Update version

D:\a\fmt\fmt\test\compile-test.cc(362,3): fatal error C1001: Internal compiler error. [D:\a\fmt\build\test\compile-test.vcxproj]
(compiler file 'D:\a\_work\1\s\src\vctools\Compiler\CxxFE\sl\p1\c\constexpr\constexpr.cpp', line 8635)

Signed-off-by: Vladislav Shchapov <vladislav@shchapov.ru>

.clang-format

@@ -0,0 +1,8 @@
+# Run manually to reformat a file:
+# clang-format -i --style=file <file>
+Language: Cpp
+BasedOnStyle: Google
+IndentPPDirectives: AfterHash
+IndentCaseLabels: false
+AlwaysBreakTemplateDeclarations: false
+DerivePointerAlignment: false

.github/issue_template.md

@@ -0,0 +1,6 @@
+<!--
+Please make sure that the problem reproduces on the current master before
+submitting an issue.
+If possible please provide a repro on Compiler Explorer:
+https://godbolt.org/z/fxccbh53W.
+-->

.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 +1,27 @@
+name: doc
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+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 update
+        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 +1,94 @@
+name: linux
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+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++-8
+            build_type: Debug
+            std: 17
+            install: sudo apt install g++-8
+            os: ubuntu-18.04
+          - cxx: g++-10
+            build_type: Debug
+            std: 17
+            os: ubuntu-18.04
+          - cxx: g++-11
+            build_type: Debug
+            std: 20
+            os: ubuntu-20.04
+            install: sudo apt install g++-11
+          - cxx: clang++-8
+            build_type: Debug
+            std: 17
+            cxxflags: -stdlib=libc++
+            os: ubuntu-18.04
+            install: sudo apt install clang-8 libc++-8-dev libc++abi-8-dev
+          - 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 update
+        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 +1,40 @@
+name: macos
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+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 +1,63 @@
+name: windows
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    runs-on: ${{matrix.os}}
+    strategy:
+      matrix:
+        # windows-2019 has MSVC 2019 installed;
+        # windows-2022 has MSVC 2022 installed:
+        # https://github.com/actions/virtual-environments.
+        os: [windows-2019]
+        platform: [Win32, x64]
+        build_type: [Debug, Release]
+        standard: [11, 17, 20]
+        include:
+          - os: windows-2019
+            platform: Win32
+            build_type: Debug
+            shared: -DBUILD_SHARED_LIBS=ON
+          - os: windows-2022
+            platform: x64
+            build_type: Debug
+            standard: 20
+        exclude:
+          - os: windows-2019
+            standard: 11
+            platform: Win32
+          - 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

@@ -1,4 +1,5 @@
 .vscode/
+.vs/
 
 *.iml
 .idea/
@@ -8,12 +9,14 @@ gradle/
 gradlew*
 local.properties
 build/
+support/.cxx
 
 bin/
 /_CPack_Packages
 /CMakeScripts
 /doc/doxyxml
 /doc/html
+/doc/node_modules
 virtualenv
 /Testing
 /install_manifest.txt
@@ -31,3 +34,4 @@ CMakeFiles
 FMT.build
 Makefile
 run-msbuild.bat
+fmt.pc

.travis.yml

@@ -1,129 +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
-      # 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
-    - env: COMPILER=clang++-6.0 BUILD=Debug STANDARD=14
-      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
-      # g++ 4.4 on Linux with C++11
-    - env: COMPILER=g++-4.4 BUILD=Debug STANDARD=11
-      compiler: gcc
-      addons:
-        apt:
-          update: true
-          packages:
-            - g++-4.4
-          sources:
-            - ubuntu-toolchain-r-test
-      # Android
-    - language: android
-      android:
-      addons:
-        apt:
-          update: true
-      components:
-        - tools
-        - platform-tools
-        - android-21
-        - sys-img-armeabi-v7a-android-21
-      env:
-        - ANDROID=true
-      before_install:
-        - git submodule update --init --recursive
-        - sudo apt-get install wget unzip tree
-      install:
-        # Accept SDK Licenses + Install NDK
-        - yes | sdkmanager --update > /dev/null 2>&1
-        - sdkmanager ndk-bundle > /dev/null 2>&1
-        # Download Gradle 4.3.1 
-        - wget https://services.gradle.org/distributions/gradle-4.3.1-bin.zip
-        - mkdir -p gradle
-        - unzip -q -d ./gradle gradle-4.3.1-bin.zip
-        - export GRADLE=${TRAVIS_BUILD_DIR}/gradle/gradle-4.3.1/bin/gradle
-      before_script:
-        - bash $GRADLE --version
-        - cd ./support
-      script:
-        - bash $GRADLE clean assemble
-      after_success:
-        - cd ${TRAVIS_BUILD_DIR}
-        - tree ./libs
-  allow_failures:
-      # Errors
-    - env: COMPILER=g++-4.4 BUILD=Debug STANDARD=11
-      compiler: gcc
-
-before_script:
-  - if [[ "${TRAVIS_OS_NAME}" == "linux" ]]; then export CXX=${COMPILER}; fi
-  - if [[ "${BUILD}" != "Doc" ]]; then ${CXX} --version; fi
-
-script:
-  - support/travis-build.py

CMakeLists.txt

@@ -1,47 +1,106 @@
-cmake_minimum_required(VERSION 3.1.0)
+cmake_minimum_required(VERSION 3.1...3.18)
 
-# Use newer policies if available, up to most recent tested version of CMake.
-if(${CMAKE_VERSION} VERSION_LESS 3.11)
+# Fallback for using newer policies on CMake <3.12.
+if(${CMAKE_VERSION} VERSION_LESS 3.12)
   cmake_policy(VERSION ${CMAKE_MAJOR_VERSION}.${CMAKE_MINOR_VERSION})
-else()
-  cmake_policy(VERSION 3.11)
 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}.
 function(join result_var)
-  set(result )
+  set(result "")
   foreach (arg ${ARGN})
     set(result "${result}${arg}")
   endforeach ()
   set(${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:
+#   set(<variable> <value>... CACHE <type> <docstring>...)
+# This allows splitting a long docstring for readability.
+function(set_verbose)
+  # cmake_parse_arguments is broken in CMake 3.4 (cannot parse CACHE) so use
+  # list instead.
+  list(GET ARGN 0 var)
+  list(REMOVE_AT ARGN 0)
+  list(GET ARGN 0 val)
+  list(REMOVE_AT ARGN 0)
+  list(REMOVE_AT ARGN 0)
+  list(GET ARGN 0 type)
+  list(REMOVE_AT ARGN 0)
+  join(doc ${ARGN})
+  set(${var} ${val} CACHE ${type} ${doc})
+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 (NOT CMAKE_BUILD_TYPE)
-  join(doc "Choose the type of build, options are: None(CMAKE_CXX_FLAGS or "
-           "CMAKE_C_FLAGS used) Debug Release RelWithDebInfo MinSizeRel.")
-  set(CMAKE_BUILD_TYPE Release CACHE STRING ${doc})
+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.")
 endif ()
 
+project(FMT CXX)
+include(GNUInstallDirs)
+set_verbose(FMT_INC_DIR ${CMAKE_INSTALL_INCLUDEDIR} CACHE STRING
+            "Installation directory for include files, a relative path that "
+            "will be joined with ${CMAKE_INSTALL_PREFIX} or an absolute path.")
+
 option(FMT_PEDANTIC "Enable extra warnings and expensive tests." OFF)
-option(FMT_WERROR "Halt the compilation with an error on compiler warnings." OFF)
+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)
+option(FMT_SYSTEM_HEADERS "Expose headers with marking them as system." OFF)
 
-project(FMT)
+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 OFF)
+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 ()
+set(FMT_SYSTEM_HEADERS_ATTRIBUTE "")
+if (FMT_SYSTEM_HEADERS)
+  set(FMT_SYSTEM_HEADERS_ATTRIBUTE SYSTEM)
+endif ()
 
 # Get version from core.h
 file(READ include/fmt/core.h core_h)
@@ -58,59 +117,72 @@ message(STATUS "Version: ${FMT_VERSION}")
 
 message(STATUS "Build type: ${CMAKE_BUILD_TYPE}")
 
-set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+if (NOT CMAKE_RUNTIME_OUTPUT_DIRECTORY)
+  set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin)
+endif ()
 
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH}
   "${CMAKE_CURRENT_SOURCE_DIR}/support/cmake")
 
 include(cxx14)
-include(CheckCXXCompilerFlag)
+include(JoinPaths)
+
+list(FIND CMAKE_CXX_COMPILE_FEATURES "cxx_variadic_templates" index)
+if (${index} GREATER -1)
+  # Use cxx_variadic_templates instead of more appropriate cxx_std_11 for
+  # compatibility with older CMake versions.
+  set(FMT_REQUIRED_FEATURES cxx_variadic_templates)
+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 -Wfloat-equal -Wlogical-op -Wundef
-      -Wredundant-decls -Wshadow -Wwrite-strings -Wpointer-arith
+      -Wold-style-cast -Wundef
+      -Wredundant-decls -Wwrite-strings -Wpointer-arith
       -Wcast-qual -Wformat=2 -Wmissing-include-dirs
-      -Wcast-align -Wnon-virtual-dtor
+      -Wcast-align
       -Wctor-dtor-privacy -Wdisabled-optimization
       -Winvalid-pch -Woverloaded-virtual
-      -Wno-ctor-dtor-privacy -Wno-dangling-else -Wno-float-equal
-      -Wno-format-nonliteral -Wno-sign-conversion -Wno-shadow)
+      -Wconversion -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
           -Wnull-dereference -Wduplicated-cond)
   endif ()
-
   set(WERROR_FLAG -Werror)
 endif ()
 
 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-  set(PEDANTIC_COMPILE_FLAGS -Weverything -Wpedantic
-      -Wno-weak-vtables -Wno-padded -Wno-gnu-statement-expression
-      -Wno-c++98-compat -Wno-c++98-compat-pedantic -Wno-reserved-id-macro
-      -Wno-global-constructors -Wno-disabled-macro-expansion
-      -Wno-switch-enum -Wno-documentation-unknown-command
-      -Wno-unused-member-function
-      -Wno-format-nonliteral -Wno-missing-noreturn -Wno-undefined-func-template
-      -Wno-shadow -Wno-sign-conversion -Wno-used-but-marked-unused
-      -Wno-covered-switch-default -Wno-missing-prototypes
-      -Wno-missing-variable-declarations -Wno-double-promotion)
-
-  set(WERROR_FLAG -Werror)
-
-  check_cxx_compiler_flag(-Wno-zero-as-null-pointer-constant HAS_NULLPTR_WARNING)
+  set(PEDANTIC_COMPILE_FLAGS -Wall -Wextra -pedantic -Wconversion -Wundef
+      -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}
-        -Wno-zero-as-null-pointer-constant)
+        -Wzero-as-null-pointer-constant)
   endif ()
+  set(WERROR_FLAG -Werror)
 endif ()
 
 if (MSVC)
@@ -118,7 +190,7 @@ 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
@@ -128,19 +200,14 @@ if (MASTER_PROJECT AND CMAKE_GENERATOR MATCHES "Visual Studio")
     set(MSBUILD_SETUP "call \"${WINSDK_SETENV}\"")
   endif ()
   # Set FrameworkPathOverride to get rid of MSB3644 warnings.
-  set(netfxpath "C:\\Program Files\\Reference Assemblies\\Microsoft\\Framework\\.NETFramework\\v4.0")
+  join(netfxpath
+       "C:\\Program Files\\Reference Assemblies\\Microsoft\\Framework\\"
+       ".NETFramework\\v4.0")
   file(WRITE run-msbuild.bat "
     ${MSBUILD_SETUP}
     ${CMAKE_MAKE_PROGRAM} -p:FrameworkPathOverride=\"${netfxpath}\" %*")
 endif ()
 
-include(CheckSymbolExists)
-if (WIN32)
-  check_symbol_exists(open io.h HAVE_OPEN)
-else ()
-  check_symbol_exists(open fcntl.h HAVE_OPEN)
-endif ()
-
 function(add_headers VAR)
   set(headers ${${VAR}})
   foreach (header ${ARGN})
@@ -150,12 +217,15 @@ function(add_headers VAR)
 endfunction()
 
 # Define the fmt library, its includes and the needed defines.
-add_headers(FMT_HEADERS color.h core.h format.h format-inl.h ostream.h printf.h
-                        time.h ranges.h)
-set(FMT_SOURCES src/format.cc)
-if (HAVE_OPEN)
-  add_headers(FMT_HEADERS posix.h)
-  set(FMT_SOURCES ${FMT_SOURCES} src/posix.cc)
+add_headers(FMT_HEADERS args.h chrono.h color.h compile.h core.h format.h
+                        format-inl.h os.h ostream.h printf.h ranges.h std.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)
 endif ()
 
 add_library(fmt ${FMT_SOURCES} ${FMT_HEADERS} README.rst ChangeLog.rst)
@@ -167,63 +237,102 @@ endif ()
 if (FMT_PEDANTIC)
   target_compile_options(fmt PRIVATE ${PEDANTIC_COMPILE_FLAGS})
 endif ()
+if (FMT_MODULE)
+  enable_module(fmt)
+endif ()
 
-target_include_directories(fmt PUBLIC
+target_compile_features(fmt INTERFACE ${FMT_REQUIRED_FEATURES})
+
+target_include_directories(fmt ${FMT_SYSTEM_HEADERS_ATTRIBUTE} PUBLIC
   $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
-  $<INSTALL_INTERFACE:include>)
+  $<INSTALL_INTERFACE:${FMT_INC_DIR}>)
+
+set(FMT_DEBUG_POSTFIX d CACHE STRING "Debug library postfix.")
 
 set_target_properties(fmt PROPERTIES
   VERSION ${FMT_VERSION} SOVERSION ${CPACK_PACKAGE_VERSION_MAJOR}
-  DEBUG_POSTFIX d)
+  PUBLIC_HEADER "${FMT_HEADERS}"
+  DEBUG_POSTFIX "${FMT_DEBUG_POSTFIX}")
+
+# Set FMT_LIB_NAME for pkg-config fmt.pc. We cannot use the OUTPUT_NAME target
+# property because it's not set by default.
+set(FMT_LIB_NAME fmt)
+if (CMAKE_BUILD_TYPE STREQUAL "Debug")
+  set(FMT_LIB_NAME ${FMT_LIB_NAME}${FMT_DEBUG_POSTFIX})
+endif ()
 
 if (BUILD_SHARED_LIBS)
-  if (UNIX AND NOT APPLE)
+  if (UNIX AND NOT APPLE AND NOT ${CMAKE_SYSTEM_NAME} MATCHES "SunOS" AND
+      NOT EMSCRIPTEN)
     # Fix rpmlint warning:
     # unused-direct-shlib-dependency /usr/lib/libformat.so.1.1.0 /lib/libm.so.6.
     target_link_libraries(fmt -Wl,--as-needed)
   endif ()
   target_compile_definitions(fmt PRIVATE FMT_EXPORT INTERFACE FMT_SHARED)
 endif ()
+if (FMT_SAFE_DURATION_CAST)
+  target_compile_definitions(fmt PUBLIC FMT_SAFE_DURATION_CAST)
+endif()
 
 add_library(fmt-header-only INTERFACE)
 add_library(fmt::fmt-header-only ALIAS fmt-header-only)
 
 target_compile_definitions(fmt-header-only INTERFACE FMT_HEADER_ONLY=1)
+target_compile_features(fmt-header-only INTERFACE ${FMT_REQUIRED_FEATURES})
 
-target_include_directories(fmt-header-only INTERFACE
+target_include_directories(fmt-header-only ${FMT_SYSTEM_HEADERS_ATTRIBUTE} INTERFACE
   $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
-  $<INSTALL_INTERFACE:include>)
+  $<INSTALL_INTERFACE:${FMT_INC_DIR}>)
 
 # Install targets.
 if (FMT_INSTALL)
-  include(GNUInstallDirs)
   include(CMakePackageConfigHelpers)
-  set(FMT_CMAKE_DIR ${CMAKE_INSTALL_LIBDIR}/cmake/fmt CACHE STRING
-    "Installation directory for cmake files, relative to ${CMAKE_INSTALL_PREFIX}.")
+  set_verbose(FMT_CMAKE_DIR ${CMAKE_INSTALL_LIBDIR}/cmake/fmt CACHE STRING
+              "Installation directory for cmake files, a relative path that "
+              "will be joined with ${CMAKE_INSTALL_PREFIX} or an absolute "
+              "path.")
   set(version_config ${PROJECT_BINARY_DIR}/fmt-config-version.cmake)
   set(project_config ${PROJECT_BINARY_DIR}/fmt-config.cmake)
+  set(pkgconfig ${PROJECT_BINARY_DIR}/fmt.pc)
   set(targets_export_name fmt-targets)
 
-  set (INSTALL_TARGETS fmt)
-  if (TARGET fmt-header-only)
-    set(INSTALL_TARGETS ${INSTALL_TARGETS} fmt-header-only)
-  endif ()
+  set_verbose(FMT_LIB_DIR ${CMAKE_INSTALL_LIBDIR} CACHE STRING
+              "Installation directory for libraries, a relative path that "
+              "will be joined to ${CMAKE_INSTALL_PREFIX} or an absolute path.")
 
-  set(FMT_LIB_DIR ${CMAKE_INSTALL_LIBDIR} CACHE STRING
-      "Installation directory for libraries, relative to ${CMAKE_INSTALL_PREFIX}.")
-
-  set(FMT_INC_DIR ${CMAKE_INSTALL_INCLUDEDIR}/fmt CACHE STRING
-      "Installation directory for include files, relative to ${CMAKE_INSTALL_PREFIX}.")
+  set_verbose(FMT_PKGCONFIG_DIR ${CMAKE_INSTALL_LIBDIR}/pkgconfig CACHE PATH
+              "Installation directory for pkgconfig (.pc) files, a relative "
+              "path that will be joined with ${CMAKE_INSTALL_PREFIX} or an "
+              "absolute path.")
 
   # Generate the version, config and target files into the build directory.
   write_basic_package_version_file(
     ${version_config}
     VERSION ${FMT_VERSION}
     COMPATIBILITY AnyNewerVersion)
+
+  join_paths(libdir_for_pc_file "\${exec_prefix}" "${FMT_LIB_DIR}")
+  join_paths(includedir_for_pc_file "\${prefix}" "${FMT_INC_DIR}")
+
+  configure_file(
+    "${PROJECT_SOURCE_DIR}/support/cmake/fmt.pc.in"
+    "${pkgconfig}"
+    @ONLY)
   configure_package_config_file(
     ${PROJECT_SOURCE_DIR}/support/cmake/fmt-config.cmake.in
     ${project_config}
     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 ${FMT_LIB_DIR}
+          PUBLIC_HEADER DESTINATION "${FMT_INC_DIR}/fmt"
+          FRAMEWORK DESTINATION "."
+          RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
+
   # Use a namespace because CMake provides better diagnostics for namespaced
   # imported targets.
   export(TARGETS ${INSTALL_TARGETS} NAMESPACE fmt::
@@ -236,10 +345,9 @@ 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}
-          DESTINATION ${FMT_LIB_DIR})
-  install(FILES ${FMT_HEADERS} DESTINATION ${FMT_INC_DIR})
+  install(FILES $<TARGET_PDB_FILE:${INSTALL_TARGETS}>
+          DESTINATION ${FMT_LIB_DIR} OPTIONAL)
+  install(FILES "${pkgconfig}" DESTINATION "${FMT_PKGCONFIG_DIR}")
 endif ()
 
 if (FMT_DOC)
@@ -251,11 +359,23 @@ if (FMT_TEST)
   add_subdirectory(test)
 endif ()
 
+# Control fuzzing independent of the unit tests.
+if (FMT_FUZZ)
+  add_subdirectory(test/fuzzing)
+
+  # The FMT_FUZZ macro is used to prevent resource exhaustion in fuzzing
+  # mode and make fuzzing practically possible. It is similar to
+  # FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION but uses a different name to
+  # avoid interfering with fuzzing of projects that use {fmt}.
+  # See also https://llvm.org/docs/LibFuzzer.html#fuzzer-friendly-build-mode.
+  target_compile_definitions(fmt PUBLIC 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)
+  list(REMOVE_ITEM lines /doc/html)
   foreach (line ${lines})
     string(REPLACE "." "[.]" line "${line}")
     string(REPLACE "*" ".*" line "${line}")

CONTRIBUTING.md

@@ -0,0 +1,20 @@
+Contributing to {fmt}
+=====================
+
+By submitting a pull request or a patch, you represent that you have the right
+to license your contribution to the {fmt} project owners and the community,
+agree that your contributions are licensed under the {fmt} license, and agree
+to future changes to the licensing.
+
+All C++ code must adhere to [Google C++ Style Guide](
+https://google.github.io/styleguide/cppguide.html) with the following
+exceptions:
+
+* Exceptions are permitted
+* snake_case should be used instead of UpperCamelCase for function and type
+  names
+
+All documentation must adhere to the [Google Developer Documentation Style
+Guide](https://developers.google.com/style).
+
+Thanks for contributing!

