<test> : formatter<int> {
 #include <sstream>
 
 #include "fmt/ostream.h"
-#include "gmock.h"
+#include "fmt/ranges.h"
+#include "gmock/gmock.h"
 #include "gtest-extra.h"
 #include "util.h"
 
-using fmt::format;
-using fmt::format_error;
-
-static std::ostream& operator<<(std::ostream& os, const Date& d) {
+std::ostream& operator<<(std::ostream& os, const date& d) {
   os << d.year() << '-' << d.month() << '-' << d.day();
   return os;
 }
 
-static std::wostream& operator<<(std::wostream& os, const Date& d) {
+std::wostream& operator<<(std::wostream& os, const date& d) {
   os << d.year() << L'-' << d.month() << L'-' << d.day();
   return os;
 }
@@ -44,99 +42,63 @@ static std::wostream& operator<<(std::wostream& os, const Date& d) {
 // Make sure that overloaded comma operators do no harm to is_streamable.
 struct type_with_comma_op {};
 template <typename T> void operator,(type_with_comma_op, const T&);
-template <typename T> type_with_comma_op operator<<(T&, const Date&);
+template <typename T> type_with_comma_op operator<<(T&, const date&);
 
 enum streamable_enum {};
-static std::ostream& operator<<(std::ostream& os, streamable_enum) {
-  return os << "streamable_enum";
-}
 
-static std::wostream& operator<<(std::wostream& os, streamable_enum) {
-  return os << L"streamable_enum";
+std::ostream& operator<<(std::ostream& os, streamable_enum) {
+  return os << "streamable_enum";
 }
 
 enum unstreamable_enum {};
 
-TEST(OStreamTest, Enum) {
+TEST(ostream_test, enum) {
   EXPECT_EQ("streamable_enum", fmt::format("{}", streamable_enum()));
   EXPECT_EQ("0", fmt::format("{}", unstreamable_enum()));
-  EXPECT_EQ(L"streamable_enum", fmt::format(L"{}", streamable_enum()));
-  EXPECT_EQ(L"0", fmt::format(L"{}", unstreamable_enum()));
 }
 
-struct test_arg_formatter
-    : fmt::detail::arg_formatter<fmt::format_context::iterator, char> {
-  fmt::format_parse_context parse_ctx;
-  test_arg_formatter(fmt::format_context& ctx, fmt::format_specs& s)
-      : fmt::detail::arg_formatter<fmt::format_context::iterator, char>(
-            ctx, &parse_ctx, &s),
-        parse_ctx("") {}
-};
-
-TEST(OStreamTest, CustomArg) {
-  fmt::memory_buffer buffer;
-  fmt::format_context ctx(fmt::detail::buffer_appender<char>{buffer},
-                          fmt::format_args());
-  fmt::format_specs spec;
-  test_arg_formatter af(ctx, spec);
-  fmt::visit_format_arg(
-      af, fmt::detail::make_arg<fmt::format_context>(streamable_enum()));
-  EXPECT_EQ("streamable_enum", std::string(buffer.data(), buffer.size()));
+TEST(ostream_test, format) {
+  EXPECT_EQ("a string", fmt::format("{0}", test_string("a string")));
+  EXPECT_EQ("The date is 2012-12-9",
+            fmt::format("The date is {0}", date(2012, 12, 9)));
 }
 
-TEST(OStreamTest, Format) {
-  EXPECT_EQ("a string", format("{0}", TestString("a string")));
-  std::string s = format("The date is {0}", Date(2012, 12, 9));
-  EXPECT_EQ("The date is 2012-12-9", s);
-  Date date(2012, 12, 9);
-  EXPECT_EQ(L"The date is 2012-12-9",
-            format(L"The date is {0}", Date(2012, 12, 9)));
+TEST(ostream_test, format_specs) {
+  using fmt::format_error;
+  EXPECT_EQ("def  ", fmt::format("{0:<5}", test_string("def")));
+  EXPECT_EQ("  def", fmt::format("{0:>5}", test_string("def")));
+  EXPECT_EQ(" def ", fmt::format("{0:^5}", test_string("def")));
+  EXPECT_EQ("def**", fmt::format("{0:*<5}", test_string("def")));
+  EXPECT_THROW_MSG(fmt::format(runtime("{0:+}"), test_string()), format_error,
+                   "format specifier requires numeric argument");
+  EXPECT_THROW_MSG(fmt::format(runtime("{0:-}"), test_string()), format_error,
+                   "format specifier requires numeric argument");
+  EXPECT_THROW_MSG(fmt::format(runtime("{0: }"), test_string()), format_error,
+                   "format specifier requires numeric argument");
+  EXPECT_THROW_MSG(fmt::format(runtime("{0:#}"), test_string()), format_error,
+                   "format specifier requires numeric argument");
+  EXPECT_THROW_MSG(fmt::format(runtime("{0:05}"), test_string()), format_error,
+                   "format specifier requires numeric argument");
+  EXPECT_EQ("test         ", fmt::format("{0:13}", test_string("test")));
+  EXPECT_EQ("test         ", fmt::format("{0:{1}}", test_string("test"), 13));
+  EXPECT_EQ("te", fmt::format("{0:.2}", test_string("test")));
+  EXPECT_EQ("te", fmt::format("{0:.{1}}", test_string("test"), 2));
 }
 
-TEST(OStreamTest, FormatSpecs) {
-  EXPECT_EQ("def  ", format("{0:<5}", TestString("def")));
-  EXPECT_EQ("  def", format("{0:>5}", TestString("def")));
-#if FMT_DEPRECATED_NUMERIC_ALIGN
-  EXPECT_THROW_MSG(format("{0:=5}", TestString("def")), format_error,
-                   "format specifier requires numeric argument");
-#endif
-  EXPECT_EQ(" def ", format("{0:^5}", TestString("def")));
-  EXPECT_EQ("def**", format("{0:*<5}", TestString("def")));
-  EXPECT_THROW_MSG(format("{0:+}", TestString()), format_error,
-                   "format specifier requires numeric argument");
-  EXPECT_THROW_MSG(format("{0:-}", TestString()), format_error,
-                   "format specifier requires numeric argument");
-  EXPECT_THROW_MSG(format("{0: }", TestString()), format_error,
-                   "format specifier requires numeric argument");
-  EXPECT_THROW_MSG(format("{0:#}", TestString()), format_error,
-                   "format specifier requires numeric argument");
-  EXPECT_THROW_MSG(format("{0:05}", TestString()), format_error,
-                   "format specifier requires numeric argument");
-  EXPECT_EQ("test         ", format("{0:13}", TestString("test")));
-  EXPECT_EQ("test         ", format("{0:{1}}", TestString("test"), 13));
-  EXPECT_EQ("te", format("{0:.2}", TestString("test")));
-  EXPECT_EQ("te", format("{0:.{1}}", TestString("test"), 2));
+struct empty_test {};
+std::ostream& operator<<(std::ostream& os, empty_test) { return os << ""; }
+
+TEST(ostream_test, empty_custom_output) {
+  EXPECT_EQ("", fmt::format("{}", empty_test()));
 }
 
-struct EmptyTest {};
-static std::ostream& operator<<(std::ostream& os, EmptyTest) {
-  return os << "";
-}
-
-TEST(OStreamTest, EmptyCustomOutput) {
-  EXPECT_EQ("", fmt::format("{}", EmptyTest()));
-}
-
-TEST(OStreamTest, Print) {
+TEST(ostream_test, print) {
   std::ostringstream os;
   fmt::print(os, "Don't {}!", "panic");
   EXPECT_EQ("Don't panic!", os.str());
-  std::wostringstream wos;
-  fmt::print(wos, L"Don't {}!", L"panic");
-  EXPECT_EQ(L"Don't panic!", wos.str());
 }
 
-TEST(OStreamTest, WriteToOStream) {
+TEST(ostream_test, write_to_ostream) {
   std::ostringstream os;
   fmt::memory_buffer buffer;
   const char* foo = "foo";
@@ -145,14 +107,14 @@ TEST(OStreamTest, WriteToOStream) {
   EXPECT_EQ("foo", os.str());
 }
 
-TEST(OStreamTest, WriteToOStreamMaxSize) {
-  size_t max_size = fmt::detail::max_value<size_t>();
-  std::streamsize max_streamsize = fmt::detail::max_value<std::streamsize>();
+TEST(ostream_test, write_to_ostream_max_size) {
+  auto max_size = fmt::detail::max_value<size_t>();
+  auto max_streamsize = fmt::detail::max_value<std::streamsize>();
   if (max_size <= fmt::detail::to_unsigned(max_streamsize)) return;
 
   struct test_buffer final : fmt::detail::buffer<char> {
     explicit test_buffer(size_t size)
-      : fmt::detail::buffer<char>(nullptr, size, size) {}
+        : fmt::detail::buffer<char>(nullptr, size, size) {}
     void grow(size_t) {}
   } buffer(max_size);
 
@@ -165,12 +127,13 @@ TEST(OStreamTest, WriteToOStreamMaxSize) {
   } streambuf;
 
   struct test_ostream : std::ostream {
-    explicit test_ostream(mock_streambuf& buffer) : std::ostream(&buffer) {}
+    explicit test_ostream(mock_streambuf& output_buffer)
+        : std::ostream(&output_buffer) {}
   } os(streambuf);
 
   testing::InSequence sequence;
   const char* data = nullptr;
-  typedef std::make_unsigned<std::streamsize>::type ustreamsize;
+  using ustreamsize = std::make_unsigned<std::streamsize>::type;
   ustreamsize size = max_size;
   do {
     auto n = std::min(size, fmt::detail::to_unsigned(max_streamsize));
@@ -182,68 +145,62 @@ TEST(OStreamTest, WriteToOStreamMaxSize) {
   fmt::detail::write_buffer(os, buffer);
 }
 
-TEST(OStreamTest, Join) {
+TEST(ostream_test, join) {
   int v[3] = {1, 2, 3};
   EXPECT_EQ("1, 2, 3", fmt::format("{}", fmt::join(v, v + 3, ", ")));
 }
 
+TEST(ostream_test, join_fallback_formatter) {
+  auto strs = std::vector<test_string>{test_string("foo"), test_string("bar")};
+  EXPECT_EQ("foo, bar", fmt::format("{}", fmt::join(strs, ", ")));
+}
+
 #if FMT_USE_CONSTEXPR
-TEST(OStreamTest, ConstexprString) {
+TEST(ostream_test, constexpr_string) {
   EXPECT_EQ("42", format(FMT_STRING("{}"), std::string("42")));
-  EXPECT_EQ("a string", format(FMT_STRING("{0}"), TestString("a string")));
+  EXPECT_EQ("a string", format(FMT_STRING("{0}"), test_string("a string")));
 }
 #endif
 
 namespace fmt_test {
-struct ABC {};
+struct abc {};
 
-template <typename Output> Output& operator<<(Output& out, ABC) {
-  out << "ABC";
-  return out;
+template <typename Output> Output& operator<<(Output& out, abc) {
+  return out << "abc";
 }
 }  // namespace fmt_test
 
-template <typename T> struct TestTemplate {};
+template <typename T> struct test_template {};
 
 template <typename T>
-std::ostream& operator<<(std::ostream& os, TestTemplate<T>) {
+std::ostream& operator<<(std::ostream& os, test_template<T>) {
   return os << 1;
 }
 
 namespace fmt {
-template <typename T> struct formatter<TestTemplate<T>> : formatter<int> {
-  template <typename FormatContext>
-  typename FormatContext::iterator format(TestTemplate<T>, FormatContext& ctx) {
+template <typename T> struct formatter<test_template<T>> : formatter<int> {
+  auto format(test_template<T>, format_context& ctx) -> decltype(ctx.out()) {
     return formatter<int>::format(2, ctx);
   }
 };
 }  // namespace fmt
 
-#if !FMT_GCC_VERSION || FMT_GCC_VERSION >= 407
-TEST(OStreamTest, Template) {
-  EXPECT_EQ("2", fmt::format("{}", TestTemplate<int>()));
+TEST(ostream_test, template) {
+  EXPECT_EQ("2", fmt::format("{}", test_template<int>()));
 }
 
-TEST(FormatTest, FormatToN) {
+TEST(ostream_test, format_to_n) {
   char buffer[4];
   buffer[3] = 'x';
-  auto result = fmt::format_to_n(buffer, 3, "{}", fmt_test::ABC());
+  auto result = fmt::format_to_n(buffer, 3, "{}", fmt_test::abc());
   EXPECT_EQ(3u, result.size);
   EXPECT_EQ(buffer + 3, result.out);
-  EXPECT_EQ("ABCx", fmt::string_view(buffer, 4));
-  result = fmt::format_to_n(buffer, 3, "x{}y", fmt_test::ABC());
+  EXPECT_EQ("abcx", fmt::string_view(buffer, 4));
+  result = fmt::format_to_n(buffer, 3, "x{}y", fmt_test::abc());
   EXPECT_EQ(5u, result.size);
   EXPECT_EQ(buffer + 3, result.out);
-  EXPECT_EQ("xABx", fmt::string_view(buffer, 4));
+  EXPECT_EQ("xabx", fmt::string_view(buffer, 4));
 }
-#endif
-
-#if FMT_USE_USER_DEFINED_LITERALS
-TEST(FormatTest, UDL) {
-  using namespace fmt::literals;
-  EXPECT_EQ("{}"_format("test"), "test");
-}
-#endif
 
 template <typename T> struct convertible {
   T value;
@@ -251,9 +208,8 @@ template <typename T> struct convertible {
   operator T() const { return value; }
 };
 
-TEST(OStreamTest, DisableBuiltinOStreamOperators) {
+TEST(ostream_test, disable_builtin_ostream_operators) {
   EXPECT_EQ("42", fmt::format("{:d}", convertible<unsigned short>(42)));
-  EXPECT_EQ(L"42", fmt::format(L"{:d}", convertible<unsigned short>(42)));
   EXPECT_EQ("foo", fmt::format("{}", convertible<const char*>("foo")));
 }
 