CONTRIBUTING.rst

@@ -1,12 +0,0 @@
-Contributing to fmt
-===================
-
-All C++ code must adhere to `Google C++ Style Guide
-<https://google.github.io/styleguide/cppguide.html>`_ with the following
-exceptions:
-
-* Exceptions are permitted
-* snake_case should be used instead of UpperCamelCase for function and type
-  names
-
-Thanks for contributing!

LICENSE.rst

@@ -1,23 +1,27 @@
-Copyright (c) 2012 - 2016, Victor Zverovich
+Copyright (c) 2012 - present, Victor Zverovich
 
-All rights reserved.
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
 
-Redistribution and use in source and binary forms, with or without
-modification, are permitted provided that the following conditions are met:
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
 
-1. Redistributions of source code must retain the above copyright notice, this
-   list of conditions and the following disclaimer.
-2. Redistributions in binary form must reproduce the above copyright notice,
-   this list of conditions and the following disclaimer in the documentation
-   and/or other materials provided with the distribution.
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
-ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
-WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
-DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR
-ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
-(INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
-LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
-ON ANY 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.
+--- Optional exception to the license ---
+
+As an exception, if, as a result of your compiling your source code, portions
+of this Software are embedded into a machine-executable object form of such
+source code, you may redistribute such embedded portions in such object form
+without including the above copyright and permission notices.

README.rst

@@ -1,324 +1,189 @@
-{fmt}
-=====
+.. image:: https://user-images.githubusercontent.com/
+           576385/156254208-f5b743a9-88cf-439d-b0c0-923d53e8d551.png
+   :width: 25%
+   :alt: {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://ci.appveyor.com/api/projects/status/ehjkiefde6gucy1v
+.. 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?svg=true
    :target: https://ci.appveyor.com/project/vitaut/fmt
-   
-.. image:: https://badges.gitter.im/Join%20Chat.svg
-   :alt: Join the chat at https://gitter.im/fmtlib/fmt
-   :target: https://gitter.im/fmtlib/fmt
 
-**{fmt}** is an open-source formatting library for C++.
-It can be used as a safe and fast alternative to (s)printf and IOStreams.
+.. image:: https://oss-fuzz-build-logs.storage.googleapis.com/badges/fmt.svg
+   :alt: fmt is continuously fuzzed at oss-fuzz
+   :target: https://bugs.chromium.org/p/oss-fuzz/issues/list?\
+            colspec=ID%20Type%20Component%20Status%20Proj%20Reported%20Owner%20\
+            Summary&q=proj%3Dfmt&can=1
 
-`Documentation <http://fmtlib.net/latest/>`__
+.. image:: https://img.shields.io/badge/stackoverflow-fmt-blue.svg
+   :alt: Ask questions at StackOverflow with the tag fmt
+   :target: https://stackoverflow.com/questions/tagged/fmt
 
-This is a development branch that implements the C++ standards proposal `P0645
-Text Formatting <http://fmtlib.net/Text%20Formatting.html>`__.
-Released versions are available from the `Releases page
-<https://github.com/fmtlib/fmt/releases>`__.
+**{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 one of the funds that
+help victims of the war in Ukraine: https://www.stopputin.net/.
+
+`Documentation <https://fmt.dev>`__
+
+`Cheat Sheets <https://hackingcpp.com/cpp/libs/fmt.html>`__
+
+Q&A: ask questions on `StackOverflow with the tag fmt
+<https://stackoverflow.com/questions/tagged/fmt>`_.
+
+Try {fmt} in `Compiler Explorer <https://godbolt.org/z/Eq5763>`_.
 
 Features
 --------
 
-* Replacement-based `format API <http://fmtlib.net/dev/api.html>`_ with
-  positional arguments for localization.
-* `Format string syntax <http://fmtlib.net/dev/syntax.html>`_ similar to the one
-  of `str.format <https://docs.python.org/2/library/stdtypes.html#str.format>`_
-  in Python.
+* Simple `format API <https://fmt.dev/latest/api.html>`_ with positional arguments
+  for localization
+* Implementation of `C++20 std::format
+  <https://en.cppreference.com/w/cpp/utility/format>`__
+* `Format string syntax <https://fmt.dev/latest/syntax.html>`_ similar to Python's
+  `format <https://docs.python.org/3/library/stdtypes.html#str.format>`_
+* Fast IEEE 754 floating-point formatter with correct rounding, shortness and
+  round-trip guarantees
 * Safe `printf implementation
-  <http://fmtlib.net/latest/api.html#printf-formatting-functions>`_ including
-  the POSIX extension for positional arguments.
-* Support for user-defined types.
-* High speed: performance of the format API is close to that of glibc's `printf
-  <http://en.cppreference.com/w/cpp/io/c/fprintf>`_ and better than the
-  performance of IOStreams. See `Speed tests`_ and
-  `Fast integer to string conversion in C++
-  <http://zverovich.net/2013/09/07/integer-to-string-conversion-in-cplusplus.html>`_.
-* Small code size both in terms of source code (the minimum configuration
-  consists of just three header files, ``core.h``, ``format.h`` and
-  ``format-inl.h``) and compiled code. See `Compile time and code bloat`_.
-* Reliability: the library has an extensive set of `unit tests
-  <https://github.com/fmtlib/fmt/tree/master/test>`_.
+  <https://fmt.dev/latest/api.html#printf-formatting>`_ including the POSIX
+  extension for positional arguments
+* Extensibility: `support for user-defined types
+  <https://fmt.dev/latest/api.html#formatting-user-defined-types>`_
+* High performance: faster than common standard library implementations of
+  ``(s)printf``, iostreams, ``to_string`` and ``to_chars``, see `Speed tests`_
+  and `Converting a hundred million integers to strings per second
+  <http://www.zverovich.net/2020/06/13/fast-int-to-string-revisited.html>`_
+* Small code size both in terms of source code with the minimum configuration
+  consisting of just three files, ``core.h``, ``format.h`` and ``format-inl.h``,
+  and compiled code; see `Compile time and code bloat`_
+* Reliability: the library has an extensive set of `tests
+  <https://github.com/fmtlib/fmt/tree/master/test>`_ and is `continuously fuzzed
+  <https://bugs.chromium.org/p/oss-fuzz/issues/list?colspec=ID%20Type%20
+  Component%20Status%20Proj%20Reported%20Owner%20Summary&q=proj%3Dfmt&can=1>`_
 * Safety: the library is fully type safe, errors in format strings can be
   reported at compile time, automatic memory management prevents buffer overflow
-  errors.
+  errors
 * Ease of use: small self-contained code base, no external dependencies,
-  permissive BSD `license
+  permissive MIT `license
   <https://github.com/fmtlib/fmt/blob/master/LICENSE.rst>`_
-* `Portability <http://fmtlib.net/latest/index.html#portability>`_ with
-  consistent output across platforms and support for older compilers.
-* Clean warning-free codebase even on high warning levels
-  (``-Wall -Wextra -pedantic``).
-* Support for wide strings.
-* Optional header-only configuration enabled with the ``FMT_HEADER_ONLY`` macro.
+* `Portability <https://fmt.dev/latest/index.html#portability>`_ with
+  consistent output across platforms and support for older compilers
+* Clean warning-free codebase even on high warning levels such as
+  ``-Wall -Wextra -pedantic``
+* Locale-independence by default
+* Optional header-only configuration enabled with the ``FMT_HEADER_ONLY`` macro
 
-See the `documentation <http://fmtlib.net/latest/>`_ for more details.
+See the `documentation <https://fmt.dev>`_ for more details.
 
 Examples
 --------
 
-This prints ``Hello, world!`` to stdout:
+**Print to stdout** (`run <https://godbolt.org/z/Tevcjh>`_)
 
 .. code:: c++
 
-    fmt::print("Hello, {}!", "world");  // uses Python-like format string syntax
-    fmt::printf("Hello, %s!", "world"); // uses printf format string syntax
-
-Arguments can be accessed by position and arguments' indices can be repeated:
-
-.. code:: c++
-
-    std::string s = fmt::format("{0}{1}{0}", "abra", "cad");
-    // s == "abracadabra"
-
-Format strings can be checked at compile time:
-
-.. code:: c++
-
-    // test.cc
-    #define FMT_STRING_ALIAS 1
-    #include <fmt/format.h>
-    std::string s = format(fmt("{2}"), 42);
-
-.. code::
-
-    $ c++ -Iinclude -std=c++14 test.cc
-    ...
-    test.cc:4:17: note: in instantiation of function template specialization 'fmt::v5::format<S, int>' requested here
-    std::string s = format(fmt("{2}"), 42);
-                    ^
-    include/fmt/core.h:778:19: note: non-constexpr function 'on_error' cannot be used in a constant expression
-        ErrorHandler::on_error(message);
-                      ^
-    include/fmt/format.h:2226:16: note: in call to '&checker.context_->on_error(&"argument index out of range"[0])'
-          context_.on_error("argument index out of range");
-                   ^
-
-{fmt} can be used as a safe portable replacement for ``itoa``
-(`godbolt <https://godbolt.org/g/NXmpU4>`_):
-
-.. code:: c++
-
-    fmt::memory_buffer buf;
-    format_to(buf, "{}", 42);    // replaces itoa(42, buffer, 10)
-    format_to(buf, "{:x}", 42);  // replaces itoa(42, buffer, 16)
-    // access the string using to_string(buf) or buf.data()
-
-An object of any user-defined type for which there is an overloaded
-:code:`std::ostream` insertion operator (``operator<<``) can be formatted:
-
-.. code:: c++
-
-    #include "fmt/ostream.h"
-
-    class Date {
-      int year_, month_, day_;
-     public:
-      Date(int year, int month, int day) : year_(year), month_(month), day_(day) {}
-
-      friend std::ostream &operator<<(std::ostream &os, const Date &d) {
-        return os << d.year_ << '-' << d.month_ << '-' << d.day_;
-      }
-    };
-
-    std::string s = fmt::format("The date is {}", Date(2012, 12, 9));
-    // s == "The date is 2012-12-9"
-
-You can create your own functions similar to `format
-<http://fmtlib.net/latest/api.html#format>`_ and
-`print <http://fmtlib.net/latest/api.html#print>`_
-which take arbitrary arguments (`godbolt <https://godbolt.org/g/MHjHVf>`_):
-
-.. code:: c++
-
-    // Prints formatted error message.
-    void vreport_error(const char *format, fmt::format_args args) {
-      fmt::print("Error: ");
-      fmt::vprint(format, args);
-    }
-    template <typename... Args>
-    void report_error(const char *format, const Args & ... args) {
-      vreport_error(format, fmt::make_format_args(args...));
+    #include <fmt/core.h>
+    
+    int main() {
+      fmt::print("Hello, world!\n");
     }
 
-    report_error("file not found: {}", path);
-
-Note that ``vreport_error`` is not parameterized on argument types which can
-improve compile times and reduce code size compared to fully parameterized version.
-
-Projects using this library
----------------------------
-
-* `0 A.D. <http://play0ad.com/>`_: A free, open-source, cross-platform real-time strategy game
-
-* `AMPL/MP <https://github.com/ampl/mp>`_:
-  An open-source library for mathematical programming
-  
-* `AvioBook <https://www.aviobook.aero/en>`_: A comprehensive aircraft operations suite
-
-* `CUAUV <http://cuauv.org/>`_: Cornell University's autonomous underwater vehicle
-
-* `HarpyWar/pvpgn <https://github.com/pvpgn/pvpgn-server>`_:
-  Player vs Player Gaming Network with tweaks
-
-* `KBEngine <http://kbengine.org/>`_: An open-source MMOG server engine
-
-* `Keypirinha <http://keypirinha.com/>`_: A semantic launcher for Windows
-
-* `Kodi <https://kodi.tv/>`_ (formerly xbmc): Home theater software
-
-* `Lifeline <https://github.com/peter-clark/lifeline>`_: A 2D game
-
-* `Drake <http://drake.mit.edu/>`_: A planning, control, and analysis toolbox
-  for nonlinear dynamical systems (MIT)
-
-* `Envoy <https://lyft.github.io/envoy/>`_: C++ L7 proxy and communication bus
-  (Lyft)
-
-* `FiveM <https://fivem.net/>`_: a modification framework for GTA V
-
-* `MongoDB Smasher <https://github.com/duckie/mongo_smasher>`_: A small tool to
-  generate randomized datasets
-
-* `OpenSpace <http://openspaceproject.com/>`_: An open-source astrovisualization
-  framework
-
-* `PenUltima Online (POL) <http://www.polserver.com/>`_:
-  An MMO server, compatible with most Ultima Online clients
-
-* `quasardb <https://www.quasardb.net/>`_: A distributed, high-performance,
-  associative database
-
-* `readpe <https://bitbucket.org/sys_dev/readpe>`_: Read Portable Executable
-
-* `redis-cerberus <https://github.com/HunanTV/redis-cerberus>`_: A Redis cluster proxy
-
-* `Saddy <https://github.com/mamontov-cpp/saddy-graphics-engine-2d>`_:
-  Small crossplatform 2D graphic engine
-
-* `Salesforce Analytics Cloud <http://www.salesforce.com/analytics-cloud/overview/>`_:
-  Business intelligence software
-
-* `Scylla <http://www.scylladb.com/>`_: A Cassandra-compatible NoSQL data store that can handle
-  1 million transactions per second on a single server
-
-* `Seastar <http://www.seastar-project.org/>`_: An advanced, open-source C++ framework for
-  high-performance server applications on modern hardware
-
-* `spdlog <https://github.com/gabime/spdlog>`_: Super fast C++ logging library
-
-* `Stellar <https://www.stellar.org/>`_: Financial platform
-
-* `Touch Surgery <https://www.touchsurgery.com/>`_: Surgery simulator
-
-* `TrinityCore <https://github.com/TrinityCore/TrinityCore>`_: Open-source MMORPG framework
-
-`More... <https://github.com/search?q=cppformat&type=Code>`_
-
-If you are aware of other projects using this library, please let me know
-by `email <mailto:victor.zverovich@gmail.com>`_ or by submitting an
-`issue <https://github.com/fmtlib/fmt/issues>`_.
-
-Motivation
-----------
-
-So why yet another formatting library?
-
-There are plenty of methods for doing this task, from standard ones like
-the printf family of function and IOStreams to Boost Format library and
-FastFormat. The reason for creating a new library is that every existing
-solution that I found either had serious issues or didn't provide
-all the features I needed.
-
-Printf
-~~~~~~
-
-The good thing about printf is that it is pretty fast and readily available
-being a part of the C standard library. The main drawback is that it
-doesn't support user-defined types. Printf also has safety issues although
-they are mostly solved with `__attribute__ ((format (printf, ...))
-<http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html>`_ in GCC.
-There is a POSIX extension that adds positional arguments required for
-`i18n <https://en.wikipedia.org/wiki/Internationalization_and_localization>`_
-to printf but it is not a part of C99 and may not be available on some
-platforms.
-
-IOStreams
-~~~~~~~~~
-
-The main issue with IOStreams is best illustrated with an example:
+**Format a string** (`run <https://godbolt.org/z/oK8h33>`_)
 
 .. code:: c++
 
-    std::cout << std::setprecision(2) << std::fixed << 1.23456 << "\n";
+    std::string s = fmt::format("The answer is {}.", 42);
+    // s == "The answer is 42."
 
-which is a lot of typing compared to printf:
+**Format a string using positional arguments** (`run <https://godbolt.org/z/Yn7Txe>`_)
 
 .. code:: c++
 
-    printf("%.2f\n", 1.23456);
+    std::string s = fmt::format("I'd rather be {1} than {0}.", "right", "happy");
+    // s == "I'd rather be happy than right."
 
-Matthew Wilson, the author of FastFormat, referred to this situation with
-IOStreams as "chevron hell". IOStreams doesn't support positional arguments
-by design.
+**Print chrono durations** (`run <https://godbolt.org/z/K8s4Mc>`_)
 
-The good part is that IOStreams supports user-defined types and is safe
-although error reporting is awkward.
+.. code:: c++
 
-Boost Format library
-~~~~~~~~~~~~~~~~~~~~
+    #include <fmt/chrono.h>
 
-This is a very powerful library which supports both printf-like format
-strings and positional arguments. Its main drawback is performance.
-According to various benchmarks it is much slower than other methods
-considered here. Boost Format also has excessive build times and severe
-code bloat issues (see `Benchmarks`_).
+    int main() {
+      using namespace std::literals::chrono_literals;
+      fmt::print("Default format: {} {}\n", 42s, 100ms);
+      fmt::print("strftime-like format: {:%H:%M:%S}\n", 3h + 15min + 30s);
+    }
 
-FastFormat
-~~~~~~~~~~
+Output::
 
-This is an interesting library which is fast, safe and has positional
-arguments. However it has significant limitations, citing its author:
+    Default format: 42s 100ms
+    strftime-like format: 03:15:30
 
-    Three features that have no hope of being accommodated within the
-    current design are:
+**Print a container** (`run <https://godbolt.org/z/MxM1YqjE7>`_)
 
-    * Leading zeros (or any other non-space padding)
-    * Octal/hexadecimal encoding
-    * Runtime width/alignment specification
+.. code:: c++
 
-It is also quite big and has a heavy dependency, STLSoft, which might be
-too restrictive for using it in some projects.
+    #include <vector>
+    #include <fmt/ranges.h>
 
-Loki SafeFormat
-~~~~~~~~~~~~~~~
+    int main() {
+      std::vector<int> v = {1, 2, 3};
+      fmt::print("{}\n", v);
+    }
 
-SafeFormat is a formatting library which uses printf-like format strings
-and is type safe. It doesn't support user-defined types or positional
-arguments. It makes unconventional use of ``operator()`` for passing
-format arguments.
+Output::
 
-Tinyformat
-~~~~~~~~~~
+    [1, 2, 3]
 
-This library supports printf-like format strings and is very small and
-fast. Unfortunately it doesn't support positional arguments and wrapping
-it in C++98 is somewhat difficult. Also its performance and code compactness
-are limited by IOStreams.
+**Check a format string at compile time**
 
-Boost Spirit.Karma
-~~~~~~~~~~~~~~~~~~
+.. code:: c++
 
-This is not really a formatting library but I decided to include it here
-for completeness. As IOStreams it suffers from the problem of mixing
-verbatim text with arguments. The library is pretty fast, but slower
-on integer formatting than ``fmt::Writer`` on Karma's own benchmark,
-see `Fast integer to string conversion in C++
-<http://zverovich.net/2013/09/07/integer-to-string-conversion-in-cplusplus.html>`_.
+    std::string s = fmt::format("{:d}", "I am not a number");
+
+This gives a compile-time error in C++20 because ``d`` is an invalid format
+specifier for a string.
+
+**Write a file from a single thread**
+
+.. code:: c++
+
+    #include <fmt/os.h>
+
+    int main() {
+      auto out = fmt::output_file("guide.txt");
+      out.print("Don't {}", "Panic");
+    }
+
+This can be `5 to 9 times faster than fprintf
+<http://www.zverovich.net/2020/08/04/optimal-file-buffer-size.html>`_.
+
+**Print with colors and text styles**
+
+.. code:: c++
+
+    #include <fmt/color.h>
+
+    int main() {
+      fmt::print(fg(fmt::color::crimson) | fmt::emphasis::bold,
+                 "Hello, {}!\n", "world");
+      fmt::print(fg(fmt::color::floral_white) | bg(fmt::color::slate_gray) |
+                 fmt::emphasis::underline, "Hello, {}!\n", "мир");
+      fmt::print(fg(fmt::color::steel_blue) | fmt::emphasis::italic,
+                 "Hello, {}!\n", "世界");
+    }
+
+Output on a modern terminal:
+
+.. image:: https://user-images.githubusercontent.com/
+           576385/88485597-d312f600-cf2b-11ea-9cbe-61f535a86e28.png
 
 Benchmarks
 ----------
@@ -326,32 +191,33 @@ Benchmarks
 Speed tests
 ~~~~~~~~~~~
 
-The following speed tests results were generated by building
-``tinyformat_test.cpp`` on Ubuntu GNU/Linux 14.04.1 with
-``g++-4.8.2 -O3 -DSPEED_TEST -DHAVE_FORMAT``, and taking the best of three
-runs.  In the test, the format string ``"%0.10f:%04d:%+g:%s:%p:%c:%%\n"`` or
-equivalent is filled 2000000 times with output sent to ``/dev/null``; for
-further details see the `source
-<https://github.com/fmtlib/format-benchmark/blob/master/tinyformat_test.cpp>`_.
-
 ================= ============= ===========
 Library           Method        Run Time, s
 ================= ============= ===========
-libc              printf          1.35
-libc++            std::ostream    3.42
-fmt 534bff7       fmt::print      1.56
-tinyformat 2.0.1  tfm::printf     3.73
-Boost Format 1.54 boost::format   8.44
-Folly Format      folly::format   2.54
+libc              printf          1.04
+libc++            std::ostream    3.05
+{fmt} 6.1.1       fmt::print      0.75
+Boost Format 1.67 boost::format   7.24
+Folly Format      folly::format   2.23
 ================= ============= ===========
 
-As you can see ``boost::format`` is much slower than the alternative methods; this
-is confirmed by `other tests <http://accu.org/index.php/journals/1539>`_.
-Tinyformat is quite good coming close to IOStreams.  Unfortunately tinyformat
-cannot be faster than the IOStreams because it uses them internally.
-Performance of fmt is close to that of printf, being `faster than printf on integer
-formatting <http://zverovich.net/2013/09/07/integer-to-string-conversion-in-cplusplus.html>`_,
-but slower on floating-point formatting which dominates this benchmark.
+{fmt} is the fastest of the benchmarked methods, ~35% faster than ``printf``.
+
+The above results were generated by building ``tinyformat_test.cpp`` on macOS
+10.14.6 with ``clang++ -O3 -DNDEBUG -DSPEED_TEST -DHAVE_FORMAT``, and taking the
+best of three runs. In the test, the format string ``"%0.10f:%04d:%+g:%s:%p:%c:%%\n"``
+or equivalent is filled 2,000,000 times with output sent to ``/dev/null``; for
+further details refer to the `source
+<https://github.com/fmtlib/format-benchmark/blob/master/src/tinyformat-test.cc>`_.
+
+{fmt} is up to 20-30x faster than ``std::ostringstream`` and ``sprintf`` on
+floating-point formatting (`dtoa-benchmark <https://github.com/fmtlib/dtoa-benchmark>`_)
+and faster than `double-conversion <https://github.com/google/double-conversion>`_ and
+`ryu <https://github.com/ulfjack/ryu>`_:
+
+.. image:: https://user-images.githubusercontent.com/576385/
+           95684665-11719600-0ba8-11eb-8e5b-972ff4e49428.png
+   :target: https://fmt.dev/unknown_mac64_clang12.0.html
 
 Compile time and code bloat
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -372,15 +238,14 @@ Method        Compile Time, s Executable size, KiB Stripped size, KiB
 ============= =============== ==================== ==================
 printf                    2.6                   29                 26
 printf+string            16.4                   29                 26
-IOStreams                31.1                   59                 55
-fmt                      19.0                   37                 34
-tinyformat               44.0                  103                 97
+iostreams                31.1                   59                 55
+{fmt}                    19.0                   37                 34
 Boost Format             91.9                  226                203
 Folly Format            115.7                  101                 88
 ============= =============== ==================== ==================
 
-As you can see, fmt has 60% less overhead in terms of resulting binary code
-size compared to IOStreams and comes pretty close to ``printf``. Boost Format
+As you can see, {fmt} has 60% less overhead in terms of resulting binary code
+size compared to iostreams and comes pretty close to ``printf``. Boost Format
 and Folly Format have the largest overheads.
 
 ``printf+string`` is the same as ``printf`` but with extra ``<string>``
@@ -393,17 +258,15 @@ Method        Compile Time, s Executable size, KiB Stripped size, KiB
 ============= =============== ==================== ==================
 printf                    2.2                   33                 30
 printf+string            16.0                   33                 30
-IOStreams                28.3                   56                 52
-fmt                      18.2                   59                 50
-tinyformat               32.6                   88                 82
+iostreams                28.3                   56                 52
+{fmt}                    18.2                   59                 50
 Boost Format             54.1                  365                303
 Folly Format             79.9                  445                430
 ============= =============== ==================== ==================
 
-``libc``, ``lib(std)c++`` and ``libfmt`` are all linked as shared
-libraries to compare formatting function overhead only. Boost Format
-and tinyformat are header-only libraries so they don't provide any
-linkage options.
+``libc``, ``lib(std)c++`` and ``libfmt`` are all linked as shared libraries to
+compare formatting function overhead only. Boost Format is a
+header-only library so it doesn't provide any linkage options.
 
 Running the tests
 ~~~~~~~~~~~~~~~~~
@@ -411,7 +274,7 @@ Running the tests
 Please refer to `Building the library`__ for the instructions on how to build
 the library and run the unit tests.
 
-__ http://fmtlib.net/latest/usage.html#building-the-library
+__ https://fmt.dev/latest/usage.html#building-the-library
 
 Benchmarks reside in a separate repository,
 `format-benchmarks <https://github.com/fmtlib/format-benchmark>`_,
@@ -429,73 +292,243 @@ Then you can run the speed test::
 or the bloat test::
 
     $ make bloat-test
+    
+Migrating code
+--------------
 
-FAQ
----
+`clang-tidy-fmt <https://github.com/mikecrowe/clang-tidy-fmt>`_ provides clang
+tidy checks for converting occurrences of ``printf`` and ``fprintf`` to
+``fmt::print``.
 
-Q: how can I capture formatting arguments and format them later?
+Projects using this library
+---------------------------
 
-A: use ``std::tuple``:
+* `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
+
+* `Aseprite <https://github.com/aseprite/aseprite>`_:
+  animated sprite editor & pixel art tool 
+
+* `AvioBook <https://www.aviobook.aero/en>`_: a comprehensive aircraft
+  operations suite
+  
+* `Blizzard Battle.net <https://battle.net/>`_: an online gaming platform
+  
+* `Celestia <https://celestia.space/>`_: real-time 3D visualization of space
+
+* `Ceph <https://ceph.com/>`_: a scalable distributed storage system
+
+* `ccache <https://ccache.dev/>`_: a compiler cache
+
+* `ClickHouse <https://github.com/ClickHouse/ClickHouse>`_: analytical database
+  management system
+
+* `CUAUV <https://cuauv.org/>`_: Cornell University's autonomous underwater
+  vehicle
+
+* `Drake <https://drake.mit.edu/>`_: a planning, control, and analysis toolbox
+  for nonlinear dynamical systems (MIT)
+
+* `Envoy <https://lyft.github.io/envoy/>`_: C++ L7 proxy and communication bus
+  (Lyft)
+
+* `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
+
+* `GemRB <https://gemrb.org/>`_: a portable open-source implementation of
+  Bioware’s Infinity Engine
+
+* `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
+
+* `KBEngine <https://github.com/kbengine/kbengine>`_: an open-source MMOG server
+  engine
+
+* `Keypirinha <https://keypirinha.com/>`_: a semantic launcher for Windows
+
+* `Kodi <https://kodi.tv/>`_ (formerly xbmc): home theater software
+
+* `Knuth <https://kth.cash/>`_: high-performance Bitcoin full-node
+
+* `Microsoft Verona <https://github.com/microsoft/verona>`_:
+  research programming language for concurrent ownership
+
+* `MongoDB <https://mongodb.com/>`_: distributed document database
+
+* `MongoDB Smasher <https://github.com/duckie/mongo_smasher>`_: a small tool to
+  generate randomized datasets
+
+* `OpenSpace <https://openspaceproject.com/>`_: an open-source
+  astrovisualization framework
+
+* `PenUltima Online (POL) <https://www.polserver.com/>`_:
+  an MMO server, compatible with most Ultima Online clients
+
+* `PyTorch <https://github.com/pytorch/pytorch>`_: an open-source machine
+  learning library
+
+* `quasardb <https://www.quasardb.net/>`_: a distributed, high-performance,
+  associative database
+  
+* `Quill <https://github.com/odygrd/quill>`_: asynchronous low-latency logging library
+
+* `QKW <https://github.com/ravijanjam/qkw>`_: generalizing aliasing to simplify
+  navigation, and executing complex multi-line terminal command sequences
+
+* `redis-cerberus <https://github.com/HunanTV/redis-cerberus>`_: a Redis cluster
+  proxy
+
+* `redpanda <https://vectorized.io/redpanda>`_: a 10x faster Kafka® replacement
+  for mission critical systems written in C++
+
+* `rpclib <http://rpclib.net/>`_: a modern C++ msgpack-RPC server and client
+  library
+
+* `Salesforce Analytics Cloud
+  <https://www.salesforce.com/analytics-cloud/overview/>`_:
+  business intelligence software
+
+* `Scylla <https://www.scylladb.com/>`_: a Cassandra-compatible NoSQL data store
+  that can handle 1 million transactions per second on a single server
+
+* `Seastar <http://www.seastar-project.org/>`_: an advanced, open-source C++
+  framework for high-performance server applications on modern hardware
+
+* `spdlog <https://github.com/gabime/spdlog>`_: super fast C++ logging library
+
+* `Stellar <https://www.stellar.org/>`_: financial platform
+
+* `Touch Surgery <https://www.touchsurgery.com/>`_: surgery simulator
+
+* `TrinityCore <https://github.com/TrinityCore/TrinityCore>`_: open-source
+  MMORPG framework
+
+* `Windows Terminal <https://github.com/microsoft/terminal>`_: the new Windows
+  terminal
+
+`More... <https://github.com/search?q=fmtlib&type=Code>`_
+
+If you are aware of other projects using this library, please let me know
+by `email <mailto:victor.zverovich@gmail.com>`_ or by submitting an
+`issue <https://github.com/fmtlib/fmt/issues>`_.
+
+Motivation
+----------
+
+So why yet another formatting library?
+
+There are plenty of methods for doing this task, from standard ones like
+the printf family of function and iostreams to Boost Format and FastFormat
+libraries. The reason for creating a new library is that every existing
+solution that I found either had serious issues or didn't provide
+all the features I needed.
+
+printf
+~~~~~~
+
+The good thing about ``printf`` is that it is pretty fast and readily available
+being a part of the C standard library. The main drawback is that it
+doesn't support user-defined types. ``printf`` also has safety issues although
+they are somewhat mitigated with `__attribute__ ((format (printf, ...))
+<https://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html>`_ in GCC.
+There is a POSIX extension that adds positional arguments required for
+`i18n <https://en.wikipedia.org/wiki/Internationalization_and_localization>`_
+to ``printf`` but it is not a part of C99 and may not be available on some
+platforms.
+
+iostreams
+~~~~~~~~~
+
+The main issue with iostreams is best illustrated with an example:
 
 .. code:: c++
 
-   template <typename... Args>
-   auto capture(const Args&... args) {
-     return std::make_tuple(args...);
-   }
+    std::cout << std::setprecision(2) << std::fixed << 1.23456 << "\n";
 
-   auto print_message = [](const auto&... args) {
-     fmt::print(args...);
-   };
+which is a lot of typing compared to printf:
 
-   // Capture and store arguments:
-   auto args = capture("{} {}", 42, "foo");
-   // Do formatting:
-   std::apply(print_message, args);
+.. code:: c++
+
+    printf("%.2f\n", 1.23456);
+
+Matthew Wilson, the author of FastFormat, called this "chevron hell". iostreams
+don't support positional arguments by design.
+
+The good part is that iostreams support user-defined types and are safe although
+error handling is awkward.
+
+Boost Format
+~~~~~~~~~~~~
+
+This is a very powerful library which supports both ``printf``-like format
+strings and positional arguments. Its main drawback is performance. According to
+various benchmarks, it is much slower than other methods considered here. Boost
+Format also has excessive build times and severe code bloat issues (see
+`Benchmarks`_).
+
+FastFormat
+~~~~~~~~~~
+
+This is an interesting library which is fast, safe and has positional arguments.
+However, it has significant limitations, citing its author:
+
+    Three features that have no hope of being accommodated within the
+    current design are:
+
+    * Leading zeros (or any other non-space padding)
+    * Octal/hexadecimal encoding
+    * Runtime width/alignment specification
+
+It is also quite big and has a heavy dependency, STLSoft, which might be too
+restrictive for using it in some projects.
+
+Boost Spirit.Karma
+~~~~~~~~~~~~~~~~~~
+
+This is not really a formatting library but I decided to include it here for
+completeness. As iostreams, it suffers from the problem of mixing verbatim text
+with arguments. The library is pretty fast, but slower on integer formatting
+than ``fmt::format_to`` with format string compilation on Karma's own benchmark,
+see `Converting a hundred million integers to strings per second
+<http://www.zverovich.net/2020/06/13/fast-int-to-string-revisited.html>`_.
 
 License
 -------
 
-fmt is distributed under the BSD `license
+{fmt} is distributed under the MIT `license
 <https://github.com/fmtlib/fmt/blob/master/LICENSE.rst>`_.
 
-The `Format String Syntax
-<http://fmtlib.net/latest/syntax.html>`_
+Documentation License
+---------------------
+
+The `Format String Syntax <https://fmt.dev/latest/syntax.html>`_
 section in the documentation is based on the one from Python `string module
-documentation <https://docs.python.org/3/library/string.html#module-string>`_
-adapted for the current library. For this reason the documentation is
-distributed under the Python Software Foundation license available in
-`doc/python-license.txt
+documentation <https://docs.python.org/3/library/string.html#module-string>`_.
+For this reason the documentation is distributed under the Python Software
+Foundation license available in `doc/python-license.txt
 <https://raw.github.com/fmtlib/fmt/master/doc/python-license.txt>`_.
-It only applies if you distribute the documentation of fmt.
+It only applies if you distribute the documentation of {fmt}.
 
-Acknowledgments
----------------
+Maintainers
+-----------
 
-The fmt library is maintained by Victor Zverovich (`vitaut
+The {fmt} library is maintained by Victor Zverovich (`vitaut
 <https://github.com/vitaut>`_) and Jonathan Müller (`foonathan
 <https://github.com/foonathan>`_) with contributions from many other people.
 See `Contributors <https://github.com/fmtlib/fmt/graphs/contributors>`_ and
 `Releases <https://github.com/fmtlib/fmt/releases>`_ for some of the names.
 Let us know if your contribution is not listed or mentioned incorrectly and
 we'll make it right.
-
-The benchmark section of this readme file and the performance tests are taken
-from the excellent `tinyformat <https://github.com/c42f/tinyformat>`_ library
-written by Chris Foster.  Boost Format library is acknowledged transitively
-since it had some influence on tinyformat.
-Some ideas used in the implementation are borrowed from `Loki
-<http://loki-lib.sourceforge.net/>`_ SafeFormat and `Diagnostic API
-<http://clang.llvm.org/doxygen/classclang_1_1Diagnostic.html>`_ in
-`Clang <http://clang.llvm.org/>`_.
-Format string syntax and the documentation are based on Python's `str.format
-<http://docs.python.org/2/library/stdtypes.html#str.format>`_.
-Thanks `Doug Turnbull <https://github.com/softwaredoug>`_ for his valuable
-comments and contribution to the design of the type-safe API and
-`Gregory Czajkowski <https://github.com/gcflymoto>`_ for implementing binary
-formatting. Thanks `Ruslan Baratov <https://github.com/ruslo>`_ for comprehensive
-`comparison of integer formatting algorithms <https://github.com/ruslo/int-dec-format-tests>`_
-and useful comments regarding performance, `Boris Kaul <https://github.com/localvoid>`_ for
-`C++ counting digits benchmark <https://github.com/localvoid/cxx-benchmark-count-digits>`_.
-Thanks to `CarterLi <https://github.com/CarterLi>`_ for contributing various
-improvements to the code.

doc/CMakeLists.txt

@@ -4,9 +4,14 @@ if (NOT DOXYGEN)
   return ()
 endif ()
 
-add_custom_target(doc
-  COMMAND ${CMAKE_CURRENT_SOURCE_DIR}/build.py ${FMT_VERSION}
-  SOURCES api.rst syntax.rst build.py conf.py _templates/layout.html)
+find_package(PythonInterp QUIET REQUIRED)
 
+add_custom_target(doc
+  COMMAND ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/build.py
+                               ${FMT_VERSION}
+  SOURCES api.rst syntax.rst usage.rst build.py conf.py _templates/layout.html)
+
+include(GNUInstallDirs)
 install(DIRECTORY ${CMAKE_CURRENT_BINARY_DIR}/html/
-        DESTINATION share/doc/fmt OPTIONAL)
+        DESTINATION ${CMAKE_INSTALL_DATAROOTDIR}/doc/fmt OPTIONAL
+        PATTERN ".doctrees" EXCLUDE)

doc/_templates/layout.html

@@ -6,14 +6,13 @@
 <meta name="author" content="Victor Zverovich">
 <link rel="stylesheet" href="_static/fmt.css">
 {# Google Analytics #}
+<script async src="https://www.googletagmanager.com/gtag/js?id=UA-20116650-4"></script>
 <script>
-  (function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
-    (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();
-    a=s.createElement(o),m=s.getElementsByTagName(o)[0];a.async=1;
-    a.src=g;m.parentNode.insertBefore(a,m)
-  })(window,document,'script','//www.google-analytics.com/analytics.js','ga');
-  ga('create', 'UA-20116650-4', 'fmtlib.net');
-  ga('send', 'pageview');
+  window.dataLayer = window.dataLayer || [];
+  function gtag(){dataLayer.push(arguments);}
+  gtag('js', new Date());
+
+  gtag('config', 'UA-20116650-4');
 </script>
 {% endblock %}
 
@@ -58,7 +57,7 @@
                 <span class="caret"></span></a>
               <ul class="dropdown-menu" role="menu">
                 {% for v in versions.split(',') %}
-                <li><a href="http://fmtlib.net/{{v}}">{{v}}</a></li>
+                <li><a href="https://fmt.dev/{{v}}">{{v}}</a></li>
                 {% endfor %}
               </ul>
             </li>
@@ -84,7 +83,7 @@
 <div class="jumbotron">
   <div class="tb-container">
     <h1>{fmt}</h1>
-    <p class="lead">Small, safe and fast formatting library</p>
+    <p class="lead">A modern formatting library</p>
     <div class="btn-group" role="group">
       {% set name = 'fmt' if version.split('.')[0]|int >= 3 else 'cppformat' %}
       <a class="btn btn-success"

doc/api.rst

@@ -6,73 +6,149 @@ 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, output iterator and user-defined type support
-* :ref:`fmt/time.h <time-api>`: date and time formatting
+* :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/std.h <std-api>`: formatters for standard library types
+* :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_`` or ``fmt``.
+macros have prefix ``FMT_``.
 
 .. _core-api:
 
 Core API
 ========
 
-``fmt/core.h`` defines the core API which provides argument handling facilities
-and a lightweight subset of formatting functions.
+``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>`
-imilar 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.
+similar to that of Python's `str.format
+<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
-fields surrounded by braces ``{}``. The fields are replaced with formatted
-arguments in the resulting string.
+*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. `~fmt::format_string` is a format string which can be
+implicitly constructed from a string literal or a ``constexpr`` string and is
+checked at compile time in C++20. To pass a runtime format string wrap it in
+`fmt::runtime`.
 
 *args* is an argument list representing objects to be formatted.
 
 .. _format:
 
-.. doxygenfunction:: format(const String&, const Args&...)
-.. doxygenfunction:: vformat(const String&, basic_format_args<typename buffer_context<Char>::type>)
+.. doxygenfunction:: format(format_string<T...> fmt, T&&... args) -> std::string
+.. doxygenfunction:: vformat(string_view fmt, format_args args) -> std::string
+
+.. 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, 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(string_view, const Args&...)
-.. doxygenfunction:: vprint(string_view, format_args)
+.. doxygenfunction:: fmt::print(format_string<T...> fmt, T&&... args)
+.. doxygenfunction:: fmt::vprint(string_view fmt, format_args args)
 
-.. doxygenfunction:: print(std::FILE *, string_view, const 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)
 
-.. doxygenfunction:: print(std::FILE *, wstring_view, const Args&...)
-.. doxygenfunction:: vprint(std::FILE *, wstring_view, wformat_args)
+Compile-Time Format String Checks
+---------------------------------
 
-Named arguments
+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.
+Requires C++14 and is a no-op in C++11.
+
+.. 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.
+
+.. doxygenclass:: fmt::basic_format_string
+   :members:
+
+.. doxygentypedef:: fmt::format_string
+
+.. doxygenfunction:: fmt::runtime(const S&)
+
+Named Arguments
 ---------------
 
-.. doxygenfunction:: fmt::arg(string_view, const T&)
+.. doxygenfunction:: fmt::arg(const S&, const T&)
 
-Argument lists
+Named arguments are not supported in compile-time checks at the moment.
+
+Argument Lists
 --------------
 
+You can create your own formatting function with compile-time checks and small
+binary footprint, for example (https://godbolt.org/z/oba4Mc):
+
+.. code:: c++
+
+    #include <fmt/format.h>
+
+    void vlog(const char* file, int line, fmt::string_view format,
+              fmt::format_args args) {
+      fmt::print("{}: {}: ", file, line);
+      fmt::vprint(format, args);
+    }
+
+    template <typename S, typename... Args>
+    void log(const char* file, int line, const S& format, Args&&... args) {
+      vlog(file, line, format, fmt::make_format_args(args...));
+    }
+
+    #define MY_LOG(format, ...) \
+      log(__FILE__, __LINE__, FMT_STRING(format), __VA_ARGS__)
+
+    MY_LOG("invalid squishiness: {}", 42);
+
+Note that ``vlog`` is not parameterized on argument types which improves compile
+times and reduces binary code size compared to a fully parameterized version.
+
 .. doxygenfunction:: fmt::make_format_args(const Args&...)
 