@@ -271,7 +227,7 @@ std::ostream& operator<<(std::ostream& os,
   return os << "bar";
 }
 
-TEST(OStreamTest, FormatExplicitlyConvertibleToStringLike) {
+TEST(ostream_test, format_explicitly_convertible_to_string_like) {
   EXPECT_EQ("bar", fmt::format("{}", explicitly_convertible_to_string_like()));
 }
 
@@ -287,7 +243,7 @@ std::ostream& operator<<(std::ostream& os,
   return os << "bar";
 }
 
-TEST(OStreamTest, FormatExplicitlyConvertibleToStdStringView) {
+TEST(ostream_test, format_explicitly_convertible_to_std_string_view) {
   EXPECT_EQ("bar", fmt::format("{}", explicitly_convertible_to_string_like()));
 }
 #endif  // FMT_USE_STRING_VIEW
@@ -300,7 +256,7 @@ std::ostream& operator<<(std::ostream& os, streamable_and_convertible_to_bool) {
   return os << "foo";
 }
 
-TEST(OStreamTest, FormatConvertibleToBool) {
+TEST(ostream_test, format_convertible_to_bool) {
   EXPECT_EQ("foo", fmt::format("{}", streamable_and_convertible_to_bool()));
 }
 
@@ -312,14 +268,15 @@ std::ostream& operator<<(std::ostream& os, copyfmt_test) {
   return os << "foo";
 }
 
-TEST(OStreamTest, CopyFmt) {
+TEST(ostream_test, copyfmt) {
   EXPECT_EQ("foo", fmt::format("{}", copyfmt_test()));
 }
 
-TEST(OStreamTest, CompileTimeString) {
-  EXPECT_EQ("42", fmt::format(FMT_STRING("{}"), 42));
+TEST(ostream_test, to_string) {
+  EXPECT_EQ("abc", fmt::to_string(fmt_test::abc()));
 }
 
-TEST(OStreamTest, ToString) {
-  EXPECT_EQ("ABC", fmt::to_string(fmt_test::ABC()));
+TEST(ostream_test, range) {
+  auto strs = std::vector<test_string>{test_string("foo"), test_string("bar")};
+  EXPECT_EQ("[foo, bar]", fmt::format("{}", strs));
 }

test/posix-mock-test.cc

@@ -23,20 +23,23 @@
 #ifdef _WIN32
 #  include <io.h>
 #  undef max
-#  undef ERROR
 #endif
 
-#include "gmock.h"
+#include "gmock/gmock.h"
 #include "gtest-extra.h"
 #include "util.h"
 
 using fmt::buffered_file;
-using fmt::error_code;
 
 using testing::_;
 using testing::Return;
 using testing::StrEq;
 
+template <typename Mock> struct scoped_mock : testing::StrictMock<Mock> {
+  scoped_mock() { Mock::instance = this; }
+  ~scoped_mock() { Mock::instance = nullptr; }
+};
+
 namespace {
 int open_count;
 int close_count;
@@ -53,7 +56,7 @@ size_t read_nbyte;
 size_t write_nbyte;
 bool sysconf_error;
 
-enum { NONE, MAX_SIZE, ERROR } fstat_sim;
+enum { none, max_size, error } fstat_sim;
 }  // namespace
 
 #define EMULATE_EINTR(func, error_result) \
@@ -91,7 +94,7 @@ static off_t max_file_size() { return std::numeric_limits<off_t>::max(); }
 
 int test::fstat(int fd, struct stat* buf) {
   int result = ::fstat(fd, buf);
-  if (fstat_sim == MAX_SIZE) buf->st_size = max_file_size();
+  if (fstat_sim == max_size) buf->st_size = max_file_size();
   return result;
 }
 
@@ -100,11 +103,11 @@ int test::fstat(int fd, struct stat* buf) {
 static LONGLONG max_file_size() { return std::numeric_limits<LONGLONG>::max(); }
 
 DWORD test::GetFileSize(HANDLE hFile, LPDWORD lpFileSizeHigh) {
-  if (fstat_sim == ERROR) {
+  if (fstat_sim == error) {
     SetLastError(ERROR_ACCESS_DENIED);
     return INVALID_FILE_SIZE;
   }
-  if (fstat_sim == MAX_SIZE) {
+  if (fstat_sim == max_size) {
     DWORD max = std::numeric_limits<DWORD>::max();
     *lpFileSizeHigh = max >> 1;
     return max;
@@ -194,15 +197,15 @@ int(test::fileno)(FILE* stream) {
 #  define EXPECT_EQ_POSIX(expected, actual)
 #endif
 
-static void write_file(fmt::cstring_view filename, fmt::string_view content) {
+#if FMT_USE_FCNTL
+void write_file(fmt::cstring_view filename, fmt::string_view content) {
   fmt::buffered_file f(filename, "w");
   f.print("{}", content);
 }
 
-#if FMT_USE_FCNTL
 using fmt::file;
 
-TEST(UtilTest, GetPageSize) {
+TEST(os_test, getpagesize) {
 #  ifdef _WIN32
   SYSTEM_INFO si = {};
   GetSystemInfo(&si);
@@ -216,7 +219,7 @@ TEST(UtilTest, GetPageSize) {
 #  endif
 }
 
-TEST(FileTest, OpenRetry) {
+TEST(file_test, open_retry) {
   write_file("temp", "there must be something here");
   std::unique_ptr<file> f{nullptr};
   EXPECT_RETRY(f.reset(new file("temp", file::RDONLY)), open,
@@ -227,7 +230,7 @@ TEST(FileTest, OpenRetry) {
 #  endif
 }
 
-TEST(FileTest, CloseNoRetryInDtor) {
+TEST(file_test, close_no_retry_in_dtor) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   std::unique_ptr<file> f(new file(std::move(read_end)));
@@ -240,11 +243,11 @@ TEST(FileTest, CloseNoRetryInDtor) {
         saved_close_count = close_count;
         close_count = 0;
       },
-      format_system_error(EINTR, "cannot close file") + "\n");
+      system_error_message(EINTR, "cannot close file") + "\n");
   EXPECT_EQ(2, saved_close_count);
 }
 
-TEST(FileTest, CloseNoRetry) {
+TEST(file_test, close_no_retry) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   close_count = 1;
@@ -253,35 +256,39 @@ TEST(FileTest, CloseNoRetry) {
   close_count = 0;
 }
 
-TEST(FileTest, Size) {
+TEST(file_test, size) {
   std::string content = "top secret, destroy before reading";
   write_file("temp", content);
   file f("temp", file::RDONLY);
   EXPECT_GE(f.size(), 0);
   EXPECT_EQ(content.size(), static_cast<unsigned long long>(f.size()));
 #  ifdef _WIN32
-  fmt::memory_buffer message;
-  fmt::detail::format_windows_error(message, ERROR_ACCESS_DENIED,
-                                    "cannot get file size");
-  fstat_sim = ERROR;
-  EXPECT_THROW_MSG(f.size(), fmt::windows_error, fmt::to_string(message));
-  fstat_sim = NONE;
+  auto error_code = std::error_code();
+  fstat_sim = error;
+  try {
+    f.size();
+  } catch (const std::system_error& e) {
+    error_code = e.code();
+  }
+  fstat_sim = none;
+  EXPECT_EQ(error_code,
+            std::error_code(ERROR_ACCESS_DENIED, fmt::system_category()));
 #  else
   f.close();
   EXPECT_SYSTEM_ERROR(f.size(), EBADF, "cannot get file attributes");
 #  endif
 }
 
-TEST(FileTest, MaxSize) {
+TEST(file_test, max_size) {
   write_file("temp", "");
   file f("temp", file::RDONLY);
-  fstat_sim = MAX_SIZE;
+  fstat_sim = max_size;
   EXPECT_GE(f.size(), 0);
   EXPECT_EQ(max_file_size(), f.size());
-  fstat_sim = NONE;
+  fstat_sim = none;
 }
 
-TEST(FileTest, ReadRetry) {
+TEST(file_test, read_retry) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   enum { SIZE = 4 };
@@ -294,7 +301,7 @@ TEST(FileTest, ReadRetry) {
   EXPECT_EQ_POSIX(static_cast<std::streamsize>(SIZE), count);
 }
 
-TEST(FileTest, WriteRetry) {
+TEST(file_test, write_retry) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   enum { SIZE = 4 };
@@ -312,7 +319,7 @@ TEST(FileTest, WriteRetry) {
 }
 
 #  ifdef _WIN32
-TEST(FileTest, ConvertReadCount) {
+TEST(file_test, convert_read_count) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   char c;
@@ -320,12 +327,12 @@ TEST(FileTest, ConvertReadCount) {
   if (sizeof(unsigned) != sizeof(size_t)) ++size;
   read_count = 1;
   read_nbyte = 0;
-  EXPECT_THROW(read_end.read(&c, size), fmt::system_error);
+  EXPECT_THROW(read_end.read(&c, size), std::system_error);
   read_count = 0;
   EXPECT_EQ(UINT_MAX, read_nbyte);
 }
 
-TEST(FileTest, ConvertWriteCount) {
+TEST(file_test, convert_write_count) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   char c;
@@ -333,13 +340,13 @@ TEST(FileTest, ConvertWriteCount) {
   if (sizeof(unsigned) != sizeof(size_t)) ++size;
   write_count = 1;
   write_nbyte = 0;
-  EXPECT_THROW(write_end.write(&c, size), fmt::system_error);
+  EXPECT_THROW(write_end.write(&c, size), std::system_error);
   write_count = 0;
   EXPECT_EQ(UINT_MAX, write_nbyte);
 }
 #  endif
 
-TEST(FileTest, DupNoRetry) {
+TEST(file_test, dup_no_retry) {
   int stdout_fd = FMT_POSIX(fileno(stdout));
   dup_count = 1;
   EXPECT_SYSTEM_ERROR(
@@ -348,7 +355,7 @@ TEST(FileTest, DupNoRetry) {
   dup_count = 0;
 }
 
-TEST(FileTest, Dup2Retry) {
+TEST(file_test, dup2_retry) {
   int stdout_fd = FMT_POSIX(fileno(stdout));
   file f1 = file::dup(stdout_fd), f2 = file::dup(stdout_fd);
   EXPECT_RETRY(f1.dup2(f2.descriptor()), dup2,
@@ -356,21 +363,21 @@ TEST(FileTest, Dup2Retry) {
                            f1.descriptor(), f2.descriptor()));
 }
 
-TEST(FileTest, Dup2NoExceptRetry) {
+TEST(file_test, dup2_no_except_retry) {
   int stdout_fd = FMT_POSIX(fileno(stdout));
   file f1 = file::dup(stdout_fd), f2 = file::dup(stdout_fd);
-  error_code ec;
+  std::error_code ec;
   dup2_count = 1;
   f1.dup2(f2.descriptor(), ec);
 #  ifndef _WIN32
   EXPECT_EQ(4, dup2_count);
 #  else
-  EXPECT_EQ(EINTR, ec.get());
+  EXPECT_EQ(EINTR, ec.value());
 #  endif
   dup2_count = 0;
 }
 
-TEST(FileTest, PipeNoRetry) {
+TEST(file_test, pipe_no_retry) {
   file read_end, write_end;
   pipe_count = 1;
   EXPECT_SYSTEM_ERROR(file::pipe(read_end, write_end), EINTR,
@@ -378,7 +385,7 @@ TEST(FileTest, PipeNoRetry) {
   pipe_count = 0;
 }
 
-TEST(FileTest, FdopenNoRetry) {
+TEST(file_test, fdopen_no_retry) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   fdopen_count = 1;
@@ -387,7 +394,7 @@ TEST(FileTest, FdopenNoRetry) {
   fdopen_count = 0;
 }
 
-TEST(BufferedFileTest, OpenRetry) {
+TEST(buffered_file_test, open_retry) {
   write_file("temp", "there must be something here");
   std::unique_ptr<buffered_file> f{nullptr};
   EXPECT_RETRY(f.reset(new buffered_file("temp", "r")), fopen,
@@ -399,7 +406,7 @@ TEST(BufferedFileTest, OpenRetry) {
 #  endif
 }
 
-TEST(BufferedFileTest, CloseNoRetryInDtor) {
+TEST(buffered_file_test, close_no_retry_in_dtor) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   std::unique_ptr<buffered_file> f(new buffered_file(read_end.fdopen("r")));
@@ -412,11 +419,11 @@ TEST(BufferedFileTest, CloseNoRetryInDtor) {
         saved_fclose_count = fclose_count;
         fclose_count = 0;
       },
-      format_system_error(EINTR, "cannot close file") + "\n");
+      system_error_message(EINTR, "cannot close file") + "\n");
   EXPECT_EQ(2, saved_fclose_count);
 }
 
-TEST(BufferedFileTest, CloseNoRetry) {
+TEST(buffered_file_test, close_no_retry) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   buffered_file f = read_end.fdopen("r");
@@ -426,7 +433,7 @@ TEST(BufferedFileTest, CloseNoRetry) {
   fclose_count = 0;
 }
 
-TEST(BufferedFileTest, FilenoNoRetry) {
+TEST(buffered_file_test, fileno_no_retry) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
   buffered_file f = read_end.fdopen("r");
@@ -441,9 +448,9 @@ struct test_mock {
   static test_mock* instance;
 } * test_mock::instance;
 
-TEST(ScopedMock, Scope) {
+TEST(scoped_mock, scope) {
   {
-    ScopedMock<test_mock> mock;
+    scoped_mock<test_mock> mock;
     EXPECT_EQ(&mock, test_mock::instance);
     test_mock& copy = mock;
     static_cast<void>(copy);
@@ -453,7 +460,7 @@ TEST(ScopedMock, Scope) {
 
 #ifdef FMT_LOCALE
 
-typedef fmt::locale::type locale_type;
+using locale_type = fmt::locale::type;
 
 struct locale_mock {
   static locale_mock* instance;
@@ -490,7 +497,8 @@ double _strtod_l(const char* nptr, char** endptr, _locale_t locale) {
 #    pragma warning(pop)
 #  endif
 
-#  if defined(__THROW) && FMT_GCC_VERSION > 0 && FMT_GCC_VERSION <= 408
+#  if defined(__THROW) && \
+      ((FMT_GCC_VERSION > 0 && FMT_GCC_VERSION <= 408) || defined(__e2k__))
 #    define FMT_LOCALE_THROW __THROW
 #  else
 #    define FMT_LOCALE_THROW
@@ -520,20 +528,20 @@ locale_t test::newlocale(int category_mask, const char* locale, locale_t base) {
   return locale_mock::instance->newlocale(category_mask, locale, base);
 }
 
-TEST(LocaleTest, LocaleMock) {
-  ScopedMock<locale_mock> mock;
-  locale_type locale = reinterpret_cast<locale_type>(11);
+TEST(locale_test, locale_mock) {
+  scoped_mock<locale_mock> mock;
+  auto locale = reinterpret_cast<locale_type>(11);
   EXPECT_CALL(mock, newlocale(222, StrEq("foo"), locale));
   FMT_SYSTEM(newlocale(222, "foo", locale));
 }
 #  endif
 
-TEST(LocaleTest, Locale) {
+TEST(locale_test, locale) {
 #  ifndef LC_NUMERIC_MASK
   enum { LC_NUMERIC_MASK = LC_NUMERIC };
 #  endif
-  ScopedMock<locale_mock> mock;
-  locale_type impl = reinterpret_cast<locale_type>(42);
+  scoped_mock<locale_mock> mock;
+  auto impl = reinterpret_cast<locale_type>(42);
   EXPECT_CALL(mock, newlocale(LC_NUMERIC_MASK, StrEq("C"), nullptr))
       .WillOnce(Return(impl));
   EXPECT_CALL(mock, freelocale(impl));
@@ -541,8 +549,8 @@ TEST(LocaleTest, Locale) {
   EXPECT_EQ(impl, loc.get());
 }
 
-TEST(LocaleTest, Strtod) {
-  ScopedMock<locale_mock> mock;
+TEST(locale_test, strtod) {
+  scoped_mock<locale_mock> mock;
   EXPECT_CALL(mock, newlocale(_, _, _))
       .WillOnce(Return(reinterpret_cast<locale_type>(42)));
   EXPECT_CALL(mock, freelocale(_));

test/printf-test.cc

@@ -11,7 +11,8 @@
 #include <climits>
 #include <cstring>
 
-#include "fmt/core.h"
+#include "fmt/ostream.h"
+#include "fmt/xchar.h"
 #include "gtest-extra.h"
 #include "util.h"
 
@@ -19,7 +20,7 @@ using fmt::format;
 using fmt::format_error;
 using fmt::detail::max_value;
 
-const unsigned BIG_NUM = INT_MAX + 1u;
+const unsigned big_num = INT_MAX + 1u;
 
 // Makes format string argument positional.
 static std::string make_positional(fmt::string_view format) {
@@ -28,7 +29,7 @@ static std::string make_positional(fmt::string_view format) {
   return s;
 }
 
-static std::wstring make_positional(fmt::wstring_view format) {
+static std::wstring make_positional(fmt::basic_string_view<wchar_t> format) {
   std::wstring s(format.data(), format.size());
   s.replace(s.find(L'%'), 1, L"%1$");
   return s;
@@ -41,7 +42,8 @@ std::string test_sprintf(fmt::string_view format, const Args&... args) {
   return fmt::sprintf(format, args...);
 }
 template <typename... Args>
-std::wstring test_sprintf(fmt::wstring_view format, const Args&... args) {
+std::wstring test_sprintf(fmt::basic_string_view<wchar_t> format,
+                          const Args&... args) {
   return fmt::sprintf(format, args...);
 }
 
@@ -50,12 +52,12 @@ std::wstring test_sprintf(fmt::wstring_view format, const Args&... args) {
       << "format: " << format;                          \
   EXPECT_EQ(expected_output, fmt::sprintf(make_positional(format), arg))
 
-TEST(PrintfTest, NoArgs) {
+TEST(printf_test, no_args) {
   EXPECT_EQ("test", test_sprintf("test"));
   EXPECT_EQ(L"test", fmt::sprintf(L"test"));
 }
 
-TEST(PrintfTest, Escape) {
+TEST(printf_test, escape) {
   EXPECT_EQ("%", test_sprintf("%%"));
   EXPECT_EQ("before %", test_sprintf("before %%"));
   EXPECT_EQ("% after", test_sprintf("%% after"));
@@ -68,7 +70,7 @@ TEST(PrintfTest, Escape) {
   EXPECT_EQ(L"%s", fmt::sprintf(L"%%s"));
 }
 
-TEST(PrintfTest, PositionalArgs) {
+TEST(printf_test, positional_args) {
   EXPECT_EQ("42", test_sprintf("%1$d", 42));
   EXPECT_EQ("before 42", test_sprintf("before %1$d", 42));
   EXPECT_EQ("42 after", test_sprintf("%1$d after", 42));
@@ -78,40 +80,40 @@ TEST(PrintfTest, PositionalArgs) {
   EXPECT_EQ("abracadabra", test_sprintf("%1$s%2$s%1$s", "abra", "cad"));
 }
 
-TEST(PrintfTest, AutomaticArgIndexing) {
+TEST(printf_test, automatic_arg_indexing) {
   EXPECT_EQ("abc", test_sprintf("%c%c%c", 'a', 'b', 'c'));
 }
 
-TEST(PrintfTest, NumberIsTooBigInArgIndex) {
-  EXPECT_THROW_MSG(test_sprintf(format("%{}$", BIG_NUM)), format_error,
-                   "number is too big");
-  EXPECT_THROW_MSG(test_sprintf(format("%{}$d", BIG_NUM)), format_error,
-                   "number is too big");
+TEST(printf_test, number_is_too_big_in_arg_index) {
+  EXPECT_THROW_MSG(test_sprintf(format("%{}$", big_num)), format_error,
+                   "argument not found");
+  EXPECT_THROW_MSG(test_sprintf(format("%{}$d", big_num)), format_error,
+                   "argument not found");
 }
 
-TEST(PrintfTest, SwitchArgIndexing) {
+TEST(printf_test, switch_arg_indexing) {
   EXPECT_THROW_MSG(test_sprintf("%1$d%", 1, 2), format_error,
                    "cannot switch from manual to automatic argument indexing");
-  EXPECT_THROW_MSG(test_sprintf(format("%1$d%{}d", BIG_NUM), 1, 2),
+  EXPECT_THROW_MSG(test_sprintf(format("%1$d%{}d", big_num), 1, 2),
                    format_error, "number is too big");
   EXPECT_THROW_MSG(test_sprintf("%1$d%d", 1, 2), format_error,
                    "cannot switch from manual to automatic argument indexing");
 
   EXPECT_THROW_MSG(test_sprintf("%d%1$", 1, 2), format_error,
                    "cannot switch from automatic to manual argument indexing");
-  EXPECT_THROW_MSG(test_sprintf(format("%d%{}$d", BIG_NUM), 1, 2), format_error,
-                   "number is too big");
+  EXPECT_THROW_MSG(test_sprintf(format("%d%{}$d", big_num), 1, 2), format_error,
+                   "cannot switch from automatic to manual argument indexing");
   EXPECT_THROW_MSG(test_sprintf("%d%1$d", 1, 2), format_error,
                    "cannot switch from automatic to manual argument indexing");
 
   // Indexing errors override width errors.
-  EXPECT_THROW_MSG(test_sprintf(format("%d%1${}d", BIG_NUM), 1, 2),
+  EXPECT_THROW_MSG(test_sprintf(format("%d%1${}d", big_num), 1, 2),
                    format_error, "number is too big");
-  EXPECT_THROW_MSG(test_sprintf(format("%1$d%{}d", BIG_NUM), 1, 2),
+  EXPECT_THROW_MSG(test_sprintf(format("%1$d%{}d", big_num), 1, 2),
                    format_error, "number is too big");
 }
 
-TEST(PrintfTest, InvalidArgIndex) {
+TEST(printf_test, invalid_arg_index) {
   EXPECT_THROW_MSG(test_sprintf("%0$d", 42), format_error,
                    "argument not found");
   EXPECT_THROW_MSG(test_sprintf("%2$d", 42), format_error,
@@ -120,16 +122,16 @@ TEST(PrintfTest, InvalidArgIndex) {
                    "argument not found");
 
   EXPECT_THROW_MSG(test_sprintf("%2$", 42), format_error, "argument not found");
-  EXPECT_THROW_MSG(test_sprintf(format("%{}$d", BIG_NUM), 42), format_error,
-                   "number is too big");
+  EXPECT_THROW_MSG(test_sprintf(format("%{}$d", big_num), 42), format_error,
+                   "argument not found");
 }
 
-TEST(PrintfTest, DefaultAlignRight) {
+TEST(printf_test, default_align_right) {
   EXPECT_PRINTF("   42", "%5d", 42);
   EXPECT_PRINTF("  abc", "%5s", "abc");
 }
 
-TEST(PrintfTest, ZeroFlag) {
+TEST(printf_test, zero_flag) {
   EXPECT_PRINTF("00042", "%05d", 42);
   EXPECT_PRINTF("-0042", "%05d", -42);
 
@@ -146,7 +148,7 @@ TEST(PrintfTest, ZeroFlag) {
   EXPECT_PRINTF("    x", "%05c", 'x');
 }
 
-TEST(PrintfTest, PlusFlag) {
+TEST(printf_test, plus_flag) {
   EXPECT_PRINTF("+42", "%+d", 42);
   EXPECT_PRINTF("-42", "%+d", -42);
   EXPECT_PRINTF("+0042", "%+05d", 42);
@@ -168,7 +170,7 @@ TEST(PrintfTest, PlusFlag) {
   EXPECT_PRINTF("x", "% +c", 'x');
 }
 
-TEST(PrintfTest, MinusFlag) {
+TEST(printf_test, minus_flag) {
   EXPECT_PRINTF("abc  ", "%-5s", "abc");
   EXPECT_PRINTF("abc  ", "%0--5s", "abc");
 
@@ -188,7 +190,7 @@ TEST(PrintfTest, MinusFlag) {
   EXPECT_PRINTF(" 42", "%- d", 42);
 }
 
-TEST(PrintfTest, SpaceFlag) {
+TEST(printf_test, space_flag) {
   EXPECT_PRINTF(" 42", "% d", 42);
   EXPECT_PRINTF("-42", "% d", -42);
   EXPECT_PRINTF(" 0042", "% 05d", 42);
@@ -198,7 +200,7 @@ TEST(PrintfTest, SpaceFlag) {
   EXPECT_PRINTF("x", "% c", 'x');
 }
 
-TEST(PrintfTest, HashFlag) {
+TEST(printf_test, hash_flag) {
   EXPECT_PRINTF("042", "%#o", 042);
   EXPECT_PRINTF(fmt::format("0{:o}", static_cast<unsigned>(-042)), "%#o", -042);
   EXPECT_PRINTF("0", "%#o", 0);
@@ -215,7 +217,7 @@ TEST(PrintfTest, HashFlag) {
   EXPECT_PRINTF("-42.000000", "%#f", -42.0);
   EXPECT_PRINTF("-42.000000", "%#F", -42.0);
 
-  char buffer[BUFFER_SIZE];
+  char buffer[256];
   safe_sprintf(buffer, "%#e", -42.0);
   EXPECT_PRINTF(buffer, "%#e", -42.0);
   safe_sprintf(buffer, "%#E", -42.0);
@@ -233,30 +235,30 @@ TEST(PrintfTest, HashFlag) {
   EXPECT_PRINTF("x", "%#c", 'x');
 }
 
-TEST(PrintfTest, Width) {
+TEST(printf_test, width) {
   EXPECT_PRINTF("  abc", "%5s", "abc");
 
   // Width cannot be specified twice.
   EXPECT_THROW_MSG(test_sprintf("%5-5d", 42), format_error,
                    "invalid type specifier");
 
-  EXPECT_THROW_MSG(test_sprintf(format("%{}d", BIG_NUM), 42), format_error,
+  EXPECT_THROW_MSG(test_sprintf(format("%{}d", big_num), 42), format_error,
                    "number is too big");
-  EXPECT_THROW_MSG(test_sprintf(format("%1${}d", BIG_NUM), 42), format_error,
+  EXPECT_THROW_MSG(test_sprintf(format("%1${}d", big_num), 42), format_error,
                    "number is too big");
 }
 
-TEST(PrintfTest, DynamicWidth) {
+TEST(printf_test, dynamic_width) {
   EXPECT_EQ("   42", test_sprintf("%*d", 5, 42));
   EXPECT_EQ("42   ", test_sprintf("%*d", -5, 42));
   EXPECT_THROW_MSG(test_sprintf("%*d", 5.0, 42), format_error,
                    "width is not integer");
   EXPECT_THROW_MSG(test_sprintf("%*d"), format_error, "argument not found");
-  EXPECT_THROW_MSG(test_sprintf("%*d", BIG_NUM, 42), format_error,
+  EXPECT_THROW_MSG(test_sprintf("%*d", big_num, 42), format_error,
                    "number is too big");
 }
 
-TEST(PrintfTest, IntPrecision) {
+TEST(printf_test, int_precision) {
   EXPECT_PRINTF("00042", "%.5d", 42);
   EXPECT_PRINTF("-00042", "%.5d", -42);
   EXPECT_PRINTF("00042", "%.5x", 0x42);
@@ -277,8 +279,8 @@ TEST(PrintfTest, IntPrecision) {
   EXPECT_PRINTF("00042     ", "%-#10.5o", 042);
 }
 