 .. doxygenclass:: fmt::format_arg_store
    :members:
 
+.. doxygenclass:: fmt::dynamic_format_arg_store
+   :members:
+
 .. doxygenclass:: fmt::basic_format_args
    :members:
 
-.. doxygenstruct:: fmt::format_args
+.. doxygentypedef:: fmt::format_args
 
 .. doxygenclass:: fmt::basic_format_arg
    :members:
 
+.. doxygenclass:: fmt::basic_format_parse_context
+   :members:
+
+.. doxygenclass:: fmt::basic_format_context
+   :members:
+
+.. doxygentypedef:: fmt::format_context
+
 Compatibility
 -------------
 
@@ -80,127 +156,221 @@ Compatibility
    :members:
 
 .. doxygentypedef:: fmt::string_view
-.. doxygentypedef:: fmt::wstring_view
+
+Locale
+------
+
+All formatting is locale-independent by default. Use the ``'L'`` format
+specifier to insert the appropriate number separator characters from the
+locale::
+
+  #include <fmt/core.h>
+  #include <locale>
+
+  std::locale::global(std::locale("en_US.UTF-8"));
+  auto s = fmt::format("{:L}", 1000000);  // s == "1,000,000"
 
 .. _format-api:
 
 Format API
 ==========
 
-``fmt/format.h`` defines the full format API providing compile-time format
-string checks, output iterator and user-defined type support.
+``fmt/format.h`` defines the full format API providing additional formatting
+functions and locale support.
 
-Compile-time format string checks
----------------------------------
+.. _udt:
 
-.. doxygendefine:: fmt
-
-Formatting user-defined types
+Formatting User-Defined Types
 -----------------------------
 
+The {fmt} library provides formatters for many standard C++ types.
+See :ref:`fmt/ranges.h <ranges-api>` for ranges and tuples including standard
+containers such as ``std::vector``, :ref:`fmt/chrono.h <chrono-api>` for date
+and time formatting and :ref:`fmt/std.h <std-api>` for path and variant 
+formatting.
+
 To make a user-defined type formattable, specialize the ``formatter<T>`` struct
 template and implement ``parse`` and ``format`` methods::
 
   #include <fmt/format.h>
 
-  struct point { double x, y; };
+  struct point {
+    double x, y;
+  };
 
-  namespace fmt {
-  template <>
-  struct formatter<point> {
-    template <typename ParseContext>
-    constexpr auto parse(ParseContext &ctx) { return ctx.begin(); }
+  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) -> 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
+      //
+      //   fmt::format("{:f} - point of interest", point{1, 2});
+      //
+      // the range will contain "f} - point of interest". The formatter should
+      // parse specifiers until '}' or the end of the range. In this example
+      // the formatter should parse the 'f' specifier and return an iterator
+      // pointing to '}'.
+      
+      // Please also note that this character range may be empty, in case of
+      // the "{}" format string, so therefore you should check ctx.begin()
+      // for equality with ctx.end().
+
+      // Parse the presentation format and store it in the formatter:
+      auto it = ctx.begin(), end = ctx.end();
+      if (it != end && (*it == 'f' || *it == 'e')) presentation = *it++;
+
+      // Check if reached the end of the range:
+      if (it != end && *it != '}') throw format_error("invalid format");
+
+      // Return an iterator past the end of the parsed range:
+      return it;
+    }
+
+    // Formats the point p using the parsed format specification (presentation)
+    // stored in this formatter.
     template <typename FormatContext>
-    auto format(const point &p, FormatContext &ctx) {
-      return format_to(ctx.begin(), "({:.1f}, {:.1f})", p.x, p.y);
+    auto format(const point& p, FormatContext& ctx) const -> decltype(ctx.out()) {
+      // ctx.out() is an output iterator to write to.
+      return presentation == 'f'
+                ? fmt::format_to(ctx.out(), "({:.1f}, {:.1f})", p.x, p.y)
+                : fmt::format_to(ctx.out(), "({:.1e}, {:.1e})", p.x, p.y);
     }
   };
-  }
 
 Then you can pass objects of type ``point`` to any formatting function::
 
   point p = {1, 2};
-  std::string s = fmt::format("{}", p);
+  std::string s = fmt::format("{:f}", p);
   // s == "(1.0, 2.0)"
 
-In the example above the ``formatter<point>::parse`` function ignores the
-contents of the format string referred to by ``ctx.begin()`` so the object will
-always be formatted in the same way. See ``formatter<tm>::parse`` in
-:file:`fmt/time.h` for an advanced example of how to parse the format string and
-customize the formatted output.
+You can also reuse existing formatters via inheritance or composition, for
+example::
 
-You can also reuse existing formatters, for example::
+  enum class color {red, green, blue};
 
-  enum color {red, green, blue};
-
-  template <>
-  struct fmt::formatter<color>: formatter<string_view> {
+  template <> struct fmt::formatter<color>: formatter<string_view> {
     // parse is inherited from formatter<string_view>.
     template <typename FormatContext>
-    auto format(color c, FormatContext &ctx) {
+    auto format(color c, FormatContext& ctx) const {
       string_view name = "unknown";
       switch (c) {
-      case red:   name = "red"; break;
-      case green: name = "green"; break;
-      case blue:  name = "blue"; break;
+      case color::red:   name = "red"; break;
+      case color::green: name = "green"; break;
+      case color::blue:  name = "blue"; break;
       }
       return formatter<string_view>::format(name, ctx);
     }
   };
 
-This section shows how to define a custom format function for a user-defined
-type. The next section describes how to get ``fmt`` to use a conventional stream
-output ``operator<<`` when one is defined for a user-defined type.
+Since ``parse`` is inherited from ``formatter<string_view>`` it will recognize
+all string format specifications, for example
 
-Output iterator support
------------------------
+.. code-block:: c++
 
-.. doxygenfunction:: fmt::format_to(OutputIt, string_view, const Args&...)
-.. doxygenfunction:: fmt::format_to_n(OutputIt, std::size_t, string_view, const Args&...)
-.. doxygenstruct:: fmt::format_to_n_result
-   :members:
+   fmt::format("{:>10}", color::blue)
 
-Literal-based API
+will return ``"      blue"``.
+
+You can also write a formatter for a hierarchy of classes::
+
+  #include <type_traits>
+  #include <fmt/format.h>
+
+  struct A {
+    virtual ~A() {}
+    virtual std::string name() const { return "A"; }
+  };
+
+  struct B : A {
+    virtual std::string name() const { return "B"; }
+  };
+
+  template <typename T>
+  struct fmt::formatter<T, std::enable_if_t<std::is_base_of<A, T>::value, char>> :
+      fmt::formatter<std::string> {
+    template <typename FormatCtx>
+    auto format(const A& a, FormatCtx& ctx) const {
+      return fmt::formatter<std::string>::format(a.name(), ctx);
+    }
+  };
+
+  int main() {
+    B b;
+    A& a = b;
+    fmt::print("{}", a); // prints "B"
+  }
+
+If a type provides both a ``formatter`` specialization and an implicit
+conversion to a formattable type, the specialization takes precedence over the
+conversion.
+
+For enums {fmt} also provides the ``format_as`` extension API. To format an enum
+via this API define ``format_as`` that takes this enum and converts it to the
+underlying type. ``format_as`` should be defined in the same namespace as the
+enum.
+
+Example (https://godbolt.org/z/r7vvGE1v7)::
+
+  #include <fmt/format.h>
+
+  namespace kevin_namespacy {
+  enum class film {
+    house_of_cards, american_beauty, se7en = 7
+  };
+  auto format_as(film f) { return fmt::underlying(f); }
+  }
+
+  int main() {
+    fmt::print("{}\n", kevin_namespacy::film::se7en); // prints "7"
+  }
+
+Literal-Based API
 -----------------
 
 The following user-defined literals are defined in ``fmt/format.h``.
 
-.. doxygenfunction:: operator""_format(const char *, std::size_t)
-
-.. doxygenfunction:: operator""_a(const char *, std::size_t)
+.. doxygenfunction:: operator""_a()
 
 Utilities
 ---------
 
-.. doxygenfunction:: fmt::formatted_size(string_view, const Args&...)
+.. 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*
 
-.. doxygenfunction:: fmt::to_string(const T&)
+.. doxygenfunction:: fmt::underlying(Enum e) -> typename std::underlying_type<Enum>::type
 
-.. doxygenfunction:: fmt::to_wstring(const T&)
+.. doxygenfunction:: fmt::to_string(const T &value) -> std::string
+
+.. doxygenfunction:: fmt::join(Range &&range, string_view sep) -> join_view<detail::iterator_t<Range>, detail::sentinel_t<Range>>
+
+.. doxygenfunction:: fmt::join(It begin, Sentinel end, string_view sep) -> join_view<It, Sentinel>
+
+.. doxygenfunction:: fmt::group_digits(T value) -> group_digits_view<T>
+
+.. doxygenclass:: fmt::detail::buffer
+   :members:
 
 .. doxygenclass:: fmt::basic_memory_buffer
    :protected-members:
    :members:
 
-System errors
+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:
-
-.. _formatstrings:
-
-Custom allocators
+Custom Allocators
 -----------------
 
 The {fmt} library supports custom dynamic memory allocators.
@@ -218,125 +388,230 @@ allocator::
 
     custom_string vformat(custom_allocator alloc, fmt::string_view format_str,
                           fmt::format_args args) {
-      custom_memory_buffer buf(alloc);
-      fmt::vformat_to(buf, format_str, args);
+      auto buf = custom_memory_buffer(alloc);
+      fmt::vformat_to(std::back_inserter(buf), format_str, args);
       return custom_string(buf.data(), buf.size(), alloc);
     }
 
     template <typename ...Args>
     inline custom_string format(custom_allocator alloc,
                                 fmt::string_view format_str,
-                                const Args & ... args) {
+                                const Args& ... args) {
       return vformat(alloc, format_str, fmt::make_format_args(args...));
     }
 
-The allocator will be used for the output container only. If you are using named
-arguments, the container that stores pointers to them will be allocated using
-the default allocator. Also floating-point formatting falls back on ``sprintf``
-which may do allocations.
+The allocator will be used for the output container only. Formatting functions
+normally don't do any allocations for built-in and string types except for
+non-default floating-point formatting that occasionally falls back on
+``sprintf``.
 
-Custom formatting of built-in types
------------------------------------
+.. _ranges-api:
 
-It is possible to change the way arguments are formatted by providing a
-custom argument formatter class::
+Range and Tuple Formatting
+==========================
 
-  using arg_formatter =
-    fmt::arg_formatter<fmt::back_insert_range<fmt::internal::buffer>>;
+The library also supports convenient formatting of ranges and tuples::
 
-  // A custom argument formatter that formats negative integers as unsigned
-  // with the ``x`` format specifier.
-  class custom_arg_formatter : public arg_formatter {
-   public:
-    custom_arg_formatter(fmt::format_context &ctx, fmt::format_specs &spec)
-      : arg_formatter(ctx, spec) {}
+  #include <fmt/ranges.h>
 
-    using arg_formatter::operator();
+  std::tuple<char, int, float> t{'a', 1, 2.0f};
+  // Prints "('a', 1, 2.0)"
+  fmt::print("{}", t);
 
-    auto operator()(int value) {
-      if (spec().type() == 'x')
-        return (*this)(static_cast<unsigned>(value)); // convert to unsigned and format
-      return arg_formatter::operator()(value);
-    }
-  };
 
-  std::string custom_vformat(fmt::string_view format_str, fmt::format_args args) {
-    fmt::memory_buffer buffer;
-    // Pass custom argument formatter as a template arg to vformat_to.
-    fmt::vformat_to<custom_arg_formatter>(buffer, format_str, args);
-    return fmt::to_string(buffer);
-  }
+NOTE: currently, the overload of ``fmt::join`` for iterables exists in the main
+``format.h`` header, but expect this to change in the future.
 
-  template <typename ...Args>
-  inline std::string custom_format(
-      fmt::string_view format_str, const Args &... args) {
-    return custom_vformat(format_str, fmt::make_format_args(args...));
-  }
+Using ``fmt::join``, you can separate tuple elements with a custom separator::
 
-  std::string s = custom_format("{:x}", -42); // s == "ffffffd6"
+  #include <fmt/ranges.h>
 
-.. doxygenclass:: fmt::arg_formatter
-   :members:
+  std::tuple<int, char> t = {1, 'a'};
+  // Prints "1, a"
+  fmt::print("{}", fmt::join(t, ", "));
 
-.. _time-api:
+.. _chrono-api:
 
-Date and time formatting
+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
 
-  #include <fmt/time.h>
+* `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>`_
 
-  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}.", *std::localtime(&t));
+The format syntax is described in :ref:`chrono-specs`.
 
-The format string syntax is described in the documentation of
-`strftime <http://en.cppreference.com/w/cpp/chrono/c/strftime>`_.
+**Example**::
+
+  #include <fmt/chrono.h>
+
+  int main() {
+    std::time_t t = std::time(nullptr);
+
+    // 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)
+
+.. _std-api:
+
+Standard Library Types Formatting
+=================================
+
+``fmt/std.h`` provides formatters for:
+
+* `std::filesystem::path <std::filesystem::path>`_
+* `std::thread::id <https://en.cppreference.com/w/cpp/thread/thread/id>`_
+* `std::monostate <https://en.cppreference.com/w/cpp/utility/variant/monostate>`_
+* `std::variant <https://en.cppreference.com/w/cpp/utility/variant/variant>`_
+
+Formatting Variants
+-------------------
+
+A ``std::variant`` is only formattable if every variant alternative is formattable, and requires the
+``__cpp_lib_variant`` `library feature <https://en.cppreference.com/w/cpp/feature_test>`_.
+  
+**Example**::
+
+  #include <fmt/std.h>
+
+  std::variant<char, float> v0{'x'};
+  // Prints "variant('x')"
+  fmt::print("{}", v0);
+
+  std::variant<std::monostate, char> v1;
+  // Prints "variant(monostate)"
+
+.. _compile-api:
+
+Format String Compilation
+=========================
+
+``fmt/compile.h`` provides format string compilation enabled via the
+``FMT_COMPILE`` macro or the ``_cf`` user-defined literal. Format strings
+marked with ``FMT_COMPILE`` or ``_cf`` 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
+
+.. doxygenfunction:: operator""_cf()
+
+.. _color-api:
+
+Terminal Color and Text Style
+=============================
+
+``fmt/color.h`` provides support for terminal color and text style output.
+
+.. doxygenfunction:: print(const text_style &ts, const S &format_str, const Args&... args)
+
+.. doxygenfunction:: fg(detail::color_type)
+
+.. doxygenfunction:: bg(detail::color_type)
+
+.. doxygenfunction:: styled(const T& value, text_style ts)
+
+.. _os-api:
+
+System APIs
+===========
+
+.. doxygenclass:: fmt::ostream
+   :members:
+
+.. doxygenfunction:: fmt::windows_error
+   :members:
 
 .. _ostream-api:
 
-``std::ostream`` support
+``std::ostream`` Support
 ========================
 
 ``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<<``).
+In order to make a type formattable via ``std::ostream`` you should provide a
+``formatter`` specialization inherited from ``ostream_formatter``::
 
   #include <fmt/ostream.h>
 
-  class date {
-    int year_, month_, day_;
-  public:
-    date(int year, int month, int day): year_(year), month_(month), day_(day) {}
+  struct date {
+    int year, month, day;
 
-    friend std::ostream &operator<<(std::ostream &os, const date &d) {
-      return os << d.year_ << '-' << d.month_ << '-' << d.day_;
+    friend std::ostream& operator<<(std::ostream& os, const date& d) {
+      return os << d.year << '-' << d.month << '-' << d.day;
     }
   };
 
-  std::string s = fmt::format("The date is {}", date(2012, 12, 9));
+  template <> struct fmt::formatter<date> : ostream_formatter {};
+
+  std::string s = fmt::format("The date is {}", date{2012, 12, 9});
   // s == "The date is 2012-12-9"
 
-.. doxygenfunction:: print(std::ostream&, string_view, const Args&...)
+.. doxygenfunction:: streamed(const T &)
+
+.. doxygenfunction:: print(std::ostream &os, format_string<T...> fmt, T&&... args)
 
 .. _printf-api:
 
-``printf`` formatting
+``printf`` Formatting
 =====================
 
 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(string_view, const Args&...)
+.. doxygenfunction:: printf(const S &format_str, const T&... args)
 
-.. doxygenfunction:: fprintf(std::FILE *, string_view, const Args&...)
+.. doxygenfunction:: fprintf(std::FILE *f, const S &fmt, const T&... args) -> int
 
-.. doxygenfunction:: fprintf(std::ostream&, string_view, const Args&...)
+.. doxygenfunction:: sprintf(const S&, const T&...)
 
-.. doxygenfunction:: sprintf(string_view, const Args&...)
+.. _xchar-api:
+
+``wchar_t`` Support
+===================
+
+The optional header ``fmt/xchar.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``
+========================================
+
+{fmt} implements nearly all of the `C++20 formatting library
+<https://en.cppreference.com/w/cpp/utility/format>`_ with the following
+differences:
+
+* Names are defined in the ``fmt`` namespace instead of ``std`` to avoid
+  collisions with standard library implementations.
+* Width calculation doesn't use grapheme clusterization. The latter has been
+  implemented in a separate branch but hasn't been integrated yet.
+* Most C++20 chrono types are not supported yet.

doc/basic-bootstrap/layout.html

@@ -90,12 +90,14 @@
         VERSION:     '{{ release|e }}',
         COLLAPSE_INDEX: false,
         FILE_SUFFIX: '{{ '' if no_search_suffix else file_suffix }}',
+        LINK_SUFFIX: '{{ link_suffix }}',
+        SOURCELINK_SUFFIX: '{{ sourcelink_suffix }}',
         HAS_SOURCE:  {{ has_source|lower }},
         SOURCELINK_SUFFIX:  '{{ sourcelink_suffix }}'
       };
     </script>
     {%- for scriptfile in script_files %}
-    <script type="text/javascript" src="{{ pathto(scriptfile, 1) }}"></script>
+    {{ js_tag(scriptfile) }}
     {%- endfor %}
 {%- endmacro %}
 

doc/build.py

@@ -1,63 +1,38 @@
-#!/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']
+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', '8.0.1', '8.1.0', '8.1.1', '9.0.0']
 
-def pip_install(package, commit=None, **kwargs):
-  "Install package using pip."
-  min_version = kwargs.get('min_version')
-  if min_version:
-    from pkg_resources import get_distribution, DistributionNotFound
-    try:
-      installed_version = get_distribution(os.path.basename(package)).version
-      if LooseVersion(installed_version) >= min_version:
-        print('{} {} already installed'.format(package, min_version))
-        return
-    except DistributionNotFound:
-      pass
-  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
-  # Install Sphinx and Breathe.
-  pip_install('sphinx-doc/sphinx', '12b83372ac9316e8cbe86e7fed889296a4cc29ee',
-              min_version='1.4.1.dev20160531')
-  pip_install('michaeljones/breathe',
-              '129222318f7c8f865d2631e7da7b033567e7f56a',
-              min_version='4.2.0')
+  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 = Pip(venv_dir)
+  pip.install('wheel')
+  pip.install('six')
+  # See: https://github.com/sphinx-doc/sphinx/issues/9777
+  pip.install('docutils==0.17.1')
+  # Jinja2 >= 3.1 incompatible with sphinx 3.3.0
+  # See: https://github.com/sphinx-doc/sphinx/issues/10291
+  pip.install('Jinja2<3.1')
+  pip.install('sphinx-doc/sphinx', 'v3.3.0')
+  pip.install('michaeljones/breathe', 'v4.25.0')
 
 def build_docs(version='dev', **kwargs):
   doc_dir = kwargs.get('doc_dir', os.path.dirname(os.path.realpath(__file__)))
@@ -66,16 +41,17 @@ 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}/core.h {0}/format.h {0}/ostream.h \
-                          {0}/printf.h {0}/time.h
+      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}/xchar.h
       QUIET             = YES
       JAVADOC_AUTOBRIEF = YES
       AUTOLINK_SUPPORT  = NO
@@ -86,25 +62,50 @@ def build_docs(version='dev', **kwargs):
       ALIASES          += "endrst=\endverbatim"
       MACRO_EXPANSION   = YES
       PREDEFINED        = _WIN32=1 \
+                          __linux__=1 \
+                          FMT_ENABLE_IF(...)= \
                           FMT_USE_VARIADIC_TEMPLATES=1 \
                           FMT_USE_RVALUE_REFERENCES=1 \
                           FMT_USE_USER_DEFINED_LITERALS=1 \
+                          FMT_USE_ALIAS_TEMPLATES=1 \
+                          FMT_USE_NONTYPE_TEMPLATE_ARGS=1 \
                           FMT_API= \
                           "FMT_BEGIN_NAMESPACE=namespace fmt {{" \
-                          "FMT_END_NAMESPACE=}}"
-      EXCLUDE_SYMBOLS   = fmt::internal::* StringValue write_str
+                          "FMT_END_NAMESPACE=}}" \
+                          "FMT_STRING_ALIAS=1" \
+                          "FMT_VARIADIC(...)=" \
+                          "FMT_VARIADIC_W(...)=" \
+                          "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

@@ -1,17 +1,18 @@
 Overview
 ========
 
-**fmt** (formerly cppformat) is an open-source formatting library.
-It can be used as a fast and safe alternative to printf and IOStreams.
+**{fmt}** is an open-source formatting library providing a fast and safe
+alternative to C stdio and C++ iostreams.
 