-TEST(PrintfTest, FloatPrecision) {
-  char buffer[BUFFER_SIZE];
+TEST(printf_test, float_precision) {
+  char buffer[256];
   safe_sprintf(buffer, "%.3e", 1234.5678);
   EXPECT_PRINTF(buffer, "%.3e", 1234.5678);
   EXPECT_PRINTF("1234.568", "%.3f", 1234.5678);
@@ -287,22 +289,22 @@ TEST(PrintfTest, FloatPrecision) {
   EXPECT_PRINTF(buffer, "%.3a", 1234.5678);
 }
 
-TEST(PrintfTest, StringPrecision) {
+TEST(printf_test, string_precision) {
   char test[] = {'H', 'e', 'l', 'l', 'o'};
   EXPECT_EQ(fmt::sprintf("%.4s", test), "Hell");
 }
 
-TEST(PrintfTest, IgnorePrecisionForNonNumericArg) {
+TEST(printf_test, ignore_precision_for_non_numeric_arg) {
   EXPECT_PRINTF("abc", "%.5s", "abc");
 }
 
-TEST(PrintfTest, DynamicPrecision) {
+TEST(printf_test, dynamic_precision) {
   EXPECT_EQ("00042", test_sprintf("%.*d", 5, 42));
   EXPECT_EQ("42", test_sprintf("%.*d", -5, 42));
   EXPECT_THROW_MSG(test_sprintf("%.*d", 5.0, 42), format_error,
                    "precision is not integer");
   EXPECT_THROW_MSG(test_sprintf("%.*d"), format_error, "argument not found");
-  EXPECT_THROW_MSG(test_sprintf("%.*d", BIG_NUM, 42), format_error,
+  EXPECT_THROW_MSG(test_sprintf("%.*d", big_num, 42), format_error,
                    "number is too big");
   if (sizeof(long long) != sizeof(int)) {
     long long prec = static_cast<long long>(INT_MIN) - 1;
@@ -325,7 +327,7 @@ SPECIALIZE_MAKE_SIGNED(unsigned long long, long long);
 
 // Test length format specifier ``length_spec``.
 template <typename T, typename U>
-void TestLength(const char* length_spec, U value) {
+void test_length(const char* length_spec, U value) {
   long long signed_value = 0;
   unsigned long long unsigned_value = 0;
   // Apply integer promotion to the argument.
@@ -364,54 +366,54 @@ void TestLength(const char* length_spec, U value) {
   EXPECT_PRINTF(os.str(), fmt::format("%{}X", length_spec), value);
 }
 
-template <typename T> void TestLength(const char* length_spec) {
+template <typename T> void test_length(const char* length_spec) {
   T min = std::numeric_limits<T>::min(), max = max_value<T>();
-  TestLength<T>(length_spec, 42);
-  TestLength<T>(length_spec, -42);
-  TestLength<T>(length_spec, min);
-  TestLength<T>(length_spec, max);
+  test_length<T>(length_spec, 42);
+  test_length<T>(length_spec, -42);
+  test_length<T>(length_spec, min);
+  test_length<T>(length_spec, max);
   long long long_long_min = std::numeric_limits<long long>::min();
   if (static_cast<long long>(min) > long_long_min)
-    TestLength<T>(length_spec, static_cast<long long>(min) - 1);
+    test_length<T>(length_spec, static_cast<long long>(min) - 1);
   unsigned long long long_long_max = max_value<long long>();
   if (static_cast<unsigned long long>(max) < long_long_max)
-    TestLength<T>(length_spec, static_cast<long long>(max) + 1);
-  TestLength<T>(length_spec, std::numeric_limits<short>::min());
-  TestLength<T>(length_spec, max_value<unsigned short>());
-  TestLength<T>(length_spec, std::numeric_limits<int>::min());
-  TestLength<T>(length_spec, max_value<int>());
-  TestLength<T>(length_spec, std::numeric_limits<unsigned>::min());
-  TestLength<T>(length_spec, max_value<unsigned>());
-  TestLength<T>(length_spec, std::numeric_limits<long long>::min());
-  TestLength<T>(length_spec, max_value<long long>());
-  TestLength<T>(length_spec, std::numeric_limits<unsigned long long>::min());
-  TestLength<T>(length_spec, max_value<unsigned long long>());
+    test_length<T>(length_spec, static_cast<long long>(max) + 1);
+  test_length<T>(length_spec, std::numeric_limits<short>::min());
+  test_length<T>(length_spec, max_value<unsigned short>());
+  test_length<T>(length_spec, std::numeric_limits<int>::min());
+  test_length<T>(length_spec, max_value<int>());
+  test_length<T>(length_spec, std::numeric_limits<unsigned>::min());
+  test_length<T>(length_spec, max_value<unsigned>());
+  test_length<T>(length_spec, std::numeric_limits<long long>::min());
+  test_length<T>(length_spec, max_value<long long>());
+  test_length<T>(length_spec, std::numeric_limits<unsigned long long>::min());
+  test_length<T>(length_spec, max_value<unsigned long long>());
 }
 
-TEST(PrintfTest, Length) {
-  TestLength<char>("hh");
-  TestLength<signed char>("hh");
-  TestLength<unsigned char>("hh");
-  TestLength<short>("h");
-  TestLength<unsigned short>("h");
-  TestLength<long>("l");
-  TestLength<unsigned long>("l");
-  TestLength<long long>("ll");
-  TestLength<unsigned long long>("ll");
-  TestLength<intmax_t>("j");
-  TestLength<size_t>("z");
-  TestLength<std::ptrdiff_t>("t");
+TEST(printf_test, length) {
+  test_length<char>("hh");
+  test_length<signed char>("hh");
+  test_length<unsigned char>("hh");
+  test_length<short>("h");
+  test_length<unsigned short>("h");
+  test_length<long>("l");
+  test_length<unsigned long>("l");
+  test_length<long long>("ll");
+  test_length<unsigned long long>("ll");
+  test_length<intmax_t>("j");
+  test_length<size_t>("z");
+  test_length<std::ptrdiff_t>("t");
   long double max = max_value<long double>();
   EXPECT_PRINTF(fmt::format("{:.6}", max), "%g", max);
   EXPECT_PRINTF(fmt::format("{:.6}", max), "%Lg", max);
 }
 
-TEST(PrintfTest, Bool) {
+TEST(printf_test, bool) {
   EXPECT_PRINTF("1", "%d", true);
   EXPECT_PRINTF("true", "%s", true);
 }
 
-TEST(PrintfTest, Int) {
+TEST(printf_test, int) {
   EXPECT_PRINTF("-42", "%d", -42);
   EXPECT_PRINTF("-42", "%i", -42);
   unsigned u = 0 - 42u;
@@ -421,20 +423,20 @@ TEST(PrintfTest, Int) {
   EXPECT_PRINTF(fmt::format("{:X}", u), "%X", -42);
 }
 
-TEST(PrintfTest, long_long) {
+TEST(printf_test, long_long) {
   // fmt::printf allows passing long long arguments to %d without length
   // specifiers.
   long long max = max_value<long long>();
   EXPECT_PRINTF(fmt::format("{}", max), "%d", max);
 }
 
-TEST(PrintfTest, Float) {
+TEST(printf_test, float) {
   EXPECT_PRINTF("392.650000", "%f", 392.65);
   EXPECT_PRINTF("392.65", "%.2f", 392.65);
   EXPECT_PRINTF("392.6", "%.1f", 392.65);
   EXPECT_PRINTF("393", "%.f", 392.65);
   EXPECT_PRINTF("392.650000", "%F", 392.65);
-  char buffer[BUFFER_SIZE];
+  char buffer[256];
   safe_sprintf(buffer, "%e", 392.65);
   EXPECT_PRINTF(buffer, "%e", 392.65);
   safe_sprintf(buffer, "%E", 392.65);
@@ -450,7 +452,7 @@ TEST(PrintfTest, Float) {
   EXPECT_EQ(buffer, format("{:A}", -392.65));
 }
 
-TEST(PrintfTest, Inf) {
+TEST(printf_test, inf) {
   double inf = std::numeric_limits<double>::infinity();
   for (const char* type = "fega"; *type; ++type) {
     EXPECT_PRINTF("inf", fmt::format("%{}", *type), inf);
@@ -459,7 +461,7 @@ TEST(PrintfTest, Inf) {
   }
 }
 
-TEST(PrintfTest, Char) {
+TEST(printf_test, char) {
   EXPECT_PRINTF("x", "%c", 'x');
   int max = max_value<int>();
   EXPECT_PRINTF(fmt::format("{}", static_cast<char>(max)), "%c", max);
@@ -468,7 +470,7 @@ TEST(PrintfTest, Char) {
   EXPECT_PRINTF(fmt::format(L"{}", static_cast<wchar_t>(max)), L"%c", max);
 }
 
-TEST(PrintfTest, String) {
+TEST(printf_test, string) {
   EXPECT_PRINTF("abc", "%s", "abc");
   const char* null_str = nullptr;
   EXPECT_PRINTF("(null)", "%s", null_str);
@@ -479,13 +481,13 @@ TEST(PrintfTest, String) {
   EXPECT_PRINTF(L"    (null)", L"%10s", null_wstr);
 }
 
-TEST(PrintfTest, UCharString) {
+TEST(printf_test, uchar_string) {
   unsigned char str[] = "test";
   unsigned char* pstr = str;
   EXPECT_EQ("test", fmt::sprintf("%s", pstr));
 }
 
-TEST(PrintfTest, Pointer) {
+TEST(printf_test, pointer) {
   int n;
   void* p = &n;
   EXPECT_PRINTF(fmt::format("{}", p), "%p", p);
@@ -508,20 +510,16 @@ TEST(PrintfTest, Pointer) {
   EXPECT_PRINTF(L"(nil)", L"%p", null_wstr);
 }
 
-TEST(PrintfTest, Location) {
-  // TODO: test %n
-}
-
 enum test_enum { answer = 42 };
 
-TEST(PrintfTest, Enum) {
+TEST(printf_test, enum) {
   EXPECT_PRINTF("42", "%d", answer);
   volatile test_enum volatile_enum = answer;
   EXPECT_PRINTF("42", "%d", volatile_enum);
 }
 
 #if FMT_USE_FCNTL
-TEST(PrintfTest, Examples) {
+TEST(printf_test, examples) {
   const char* weekday = "Thursday";
   const char* month = "August";
   int day = 21;
@@ -529,7 +527,7 @@ TEST(PrintfTest, Examples) {
                "Thursday, 21 August");
 }
 
-TEST(PrintfTest, PrintfError) {
+TEST(printf_test, printf_error) {
   fmt::file read_end, write_end;
   fmt::file::pipe(read_end, write_end);
   int result = fmt::fprintf(read_end.fdopen("r").get(), "test");
@@ -537,26 +535,20 @@ TEST(PrintfTest, PrintfError) {
 }
 #endif
 
-TEST(PrintfTest, WideString) { EXPECT_EQ(L"abc", fmt::sprintf(L"%s", L"abc")); }
-
-TEST(PrintfTest, PrintfCustom) {
-  EXPECT_EQ("abc", test_sprintf("%s", TestString("abc")));
+TEST(printf_test, wide_string) {
+  EXPECT_EQ(L"abc", fmt::sprintf(L"%s", L"abc"));
 }
 
-TEST(PrintfTest, OStream) {
-  std::ostringstream os;
-  int ret = fmt::fprintf(os, "Don't %s!", "panic");
-  EXPECT_EQ("Don't panic!", os.str());
-  EXPECT_EQ(12, ret);
+TEST(printf_test, printf_custom) {
+  EXPECT_EQ("abc", test_sprintf("%s", test_string("abc")));
 }
 
-TEST(PrintfTest, VPrintf) {
+TEST(printf_test, vprintf) {
   fmt::format_arg_store<fmt::printf_context, int> as{42};
   fmt::basic_format_args<fmt::printf_context> args(as);
   EXPECT_EQ(fmt::vsprintf("%d", args), "42");
   EXPECT_WRITE(stdout, fmt::vprintf("%d", args), "42");
   EXPECT_WRITE(stdout, fmt::vfprintf(stdout, "%d", args), "42");
-  EXPECT_WRITE(stdout, fmt::vfprintf(std::cout, "%d", args), "42");
 }
 
 template <typename... Args>
@@ -564,15 +556,15 @@ void check_format_string_regression(fmt::string_view s, const Args&... args) {
   fmt::sprintf(s, args...);
 }
 
-TEST(PrintfTest, CheckFormatStringRegression) {
+TEST(printf_test, check_format_string_regression) {
   check_format_string_regression("%c%s", 'x', "");
 }
 
-TEST(PrintfTest, FixedLargeExponent) {
+TEST(printf_test, fixed_large_exponent) {
   EXPECT_EQ("1000000000000000000000", fmt::sprintf("%.*f", -13, 1e21));
 }
 
-TEST(PrintfTest, VSPrintfMakeArgsExample) {
+TEST(printf_test, vsprintf_make_args_example) {
   fmt::format_arg_store<fmt::printf_context, int, const char*> as{42,
                                                                   "something"};
   fmt::basic_format_args<fmt::printf_context> args(as);
@@ -581,15 +573,12 @@ TEST(PrintfTest, VSPrintfMakeArgsExample) {
   fmt::basic_format_args<fmt::printf_context> args2(as2);
   EXPECT_EQ("[42] something happened",
             fmt::vsprintf("[%d] %s happened", args2));
-  // The older gcc versions can't cast the return value.
-#if !defined(__GNUC__) || (__GNUC__ > 4)
   EXPECT_EQ("[42] something happened",
             fmt::vsprintf("[%d] %s happened",
                           {fmt::make_printf_args(42, "something")}));
-#endif
 }
 