 .. raw:: html
 
    <div class="panel panel-default">
      <div class="panel-heading">What users say:</div>
      <div class="panel-body">
-       Thanks for creating this library. It’s been a hole in C++ for a long
-       time. I’ve used both boost::format and loki::SPrintf, and neither felt
-       like the right answer. This does.
+       Thanks for creating this library. It’s been a hole in C++ for
+       a long time. I’ve used both <code>boost::format</code> and
+       <code>loki::SPrintf</code>, and neither felt like the right answer.
+       This does.
      </div>
    </div>
 
@@ -20,47 +21,48 @@ It can be used as a fast and safe alternative to printf and IOStreams.
 Format API
 ----------
 
-The replacement-based Format API provides a safe alternative to ``printf``,
-``sprintf`` and friends with comparable or `better performance
-<http://zverovich.net/2013/09/07/integer-to-string-conversion-in-cplusplus.html>`_.
+The format API is similar in spirit to the C ``printf`` family of function but
+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 Python:
+`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 file:
+The ``fmt::print`` function performs formatting and writes the result to a stream:
 
 .. code:: c++
 
   fmt::print(stderr, "System error code = {}\n", errno);
 
-The file argument can be omitted in which case the function prints to
-``stdout``:
+If you omit the file argument the function will print to ``stdout``:
 
 .. code:: c++
 
   fmt::print("Don't {}\n", "panic");
 
-The Format API also supports positional arguments useful for localization:
+The format API also supports positional arguments useful for localization:
 
 .. code:: c++
 
   fmt::print("I'd rather be {1} than {0}.", "right", "happy");
 
-Named arguments can be created with ``fmt::arg``. This makes it easier to track 
-what goes where when multiple values are being inserted:
+You can pass named arguments with ``fmt::arg``:
 
 .. code:: c++
 
@@ -72,21 +74,10 @@ an alternative, slightly terser syntax for named arguments:
 
 .. code:: c++
 
+  using namespace fmt::literals;
   fmt::print("Hello, {name}! The answer is {number}. Goodbye, {name}.",
              "name"_a="World", "number"_a=42);
 
-The ``_format`` suffix may be used to format string literals similar to Python:
-
-.. code:: c++
-
-  std::string message = "{0}{1}{0}"_format("abra", "cad"); 
-
-Other than the placement of the format string on the left of the operator, 
-``_format`` is functionally identical to ``fmt::format``. In order to use the 
-literal operators, they must be made visible with the directive 
-``using namespace fmt::literals;``. Note that this brings in only ``_a`` and 
-``_format`` but nothing else from the ``fmt`` namespace.
-
 .. _safety:
 
 Safety
@@ -94,22 +85,23 @@ Safety
 
 The library is fully type safe, automatic memory management prevents buffer
 overflow, errors in format strings are reported using exceptions or at compile
-tim. For example, the code
+time. For example, the code
 
 .. code:: c++
 
   fmt::format("The answer is {:d}", "forty-two");
 
-throws a ``format_error`` exception with description "unknown format code 'd' for
-string", because the argument ``"forty-two"`` is a string while the format code
-``d`` only applies to integers, while
+throws the ``format_error`` exception because the argument ``"forty-two"`` is a
+string while the format code ``d`` only applies to integers.
+
+The code
 
 .. code:: c++
 
-  format(fmt("The answer is {:d}"), "forty-two");
+  format(FMT_STRING("The answer is {:d}"), "forty-two");
 
-reports a compile-time error for the same reason on compilers that support
-relaxed ``constexpr``.
+reports a compile-time error on compilers that support relaxed ``constexpr``.
+See `here <api.html#compile-time-format-string-checks>`_ for details.
 
 The following code
 
@@ -118,21 +110,15 @@ 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:
+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.
 
-.. 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 what is
-needed.
-
-Compact binary code
+Compact Binary Code
 -------------------
 
-The library is designed to produce compact per-call compiled code. For example
+The library produces compact per-call compiled code. For example
 (`godbolt <https://godbolt.org/g/TZU4KF>`_),
 
 .. code:: c++
@@ -153,8 +139,8 @@ compiles to just
      mov rcx, rsp
      mov edi, offset .L.str
      mov esi, 17
-     mov edx, 2
-     call fmt::v5::vprint(fmt::v5::basic_string_view<char>, fmt::v5::format_args)
+     mov edx, 1
+     call fmt::v7::vprint(fmt::v7::basic_string_view<char>, fmt::v7::format_args)
      xor eax, eax
      add rsp, 24
      ret
@@ -174,37 +160,39 @@ The library is highly portable and relies only on a small set of C++11 features:
 * decltype
 * trailing return types
 * deleted functions
+* alias templates
 
-These are available since GCC 4.4, Clang 2.9 and MSVC 18.0 (2013). For older
-compilers use fmt `version 4.x
-<https://github.com/fmtlib/fmt/releases/tag/4.1.0>`_ which continues to be
-maintained and only requires C++98.
+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.
 
-The output of all formatting functions is consistent across platforms. In
-particular, formatting a floating-point infinity always gives ``inf`` while the
-output of ``printf`` is platform-dependent in this case. For example,
+The output of all formatting functions is consistent across platforms.
+For example,
 
 .. code::
 
   fmt::print("{}", std::numeric_limits<double>::infinity());
 
-always prints ``inf``.
+always prints ``inf`` while the output of ``printf`` is platform-dependent.
 
 .. _ease-of-use:
 
 Ease of Use
 -----------
 
-fmt has a small self-contained code base with the core library consisting of
+{fmt} has a small self-contained code base with the core library consisting of
 just three header files and no external dependencies.
-A permissive BSD `license <https://github.com/fmtlib/fmt#license>`_ allows
+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.
 
@@ -75,20 +75,20 @@ 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`]
-   fill: <a character other than '{', '}' or '\0'>
-   align: "<" | ">" | "=" | "^"
+   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" | "p" | "s"
-   int_type: "b" | "B" | "d" | "n" | "o" | "x" | "X"
+   width: `integer` | "{" [`arg_id`] "}"
+   precision: `integer` | "{" [`arg_id`] "}"
+   type: "a" | "A" | "b" | "B" | "c" | "d" | "e" | "E" | "f" | "F" | "g" | "G" |
+       : "o" | "p" | "s" | "x" | "X"
 
-The *fill* character can be any character other than '{', '}' or '\\0'. The
-presence of a fill character is signaled by the character following it, which
-must be one of the alignment options.  If the second character of *format_spec*
-is not a valid alignment option, then it is assumed that both the fill character
-and the alignment option are absent.
+The *fill* character can be any Unicode code point other than ``'{'`` or
+``'}'``. The presence of a fill character is signaled by the character following
+it, which must be one of the alignment options. If the second character of
+*format_spec* is not a valid alignment option, then it is assumed that both the
+fill character and the alignment option are absent.
 
 The meaning of the various alignment options is as follows:
 
@@ -101,11 +101,6 @@ The meaning of the various alignment options is as follows:
 | ``'>'`` | Forces the field to be right-aligned within the          |
 |         | available space (this is the default for numbers).       |
 +---------+----------------------------------------------------------+
-| ``'='`` | Forces the padding to be placed after the sign (if any)  |
-|         | but before the digits.  This is used for printing fields |
-|         | in the form '+000000120'. This alignment option is only  |
-|         | valid for numeric types.                                 |
-+---------+----------------------------------------------------------+
 | ``'^'`` | Forces the field to be centered within the available     |
 |         | space.                                                   |
 +---------+----------------------------------------------------------+
@@ -117,18 +112,18 @@ meaning in this case.
 The *sign* option is only valid for number types, and can be one of the
 following:
 
-+---------+----------------------------------------------------------+
-| Option  | Meaning                                                  |
-+=========+==========================================================+
-| ``'+'`` | indicates that a sign should be used for both            |
-|         | positive as well as negative numbers.                    |
-+---------+----------------------------------------------------------+
-| ``'-'`` | indicates that a sign should be used only for negative   |
-|         | numbers (this is the default behavior).                  |
-+---------+----------------------------------------------------------+
-| space   | indicates that a leading space should be used on         |
-|         | positive numbers, and a minus sign on negative numbers.  |
-+---------+----------------------------------------------------------+
++---------+------------------------------------------------------------+
+| Option  | Meaning                                                    |
++=========+============================================================+
+| ``'+'`` | indicates that a sign should be used for both              |
+|         | nonnegative as well as negative numbers.                   |
++---------+------------------------------------------------------------+
+| ``'-'`` | indicates that a sign should be used only for negative     |
+|         | numbers (this is the default behavior).                    |
++---------+------------------------------------------------------------+
+| space   | indicates that a leading space should be used on           |
+|         | nonnegative numbers, and a minus sign on negative numbers. |
++---------+------------------------------------------------------------+
 
 The ``'#'`` option causes the "alternate form" to be used for the
 conversion.  The alternate form is defined differently for different
@@ -148,15 +143,17 @@ conversions, trailing zeros are not removed from the result.
 .. ifconfig:: False
 
    The ``','`` option signals the use of a comma for a thousands separator.
-   For a locale aware separator, use the ``'n'`` integer presentation type
+   For a locale aware separator, use the ``'L'`` integer presentation type
    instead.
 
 *width* is a decimal integer defining the minimum field width.  If not
 specified, then the field width will be determined by the content.
 
-Preceding the *width* field by a zero (``'0'``) character enables
-sign-aware zero-padding for numeric types.  This is equivalent to a *fill*
-character of ``'0'`` with an *alignment* type of ``'='``.
+Preceding the *width* field by a zero (``'0'``) character enables sign-aware
+zero-padding for numeric types. It forces the padding to be placed after the
+sign or base (if any) but before the digits. This is used for printing fields in
+the form '+000000120'. This option is only valid for numeric types and it has no
+effect on formatting of infinity and NaN.
 
 The *precision* is a decimal number indicating how many digits should be
 displayed after the decimal point for a floating-point value formatted with
@@ -164,7 +161,11 @@ displayed after the decimal point for a floating-point value formatted with
 value formatted with ``'g'`` or ``'G'``.  For non-number types the field
 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.
+character, Boolean, and pointer values. Note that a C string must be
+null-terminated even if precision is specified.
+
+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.
 
@@ -203,6 +204,8 @@ 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.              |
@@ -217,10 +220,6 @@ The available integer presentation types are:
 |         | ``'#'`` option with this type adds the prefix ``"0X"``   |
 |         | to the output value.                                     |
 +---------+----------------------------------------------------------+
-| ``'n'`` | Number. 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'``.                                     |
 +---------+----------------------------------------------------------+
 
@@ -244,7 +243,7 @@ The available presentation types for floating-point values are:
 |         | notation using the letter 'e' to indicate the exponent.  |
 +---------+----------------------------------------------------------+
 | ``'E'`` | Exponent notation. Same as ``'e'`` except it uses an     |
-|         | upper-case 'E' as the separator character.               |
+|         | upper-case ``'E'`` as the separator character.           |
 +---------+----------------------------------------------------------+
 | ``'f'`` | Fixed point. Displays the number as a fixed-point        |
 |         | number.                                                  |
@@ -264,11 +263,10 @@ 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. |
 +---------+----------------------------------------------------------+
-| none    | The same as ``'g'``.                                     |
+| none    | Similar to ``'g'``, except that the default precision is |
+|         | as high as needed to represent the particular value.     |
 +---------+----------------------------------------------------------+
 
-Floating-point formatting is locale-dependent.
-
 .. ifconfig:: False
 
    +---------+----------------------------------------------------------+
@@ -301,9 +299,89 @@ The available presentation types for pointers are:
 | none    | The same as ``'p'``.                                     |
 +---------+----------------------------------------------------------+
 
+.. _chrono-specs:
+
+Chrono Format Specifications
+============================
+
+Format specifications for chrono types and ``std::tm`` 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.
+
+.. range-specs:
+
+Range Format Specifications
+===========================
+
+Format specifications for range types have the following syntax:
+
+..productionlist:: sf
+  range_format_spec: [":" [`underlying_spec`]]
+
+The `underlying_spec` is parsed based on the formatter of the range's
+reference type.
+
+By default, a range of characters or strings is printed escaped and quoted. But
+if any `underlying_spec` is provided (even if it is empty), then the characters
+or strings are printed according to the provided specification.
+
+Examples:
+
+  fmt::format("{}", std::vector{10, 20, 30});
+  // Result: [10, 20, 30]
+  fmt::format("{::#x}", std::vector{10, 20, 30});
+  // Result: [0xa, 0x14, 0x13]
+  fmt::format("{}", vector{'h', 'e', 'l', 'l', 'o'});
+  // Result: ['h', 'e', 'l', 'l', 'o']
+  fmt::format("{::}", vector{'h', 'e', 'l', 'l', 'o'});
+  // Result: [h, e, l, l, o]
+  fmt::format("{::d}", vector{'h', 'e', 'l', 'l', 'o'});
+  // Result: [104, 101, 108, 108, 111]
+
 .. _formatexamples:
 
-Format examples
+Format Examples
 ===============
 
 This section contains examples of the format syntax and comparison with
@@ -318,72 +396,94 @@ following examples.
 
 Accessing arguments by position::
 
-   format("{0}, {1}, {2}", 'a', 'b', 'c');
+   fmt::format("{0}, {1}, {2}", 'a', 'b', 'c');
    // Result: "a, b, c"
-   format("{}, {}, {}", 'a', 'b', 'c');
+   fmt::format("{}, {}, {}", 'a', 'b', 'c');
    // Result: "a, b, c"
-   format("{2}, {1}, {0}", 'a', 'b', 'c');
+   fmt::format("{2}, {1}, {0}", 'a', 'b', 'c');
    // Result: "c, b, a"
-   format("{0}{1}{0}", "abra", "cad");  // arguments' indices can be repeated
+   fmt::format("{0}{1}{0}", "abra", "cad");  // arguments' indices can be repeated
    // Result: "abracadabra"
 
 Aligning the text and specifying a width::
 
-   format("{:<30}", "left aligned");
+   fmt::format("{:<30}", "left aligned");
    // Result: "left aligned                  "
-   format("{:>30}", "right aligned");
+   fmt::format("{:>30}", "right aligned");
    // Result: "                 right aligned"
-   format("{:^30}", "centered");
+   fmt::format("{:^30}", "centered");
    // Result: "           centered           "
-   format("{:*^30}", "centered");  // use '*' as a fill char
+   fmt::format("{:*^30}", "centered");  // use '*' as a fill char
    // Result: "***********centered***********"
 
 Dynamic width::
 
-   format("{:<{}}", "left aligned", 30);
+   fmt::format("{:<{}}", "left aligned", 30);
    // Result: "left aligned                  "
 
 Dynamic precision::
 
-   format("{:.{}f}", 3.14, 1);
+   fmt::format("{:.{}f}", 3.14, 1);
    // Result: "3.1"
 
 Replacing ``%+f``, ``%-f``, and ``% f`` and specifying a sign::
 
-   format("{:+f}; {:+f}", 3.14, -3.14);  // show it always
+   fmt::format("{:+f}; {:+f}", 3.14, -3.14);  // show it always
    // Result: "+3.140000; -3.140000"
-   format("{: f}; {: f}", 3.14, -3.14);  // show a space for positive numbers
+   fmt::format("{: f}; {: f}", 3.14, -3.14);  // show a space for positive numbers
    // Result: " 3.140000; -3.140000"
-   format("{:-f}; {:-f}", 3.14, -3.14);  // show only the minus -- same as '{:f}; {:f}'
+   fmt::format("{:-f}; {:-f}", 3.14, -3.14);  // show only the minus -- same as '{:f}; {:f}'
    // Result: "3.140000; -3.140000"
 
 Replacing ``%x`` and ``%o`` and converting the value to different bases::
 
-   format("int: {0:d};  hex: {0:x};  oct: {0:o}; bin: {0:b}", 42);
+   fmt::format("int: {0:d};  hex: {0:x};  oct: {0:o}; bin: {0:b}", 42);
    // Result: "int: 42;  hex: 2a;  oct: 52; bin: 101010"
    // with 0x or 0 or 0b as prefix:
-   format("int: {0:d};  hex: {0:#x};  oct: {0:#o};  bin: {0:#b}", 42);
+   fmt::format("int: {0:d};  hex: {0:#x};  oct: {0:#o};  bin: {0:#b}", 42);
    // Result: "int: 42;  hex: 0x2a;  oct: 052;  bin: 0b101010"
 
 Padded hex byte with prefix and always prints both hex characters::
 
-   format("{:#04x}", 0);
+   fmt::format("{:#04x}", 0);
    // Result: "0x00"
 
+Box drawing using Unicode fill::
+
+   fmt::print(
+     "┌{0:─^{2}}┐\n"
+     "│{1: ^{2}}│\n"
+     "└{0:─^{2}}┘\n", "", "Hello, world!", 20);
+
+prints::
+
+   ┌────────────────────┐
+   │   Hello, world!    │
+   └────────────────────┘
+
+Using type-specific formatting::
+
+   #include <fmt/chrono.h>
+
+   auto t = tm();
+   t.tm_year = 2010 - 1900;
+   t.tm_mon = 7;
+   t.tm_mday = 4;
+   t.tm_hour = 12;
+   t.tm_min = 15;
+   t.tm_sec = 58;
+   fmt::print("{:%Y-%m-%d %H:%M:%S}", t);
+   // Prints: 2010-08-04 12:15:58
+
+Using the comma as a thousands separator::
+
+   #include <fmt/format.h>
+
+   auto s = fmt::format(std::locale("en_US.UTF-8"), "{:L}", 1234567890);
+   // s == "1,234,567,890"
+
 .. ifconfig:: False
 
-   Using the comma as a thousands separator::
-
-      format("{:,}", 1234567890);
-      '1,234,567,890'
-
-   Using type-specific formatting::
-
-      >>> import datetime
-      >>> d = datetime.datetime(2010, 7, 4, 12, 15, 58)
-      Format("{:%Y-%m-%d %H:%M:%S}") << d)
-      '2010-07-04 12:15:58'
-
    Nesting arguments and more complex examples::
 
       >>> for align, text in zip('<^>', ['left', 'center', 'right']):
@@ -412,4 +512,3 @@ Padded hex byte with prefix and always prints both hex characters::
           9     9    11  1001
          10     A    12  1010
          11     B    13  1011
-

doc/usage.rst

@@ -2,26 +2,20 @@
 Usage
 *****
 
-To use the fmt library, add :file:`format.h` and :file:`format.cc` from
-a `release archive <https://github.com/fmtlib/fmt/releases/latest>`_
-or the `Git repository <https://github.com/fmtlib/fmt>`_ to your project.
+To use the {fmt} library, add :file:`fmt/core.h`, :file:`fmt/format.h`,
+:file:`fmt/format-inl.h`, :file:`src/format.cc` and optionally other headers
+from a `release archive <https://github.com/fmtlib/fmt/releases/latest>`_ or
+the `Git repository <https://github.com/fmtlib/fmt>`_ to your project.
 Alternatively, you can :ref:`build the library with CMake <building>`.
 
-If you are using Visual C++ with precompiled headers, you might need to add
-the line ::
-
-   #include "stdafx.h"
-
-before other includes in :file:`format.cc`.
-
 .. _building:
 
-Building the library
+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
 
@@ -31,7 +25,7 @@ workflow starts with::
 
   mkdir build          # Create a directory to hold the build output.
   cd build
-  cmake <path/to/fmt>  # Generate native build scripts.
+  cmake ..  # Generate native build scripts.
 
 where :file:`{<path/to/fmt>}` is a path to the ``fmt`` repository.
 
@@ -45,7 +39,7 @@ You can control generation of the make ``test`` target with the ``FMT_TEST``
 CMake option. This can be useful if you include fmt as a subdirectory in
 your project but don't want to add fmt's tests to your ``test`` target.
 
-If you use Windows and have Visual Studio installed, a :file:`FORMAT.sln`
+If you use Windows and have Visual Studio installed, a :file:`FMT.sln`
 file and several :file:`.vcproj` files will be created. You can then build them
 using Visual Studio or msbuild.
 
@@ -56,10 +50,24 @@ 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
 
-Header-only usage with CMake
-============================
+
+To build a `static library` with position independent code (required if the main
+consumer of the fmt library is a shared library i.e. a Python extension) set the
+``CMAKE_POSITION_INDEPENDENT_CODE`` CMake variable to ``TRUE``::
+
+  cmake -DCMAKE_POSITION_INDEPENDENT_CODE=TRUE ...
+
+
+Installing the Library
+======================
+
+After building the library you can install it on a Unix-like system by running
+:command:`sudo make install`.
+
+Usage with CMake
+================
 
 You can add the ``fmt`` library directory into your project and include it in
 your ``CMakeLists.txt`` file::
@@ -74,11 +82,59 @@ or
 
 to exclude it from ``make``, ``make all``, or ``cmake --build .``.
 