-TEST(PrintfTest, VSPrintfMakeWArgsExample) {
+TEST(printf_test, vsprintf_make_wargs_example) {
   fmt::format_arg_store<fmt::wprintf_context, int, const wchar_t*> as{
       42, L"something"};
   fmt::basic_format_args<fmt::wprintf_context> args(as);
@@ -599,30 +588,7 @@ TEST(PrintfTest, VSPrintfMakeWArgsExample) {
   fmt::basic_format_args<fmt::wprintf_context> args2(as2);
   EXPECT_EQ(L"[42] something happened",
             fmt::vsprintf(L"[%d] %s happened", args2));
-  // the older gcc versions can't cast the return value
-#if !defined(__GNUC__) || (__GNUC__ > 4)
   EXPECT_EQ(L"[42] something happened",
             fmt::vsprintf(L"[%d] %s happened",
                           {fmt::make_wprintf_args(42, L"something")}));
-#endif
-}
-
-TEST(PrintfTest, PrintfDetermineOutputSize) {
-  using backit = std::back_insert_iterator<std::vector<char>>;
-  using truncated_printf_context =
-      fmt::basic_printf_context<fmt::detail::truncating_iterator<backit>, char>;
-
-  auto v = std::vector<char>{};
-  auto it = std::back_inserter(v);
-
-  const auto format_string = "%s";
-  const auto format_arg = "Hello";
-  const auto expected_size = fmt::sprintf(format_string, format_arg).size();
-
-  EXPECT_EQ((truncated_printf_context(
-                 fmt::detail::truncating_iterator<backit>(it, 0), format_string,
-                 fmt::make_format_args<truncated_printf_context>(format_arg))
-                 .format()
-                 .count()),
-            expected_size);
 }

test/ranges-test.cc

@@ -11,106 +11,104 @@
 
 #include "fmt/ranges.h"
 
-#include "gtest.h"
+#include <map>
+#include <string>
+#include <vector>
 
-// Check if  'if constexpr' is supported.
-#if (__cplusplus > 201402L) || \
-    (defined(_MSVC_LANG) && _MSVC_LANG > 201402L && _MSC_VER >= 1910)
+#include "gtest/gtest.h"
 
-#  include <array>
-#  include <map>
-#  include <string>
-#  include <vector>
+#if !FMT_GCC_VERSION || FMT_GCC_VERSION >= 601
+#  define FMT_RANGES_TEST_ENABLE_C_STYLE_ARRAY
+#endif
 
-TEST(RangesTest, FormatVector) {
-  std::vector<int32_t> iv{1, 2, 3, 5, 7, 11};
-  auto ivf = fmt::format("{}", iv);
-  EXPECT_EQ("{1, 2, 3, 5, 7, 11}", ivf);
+#if !FMT_MSC_VER || FMT_MSC_VER > 1910
+#  define FMT_RANGES_TEST_ENABLE_JOIN
+#  define FMT_RANGES_TEST_ENABLE_FORMAT_STRUCT
+#endif
+
+#ifdef FMT_RANGES_TEST_ENABLE_C_STYLE_ARRAY
+TEST(ranges_test, format_array) {
+  int arr[] = {1, 2, 3, 5, 7, 11};
+  EXPECT_EQ(fmt::format("{}", arr), "[1, 2, 3, 5, 7, 11]");
 }
 
-TEST(RangesTest, FormatVector2) {
-  std::vector<std::vector<int32_t>> ivv{{1, 2}, {3, 5}, {7, 11}};
-  auto ivf = fmt::format("{}", ivv);
-  EXPECT_EQ("{{1, 2}, {3, 5}, {7, 11}}", ivf);
+TEST(ranges_test, format_2d_array) {
+  int arr[][2] = {{1, 2}, {3, 5}, {7, 11}};
+  EXPECT_EQ(fmt::format("{}", arr), "[[1, 2], [3, 5], [7, 11]]");
 }
 
-TEST(RangesTest, FormatMap) {
-  std::map<std::string, int32_t> simap{{"one", 1}, {"two", 2}};
-  EXPECT_EQ("{(\"one\", 1), (\"two\", 2)}", fmt::format("{}", simap));
+TEST(ranges_test, format_array_of_literals) {
+  const char* arr[] = {"1234", "abcd"};
+  EXPECT_EQ(fmt::format("{}", arr), "[\"1234\", \"abcd\"]");
+}
+#endif  // FMT_RANGES_TEST_ENABLE_C_STYLE_ARRAY
+
+TEST(ranges_test, format_vector) {
+  auto v = std::vector<int>{1, 2, 3, 5, 7, 11};
+  EXPECT_EQ(fmt::format("{}", v), "[1, 2, 3, 5, 7, 11]");
 }
 
-TEST(RangesTest, FormatPair) {
-  std::pair<int64_t, float> pa1{42, 1.5f};
-  EXPECT_EQ("(42, 1.5)", fmt::format("{}", pa1));
+TEST(ranges_test, format_vector2) {
+  auto v = std::vector<std::vector<int>>{{1, 2}, {3, 5}, {7, 11}};
+  EXPECT_EQ(fmt::format("{}", v), "[[1, 2], [3, 5], [7, 11]]");
 }
 
-TEST(RangesTest, FormatTuple) {
-  std::tuple<int64_t, float, std::string, char> t{42, 1.5f, "this is tuple",
-                                                  'i'};
-  EXPECT_EQ("(42, 1.5, \"this is tuple\", 'i')", fmt::format("{}", t));
-  EXPECT_EQ("()", fmt::format("{}", std::tuple<>()));
+TEST(ranges_test, format_map) {
+  auto m = std::map<std::string, int>{{"one", 1}, {"two", 2}};
+  EXPECT_EQ(fmt::format("{}", m), "[(\"one\", 1), (\"two\", 2)]");
 }
 
-TEST(RangesTest, JoinTuple) {
-  // Value tuple args
-  std::tuple<char, int, float> t1 = std::make_tuple('a', 1, 2.0f);
-  EXPECT_EQ("(a, 1, 2)", fmt::format("({})", fmt::join(t1, ", ")));
-
-  // Testing lvalue tuple args
-  int x = 4;
-  std::tuple<char, int&> t2{'b', x};
-  EXPECT_EQ("b + 4", fmt::format("{}", fmt::join(t2, " + ")));
-
-  // Empty tuple
-  std::tuple<> t3;
-  EXPECT_EQ("", fmt::format("{}", fmt::join(t3, "|")));
-
-  // Single element tuple
-  std::tuple<float> t4{4.0f};
-  EXPECT_EQ("4", fmt::format("{}", fmt::join(t4, "/")));
+TEST(ranges_test, format_pair) {
+  auto p = std::pair<int, float>(42, 1.5f);
+  EXPECT_EQ(fmt::format("{}", p), "(42, 1.5)");
 }
 
-TEST(RangesTest, JoinInitializerList) {
-  EXPECT_EQ("1, 2, 3", fmt::format("{}", fmt::join({1, 2, 3}, ", ")));
-  EXPECT_EQ("fmt rocks !",
-            fmt::format("{}", fmt::join({"fmt", "rocks", "!"}, " ")));
+TEST(ranges_test, format_tuple) {
+  auto t =
+      std::tuple<int, float, std::string, char>(42, 1.5f, "this is tuple", 'i');
+  EXPECT_EQ(fmt::format("{}", t), "(42, 1.5, \"this is tuple\", 'i')");
+  EXPECT_EQ(fmt::format("{}", std::tuple<>()), "()");
 }
 
-struct my_struct {
-  int32_t i;
-  std::string str;  // can throw
-  template <size_t N> decltype(auto) get() const noexcept {
-    if constexpr (N == 0)
-      return i;
-    else if constexpr (N == 1)
-      return fmt::string_view{str};
+#ifdef FMT_RANGES_TEST_ENABLE_FORMAT_STRUCT
+struct tuple_like {
+  int i;
+  std::string str;
+
+  template <size_t N> fmt::enable_if_t<N == 0, int> get() const noexcept {
+    return i;
+  }
+  template <size_t N>
+  fmt::enable_if_t<N == 1, fmt::string_view> get() const noexcept {
+    return str;
   }
 };
 
-template <size_t N> decltype(auto) get(const my_struct& s) noexcept {
-  return s.get<N>();
+template <size_t N>
+auto get(const tuple_like& t) noexcept -> decltype(t.get<N>()) {
+  return t.get<N>();
 }
 
 namespace std {
+template <>
+struct tuple_size<tuple_like> : std::integral_constant<size_t, 2> {};
 
-template <> struct tuple_size<my_struct> : std::integral_constant<size_t, 2> {};
-
-template <size_t N> struct tuple_element<N, my_struct> {
-  using type = decltype(std::declval<my_struct>().get<N>());
+template <size_t N> struct tuple_element<N, tuple_like> {
+  using type = decltype(std::declval<tuple_like>().get<N>());
 };
-
 }  // namespace std
 
-TEST(RangesTest, FormatStruct) {
-  my_struct mst{13, "my struct"};
-  EXPECT_EQ("(13, \"my struct\")", fmt::format("{}", mst));
+TEST(ranges_test, format_struct) {
+  auto t = tuple_like{42, "foo"};
+  EXPECT_EQ(fmt::format("{}", t), "(42, \"foo\")");
 }
+#endif  // FMT_RANGES_TEST_ENABLE_FORMAT_STRUCT
 
-TEST(RangesTest, FormatTo) {
+TEST(ranges_test, format_to) {
   char buf[10];
-  auto end = fmt::format_to(buf, "{}", std::vector{1, 2, 3});
+  auto end = fmt::format_to(buf, "{}", std::vector<int>{1, 2, 3});
   *end = '\0';
-  EXPECT_STREQ(buf, "{1, 2, 3}");
+  EXPECT_STREQ(buf, "[1, 2, 3]");
 }
 
 struct path_like {
@@ -120,13 +118,10 @@ struct path_like {
   operator std::string() const;
 };
 
-TEST(RangesTest, PathLike) {
+TEST(ranges_test, path_like) {
   EXPECT_FALSE((fmt::is_range<path_like, char>::value));
 }
 
-#endif  // (__cplusplus > 201402L) || (defined(_MSVC_LANG) && _MSVC_LANG >
-        // 201402L && _MSC_VER >= 1910)
-
 #ifdef FMT_USE_STRING_VIEW
 struct string_like {
   const char* begin();
@@ -135,11 +130,101 @@ struct string_like {
   explicit operator std::string_view() const { return "foo"; }
 };
 
-TEST(RangesTest, FormatStringLike) {
-  EXPECT_EQ("foo", fmt::format("{}", string_like()));
+TEST(ranges_test, format_string_like) {
+  EXPECT_EQ(fmt::format("{}", string_like()), "foo");
 }
 #endif  // FMT_USE_STRING_VIEW
 
+// A range that provides non-const only begin()/end() to test fmt::join handles
+// that.
+//
+// Some ranges (e.g. those produced by range-v3's views::filter()) can cache
+// information during iteration so they only provide non-const begin()/end().
+template <typename T> class non_const_only_range {
+ private:
+  std::vector<T> vec;
+
+ public:
+  using const_iterator = typename ::std::vector<T>::const_iterator;
+
+  template <typename... Args>
+  explicit non_const_only_range(Args&&... args)
+      : vec(std::forward<Args>(args)...) {}
+
+  const_iterator begin() { return vec.begin(); }
+  const_iterator end() { return vec.end(); }
+};
+
+template <typename T> class noncopyable_range {
+ private:
+  std::vector<T> vec;
+
+ public:
+  using const_iterator = typename ::std::vector<T>::const_iterator;
+
+  template <typename... Args>
+  explicit noncopyable_range(Args&&... args)
+      : vec(std::forward<Args>(args)...) {}
+
+  noncopyable_range(noncopyable_range const&) = delete;
+  noncopyable_range(noncopyable_range&) = delete;
+
+  const_iterator begin() const { return vec.begin(); }
+  const_iterator end() const { return vec.end(); }
+};
+
+TEST(ranges_test, range) {
+  noncopyable_range<int> w(3u, 0);
+  EXPECT_EQ(fmt::format("{}", w), "[0, 0, 0]");
+  EXPECT_EQ(fmt::format("{}", noncopyable_range<int>(3u, 0)), "[0, 0, 0]");
+
+  non_const_only_range<int> x(3u, 0);
+  EXPECT_EQ(fmt::format("{}", x), "[0, 0, 0]");
+  EXPECT_EQ(fmt::format("{}", non_const_only_range<int>(3u, 0)), "[0, 0, 0]");
+
+  auto y = std::vector<int>(3u, 0);
+  EXPECT_EQ(fmt::format("{}", y), "[0, 0, 0]");
+  EXPECT_EQ(fmt::format("{}", std::vector<int>(3u, 0)), "[0, 0, 0]");
+
+  const auto z = std::vector<int>(3u, 0);
+  EXPECT_EQ(fmt::format("{}", z), "[0, 0, 0]");
+}
+
+#if !FMT_MSC_VER || FMT_MSC_VER >= 1927
+struct unformattable {};
+
+TEST(ranges_test, unformattable_range) {
+  EXPECT_FALSE((fmt::has_formatter<std::vector<unformattable>,
+                                   fmt::format_context>::value));
+}
+#endif
+
+#ifdef FMT_RANGES_TEST_ENABLE_JOIN
+TEST(ranges_test, join_tuple) {
+  // Value tuple args.
+  auto t1 = std::tuple<char, int, float>('a', 1, 2.0f);
+  EXPECT_EQ(fmt::format("({})", fmt::join(t1, ", ")), "(a, 1, 2)");
+
+  // Testing lvalue tuple args.
+  int x = 4;
+  auto t2 = std::tuple<char, int&>('b', x);
+  EXPECT_EQ(fmt::format("{}", fmt::join(t2, " + ")), "b + 4");
+
+  // Empty tuple.
+  auto t3 = std::tuple<>();
+  EXPECT_EQ(fmt::format("{}", fmt::join(t3, "|")), "");
+
+  // Single element tuple.
+  auto t4 = std::tuple<float>(4.0f);
+  EXPECT_EQ(fmt::format("{}", fmt::join(t4, "/")), "4");
+}
+
+TEST(ranges_test, join_initializer_list) {
+  EXPECT_EQ(fmt::format("{}", fmt::join({1, 2, 3}, ", ")), "1, 2, 3");
+  EXPECT_EQ(fmt::format("{}", fmt::join({"fmt", "rocks", "!"}, " ")),
+            "fmt rocks !");
+}
+
 struct zstring_sentinel {};
 
 bool operator==(const char* p, zstring_sentinel) { return *p == '\0'; }
@@ -151,53 +236,29 @@ struct zstring {
   zstring_sentinel end() const { return {}; }
 };
 