-Settting up your target to use a header-only version of ``fmt`` is equaly easy::
+You can detect and use an installed version of {fmt} as follows::
 
-   target_link_libraries(<your-target> PRIVATE fmt-header-only)
+   find_package(fmt)
+   target_link_libraries(<your-target> fmt::fmt)
 
-Building the documentation
+Setting up your target to use a header-only version of ``fmt`` is equally easy::
+
+   target_link_libraries(<your-target> PRIVATE fmt::fmt-header-only)
+
+Usage with build2
+=================
+
+You can use `build2 <https://build2.org>`_, a dependency manager and a
+build-system combined, to use ``fmt``.
+
+Currently this package is available in these package repositories:
+
+- **https://cppget.org/fmt/** for released and published versions.
+- `The git repository with the sources of the build2 package of fmt <https://github.com/build2-packaging/fmt.git>`_
+  for unreleased or custom revisions of ``fmt``.
+
+**Usage:**
+
+- ``build2`` package name: ``fmt``
+- Library target name : ``lib{fmt}``
+
+For example, to make your ``build2`` project depend on ``fmt``:
+
+- Add one of the repositories to your configurations, or in your
+  ``repositories.manifest``, if not already there::
+
+    :
+    role: prerequisite
+    location: https://pkg.cppget.org/1/stable
+
+- Add this package as a dependency to your ``./manifest`` file
+  (example for ``v7.0.x``)::
+
+    depends: fmt ~7.0.0
+
+- Import the target and use it as a prerequisite to your own target
+  using `fmt` in the appropriate ``buildfile``::
+
+    import fmt = fmt%lib{fmt}
+    lib{mylib} : cxx{**} ... $fmt
+
+Then build your project as usual with `b` or `bdep update`.
+
+For ``build2`` newcomers or to get more details and use cases, you can read the
+``build2``
+`toolchain introduction <https://build2.org/build2-toolchain/doc/build2-toolchain-intro.xhtml>`_.
+
+Building the Documentation
 ==========================
 
 To build the documentation you need the following software installed on your
@@ -98,7 +154,45 @@ the previous section. Then compile the ``doc`` target/project, for example::
   make doc
 
 This will generate the HTML documentation in ``doc/html``.
-  
+
+Conda
+=====
+
+fmt can be installed on Linux, macOS and Windows with
+`Conda <https://docs.conda.io/en/latest/>`__, using its
+`conda-forge <https://conda-forge.org>`__
+`package <https://github.com/conda-forge/fmt-feedstock>`__, as follows::
+
+  conda install -c conda-forge fmt
+
+Vcpkg
+=====
+
+You can download and install fmt using the `vcpkg
+<https://github.com/Microsoft/vcpkg>`__ dependency manager::
+
+  git clone https://github.com/Microsoft/vcpkg.git
+  cd vcpkg
+  ./bootstrap-vcpkg.sh
+  ./vcpkg integrate install
+  ./vcpkg install fmt
+
+The fmt port in vcpkg is kept up to date by Microsoft team members and community
+contributors. If the version is out of date, please `create an issue or pull
+request <https://github.com/Microsoft/vcpkg>`__ on the vcpkg repository.
+
+LHelper
+=======
+
+You can download and install fmt using
+`lhelper <https://github.com/franko/lhelper>`__ dependency manager::
+
+  lhelper activate <some-environment>
+  lhelper install fmt
+
+All the recipes for lhelper are kept in the
+`lhelper's recipe <https://github.com/franko/lhelper-recipes>`__ repository.
+
 Android NDK
 ===========
 
@@ -108,11 +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 +1,234 @@
+// 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<
+      std::is_convertible<T, std::basic_string<char_type>>::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:
+  constexpr dynamic_format_arg_store() = default;
+
+  /**
+    \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/color.h

@@ -11,268 +11,641 @@
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
 
-#ifdef FMT_DEPRECATED_COLORS
-
-// color and (v)print_colored are deprecated.
-enum color { black, red, green, yellow, blue, magenta, cyan, white };
-FMT_API void vprint_colored(color c, string_view format, format_args args);
-FMT_API void vprint_colored(color c, wstring_view format, wformat_args args);
-template <typename... Args>
-inline void print_colored(color c, string_view format_str,
-                          const Args & ... args) {
-  vprint_colored(c, format_str, make_format_args(args...));
-}
-template <typename... Args>
-inline void print_colored(color c, wstring_view format_str,
-                          const Args & ... args) {
-  vprint_colored(c, format_str, make_format_args<wformat_context>(args...));
-}
-
-inline void vprint_colored(color c, string_view format, format_args args) {
-  char escape[] = "\x1b[30m";
-  escape[3] = static_cast<char>('0' + c);
-  std::fputs(escape, stdout);
-  vprint(format, args);
-  std::fputs(internal::data::RESET_COLOR, stdout);
-}
-
-inline void vprint_colored(color c, wstring_view format, wformat_args args) {
-  wchar_t escape[] = L"\x1b[30m";
-  escape[3] = static_cast<wchar_t>('0' + c);
-  std::fputws(escape, stdout);
-  vprint(format, args);
-  std::fputws(internal::data::WRESET_COLOR, stdout);
-}
-
-#else
-
-// Experimental color support.
 enum class color : uint32_t {
-  alice_blue              = 0xF0F8FF, // rgb(240,248,255)
-  antique_white           = 0xFAEBD7, // rgb(250,235,215)
-  aqua                    = 0x00FFFF, // rgb(0,255,255)
-  aquamarine              = 0x7FFFD4, // rgb(127,255,212)
-  azure                   = 0xF0FFFF, // rgb(240,255,255)
-  beige                   = 0xF5F5DC, // rgb(245,245,220)
-  bisque                  = 0xFFE4C4, // rgb(255,228,196)
-  black                   = 0x000000, // rgb(0,0,0)
-  blanched_almond         = 0xFFEBCD, // rgb(255,235,205)
-  blue                    = 0x0000FF, // rgb(0,0,255)
-  blue_violet             = 0x8A2BE2, // rgb(138,43,226)
-  brown                   = 0xA52A2A, // rgb(165,42,42)
-  burly_wood              = 0xDEB887, // rgb(222,184,135)
-  cadet_blue              = 0x5F9EA0, // rgb(95,158,160)
-  chartreuse              = 0x7FFF00, // rgb(127,255,0)
-  chocolate               = 0xD2691E, // rgb(210,105,30)
-  coral                   = 0xFF7F50, // rgb(255,127,80)
-  cornflower_blue         = 0x6495ED, // rgb(100,149,237)
-  cornsilk                = 0xFFF8DC, // rgb(255,248,220)
-  crimson                 = 0xDC143C, // rgb(220,20,60)
-  cyan                    = 0x00FFFF, // rgb(0,255,255)
-  dark_blue               = 0x00008B, // rgb(0,0,139)
-  dark_cyan               = 0x008B8B, // rgb(0,139,139)
-  dark_golden_rod         = 0xB8860B, // rgb(184,134,11)
-  dark_gray               = 0xA9A9A9, // rgb(169,169,169)
-  dark_green              = 0x006400, // rgb(0,100,0)
-  dark_khaki              = 0xBDB76B, // rgb(189,183,107)
-  dark_magenta            = 0x8B008B, // rgb(139,0,139)
-  dark_olive_green        = 0x556B2F, // rgb(85,107,47)
-  dark_orange             = 0xFF8C00, // rgb(255,140,0)
-  dark_orchid             = 0x9932CC, // rgb(153,50,204)
-  dark_red                = 0x8B0000, // rgb(139,0,0)
-  dark_salmon             = 0xE9967A, // rgb(233,150,122)
-  dark_sea_green          = 0x8FBC8F, // rgb(143,188,143)
-  dark_slate_blue         = 0x483D8B, // rgb(72,61,139)
-  dark_slate_gray         = 0x2F4F4F, // rgb(47,79,79)
-  dark_turquoise          = 0x00CED1, // rgb(0,206,209)
-  dark_violet             = 0x9400D3, // rgb(148,0,211)
-  deep_pink               = 0xFF1493, // rgb(255,20,147)
-  deep_sky_blue           = 0x00BFFF, // rgb(0,191,255)
-  dim_gray                = 0x696969, // rgb(105,105,105)
-  dodger_blue             = 0x1E90FF, // rgb(30,144,255)
-  fire_brick              = 0xB22222, // rgb(178,34,34)
-  floral_white            = 0xFFFAF0, // rgb(255,250,240)
-  forest_green            = 0x228B22, // rgb(34,139,34)
-  fuchsia                 = 0xFF00FF, // rgb(255,0,255)
-  gainsboro               = 0xDCDCDC, // rgb(220,220,220)
-  ghost_white             = 0xF8F8FF, // rgb(248,248,255)
-  gold                    = 0xFFD700, // rgb(255,215,0)
-  golden_rod              = 0xDAA520, // rgb(218,165,32)
-  gray                    = 0x808080, // rgb(128,128,128)
-  green                   = 0x008000, // rgb(0,128,0)
-  green_yellow            = 0xADFF2F, // rgb(173,255,47)
-  honey_dew               = 0xF0FFF0, // rgb(240,255,240)
-  hot_pink                = 0xFF69B4, // rgb(255,105,180)
-  indian_red              = 0xCD5C5C, // rgb(205,92,92)
-  indigo                  = 0x4B0082, // rgb(75,0,130)
-  ivory                   = 0xFFFFF0, // rgb(255,255,240)
-  khaki                   = 0xF0E68C, // rgb(240,230,140)
-  lavender                = 0xE6E6FA, // rgb(230,230,250)
-  lavender_blush          = 0xFFF0F5, // rgb(255,240,245)
-  lawn_green              = 0x7CFC00, // rgb(124,252,0)
-  lemon_chiffon           = 0xFFFACD, // rgb(255,250,205)
-  light_blue              = 0xADD8E6, // rgb(173,216,230)
-  light_coral             = 0xF08080, // rgb(240,128,128)
-  light_cyan              = 0xE0FFFF, // rgb(224,255,255)
-  light_golden_rod_yellow = 0xFAFAD2, // rgb(250,250,210)
-  light_gray              = 0xD3D3D3, // rgb(211,211,211)
-  light_green             = 0x90EE90, // rgb(144,238,144)
-  light_pink              = 0xFFB6C1, // rgb(255,182,193)
-  light_salmon            = 0xFFA07A, // rgb(255,160,122)
-  light_sea_green         = 0x20B2AA, // rgb(32,178,170)
-  light_sky_blue          = 0x87CEFA, // rgb(135,206,250)
-  light_slate_gray        = 0x778899, // rgb(119,136,153)
-  light_steel_blue        = 0xB0C4DE, // rgb(176,196,222)
-  light_yellow            = 0xFFFFE0, // rgb(255,255,224)
-  lime                    = 0x00FF00, // rgb(0,255,0)
-  lime_green              = 0x32CD32, // rgb(50,205,50)
-  linen                   = 0xFAF0E6, // rgb(250,240,230)
-  magenta                 = 0xFF00FF, // rgb(255,0,255)
-  maroon                  = 0x800000, // rgb(128,0,0)
-  medium_aquamarine       = 0x66CDAA, // rgb(102,205,170)
-  medium_blue             = 0x0000CD, // rgb(0,0,205)
-  medium_orchid           = 0xBA55D3, // rgb(186,85,211)
-  medium_purple           = 0x9370DB, // rgb(147,112,219)
-  medium_sea_green        = 0x3CB371, // rgb(60,179,113)
-  medium_slate_blue       = 0x7B68EE, // rgb(123,104,238)
-  medium_spring_green     = 0x00FA9A, // rgb(0,250,154)
-  medium_turquoise        = 0x48D1CC, // rgb(72,209,204)
-  medium_violet_red       = 0xC71585, // rgb(199,21,133)
-  midnight_blue           = 0x191970, // rgb(25,25,112)
-  mint_cream              = 0xF5FFFA, // rgb(245,255,250)
-  misty_rose              = 0xFFE4E1, // rgb(255,228,225)
-  moccasin                = 0xFFE4B5, // rgb(255,228,181)
-  navajo_white            = 0xFFDEAD, // rgb(255,222,173)
-  navy                    = 0x000080, // rgb(0,0,128)
-  old_lace                = 0xFDF5E6, // rgb(253,245,230)
-  olive                   = 0x808000, // rgb(128,128,0)
-  olive_drab              = 0x6B8E23, // rgb(107,142,35)
-  orange                  = 0xFFA500, // rgb(255,165,0)
-  orange_red              = 0xFF4500, // rgb(255,69,0)
-  orchid                  = 0xDA70D6, // rgb(218,112,214)
-  pale_golden_rod         = 0xEEE8AA, // rgb(238,232,170)
-  pale_green              = 0x98FB98, // rgb(152,251,152)
-  pale_turquoise          = 0xAFEEEE, // rgb(175,238,238)
-  pale_violet_red         = 0xDB7093, // rgb(219,112,147)
-  papaya_whip             = 0xFFEFD5, // rgb(255,239,213)
-  peach_puff              = 0xFFDAB9, // rgb(255,218,185)
-  peru                    = 0xCD853F, // rgb(205,133,63)
-  pink                    = 0xFFC0CB, // rgb(255,192,203)
-  plum                    = 0xDDA0DD, // rgb(221,160,221)
-  powder_blue             = 0xB0E0E6, // rgb(176,224,230)
-  purple                  = 0x800080, // rgb(128,0,128)
-  rebecca_purple          = 0x663399, // rgb(102,51,153)
-  red                     = 0xFF0000, // rgb(255,0,0)
-  rosy_brown              = 0xBC8F8F, // rgb(188,143,143)
-  royal_blue              = 0x4169E1, // rgb(65,105,225)
-  saddle_brown            = 0x8B4513, // rgb(139,69,19)
-  salmon                  = 0xFA8072, // rgb(250,128,114)
-  sandy_brown             = 0xF4A460, // rgb(244,164,96)
-  sea_green               = 0x2E8B57, // rgb(46,139,87)
-  sea_shell               = 0xFFF5EE, // rgb(255,245,238)
-  sienna                  = 0xA0522D, // rgb(160,82,45)
-  silver                  = 0xC0C0C0, // rgb(192,192,192)
-  sky_blue                = 0x87CEEB, // rgb(135,206,235)
-  slate_blue              = 0x6A5ACD, // rgb(106,90,205)
-  slate_gray              = 0x708090, // rgb(112,128,144)
-  snow                    = 0xFFFAFA, // rgb(255,250,250)
-  spring_green            = 0x00FF7F, // rgb(0,255,127)
-  steel_blue              = 0x4682B4, // rgb(70,130,180)
-  tan                     = 0xD2B48C, // rgb(210,180,140)
-  teal                    = 0x008080, // rgb(0,128,128)
-  thistle                 = 0xD8BFD8, // rgb(216,191,216)
-  tomato                  = 0xFF6347, // rgb(255,99,71)
-  turquoise               = 0x40E0D0, // rgb(64,224,208)
-  violet                  = 0xEE82EE, // rgb(238,130,238)
-  wheat                   = 0xF5DEB3, // rgb(245,222,179)
-  white                   = 0xFFFFFF, // rgb(255,255,255)
-  white_smoke             = 0xF5F5F5, // rgb(245,245,245)
-  yellow                  = 0xFFFF00, // rgb(255,255,0)
-  yellow_green            = 0x9ACD32, // rgb(154,205,50)
-};  // enum class color
+  alice_blue = 0xF0F8FF,               // rgb(240,248,255)
+  antique_white = 0xFAEBD7,            // rgb(250,235,215)
+  aqua = 0x00FFFF,                     // rgb(0,255,255)
+  aquamarine = 0x7FFFD4,               // rgb(127,255,212)
+  azure = 0xF0FFFF,                    // rgb(240,255,255)
+  beige = 0xF5F5DC,                    // rgb(245,245,220)
+  bisque = 0xFFE4C4,                   // rgb(255,228,196)
+  black = 0x000000,                    // rgb(0,0,0)
+  blanched_almond = 0xFFEBCD,          // rgb(255,235,205)
+  blue = 0x0000FF,                     // rgb(0,0,255)
+  blue_violet = 0x8A2BE2,              // rgb(138,43,226)
+  brown = 0xA52A2A,                    // rgb(165,42,42)
+  burly_wood = 0xDEB887,               // rgb(222,184,135)
+  cadet_blue = 0x5F9EA0,               // rgb(95,158,160)
+  chartreuse = 0x7FFF00,               // rgb(127,255,0)
+  chocolate = 0xD2691E,                // rgb(210,105,30)
+  coral = 0xFF7F50,                    // rgb(255,127,80)
+  cornflower_blue = 0x6495ED,          // rgb(100,149,237)
+  cornsilk = 0xFFF8DC,                 // rgb(255,248,220)
+  crimson = 0xDC143C,                  // rgb(220,20,60)
+  cyan = 0x00FFFF,                     // rgb(0,255,255)
+  dark_blue = 0x00008B,                // rgb(0,0,139)
+  dark_cyan = 0x008B8B,                // rgb(0,139,139)
+  dark_golden_rod = 0xB8860B,          // rgb(184,134,11)
+  dark_gray = 0xA9A9A9,                // rgb(169,169,169)
+  dark_green = 0x006400,               // rgb(0,100,0)
+  dark_khaki = 0xBDB76B,               // rgb(189,183,107)
+  dark_magenta = 0x8B008B,             // rgb(139,0,139)
+  dark_olive_green = 0x556B2F,         // rgb(85,107,47)
+  dark_orange = 0xFF8C00,              // rgb(255,140,0)
+  dark_orchid = 0x9932CC,              // rgb(153,50,204)
+  dark_red = 0x8B0000,                 // rgb(139,0,0)
+  dark_salmon = 0xE9967A,              // rgb(233,150,122)
+  dark_sea_green = 0x8FBC8F,           // rgb(143,188,143)
+  dark_slate_blue = 0x483D8B,          // rgb(72,61,139)
+  dark_slate_gray = 0x2F4F4F,          // rgb(47,79,79)
+  dark_turquoise = 0x00CED1,           // rgb(0,206,209)
+  dark_violet = 0x9400D3,              // rgb(148,0,211)
+  deep_pink = 0xFF1493,                // rgb(255,20,147)
+  deep_sky_blue = 0x00BFFF,            // rgb(0,191,255)
+  dim_gray = 0x696969,                 // rgb(105,105,105)
+  dodger_blue = 0x1E90FF,              // rgb(30,144,255)
+  fire_brick = 0xB22222,               // rgb(178,34,34)
+  floral_white = 0xFFFAF0,             // rgb(255,250,240)
+  forest_green = 0x228B22,             // rgb(34,139,34)
+  fuchsia = 0xFF00FF,                  // rgb(255,0,255)
+  gainsboro = 0xDCDCDC,                // rgb(220,220,220)
+  ghost_white = 0xF8F8FF,              // rgb(248,248,255)
+  gold = 0xFFD700,                     // rgb(255,215,0)
+  golden_rod = 0xDAA520,               // rgb(218,165,32)
+  gray = 0x808080,                     // rgb(128,128,128)
+  green = 0x008000,                    // rgb(0,128,0)
+  green_yellow = 0xADFF2F,             // rgb(173,255,47)
+  honey_dew = 0xF0FFF0,                // rgb(240,255,240)
+  hot_pink = 0xFF69B4,                 // rgb(255,105,180)
+  indian_red = 0xCD5C5C,               // rgb(205,92,92)
+  indigo = 0x4B0082,                   // rgb(75,0,130)
+  ivory = 0xFFFFF0,                    // rgb(255,255,240)
+  khaki = 0xF0E68C,                    // rgb(240,230,140)
+  lavender = 0xE6E6FA,                 // rgb(230,230,250)
+  lavender_blush = 0xFFF0F5,           // rgb(255,240,245)
+  lawn_green = 0x7CFC00,               // rgb(124,252,0)
+  lemon_chiffon = 0xFFFACD,            // rgb(255,250,205)
+  light_blue = 0xADD8E6,               // rgb(173,216,230)
+  light_coral = 0xF08080,              // rgb(240,128,128)
+  light_cyan = 0xE0FFFF,               // rgb(224,255,255)
+  light_golden_rod_yellow = 0xFAFAD2,  // rgb(250,250,210)
+  light_gray = 0xD3D3D3,               // rgb(211,211,211)
+  light_green = 0x90EE90,              // rgb(144,238,144)
+  light_pink = 0xFFB6C1,               // rgb(255,182,193)
+  light_salmon = 0xFFA07A,             // rgb(255,160,122)
+  light_sea_green = 0x20B2AA,          // rgb(32,178,170)
+  light_sky_blue = 0x87CEFA,           // rgb(135,206,250)
+  light_slate_gray = 0x778899,         // rgb(119,136,153)
+  light_steel_blue = 0xB0C4DE,         // rgb(176,196,222)
+  light_yellow = 0xFFFFE0,             // rgb(255,255,224)
+  lime = 0x00FF00,                     // rgb(0,255,0)
+  lime_green = 0x32CD32,               // rgb(50,205,50)
+  linen = 0xFAF0E6,                    // rgb(250,240,230)
+  magenta = 0xFF00FF,                  // rgb(255,0,255)
+  maroon = 0x800000,                   // rgb(128,0,0)
+  medium_aquamarine = 0x66CDAA,        // rgb(102,205,170)
+  medium_blue = 0x0000CD,              // rgb(0,0,205)
+  medium_orchid = 0xBA55D3,            // rgb(186,85,211)
+  medium_purple = 0x9370DB,            // rgb(147,112,219)
+  medium_sea_green = 0x3CB371,         // rgb(60,179,113)
+  medium_slate_blue = 0x7B68EE,        // rgb(123,104,238)
+  medium_spring_green = 0x00FA9A,      // rgb(0,250,154)
+  medium_turquoise = 0x48D1CC,         // rgb(72,209,204)
+  medium_violet_red = 0xC71585,        // rgb(199,21,133)
+  midnight_blue = 0x191970,            // rgb(25,25,112)
+  mint_cream = 0xF5FFFA,               // rgb(245,255,250)
+  misty_rose = 0xFFE4E1,               // rgb(255,228,225)
+  moccasin = 0xFFE4B5,                 // rgb(255,228,181)
+  navajo_white = 0xFFDEAD,             // rgb(255,222,173)
+  navy = 0x000080,                     // rgb(0,0,128)
+  old_lace = 0xFDF5E6,                 // rgb(253,245,230)
+  olive = 0x808000,                    // rgb(128,128,0)
+  olive_drab = 0x6B8E23,               // rgb(107,142,35)
+  orange = 0xFFA500,                   // rgb(255,165,0)
+  orange_red = 0xFF4500,               // rgb(255,69,0)
+  orchid = 0xDA70D6,                   // rgb(218,112,214)
+  pale_golden_rod = 0xEEE8AA,          // rgb(238,232,170)
+  pale_green = 0x98FB98,               // rgb(152,251,152)
+  pale_turquoise = 0xAFEEEE,           // rgb(175,238,238)
+  pale_violet_red = 0xDB7093,          // rgb(219,112,147)
+  papaya_whip = 0xFFEFD5,              // rgb(255,239,213)
+  peach_puff = 0xFFDAB9,               // rgb(255,218,185)
+  peru = 0xCD853F,                     // rgb(205,133,63)
+  pink = 0xFFC0CB,                     // rgb(255,192,203)
+  plum = 0xDDA0DD,                     // rgb(221,160,221)
+  powder_blue = 0xB0E0E6,              // rgb(176,224,230)
+  purple = 0x800080,                   // rgb(128,0,128)
+  rebecca_purple = 0x663399,           // rgb(102,51,153)
+  red = 0xFF0000,                      // rgb(255,0,0)
+  rosy_brown = 0xBC8F8F,               // rgb(188,143,143)
+  royal_blue = 0x4169E1,               // rgb(65,105,225)
+  saddle_brown = 0x8B4513,             // rgb(139,69,19)
+  salmon = 0xFA8072,                   // rgb(250,128,114)
+  sandy_brown = 0xF4A460,              // rgb(244,164,96)
+  sea_green = 0x2E8B57,                // rgb(46,139,87)
+  sea_shell = 0xFFF5EE,                // rgb(255,245,238)
+  sienna = 0xA0522D,                   // rgb(160,82,45)
+  silver = 0xC0C0C0,                   // rgb(192,192,192)
+  sky_blue = 0x87CEEB,                 // rgb(135,206,235)
+  slate_blue = 0x6A5ACD,               // rgb(106,90,205)
+  slate_gray = 0x708090,               // rgb(112,128,144)
+  snow = 0xFFFAFA,                     // rgb(255,250,250)
+  spring_green = 0x00FF7F,             // rgb(0,255,127)
+  steel_blue = 0x4682B4,               // rgb(70,130,180)
+  tan = 0xD2B48C,                      // rgb(210,180,140)
+  teal = 0x008080,                     // rgb(0,128,128)
+  thistle = 0xD8BFD8,                  // rgb(216,191,216)
+  tomato = 0xFF6347,                   // rgb(255,99,71)
+  turquoise = 0x40E0D0,                // rgb(64,224,208)
+  violet = 0xEE82EE,                   // rgb(238,130,238)
+  wheat = 0xF5DEB3,                    // rgb(245,222,179)
+  white = 0xFFFFFF,                    // rgb(255,255,255)
+  white_smoke = 0xF5F5F5,              // rgb(245,245,245)
+  yellow = 0xFFFF00,                   // rgb(255,255,0)
+  yellow_green = 0x9ACD32              // rgb(154,205,50)
+};                                     // enum class color
+
+enum class terminal_color : uint8_t {
+  black = 30,
+  red,
+  green,
+  yellow,
+  blue,
+  magenta,
+  cyan,
+  white,
+  bright_black = 90,
+  bright_red,
+  bright_green,
+  bright_yellow,
+  bright_blue,
+  bright_magenta,
+  bright_cyan,
+  bright_white
+};
+
+enum class emphasis : uint8_t {
+  bold = 1,
+  faint = 1 << 1,
+  italic = 1 << 2,
+  underline = 1 << 3,
+  blink = 1 << 4,
+  reverse = 1 << 5,
+  conceal = 1 << 6,
+  strikethrough = 1 << 7,
+};
 
 // rgb is a struct for red, green and blue colors.
-// We use rgb as name because some editors will show it as color direct in the
-// editor.
+// Using the name "rgb" makes some editors show the color in a tooltip.
 struct rgb {
-  FMT_CONSTEXPR_DECL rgb() : r(0), g(0), b(0) {}
-  FMT_CONSTEXPR_DECL rgb(uint8_t r_, uint8_t g_, uint8_t b_)
-    : r(r_), g(g_), b(b_) {}
-  FMT_CONSTEXPR_DECL rgb(uint32_t hex)
-    : r((hex >> 16) & 0xFF), g((hex >> 8) & 0xFF), b((hex) & 0xFF) {}
-  FMT_CONSTEXPR_DECL rgb(color hex)
-    : r((uint32_t(hex) >> 16) & 0xFF), g((uint32_t(hex) >> 8) & 0xFF),
-      b(uint32_t(hex) & 0xFF) {}
+  FMT_CONSTEXPR rgb() : r(0), g(0), b(0) {}
+  FMT_CONSTEXPR rgb(uint8_t r_, uint8_t g_, uint8_t b_) : r(r_), g(g_), b(b_) {}
+  FMT_CONSTEXPR rgb(uint32_t hex)
+      : r((hex >> 16) & 0xFF), g((hex >> 8) & 0xFF), b(hex & 0xFF) {}
+  FMT_CONSTEXPR rgb(color hex)
+      : r((uint32_t(hex) >> 16) & 0xFF),
+        g((uint32_t(hex) >> 8) & 0xFF),
+        b(uint32_t(hex) & 0xFF) {}
   uint8_t r;
   uint8_t g;
   uint8_t b;
 };
 
-void vprint_rgb(rgb fd, string_view format, format_args args);
-void vprint_rgb(rgb fd, rgb bg, string_view format, format_args args);
+FMT_BEGIN_DETAIL_NAMESPACE
 
-/**
-  Formats a string and prints it to stdout using ANSI escape sequences to
-  specify foreground color 'fd'.
-  Example:
-    fmt::print(fmt::color::red, "Elapsed time: {0:.2f} seconds", 1.23);
- */
-template <typename... Args>
-inline void print(rgb fd, string_view format_str, const Args & ... args) {
-  vprint_rgb(fd, format_str, make_format_args(args...));
+// color is a struct of either a rgb color or a terminal color.
+struct color_type {
+  FMT_CONSTEXPR color_type() noexcept : is_rgb(), value{} {}
+  FMT_CONSTEXPR color_type(color rgb_color) noexcept : is_rgb(true), value{} {
+    value.rgb_color = static_cast<uint32_t>(rgb_color);
+  }
+  FMT_CONSTEXPR color_type(rgb rgb_color) noexcept : is_rgb(true), value{} {
+    value.rgb_color = (static_cast<uint32_t>(rgb_color.r) << 16) |
+                      (static_cast<uint32_t>(rgb_color.g) << 8) | rgb_color.b;
+  }
+  FMT_CONSTEXPR color_type(terminal_color term_color) noexcept
+      : is_rgb(), value{} {
+    value.term_color = static_cast<uint8_t>(term_color);
+  }
+  bool is_rgb;
+  union color_union {
+    uint8_t term_color;
+    uint32_t rgb_color;
+  } value;
+};
+
+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()) noexcept
+      : set_foreground_color(), set_background_color(), ems(em) {}
+
+  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 OR 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 OR 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 text_style operator|(text_style lhs,
+                                            const text_style& rhs) {
+    return lhs |= rhs;
+  }
+
+  FMT_CONSTEXPR bool has_foreground() const noexcept {
+    return set_foreground_color;
+  }
+  FMT_CONSTEXPR bool has_background() const noexcept {
+    return set_background_color;
+  }
+  FMT_CONSTEXPR bool has_emphasis() const noexcept {
+    return static_cast<uint8_t>(ems) != 0;
+  }
+  FMT_CONSTEXPR detail::color_type get_foreground() const noexcept {
+    FMT_ASSERT(has_foreground(), "no foreground specified for this style");
+    return foreground_color;
+  }
+  FMT_CONSTEXPR detail::color_type get_background() const noexcept {
+    FMT_ASSERT(has_background(), "no background specified for this style");
+    return background_color;
+  }
+  FMT_CONSTEXPR emphasis get_emphasis() const noexcept {
+    FMT_ASSERT(has_emphasis(), "no emphasis specified for this style");
+    return ems;
+  }
+
+ private:
+  FMT_CONSTEXPR text_style(bool is_foreground,
+                           detail::color_type text_color) noexcept
+      : set_foreground_color(), set_background_color(), ems() {
+    if (is_foreground) {
+      foreground_color = text_color;
+      set_foreground_color = true;
+    } else {
+      background_color = text_color;
+      set_background_color = true;
+    }
+  }
+
+  friend FMT_CONSTEXPR text_style fg(detail::color_type foreground) noexcept;
+
+  friend FMT_CONSTEXPR text_style bg(detail::color_type background) noexcept;
+
+  detail::color_type foreground_color;
+  detail::color_type background_color;
+  bool set_foreground_color;
+  bool set_background_color;
+  emphasis ems;
+};
+
+/** Creates a text style from the foreground (text) color. */
+FMT_CONSTEXPR inline text_style fg(detail::color_type foreground) noexcept {
+  return text_style(true, foreground);
+}
+
+/** Creates a text style from the background color. */
+FMT_CONSTEXPR inline text_style bg(detail::color_type background) noexcept {
+  return text_style(false, background);
+}
+
+FMT_CONSTEXPR inline text_style operator|(emphasis lhs, emphasis rhs) noexcept {
+  return text_style(lhs) | rhs;
+}
+
+FMT_BEGIN_DETAIL_NAMESPACE
+
+template <typename Char> struct ansi_color_escape {
+  FMT_CONSTEXPR ansi_color_escape(detail::color_type text_color,
+                                  const char* esc) noexcept {
+    // If we have a terminal color, we need to output another escape code
+    // sequence.
+    if (!text_color.is_rgb) {
+      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.
+      if (is_background) value += 10u;
+
+      size_t index = 0;
+      buffer[index++] = static_cast<Char>('\x1b');
+      buffer[index++] = static_cast<Char>('[');
+
+      if (value >= 100u) {
+        buffer[index++] = static_cast<Char>('1');
+        value %= 100u;
+      }
+      buffer[index++] = static_cast<Char>('0' + value / 10u);
+      buffer[index++] = static_cast<Char>('0' + value % 10u);
+
+      buffer[index++] = static_cast<Char>('m');
+      buffer[index++] = static_cast<Char>('\0');
+      return;
+    }
+
+    for (int i = 0; i < 7; i++) {
+      buffer[i] = static_cast<Char>(esc[i]);
+    }
+    rgb color(text_color.value.rgb_color);
+    to_esc(color.r, buffer + 7, ';');
+    to_esc(color.g, buffer + 11, ';');
+    to_esc(color.b, buffer + 15, 'm');
+    buffer[19] = static_cast<Char>(0);
+  }
+  FMT_CONSTEXPR ansi_color_escape(emphasis em) noexcept {
+    uint8_t em_codes[num_emphases] = {};
+    if (has_emphasis(em, emphasis::bold)) em_codes[0] = 1;
+    if (has_emphasis(em, emphasis::faint)) em_codes[1] = 2;
+    if (has_emphasis(em, emphasis::italic)) em_codes[2] = 3;
+    if (has_emphasis(em, emphasis::underline)) em_codes[3] = 4;
+    if (has_emphasis(em, emphasis::blink)) em_codes[4] = 5;
+    if (has_emphasis(em, emphasis::reverse)) em_codes[5] = 7;
+    if (has_emphasis(em, emphasis::conceal)) em_codes[6] = 8;
+    if (has_emphasis(em, emphasis::strikethrough)) em_codes[7] = 9;
+
+    size_t index = 0;
+    for (size_t i = 0; i < num_emphases; ++i) {
+      if (!em_codes[i]) continue;
+      buffer[index++] = static_cast<Char>('\x1b');
+      buffer[index++] = static_cast<Char>('[');
+      buffer[index++] = static_cast<Char>('0' + em_codes[i]);
+      buffer[index++] = static_cast<Char>('m');
+    }
+    buffer[index++] = static_cast<Char>(0);
+  }
+  FMT_CONSTEXPR operator const Char*() const noexcept { return buffer; }
+
+  FMT_CONSTEXPR const Char* begin() const noexcept { return buffer; }
+  FMT_CONSTEXPR_CHAR_TRAITS const Char* end() const noexcept {
+    return buffer + std::char_traits<Char>::length(buffer);
+  }
+
+ private:
+  static constexpr size_t num_emphases = 8;
+  Char buffer[7u + 3u * num_emphases + 1u];
+
+  static FMT_CONSTEXPR void to_esc(uint8_t c, Char* out,
+                                   char delimiter) noexcept {
+    out[0] = static_cast<Char>('0' + c / 100);
+    out[1] = static_cast<Char>('0' + c / 10 % 10);
+    out[2] = static_cast<Char>('0' + c % 10);
+    out[3] = static_cast<Char>(delimiter);
+  }
+  static FMT_CONSTEXPR bool has_emphasis(emphasis em, emphasis mask) noexcept {
+    return static_cast<uint8_t>(em) & static_cast<uint8_t>(mask);
+  }
+};
+
+template <typename Char>
+FMT_CONSTEXPR ansi_color_escape<Char> make_foreground_color(
+    detail::color_type foreground) noexcept {
+  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) noexcept {
+  return ansi_color_escape<Char>(background, "\x1b[48;2;");
+}
+
+template <typename Char>
+FMT_CONSTEXPR ansi_color_escape<Char> make_emphasis(emphasis em) noexcept {
+  return ansi_color_escape<Char>(em);
+}
+
+template <typename Char> inline void fputs(const Char* chars, FILE* stream) {
+  int result = std::fputs(chars, stream);
+  if (result < 0)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+template <> inline void fputs<wchar_t>(const wchar_t* chars, FILE* stream) {
+  int result = std::fputws(chars, stream);
+  if (result < 0)
+    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
+}
+
+template <typename Char> inline void reset_color(FILE* stream) {
+  fputs("\x1b[0m", stream);
+}
+
+template <> inline void reset_color<wchar_t>(FILE* stream) {
+  fputs(L"\x1b[0m", stream);
+}
+
+template <typename Char> inline void reset_color(buffer<Char>& buffer) {
+  auto reset_color = string_view("\x1b[0m");
+  buffer.append(reset_color.begin(), reset_color.end());
+}
+
+template <typename T> struct styled_arg {
+  const T& value;
+  text_style style;
+};
+
+template <typename Char>
+void vformat_to(buffer<Char>& buf, const text_style& ts,
+                basic_string_view<Char> format_str,
+                basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  bool has_style = false;
+  if (ts.has_emphasis()) {
+    has_style = true;
+    auto emphasis = detail::make_emphasis<Char>(ts.get_emphasis());
+    buf.append(emphasis.begin(), emphasis.end());
+  }
+  if (ts.has_foreground()) {
+    has_style = true;
+    auto foreground = detail::make_foreground_color<Char>(ts.get_foreground());
+    buf.append(foreground.begin(), foreground.end());
+  }
+  if (ts.has_background()) {
+    has_style = true;
+    auto background = detail::make_background_color<Char>(ts.get_background());
+    buf.append(background.begin(), background.end());
+  }
+  detail::vformat_to(buf, format_str, args, {});
+  if (has_style) detail::reset_color<Char>(buf);
+}
+
+FMT_END_DETAIL_NAMESPACE
+
+template <typename S, typename Char = char_t<S>>
+void vprint(std::FILE* f, const text_style& ts, const S& format,
+            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  basic_memory_buffer<Char> buf;
+  detail::vformat_to(buf, ts, detail::to_string_view(format), args);
+  if (detail::is_utf8()) {
+    detail::print(f, basic_string_view<Char>(buf.begin(), buf.size()));
+  } else {
+    buf.push_back(Char(0));
+    detail::fputs(buf.data(), f);
+  }
 }
 
 /**
-  Formats a string and prints it to stdout using ANSI escape sequences to
-  specify foreground color 'fd' and background color 'bg'.
-  Example:
-    fmt::print(fmt::color::red, fmt::color::black,
+  \rst
+  Formats a string and prints it to the specified file stream using ANSI
+  escape sequences to specify text formatting.
+
+  **Example**::
+
+    fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
                "Elapsed time: {0:.2f} seconds", 1.23);
+  \endrst
  */
-template <typename... Args>
-inline void print(rgb fd, rgb bg, string_view format_str,
-                  const Args & ... args) {
-  vprint_rgb(fd, bg, format_str, make_format_args(args...));
-}
-namespace internal {
-FMT_CONSTEXPR void to_esc(uint8_t c, char out[], int offset) {
-  out[offset + 0] = static_cast<char>('0' + c / 100);
-  out[offset + 1] = static_cast<char>('0' + c / 10 % 10);
-  out[offset + 2] = static_cast<char>('0' + c % 10);
-}
-} // namespace internal
-
-inline void vprint_rgb(rgb fd, string_view format, format_args args) {
-  char escape_fd[] = "\x1b[38;2;000;000;000m";
-  internal::to_esc(fd.r, escape_fd, 7);
-  internal::to_esc(fd.g, escape_fd, 11);
-  internal::to_esc(fd.b, escape_fd, 15);
-
-  std::fputs(escape_fd, stdout);
-  vprint(format, args);
-  std::fputs(internal::data::RESET_COLOR, stdout);
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_string<S>::value)>
+void print(std::FILE* f, const text_style& ts, const S& format_str,
+           const Args&... args) {
+  vprint(f, ts, format_str,
+         fmt::make_format_args<buffer_context<char_t<S>>>(args...));
 }
 
-inline void vprint_rgb(rgb fd, rgb bg, string_view format, format_args args) {
-  char escape_fd[] = "\x1b[38;2;000;000;000m"; // foreground color
-  char escape_bg[] = "\x1b[48;2;000;000;000m"; // background color
-  internal::to_esc(fd.r, escape_fd, 7);
-  internal::to_esc(fd.g, escape_fd, 11);
-  internal::to_esc(fd.b, escape_fd, 15);
+/**
+  \rst
+  Formats a string and prints it to stdout using ANSI escape sequences to
+  specify text formatting.
 