-TEST(RangesTest, JoinSentinel) {
-  zstring hello{"hello"};
-  EXPECT_EQ("{'h', 'e', 'l', 'l', 'o'}", fmt::format("{}", hello));
-  EXPECT_EQ("h_e_l_l_o", fmt::format("{}", fmt::join(hello, "_")));
+TEST(ranges_test, join_sentinel) {
+  auto hello = zstring{"hello"};
+  EXPECT_EQ(fmt::format("{}", hello), "['h', 'e', 'l', 'l', 'o']");
+  EXPECT_EQ(fmt::format("{}", fmt::join(hello, "_")), "h_e_l_l_o");
 }
 
-// A range that provides non-const only begin()/end() to test fmt::join handles
-// that
-//
-// Some ranges (eg those produced by range-v3's views::filter()) can cache
-// information during iteration so they only provide non-const begin()/end().
-template <typename T> class non_const_only_range {
- private:
-  std::vector<T> vec;
+TEST(ranges_test, join_range) {
+  noncopyable_range<int> w(3u, 0);
+  EXPECT_EQ(fmt::format("{}", fmt::join(w, ",")), "0,0,0");
+  EXPECT_EQ(fmt::format("{}", fmt::join(noncopyable_range<int>(3u, 0), ",")),
+            "0,0,0");
 
- public:
-  using const_iterator = typename ::std::vector<T>::const_iterator;
-
-  template <typename... Args>
-  explicit non_const_only_range(Args&&... args)
-      : vec(::std::forward<Args>(args)...) {}
-
-  const_iterator begin() { return vec.begin(); }
-  const_iterator end() { return vec.end(); }
-};
-
-TEST(RangesTest, JoinRange) {
   non_const_only_range<int> x(3u, 0);
-  EXPECT_EQ("0,0,0", fmt::format("{}", fmt::join(x, ",")));
-  EXPECT_EQ(
-      "0,0,0",
-      fmt::format("{}", fmt::join(non_const_only_range<int>(3u, 0), ",")));
+  EXPECT_EQ(fmt::format("{}", fmt::join(x, ",")), "0,0,0");
+  EXPECT_EQ(fmt::format("{}", fmt::join(non_const_only_range<int>(3u, 0), ",")),
+            "0,0,0");
 
-  std::vector<int> y(3u, 0);
-  EXPECT_EQ("0,0,0", fmt::format("{}", fmt::join(y, ",")));
-  EXPECT_EQ("0,0,0",
-            fmt::format("{}", fmt::join(std::vector<int>(3u, 0), ",")));
+  auto y = std::vector<int>(3u, 0);
+  EXPECT_EQ(fmt::format("{}", fmt::join(y, ",")), "0,0,0");
+  EXPECT_EQ(fmt::format("{}", fmt::join(std::vector<int>(3u, 0), ",")),
+            "0,0,0");
 
-  const std::vector<int> z(3u, 0);
-  EXPECT_EQ("0,0,0", fmt::format("{}", fmt::join(z, ",")));
+  const auto z = std::vector<int>(3u, 0);
+  EXPECT_EQ(fmt::format("{}", fmt::join(z, ",")), "0,0,0");
 }
-
-#if !FMT_MSC_VER || FMT_MSC_VER >= 1927
-struct unformattable {};
-
-TEST(RangesTest, UnformattableRange) {
-  EXPECT_FALSE((fmt::has_formatter<std::vector<unformattable>,
-                                   fmt::format_context>::value));
-}
-#endif
+#endif  // FMT_RANGES_TEST_ENABLE_JOIN

test/scan-test.cc

@@ -11,25 +11,25 @@
 
 #include <climits>
 
-#include "gmock.h"
+#include "gmock/gmock.h"
 #include "gtest-extra.h"
 
-TEST(ScanTest, ReadText) {
-  fmt::string_view s = "foo";
+TEST(scan_test, read_text) {
+  auto s = fmt::string_view("foo");
   auto end = fmt::scan(s, "foo");
   EXPECT_EQ(end, s.end());
   EXPECT_THROW_MSG(fmt::scan("fob", "foo"), fmt::format_error, "invalid input");
 }
 
-TEST(ScanTest, ReadInt) {
-  int n = 0;
+TEST(scan_test, read_int) {
+  auto n = int();
   fmt::scan("42", "{}", n);
   EXPECT_EQ(n, 42);
   fmt::scan("-42", "{}", n);
   EXPECT_EQ(n, -42);
 }
 
-TEST(ScanTest, ReadLongLong) {
+TEST(scan_test, read_longlong) {
   long long n = 0;
   fmt::scan("42", "{}", n);
   EXPECT_EQ(n, 42);
@@ -37,15 +37,15 @@ TEST(ScanTest, ReadLongLong) {
   EXPECT_EQ(n, -42);
 }
 
-TEST(ScanTest, ReadUInt) {
-  unsigned n = 0;
+TEST(scan_test, read_uint) {
+  auto n = unsigned();
   fmt::scan("42", "{}", n);
   EXPECT_EQ(n, 42);
   EXPECT_THROW_MSG(fmt::scan("-42", "{}", n), fmt::format_error,
                    "invalid input");
 }
 
-TEST(ScanTest, ReadULongLong) {
+TEST(scan_test, read_ulonglong) {
   unsigned long long n = 0;
   fmt::scan("42", "{}", n);
   EXPECT_EQ(n, 42);
@@ -53,14 +53,14 @@ TEST(ScanTest, ReadULongLong) {
                    "invalid input");
 }
 
-TEST(ScanTest, ReadString) {
-  std::string s;
+TEST(scan_test, read_string) {
+  auto s = std::string();
   fmt::scan("foo", "{}", s);
   EXPECT_EQ(s, "foo");
 }
 
-TEST(ScanTest, ReadStringView) {
-  fmt::string_view s;
+TEST(scan_test, read_string_view) {
+  auto s = fmt::string_view();
   fmt::scan("foo", "{}", s);
   EXPECT_EQ(s, "foo");
 }
@@ -90,8 +90,8 @@ template <> struct scanner<tm> {
 };
 }  // namespace fmt
 
-TEST(ScanTest, ReadCustom) {
-  const char* input = "Date: 1985-10-25";
+TEST(scan_test, read_custom) {
+  auto input = "Date: 1985-10-25";
   auto t = tm();
   fmt::scan(input, "Date: {0:%Y-%m-%d}", t);
   EXPECT_EQ(t.tm_year, 85);
@@ -100,16 +100,16 @@ TEST(ScanTest, ReadCustom) {
 }
 #endif
 
-TEST(ScanTest, InvalidFormat) {
+TEST(scan_test, invalid_format) {
   EXPECT_THROW_MSG(fmt::scan("", "{}"), fmt::format_error,
                    "argument index out of range");
   EXPECT_THROW_MSG(fmt::scan("", "{"), fmt::format_error,
                    "invalid format string");
 }
 
-TEST(ScanTest, Example) {
-  std::string key;
-  int value;
+TEST(scan_test, example) {
+  auto key = std::string();
+  auto value = int();
   fmt::scan("answer = 42", "{} = {}", key, value);
   EXPECT_EQ(key, "answer");
   EXPECT_EQ(value, 42);

test/scan.h

@@ -169,13 +169,16 @@ struct scan_handler : error_handler {
     scan_ctx_.advance_to(it + size);
   }
 
-  int on_arg_id() { return on_arg_id(next_arg_id_++); }
-  int on_arg_id(int id) {
+  FMT_CONSTEXPR int on_arg_id() { return on_arg_id(next_arg_id_++); }
+  FMT_CONSTEXPR int on_arg_id(int id) {
     if (id >= args_.size) on_error("argument index out of range");
     arg_ = args_.data[id];
     return id;
   }
-  int on_arg_id(string_view) { return on_error("invalid format"), 0; }
+  FMT_CONSTEXPR int on_arg_id(string_view id) {
+    if (id.data()) on_error("invalid format");
+    return 0;
+  }
 
   void on_replacement_field(int, const char*) {
     auto it = scan_ctx_.begin(), end = scan_ctx_.end();

test/static-export-test/CMakeLists.txt

@@ -0,0 +1,30 @@
+cmake_minimum_required(VERSION 3.1...3.18)
+
+project(fmt-link CXX)
+
+set(BUILD_SHARED_LIBS OFF)
+set(CMAKE_VISIBILITY_INLINES_HIDDEN TRUE)
+set(CMAKE_CXX_VISIBILITY_PRESET "hidden")
+
+# Broken LTO on GCC 4
+if (CMAKE_COMPILER_IS_GNUCXX AND CMAKE_CXX_COMPILER_VERSION VERSION_LESS 5)
+  set(BROKEN_LTO ON)
+endif ()
+
+if (NOT BROKEN_LTO AND CMAKE_VERSION VERSION_GREATER "3.8")
+  # CMake 3.9+
+  include(CheckIPOSupported)
+  check_ipo_supported(RESULT HAVE_IPO)
+  if (HAVE_IPO)
+    set(CMAKE_INTERPROCEDURAL_OPTIMIZATION TRUE)
+  endif ()
+endif ()
+
+add_subdirectory(../.. fmt)
+set_property(TARGET fmt PROPERTY POSITION_INDEPENDENT_CODE ON)
+
+add_library(library-test SHARED library.cc)
+target_link_libraries(library-test PRIVATE fmt::fmt)
+
+add_executable(exe-test main.cc)
+target_link_libraries(exe-test PRIVATE library-test)

test/static-export-test/library.cc

@@ -0,0 +1,5 @@
+#include <fmt/compile.h>
+
+__attribute__((visibility("default"))) std::string foo() {
+  return fmt::format(FMT_COMPILE("foo bar {}"), 4242);
+}

test/static-export-test/main.cc

@@ -0,0 +1,6 @@
+#include <iostream>
+#include <string>
+
+extern std::string foo();
+
+int main() { std::cout << foo() << std::endl; }

test/std-format-test.cc

@@ -1,14 +1,14 @@
 #include <format>
 
-#include "gtest.h"
+#include "gtest/gtest.h"
 
-TEST(StdFormatTest, Escaping) {
+TEST(std_format_test, escaping) {
   using namespace std;
   string s = format("{0}-{{", 8);  // s == "8-{"
   EXPECT_EQ(s, "8-{");
 }
 
-TEST(StdFormatTest, Indexing) {
+TEST(std_format_test, indexing) {
   using namespace std;
   string s0 = format("{} to {}", "a", "b");    // OK: automatic indexing
   string s1 = format("{1} to {0}", "a", "b");  // OK: manual indexing
@@ -20,7 +20,7 @@ TEST(StdFormatTest, Indexing) {
   EXPECT_THROW(string s3 = format("{} to {1}", "a", "b"), std::format_error);
 }
 
-TEST(StdFormatTest, Alignment) {
+TEST(std_format_test, alignment) {
   using namespace std;
   char c = 120;
   string s0 = format("{:6}", 42);     // s0 == "    42"
@@ -41,7 +41,7 @@ TEST(StdFormatTest, Alignment) {
   EXPECT_EQ(s7, "true  ");
 }
 
-TEST(StdFormatTest, Float) {
+TEST(std_format_test, float) {
   using namespace std;
   double inf = numeric_limits<double>::infinity();
   double nan = numeric_limits<double>::quiet_NaN();
@@ -57,7 +57,7 @@ TEST(StdFormatTest, Float) {
   EXPECT_EQ(s3, "nan +nan nan  nan");
 }
 
-TEST(StdFormatTest, Int) {
+TEST(std_format_test, int) {
   using namespace std;
   string s0 = format("{}", 42);                       // s0 == "42"
   string s1 = format("{0:b} {0:d} {0:o} {0:x}", 42);  // s1 == "101010 42 52 2a"
@@ -83,7 +83,7 @@ template <> struct std::formatter<color> : std::formatter<const char*> {
 
 struct err {};
 
-TEST(StdFormatTest, Formatter) {
+TEST(std_format_test, formatter) {
   std::string s0 = std::format("{}", 42);  // OK: library-provided formatter
   // std::string s1 = std::format("{}", L"foo"); // Ill-formed: disabled
   // formatter
@@ -103,15 +103,19 @@ template <> struct std::formatter<S> {
 
   // Parses a width argument id in the format { <digit> }.
   constexpr auto parse(format_parse_context& ctx) {
+    constexpr auto is_ascii_digit = [](const char c) {
+      return c >= '0' && c <= '9';
+    };
+
     auto iter = ctx.begin();
     // auto get_char = [&]() { return iter != ctx.end() ? *iter : 0; };
     auto get_char = [&]() { return iter != ctx.end() ? *iter : '\0'; };
     if (get_char() != '{') return iter;
     ++iter;
     char c = get_char();
-    if (!isdigit(c) || (++iter, get_char()) != '}')
+    if (!is_ascii_digit(c) || (++iter, get_char()) != '}')
       throw format_error("invalid format");
-    width_arg_id = c - '0';
+    width_arg_id = fmt::detail::to_unsigned(c - '0');
     ctx.check_arg_id(width_arg_id);
     return ++iter;
   }
@@ -135,7 +139,7 @@ template <> struct std::formatter<S> {
   }
 };
 
-TEST(StdFormatTest, Parsing) {
+TEST(std_format_test, parsing) {
   std::string s = std::format("{0:{1}}", S{42}, 10);  // s == "        42"
   EXPECT_EQ(s, "        42");
 }
@@ -149,7 +153,7 @@ template <> struct std::formatter<__int128_t> : std::formatter<long long> {
   }
 };
 
-TEST(StdFormatTest, Int128) {
+TEST(std_format_test, int128) {
   __int128_t n = 42;
   auto s = std::format("{}", n);
   EXPECT_EQ(s, "42");

test/test-assert.h

@@ -10,7 +10,11 @@
 
 #include <stdexcept>
 
-#include "gtest.h"
+void throw_assertion_failure(const char* message);
+#define FMT_ASSERT(condition, message) \
+  if (!(condition)) throw_assertion_failure(message);
+
+#include "gtest/gtest.h"
 
 class assertion_failure : public std::logic_error {
  public:
@@ -22,8 +26,11 @@ class assertion_failure : public std::logic_error {
 
 void assertion_failure::avoid_weak_vtable() {}
 
-#define FMT_ASSERT(condition, message) \
-  if (!(condition)) throw assertion_failure(message);
+// We use a separate function (rather than throw directly from FMT_ASSERT) to
+// avoid GCC's -Wterminate warning when FMT_ASSERT is used in a destructor.
+inline void throw_assertion_failure(const char* message) {
+  throw assertion_failure(message);
+}
 
 // Expects an assertion failure.
 #define EXPECT_ASSERT(stmt, message) \

test/test-main.cc

@@ -7,7 +7,7 @@
 
 #include <cstdlib>
 
-#include "gtest.h"
+#include "gtest/gtest.h"
 
 #ifdef _WIN32
 #  include <windows.h>

test/unicode-test.cc

@@ -0,0 +1,48 @@
+// Formatting library for C++ - Unicode tests
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#include <iomanip>
+#include <locale>
+#include <vector>
+
+#include "fmt/chrono.h"
+#include "gmock/gmock.h"
+#include "util.h"  // get_locale
+
+using testing::Contains;
+
+TEST(unicode_test, is_utf8) { EXPECT_TRUE(fmt::detail::is_utf8()); }
+
+TEST(unicode_test, legacy_locale) {
+  auto loc = get_locale("ru_RU.CP1251", "Russian.1251");
+  if (loc == std::locale::classic()) return;
+
+  auto s = std::string();
+  try {
+    s = fmt::format(loc, "День недели: {:L}", fmt::weekday(1));
+  } catch (const fmt::format_error& e) {
+    // Formatting can fail due to an unsupported encoding.
+    fmt::print("Format error: {}\n", e.what());
+    return;
+  }
+
+#if !FMT_GCC_VERSION || FMT_GCC_VERSION >= 500
+  auto&& os = std::ostringstream();
+  os.imbue(loc);
+  auto tm = std::tm();
+  tm.tm_wday = 1;
+  os << std::put_time(&tm, "%a");
+  auto wd = os.str();
+  if (wd == "??") {
+    EXPECT_EQ(s, "День недели: ??");
+    fmt::print("std::locale gives ?? as a weekday.\n");
+    return;
+  }
+#endif
+  EXPECT_THAT((std::vector<std::string>{"День недели: пн", "День недели: Пн"}),
+              Contains(s));
+}

test/util.cc

@@ -9,42 +9,38 @@
 
 #include <cstring>
 
-void increment(char* s) {
-  for (int i = static_cast<int>(std::strlen(s)) - 1; i >= 0; --i) {
-    if (s[i] != '9') {
-      ++s[i];
-      break;
-    }
-    s[i] = '0';
-  }
-}
-
-std::string get_system_error(int error_code) {
-#if defined(__MINGW32__) || !defined(_WIN32)
-  return strerror(error_code);
-#else
-  enum { BUFFER_SIZE = 200 };
-  char buffer[BUFFER_SIZE];
-  if (strerror_s(buffer, BUFFER_SIZE, error_code))
-    throw std::exception("strerror_s failed");
-  return buffer;
-#endif
-}
-
-const char* const FILE_CONTENT = "Don't panic!";
+const char* const file_content = "Don't panic!";
 
 fmt::buffered_file open_buffered_file(FILE** fp) {
 #if FMT_USE_FCNTL
   fmt::file read_end, write_end;
   fmt::file::pipe(read_end, write_end);
-  write_end.write(FILE_CONTENT, std::strlen(FILE_CONTENT));
+  write_end.write(file_content, std::strlen(file_content));
   write_end.close();
   fmt::buffered_file f = read_end.fdopen("r");
   if (fp) *fp = f.get();
 #else
   fmt::buffered_file f("test-file", "w");
-  fputs(FILE_CONTENT, f.get());
+  fputs(file_content, f.get());
   if (fp) *fp = f.get();
 #endif
   return f;
 }
+
+std::locale do_get_locale(const char* name) {
+  try {
+    return std::locale(name);
+  } catch (const std::runtime_error&) {
+  }
+  return std::locale::classic();
+}
+
+std::locale get_locale(const char* name, const char* alt_name) {
+  auto loc = do_get_locale(name);
+  if (loc == std::locale::classic() && alt_name) {
+    loc = do_get_locale(alt_name);
+  }
+  if (loc == std::locale::classic())
+    fmt::print(stderr, "{} locale is missing.\n", name);
+  return loc;
+}

test/util.h

@@ -7,12 +7,11 @@
 
 #include <cstdarg>
 #include <cstdio>
+#include <locale>
 #include <string>
 
 #include "fmt/os.h"
 
-enum { BUFFER_SIZE = 256 };
-
 #ifdef _MSC_VER
 #  define FMT_VSNPRINTF vsprintf_s
 #else
@@ -27,12 +26,7 @@ void safe_sprintf(char (&buffer)[SIZE], const char* format, ...) {
   va_end(args);
 }
 
-// Increment a number in a string.
-void increment(char* s);
-
-std::string get_system_error(int error_code);
-
-extern const char* const FILE_CONTENT;
+extern const char* const file_content;
 
 // Opens a buffered file for reading.
 fmt::buffered_file open_buffered_file(FILE** fp = nullptr);
@@ -48,37 +42,40 @@ inline FILE* safe_fopen(const char* filename, const char* mode) {
 #endif
 }
 
-template <typename Char> class BasicTestString {
+template <typename Char> class basic_test_string {
  private:
   std::basic_string<Char> value_;
 
-  static const Char EMPTY[];
+  static const Char empty[];
 
  public:
-  explicit BasicTestString(const Char* value = EMPTY) : value_(value) {}
+  explicit basic_test_string(const Char* value = empty) : value_(value) {}
 
   const std::basic_string<Char>& value() const { return value_; }
 };
 
-template <typename Char> const Char BasicTestString<Char>::EMPTY[] = {0};
+template <typename Char> const Char basic_test_string<Char>::empty[] = {0};
 
-typedef BasicTestString<char> TestString;
-typedef BasicTestString<wchar_t> TestWString;
+typedef basic_test_string<char> test_string;
+typedef basic_test_string<wchar_t> test_wstring;
 
 template <typename Char>
 std::basic_ostream<Char>& operator<<(std::basic_ostream<Char>& os,
-                                     const BasicTestString<Char>& s) {
+                                     const basic_test_string<Char>& s) {
   os << s.value();
   return os;
 }
 
-class Date {
+class date {
   int year_, month_, day_;
 
  public:
-  Date(int year, int month, int day) : year_(year), month_(month), day_(day) {}
+  date(int year, int month, int day) : year_(year), month_(month), day_(day) {}
 
   int year() const { return year_; }
   int month() const { return month_; }
   int day() const { return day_; }
 };
+
+// Returns a locale with the given name if available or classic locale othewise.
+std::locale get_locale(const char* name, const char* alt_name = nullptr);

test/xchar-test.cc

@@ -0,0 +1,427 @@
+// Formatting library for C++ - formatting library tests
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#include "fmt/xchar.h"
+
+#include <complex>
+
+#include "fmt/chrono.h"
+#include "fmt/color.h"
+#include "fmt/ostream.h"
+#include "fmt/ranges.h"
+#include "gtest/gtest.h"
+
+using fmt::detail::max_value;
+
+namespace test_ns {
+template <typename Char> class test_string {
+ private:
+  std::basic_string<Char> s_;
+
+ public:
+  test_string(const Char* s) : s_(s) {}
+  const Char* data() const { return s_.data(); }
+  size_t length() const { return s_.size(); }
+  operator const Char*() const { return s_.c_str(); }
+};
+
+template <typename Char>
+fmt::basic_string_view<Char> to_string_view(const test_string<Char>& s) {
+  return {s.data(), s.length()};
+}
+
+struct non_string {};
+}  // namespace test_ns
+
+template <typename T> class is_string_test : public testing::Test {};
+
+using string_char_types = testing::Types<char, wchar_t, char16_t, char32_t>;
+TYPED_TEST_SUITE(is_string_test, string_char_types);
+
+template <typename Char>
+struct derived_from_string_view : fmt::basic_string_view<Char> {};
+
+TYPED_TEST(is_string_test, is_string) {
+  EXPECT_TRUE(fmt::detail::is_string<TypeParam*>::value);
+  EXPECT_TRUE(fmt::detail::is_string<const TypeParam*>::value);
+  EXPECT_TRUE(fmt::detail::is_string<TypeParam[2]>::value);
+  EXPECT_TRUE(fmt::detail::is_string<const TypeParam[2]>::value);
+  EXPECT_TRUE(fmt::detail::is_string<std::basic_string<TypeParam>>::value);
+  EXPECT_TRUE(fmt::detail::is_string<fmt::basic_string_view<TypeParam>>::value);
+  EXPECT_TRUE(
+      fmt::detail::is_string<derived_from_string_view<TypeParam>>::value);
+  using fmt_string_view = fmt::detail::std_string_view<TypeParam>;
+  EXPECT_TRUE(std::is_empty<fmt_string_view>::value !=
+              fmt::detail::is_string<fmt_string_view>::value);
+  EXPECT_TRUE(fmt::detail::is_string<test_ns::test_string<TypeParam>>::value);
+  EXPECT_FALSE(fmt::detail::is_string<test_ns::non_string>::value);
+}
+
+// std::is_constructible is broken in MSVC until version 2015.
+#if !FMT_MSC_VER || FMT_MSC_VER >= 1900
+struct explicitly_convertible_to_wstring_view {
+  explicit operator fmt::wstring_view() const { return L"foo"; }
+};
+
+TEST(xchar_test, format_explicitly_convertible_to_wstring_view) {
+  EXPECT_EQ(L"foo",
+            fmt::format(L"{}", explicitly_convertible_to_wstring_view()));
+}
+#endif
+
+TEST(xchar_test, format) {
+  EXPECT_EQ(L"42", fmt::format(L"{}", 42));
+  EXPECT_EQ(L"4.2", fmt::format(L"{}", 4.2));
+  EXPECT_EQ(L"abc", fmt::format(L"{}", L"abc"));
+  EXPECT_EQ(L"z", fmt::format(L"{}", L'z'));
+  EXPECT_THROW(fmt::format(L"{:*\x343E}", 42), fmt::format_error);
+  EXPECT_EQ(L"true", fmt::format(L"{}", true));
+  EXPECT_EQ(L"a", fmt::format(L"{0}", 'a'));
+  EXPECT_EQ(L"a", fmt::format(L"{0}", L'a'));
+  EXPECT_EQ(L"Cyrillic letter \x42e",
+            fmt::format(L"Cyrillic letter {}", L'\x42e'));
+  EXPECT_EQ(L"abc1", fmt::format(L"{}c{}", L"ab", 1));
+}
+
+TEST(xchar_test, compile_time_string) {
+#if defined(FMT_USE_STRING_VIEW) && __cplusplus >= 201703L
+  EXPECT_EQ(L"42", fmt::format(FMT_STRING(std::wstring_view(L"{}")), 42));
+#endif
+}
+
+#if __cplusplus > 201103L
+struct custom_char {
+  int value;
+  custom_char() = default;
+
+  template <typename T>
+  constexpr custom_char(T val) : value(static_cast<int>(val)) {}
+
+  operator int() const { return value; }
+};
+
+int to_ascii(custom_char c) { return c; }
+
+FMT_BEGIN_NAMESPACE
+template <> struct is_char<custom_char> : std::true_type {};
+FMT_END_NAMESPACE
+
+TEST(xchar_test, format_custom_char) {
+  const custom_char format[] = {'{', '}', 0};
+  auto result = fmt::format(format, custom_char('x'));
+  EXPECT_EQ(result.size(), 1);
+  EXPECT_EQ(result[0], custom_char('x'));
+}
+#endif
+
+// Convert a char8_t string to std::string. Otherwise GTest will insist on
+// inserting `char8_t` NTBS into a `char` stream which is disabled by P1423.
+template <typename S> std::string from_u8str(const S& str) {
+  return std::string(str.begin(), str.end());
+}
+
+TEST(xchar_test, format_utf8_precision) {
+  using str_type = std::basic_string<fmt::detail::char8_type>;
+  auto format =
+      str_type(reinterpret_cast<const fmt::detail::char8_type*>(u8"{:.4}"));
+  auto str = str_type(reinterpret_cast<const fmt::detail::char8_type*>(
+      u8"caf\u00e9s"));  // cafés
+  auto result = fmt::format(format, str);
+  EXPECT_EQ(fmt::detail::compute_width(result), 4);
+  EXPECT_EQ(result.size(), 5);
+  EXPECT_EQ(from_u8str(result), from_u8str(str.substr(0, 5)));
+}
+
+TEST(xchar_test, format_to) {
+  auto buf = std::vector<wchar_t>();
+  fmt::format_to(std::back_inserter(buf), L"{}{}", 42, L'\0');
+  EXPECT_STREQ(buf.data(), L"42");
+}
+
+TEST(xchar_test, vformat_to) {
+  using wcontext = fmt::wformat_context;
+  fmt::basic_format_arg<wcontext> warg = fmt::detail::make_arg<wcontext>(42);
+  auto wargs = fmt::basic_format_args<wcontext>(&warg, 1);
+  auto w = std::wstring();
+  fmt::vformat_to(std::back_inserter(w), L"{}", wargs);
+  EXPECT_EQ(L"42", w);
+  w.clear();
+  fmt::vformat_to(std::back_inserter(w), FMT_STRING(L"{}"), wargs);
+  EXPECT_EQ(L"42", w);
+}
+
+TEST(format_test, wide_format_to_n) {
+  wchar_t buffer[4];
+  buffer[3] = L'x';
+  auto result = fmt::format_to_n(buffer, 3, L"{}", 12345);
+  EXPECT_EQ(5u, result.size);
+  EXPECT_EQ(buffer + 3, result.out);
+  EXPECT_EQ(L"123x", fmt::wstring_view(buffer, 4));
+  buffer[0] = L'x';
+  buffer[1] = L'x';
+  buffer[2] = L'x';
+  result = fmt::format_to_n(buffer, 3, L"{}", L'A');
+  EXPECT_EQ(1u, result.size);
+  EXPECT_EQ(buffer + 1, result.out);
+  EXPECT_EQ(L"Axxx", fmt::wstring_view(buffer, 4));
+  result = fmt::format_to_n(buffer, 3, L"{}{} ", L'B', L'C');
+  EXPECT_EQ(3u, result.size);
+  EXPECT_EQ(buffer + 3, result.out);
+  EXPECT_EQ(L"BC x", fmt::wstring_view(buffer, 4));
+}
+
+#if FMT_USE_USER_DEFINED_LITERALS
+TEST(xchar_test, format_udl) {
+  using namespace fmt::literals;
+  EXPECT_EQ(L"{}c{}"_format(L"ab", 1), fmt::format(L"{}c{}", L"ab", 1));
+}
+
+TEST(xchar_test, named_arg_udl) {
+  using namespace fmt::literals;
+  auto udl_a =
+      fmt::format(L"{first}{second}{first}{third}", L"first"_a = L"abra",
+                  L"second"_a = L"cad", L"third"_a = 99);
+  EXPECT_EQ(
+      fmt::format(L"{first}{second}{first}{third}", fmt::arg(L"first", L"abra"),
+                  fmt::arg(L"second", L"cad"), fmt::arg(L"third", 99)),
+      udl_a);
+}
+#endif  // FMT_USE_USER_DEFINED_LITERALS
+
+TEST(xchar_test, print) {
+  // Check that the wide print overload compiles.
+  if (fmt::detail::const_check(false)) fmt::print(L"test");
+}
+
+TEST(xchar_test, join) {
+  int v[3] = {1, 2, 3};
+  EXPECT_EQ(fmt::format(L"({})", fmt::join(v, v + 3, L", ")), L"(1, 2, 3)");
+  auto t = std::tuple<wchar_t, int, float>('a', 1, 2.0f);
+  EXPECT_EQ(fmt::format(L"({})", fmt::join(t, L", ")), L"(a, 1, 2)");
+}
+
+enum streamable_enum {};
+
+std::wostream& operator<<(std::wostream& os, streamable_enum) {
+  return os << L"streamable_enum";
+}
+
+enum unstreamable_enum {};
+
+TEST(xchar_test, enum) {
+  EXPECT_EQ(L"streamable_enum", fmt::format(L"{}", streamable_enum()));
+  EXPECT_EQ(L"0", fmt::format(L"{}", unstreamable_enum()));
+}
+
+TEST(xchar_test, sign_not_truncated) {
+  wchar_t format_str[] = {
+      L'{', L':',
+      '+' | static_cast<wchar_t>(1 << fmt::detail::num_bits<char>()), L'}', 0};
+  EXPECT_THROW(fmt::format(format_str, 42), fmt::format_error);
+}
+
+namespace fake_qt {
+class QString {
+ public:
+  QString(const wchar_t* s) : s_(s) {}
+  const wchar_t* utf16() const FMT_NOEXCEPT { return s_.data(); }
+  int size() const FMT_NOEXCEPT { return static_cast<int>(s_.size()); }
+
+ private:
+  std::wstring s_;
+};
+
+fmt::basic_string_view<wchar_t> to_string_view(const QString& s) FMT_NOEXCEPT {
+  return {s.utf16(), static_cast<size_t>(s.size())};
+}
+}  // namespace fake_qt
+
+TEST(format_test, format_foreign_strings) {
+  using fake_qt::QString;
+  EXPECT_EQ(fmt::format(QString(L"{}"), 42), L"42");
+  EXPECT_EQ(fmt::format(QString(L"{}"), QString(L"42")), L"42");
+}
+
+TEST(xchar_test, chrono) {
+  auto tm = std::tm();
+  tm.tm_year = 116;
+  tm.tm_mon = 3;
+  tm.tm_mday = 25;
+  tm.tm_hour = 11;
+  tm.tm_min = 22;
+  tm.tm_sec = 33;
+  EXPECT_EQ(fmt::format("The date is {:%Y-%m-%d %H:%M:%S}.", tm),
+            "The date is 2016-04-25 11:22:33.");
+  EXPECT_EQ(L"42s", fmt::format(L"{}", std::chrono::seconds(42)));
+}
+
+TEST(xchar_test, color) {
+  EXPECT_EQ(fmt::format(fg(fmt::rgb(255, 20, 30)), L"rgb(255,20,30) wide"),
+            L"\x1b[38;2;255;020;030mrgb(255,20,30) wide\x1b[0m");
+}
+
+TEST(xchar_test, ostream) {
+  std::wostringstream wos;
+  fmt::print(wos, L"Don't {}!", L"panic");
+  EXPECT_EQ(L"Don't panic!", wos.str());
+}
+
+TEST(xchar_test, to_wstring) { EXPECT_EQ(L"42", fmt::to_wstring(42)); }
+
+#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+template <typename Char> struct numpunct : std::numpunct<Char> {
+ protected:
+  Char do_decimal_point() const override { return '?'; }
+  std::string do_grouping() const override { return "\03"; }
+  Char do_thousands_sep() const override { return '~'; }
+};
+
+template <typename Char> struct no_grouping : std::numpunct<Char> {
+ protected:
+  Char do_decimal_point() const override { return '.'; }
+  std::string do_grouping() const override { return ""; }
+  Char do_thousands_sep() const override { return ','; }
+};
+
+template <typename Char> struct special_grouping : std::numpunct<Char> {
+ protected:
+  Char do_decimal_point() const override { return '.'; }
+  std::string do_grouping() const override { return "\03\02"; }
+  Char do_thousands_sep() const override { return ','; }
+};
+
+template <typename Char> struct small_grouping : std::numpunct<Char> {
+ protected:
+  Char do_decimal_point() const override { return '.'; }
+  std::string do_grouping() const override { return "\01"; }
+  Char do_thousands_sep() const override { return ','; }
+};
+
+TEST(locale_test, double_decimal_point) {
+  auto loc = std::locale(std::locale(), new numpunct<char>());
+  EXPECT_EQ("1?23", fmt::format(loc, "{:L}", 1.23));
+  EXPECT_EQ("1?230000", fmt::format(loc, "{:Lf}", 1.23));
+}
+
+TEST(locale_test, format) {
+  auto loc = std::locale(std::locale(), new numpunct<char>());
+  EXPECT_EQ("1234567", fmt::format(std::locale(), "{:L}", 1234567));
+  EXPECT_EQ("1~234~567", fmt::format(loc, "{:L}", 1234567));
+  EXPECT_EQ("-1~234~567", fmt::format(loc, "{:L}", -1234567));
+  EXPECT_EQ("-256", fmt::format(loc, "{:L}", -256));
+  fmt::format_arg_store<fmt::format_context, int> as{1234567};
+  EXPECT_EQ("1~234~567", fmt::vformat(loc, "{:L}", fmt::format_args(as)));
+  auto s = std::string();
+  fmt::format_to(std::back_inserter(s), loc, "{:L}", 1234567);
+  EXPECT_EQ("1~234~567", s);
+
+  auto no_grouping_loc = std::locale(std::locale(), new no_grouping<char>());
+  EXPECT_EQ("1234567", fmt::format(no_grouping_loc, "{:L}", 1234567));
+
+  auto special_grouping_loc =
+      std::locale(std::locale(), new special_grouping<char>());
+  EXPECT_EQ("1,23,45,678", fmt::format(special_grouping_loc, "{:L}", 12345678));
+  EXPECT_EQ("12,345", fmt::format(special_grouping_loc, "{:L}", 12345));
+
+  auto small_grouping_loc =
+      std::locale(std::locale(), new small_grouping<char>());
+  EXPECT_EQ("4,2,9,4,9,6,7,2,9,5",
+            fmt::format(small_grouping_loc, "{:L}", max_value<uint32_t>()));
+}
+
+TEST(locale_test, format_detault_align) {
+  auto loc = std::locale({}, new special_grouping<char>());
+  EXPECT_EQ("  12,345", fmt::format(loc, "{:8L}", 12345));
+}
+
+TEST(locale_test, format_plus) {
+  auto loc = std::locale({}, new special_grouping<char>());
+  EXPECT_EQ("+100", fmt::format(loc, "{:+L}", 100));
+}
+
+TEST(locale_test, wformat) {
+  auto loc = std::locale(std::locale(), new numpunct<wchar_t>());
+  EXPECT_EQ(L"1234567", fmt::format(std::locale(), L"{:L}", 1234567));
+  EXPECT_EQ(L"1~234~567", fmt::format(loc, L"{:L}", 1234567));
+  using wcontext = fmt::buffer_context<wchar_t>;
+  fmt::format_arg_store<wcontext, int> as{1234567};
+  EXPECT_EQ(L"1~234~567",
+            fmt::vformat(loc, L"{:L}", fmt::basic_format_args<wcontext>(as)));
+  EXPECT_EQ(L"1234567", fmt::format(std::locale("C"), L"{:L}", 1234567));
+
+  auto no_grouping_loc = std::locale(std::locale(), new no_grouping<wchar_t>());
+  EXPECT_EQ(L"1234567", fmt::format(no_grouping_loc, L"{:L}", 1234567));
+
+  auto special_grouping_loc =
+      std::locale(std::locale(), new special_grouping<wchar_t>());
+  EXPECT_EQ(L"1,23,45,678",
+            fmt::format(special_grouping_loc, L"{:L}", 12345678));
+
+  auto small_grouping_loc =
+      std::locale(std::locale(), new small_grouping<wchar_t>());
+  EXPECT_EQ(L"4,2,9,4,9,6,7,2,9,5",
+            fmt::format(small_grouping_loc, L"{:L}", max_value<uint32_t>()));
+}
+
+TEST(locale_test, double_formatter) {
+  auto loc = std::locale(std::locale(), new special_grouping<char>());
+  auto f = fmt::formatter<int>();
+  auto parse_ctx = fmt::format_parse_context("L");
+  f.parse(parse_ctx);
+  char buf[10] = {};
+  fmt::basic_format_context<char*, char> format_ctx(
+      buf, {}, fmt::detail::locale_ref(loc));
+  *f.format(12345, format_ctx) = 0;
+  EXPECT_STREQ("12,345", buf);
+}
+
+FMT_BEGIN_NAMESPACE
+template <class charT> struct formatter<std::complex<double>, charT> {
+ private:
+  detail::dynamic_format_specs<char> specs_;
+
+ public:
+  FMT_CONSTEXPR typename basic_format_parse_context<charT>::iterator parse(
+      basic_format_parse_context<charT>& ctx) {
+    using handler_type =
+        detail::dynamic_specs_handler<basic_format_parse_context<charT>>;
+    detail::specs_checker<handler_type> handler(handler_type(specs_, ctx),
+                                                detail::type::string_type);
+    auto it = parse_format_specs(ctx.begin(), ctx.end(), handler);
+    detail::parse_float_type_spec(specs_, ctx.error_handler());
+    return it;
+  }
+
+  template <class FormatContext>
+  typename FormatContext::iterator format(const std::complex<double>& c,
+                                          FormatContext& ctx) {
+    detail::handle_dynamic_spec<detail::precision_checker>(
+        specs_.precision, specs_.precision_ref, ctx);
+    auto specs = std::string();
+    if (specs_.precision > 0) specs = fmt::format(".{}", specs_.precision);
+    if (specs_.type) specs += specs_.type;
+    auto real = fmt::format(ctx.locale().template get<std::locale>(),
+                            fmt::runtime("{:" + specs + "}"), c.real());
+    auto imag = fmt::format(ctx.locale().template get<std::locale>(),
+                            fmt::runtime("{:" + specs + "}"), c.imag());
+    auto fill_align_width = std::string();
+    if (specs_.width > 0) fill_align_width = fmt::format(">{}", specs_.width);
+    return format_to(ctx.out(), runtime("{:" + fill_align_width + "}"),
+                     c.real() != 0 ? fmt::format("({}+{}i)", real, imag)
+                                   : fmt::format("{}i", imag));
+  }
+};
+FMT_END_NAMESPACE
+
+TEST(locale_test, complex) {
+  std::string s = fmt::format("{}", std::complex<double>(1, 2));
+  EXPECT_EQ(s, "(1+2i)");
+  EXPECT_EQ(fmt::format("{:.2f}", std::complex<double>(1, 2)), "(1.00+2.00i)");
+  EXPECT_EQ(fmt::format("{:8}", std::complex<double>(1, 2)), "  (1+2i)");
+}
+
+#endif  // FMT_STATIC_THOUSANDS_SEPARATOR