-  internal::to_esc(bg.r, escape_bg, 7);
-  internal::to_esc(bg.g, escape_bg, 11);
-  internal::to_esc(bg.b, escape_bg, 15);
+  **Example**::
 
-  std::fputs(escape_fd, stdout);
-  std::fputs(escape_bg, stdout);
-  vprint(format, args);
-  std::fputs(internal::data::RESET_COLOR, stdout);
+    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)>
+void print(const text_style& ts, const S& format_str, const Args&... args) {
+  return print(stdout, ts, format_str, args...);
 }
 
-#endif
+template <typename S, typename Char = char_t<S>>
+inline std::basic_string<Char> vformat(
+    const text_style& ts, const S& format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  basic_memory_buffer<Char> buf;
+  detail::vformat_to(buf, ts, detail::to_string_view(format_str), args);
+  return fmt::to_string(buf);
+}
 
+/**
+  \rst
+  Formats arguments and returns the result as a string using ANSI
+  escape sequences to specify text formatting.
+
+  **Example**::
+
+    #include <fmt/color.h>
+    std::string message = fmt::format(fmt::emphasis::bold | fg(fmt::color::red),
+                                      "The answer is {}", 42);
+  \endrst
+*/
+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 fmt::vformat(ts, detail::to_string_view(format_str),
+                      fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+/**
+  Formats a string with the given text_style and writes the output to ``out``.
+ */
+template <typename OutputIt, typename Char,
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value)>
+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) {
+  auto&& buf = detail::get_buffer<Char>(out);
+  detail::vformat_to(buf, ts, format_str, args);
+  return detail::get_iterator(buf);
+}
+
+/**
+  \rst
+  Formats arguments with the given text_style, writes the result to the output
+  iterator ``out`` and returns the iterator past the end of the output range.
+
+  **Example**::
+
+    std::vector<char> out;
+    fmt::format_to(std::back_inserter(out),
+                   fmt::emphasis::bold | fg(fmt::color::red), "{}", 42);
+  \endrst
+*/
+template <typename OutputIt, typename S, typename... Args,
+          bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value&&
+              detail::is_string<S>::value>
+inline auto format_to(OutputIt out, const text_style& ts, const S& format_str,
+                      Args&&... args) ->
+    typename std::enable_if<enable, OutputIt>::type {
+  return vformat_to(out, ts, detail::to_string_view(format_str),
+                    fmt::make_format_args<buffer_context<char_t<S>>>(args...));
+}
+
+template <typename T, typename Char>
+struct formatter<detail::styled_arg<T>, Char> : formatter<T, Char> {
+  template <typename FormatContext>
+  auto format(const detail::styled_arg<T>& arg, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    const auto& ts = arg.style;
+    const auto& value = arg.value;
+    auto out = ctx.out();
+
+    bool has_style = false;
+    if (ts.has_emphasis()) {
+      has_style = true;
+      auto emphasis = detail::make_emphasis<Char>(ts.get_emphasis());
+      out = std::copy(emphasis.begin(), emphasis.end(), out);
+    }
+    if (ts.has_foreground()) {
+      has_style = true;
+      auto foreground =
+          detail::make_foreground_color<Char>(ts.get_foreground());
+      out = std::copy(foreground.begin(), foreground.end(), out);
+    }
+    if (ts.has_background()) {
+      has_style = true;
+      auto background =
+          detail::make_background_color<Char>(ts.get_background());
+      out = std::copy(background.begin(), background.end(), out);
+    }
+    out = formatter<T, Char>::format(value, ctx);
+    if (has_style) {
+      auto reset_color = string_view("\x1b[0m");
+      out = std::copy(reset_color.begin(), reset_color.end(), out);
+    }
+    return out;
+  }
+};
+
+/**
+  \rst
+  Returns an argument that will be formatted using ANSI escape sequences,
+  to be used in a formatting function.
+
+  **Example**::
+
+    fmt::print("Elapsed time: {s:.2f} seconds",
+               fmt::styled(1.23, fmt::fg(fmt::color::green) |
+                                 fmt::bg(fmt::color::blue)));
+  \endrst
+ */
+template <typename T>
+FMT_CONSTEXPR auto styled(const T& value, text_style ts)
+    -> detail::styled_arg<remove_cvref_t<T>> {
+  return detail::styled_arg<remove_cvref_t<T>>{value, ts};
+}
+
+FMT_MODULE_EXPORT_END
 FMT_END_NAMESPACE
 
 #endif  // FMT_COLOR_H_

include/fmt/compile.h

@@ -0,0 +1,603 @@
+// Formatting library for C++ - experimental format string compilation
+//
+// Copyright (c) 2012 - present, Victor Zverovich and fmt contributors
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_COMPILE_H_
+#define FMT_COMPILE_H_
+
+#include "format.h"
+
+FMT_BEGIN_NAMESPACE
+namespace detail {
+
+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;
+  FMT_UNCHECKED_ITERATOR(truncating_iterator_base);
+
+  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 {};
+
+template <typename S>
+struct is_compiled_string : std::is_base_of<compiled_string, S> {};
+
+/**
+  \rst
+  Converts a string literal *s* into a format string that will be parsed at
+  compile time and converted into efficient formatting code. Requires C++17
+  ``constexpr if`` compiler support.
+
+  **Example**::
+
+    // Converts 42 into std::string using the most efficient method and no
+    // runtime format string processing.
+    std::string s = fmt::format(FMT_COMPILE("{}"), 42);
+  \endrst
+ */
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+#  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_ARGS
+template <typename Char, size_t N,
+          fmt::detail_exported::fixed_string<Char, N> Str>
+struct udl_compiled_string : compiled_string {
+  using char_type = Char;
+  explicit 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;
+}
+
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+template <typename... Args> struct type_list {};
+
+// Returns a reference to the argument at index N from [first, rest...].
+template <int N, typename T, typename... Args>
+constexpr const auto& get([[maybe_unused]] const T& first,
+                          [[maybe_unused]] const Args&... rest) {
+  static_assert(N < 1 + sizeof...(Args), "index is out of bounds");
+  if constexpr (N == 0)
+    return first;
+  else
+    return detail::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...>> {
+  using type =
+      remove_cvref_t<decltype(detail::get<N>(std::declval<Args>()...))>;
+};
+
+template <int N, typename T>
+using get_type = typename get_type_impl<N, T>::type;
+
+template <typename T> struct is_compiled_format : std::false_type {};
+
+template <typename Char> struct text {
+  basic_string_view<Char> data;
+  using char_type = Char;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&...) const {
+    return write<Char>(out, data);
+  }
+};
+
+template <typename Char>
+struct is_compiled_format<text<Char>> : std::true_type {};
+
+template <typename Char>
+constexpr text<Char> make_text(basic_string_view<Char> s, size_t pos,
+                               size_t size) {
+  return {{&s[pos], size}};
+}
+
+template <typename Char> struct code_unit {
+  Char value;
+  using char_type = Char;
+
+  template <typename OutputIt, typename... Args>
+  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 = detail::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 {};
+
+// A replacement field that refers to argument N.
+template <typename Char, typename T, int N> struct field {
+  using char_type = Char;
+
+  template <typename OutputIt, typename... Args>
+  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) {
+      FMT_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;
+  formatter<T, Char> fmt;
+
+  template <typename OutputIt, typename... Args>
+  constexpr FMT_INLINE OutputIt format(OutputIt out,
+                                       const Args&... args) const {
+    const auto& vargs =
+        fmt::make_format_args<basic_format_context<OutputIt, Char>>(args...);
+    basic_format_context<OutputIt, Char> ctx(out, vargs);
+    return fmt.format(get_arg_checked<T, N>(args...), ctx);
+  }
+};
+
+template <typename Char, typename T, int N>
+struct is_compiled_format<spec_field<Char, T, N>> : std::true_type {};
+
+template <typename L, typename R> struct concat {
+  L lhs;
+  R rhs;
+  using char_type = typename L::char_type;
+
+  template <typename OutputIt, typename... Args>
+  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+    out = lhs.format(out, args...);
+    return rhs.format(out, args...);
+  }
+};
+
+template <typename L, typename R>
+struct is_compiled_format<concat<L, R>> : std::true_type {};
+
+template <typename L, typename R>
+constexpr concat<L, R> make_concat(L lhs, R rhs) {
+  return {lhs, rhs};
+}
+
+struct unknown_format {};
+
+template <typename Char>
+constexpr size_t parse_text(basic_string_view<Char> str, size_t pos) {
+  for (size_t size = str.size(); pos != size; ++pos) {
+    if (str[pos] == '{' || str[pos] == '}') break;
+  }
+  return pos;
+}
+
+template <typename Args, size_t POS, int ID, typename S>
+constexpr auto compile_format_string(S format_str);
+
+template <typename Args, size_t POS, int ID, typename T, typename S>
+constexpr auto parse_tail(T head, S format_str) {
+  if constexpr (POS !=
+                basic_string_view<typename S::char_type>(format_str).size()) {
+    constexpr auto tail = compile_format_string<Args, POS, ID>(format_str);
+    if constexpr (std::is_same<remove_cvref_t<decltype(tail)>,
+                               unknown_format>())
+      return tail;
+    else
+      return make_concat(head, tail);
+  } else {
+    return head;
+  }
+}
+
+template <typename T, typename Char> struct parse_specs_result {
+  formatter<T, Char> fmt;
+  size_t end;
+  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 next_arg_id) {
+  str.remove_prefix(pos);
+  auto ctx = compile_parse_context<Char>(str, max_value<int>(), nullptr, {},
+                                         next_arg_id);
+  auto f = formatter<T, Char>();
+  auto end = f.parse(ctx);
+  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) {
+    FMT_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
+// or unknown_format() on unrecognized input.
+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 auto str = basic_string_view<char_type>(format_str);
+  if constexpr (str[POS] == '{') {
+    if constexpr (POS + 1 == str.size())
+      FMT_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] == '}' || 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 {
+      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 constexpr (POS + 1 == str.size())
+      FMT_THROW(format_error("unmatched '}' in format string"));
+    return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+  } else {
+    constexpr auto end = parse_text(str, POS + 1);
+    if constexpr (end - POS > 1) {
+      return parse_tail<Args, end, ID>(make_text(str, POS, end - POS),
+                                       format_str);
+    } else {
+      return parse_tail<Args, end, ID>(code_unit<char_type>{str[POS]},
+                                       format_str);
+    }
+  }
+}
+
+template <typename... Args, typename S,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+constexpr auto compile(S 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);
+    return result;
+  }
+}
+#endif  // defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+}  // namespace detail
+
+FMT_MODULE_EXPORT_BEGIN
+
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+
+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) {
+  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)>
+constexpr FMT_INLINE OutputIt format_to(OutputIt out, const CompiledFormat& cf,
+                                        const Args&... args) {
+  return cf.format(out, args...);
+}
+
+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) {
+  if constexpr (std::is_same<typename S::char_type, char>::value) {
+    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 fmt::format(
+        static_cast<basic_string_view<typename S::char_type>>(S()),
+        std::forward<Args>(args)...);
+  } else {
+    return fmt::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 fmt::format_to(
+        out, static_cast<basic_string_view<typename S::char_type>>(S()),
+        std::forward<Args>(args)...);
+  } else {
+    return fmt::format_to(out, compiled, std::forward<Args>(args)...);
+  }
+}
+#endif
+
+template <typename OutputIt, 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& format_str, Args&&... args) {
+  auto it = fmt::format_to(detail::truncating_iterator<OutputIt>(out, n),
+                           format_str, std::forward<Args>(args)...);
+  return {it.base(), it.count()};
+}
+
+template <typename S, typename... Args,
+          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+size_t formatted_size(const S& format_str, const Args&... args) {
+  return fmt::format_to(detail::counting_iterator(), format_str, 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;
+  fmt::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_ARGS
+inline namespace literals {
+template <detail_exported::fixed_string Str> constexpr auto operator""_cf() {
+  using char_t = remove_cvref_t<decltype(Str.data[0])>;
+  return detail::udl_compiled_string<char_t, sizeof(Str.data) / sizeof(char_t),
+                                     Str>();
+}
+}  // namespace literals
+#endif
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_COMPILE_H_

include/fmt/os.h

@@ -0,0 +1,478 @@
+// Formatting library for C++ - optional OS-specific functionality
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_OS_H_
+#define FMT_OS_H_
+
+#include <cerrno>
+#include <cstddef>
+#include <cstdio>
+#include <system_error>  // std::system_error
+
+#if defined __APPLE__ || defined(__FreeBSD__)
+#  include <xlocale.h>  // for LC_NUMERIC_MASK on OS X
+#endif
+
+#include "format.h"
+
+#ifndef FMT_USE_FCNTL
+// UWP doesn't provide _pipe.
+#  if FMT_HAS_INCLUDE("winapifamily.h")
+#    include <winapifamily.h>
+#  endif
+#  if (FMT_HAS_INCLUDE(<fcntl.h>) || defined(__APPLE__) || \
+       defined(__linux__)) &&                              \
+      (!defined(WINAPI_FAMILY) ||                          \
+       (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
+#    include <fcntl.h>  // for O_RDONLY
+#    define FMT_USE_FCNTL 1
+#  else
+#    define FMT_USE_FCNTL 0
+#  endif
+#endif
+
+#ifndef FMT_POSIX
+#  if defined(_WIN32) && !defined(__MINGW32__)
+// Fix warnings about deprecated symbols.
+#    define FMT_POSIX(call) _##call
+#  else
+#    define FMT_POSIX(call) call
+#  endif
+#endif
+
+// Calls to system functions are wrapped in FMT_SYSTEM for testability.
+#ifdef FMT_SYSTEM
+#  define FMT_POSIX_CALL(call) FMT_SYSTEM(call)
+#else
+#  define FMT_SYSTEM(call) ::call
+#  ifdef _WIN32
+// Fix warnings about deprecated symbols.
+#    define FMT_POSIX_CALL(call) ::_##call
+#  else
+#    define FMT_POSIX_CALL(call) ::call
+#  endif
+#endif
+
+// Retries the expression while it evaluates to error_result and errno
+// equals to EINTR.
+#ifndef _WIN32
+#  define FMT_RETRY_VAL(result, expression, error_result) \
+    do {                                                  \
+      (result) = (expression);                            \
+    } while ((result) == (error_result) && errno == EINTR)
+#else
+#  define FMT_RETRY_VAL(result, expression, error_result) result = (expression)
+#endif
+
+#define FMT_RETRY(result, expression) FMT_RETRY_VAL(result, expression, -1)
+
+FMT_BEGIN_NAMESPACE
+FMT_MODULE_EXPORT_BEGIN
+
+/**
+  \rst
+  A reference to a null-terminated string. It can be constructed from a C
+  string or ``std::string``.
+
+  You can use one of the following type aliases for common character types:
+
+  +---------------+-----------------------------+
+  | Type          | Definition                  |
+  +===============+=============================+
+  | cstring_view  | basic_cstring_view<char>    |
+  +---------------+-----------------------------+
+  | wcstring_view | basic_cstring_view<wchar_t> |
+  +---------------+-----------------------------+
+
+  This class is most useful as a parameter type to allow passing
+  different types of strings to a function, for example::
+
+    template <typename... Args>
+    std::string format(cstring_view format_str, const Args & ... args);
+
+    format("{}", 42);
+    format(std::string("{}"), 42);
+  \endrst
+ */
+template <typename Char> class basic_cstring_view {
+ private:
+  const Char* data_;
+
+ public:
+  /** Constructs a string reference object from a C string. */
+  basic_cstring_view(const Char* s) : data_(s) {}
+
+  /**
+    \rst
+    Constructs a string reference from an ``std::string`` object.
+    \endrst
+   */
+  basic_cstring_view(const std::basic_string<Char>& s) : data_(s.c_str()) {}
+
+  /** Returns the pointer to a C string. */
+  const Char* c_str() const { return data_; }
+};
+
+using cstring_view = basic_cstring_view<char>;
+using wcstring_view = basic_cstring_view<wchar_t>;
+
+template <typename Char> struct formatter<std::error_code, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  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
+FMT_API const std::error_category& system_category() 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 {
+ private:
+  memory_buffer buffer_;
+
+ public:
+  utf16_to_utf8() {}
+  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]; }
+  std::string str() const { return std::string(&buffer_[0], size()); }
+
+  // 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(basic_string_view<wchar_t> s);
+};
+
+FMT_API void format_windows_error(buffer<char>& out, int error_code,
+                                  const char* message) noexcept;
+FMT_END_DETAIL_NAMESPACE
+
+FMT_API std::system_error vwindows_error(int error_code, string_view format_str,
+                                         format_args args);
+
+/**
+ \rst
+ Constructs a :class:`std::system_error` object with the description
+ of the form
+
+ .. 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".
+
+ **Example**::
+
+   // 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, const char* message) noexcept;
+#else
+inline const std::error_category& system_category() 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:
+  FILE* file_;
+
+  friend class file;
+
+  explicit buffered_file(FILE* f) : file_(f) {}
+
+ public:
+  buffered_file(const buffered_file&) = delete;
+  void operator=(const buffered_file&) = delete;
+
+  // Constructs a buffered_file object which doesn't represent any file.
+  buffered_file() noexcept : file_(nullptr) {}
+
+  // Destroys the object closing the file it represents if any.
+  FMT_API ~buffered_file() noexcept;
+
+ public:
+  buffered_file(buffered_file&& other) noexcept : file_(other.file_) {
+    other.file_ = nullptr;
+  }
+
+  buffered_file& operator=(buffered_file&& other) {
+    close();
+    file_ = other.file_;
+    other.file_ = nullptr;
+    return *this;
+  }
+
+  // Opens a file.
+  FMT_API buffered_file(cstring_view filename, cstring_view mode);
+
+  // Closes the file.
+  FMT_API void close();
+
+  // Returns the pointer to a FILE object representing this file.
+  FILE* get() const noexcept { return file_; }
+
+  FMT_API int descriptor() const;
+
+  void vprint(string_view format_str, format_args args) {
+    fmt::vprint(file_, format_str, args);
+  }
+
+  template <typename... Args>
+  inline void print(string_view format_str, const Args&... args) {
+    vprint(format_str, fmt::make_format_args(args...));
+  }
+};
+
+#if FMT_USE_FCNTL
+// A file. Closed file is represented by a file object with descriptor -1.
+// Methods that are not declared with noexcept may throw
+// fmt::system_error in case of failure. Note that some errors such as
+// closing the file multiple times will cause a crash on Windows rather
+// than an exception. You can get standard behavior by overriding the
+// invalid parameter handler with _set_invalid_parameter_handler.
+class FMT_API file {
+ private:
+  int fd_;  // File descriptor.
+
+  // Constructs a file object with a given descriptor.
+  explicit file(int fd) : fd_(fd) {}
+
+ public:
+  // Possible values for the oflag argument to the constructor.
+  enum {
+    RDONLY = FMT_POSIX(O_RDONLY),  // Open for reading only.
+    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.
+    TRUNC = FMT_POSIX(O_TRUNC)     // Truncate the content of the file.
+  };
+
+  // Constructs a file object which doesn't represent any file.
+  file() noexcept : fd_(-1) {}
+
+  // Opens a file and constructs a file object representing this file.
+  file(cstring_view path, int oflag);
+
+ public:
+  file(const file&) = delete;
+  void operator=(const file&) = delete;
+
+  file(file&& other) noexcept : fd_(other.fd_) { other.fd_ = -1; }
+
+  // Move assignment is not noexcept because close may throw.
+  file& operator=(file&& other) {
+    close();
+    fd_ = other.fd_;
+    other.fd_ = -1;
+    return *this;
+  }
+
+  // Destroys the object closing the file it represents if any.
+  ~file() noexcept;
+
+  // Returns the file descriptor.
+  int descriptor() const noexcept { return fd_; }
+
+  // Closes the file.
+  void close();
+
+  // Returns the file size. The size has signed type for consistency with
+  // stat::st_size.
+  long long size() const;
+
+  // Attempts to read count bytes from the file into the specified buffer.
+  size_t read(void* buffer, size_t count);
+
+  // Attempts to write count bytes from the specified buffer to the file.
+  size_t write(const void* buffer, size_t count);
+
+  // Duplicates a file descriptor with the dup function and returns
+  // the duplicate as a file object.
+  static file dup(int fd);
+
+  // Makes fd be the copy of this file descriptor, closing fd first if
+  // necessary.
+  void dup2(int fd);
+
+  // Makes fd be the copy of this file descriptor, closing fd first if
+  // necessary.
+  void dup2(int fd, std::error_code& ec) noexcept;
+
+  // Creates a pipe setting up read_end and write_end file objects for reading
+  // and writing respectively.
+  static void pipe(file& read_end, file& write_end);
+
+  // Creates a buffered_file object associated with this file and detaches
+  // this file object from the file.
+  buffered_file fdopen(const char* mode);
+};
+
+// Returns the memory page size.
+long getpagesize();
+
+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();
+    bs.value = val;
+    return bs;
+  }
+};
+
+struct ostream_params {
+  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 new_oflag) : ostream_params(params...) {
+    oflag = new_oflag;
+  }
+
+  template <typename... T>
+  ostream_params(T... params, detail::buffer_size bs)
+      : ostream_params(params...) {
+    this->buffer_size = bs.value;
+  }
+
+// Intel has a bug that results in failure to deduce a constructor
+// for empty parameter packs.
+#  if defined(__INTEL_COMPILER) && __INTEL_COMPILER < 2000
+  ostream_params(int new_oflag) : oflag(new_oflag) {}
+  ostream_params(detail::buffer_size bs) : buffer_size(bs.value) {}
+#  endif
+};
+
+FMT_END_DETAIL_NAMESPACE
+
+// Added {} below to work around default constructor error known to
+// occur in Xcode versions 7.2.1 and 8.2.1.
+constexpr detail::buffer_size buffer_size{};
+
+/** A fast output stream which is not thread-safe. */
+class FMT_API ostream final : private detail::buffer<char> {
+ private:
+  file file_;
+
+  void grow(size_t) override;
+
+  ostream(cstring_view path, const detail::ostream_params& params)
+      : file_(path, params.oflag) {
+    set(new char[params.buffer_size], params.buffer_size);
+  }
+
+ public:
+  ostream(ostream&& other)
+      : detail::buffer<char>(other.data(), other.size(), other.capacity()),
+        file_(std::move(other.file_)) {
+    other.clear();
+    other.set(nullptr, 0);
+  }
+  ~ostream() {
+    flush();
+    delete[] data();
+  }
+
+  void flush() {
+    if (size() == 0) return;
+    file_.write(data(), size());
+    clear();
+  }
+
+  template <typename... T>
+  friend ostream output_file(cstring_view path, T... params);
+
+  void close() {
+    flush();
+    file_.close();
+  }
+
+  /**
+    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...));
+  }
+};
+
+/**
+  \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 | file::TRUNC`` 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) {
+  return {path, detail::ostream_params(params...)};
+}
+#endif  // FMT_USE_FCNTL
+
+FMT_MODULE_EXPORT_END
+FMT_END_NAMESPACE
+
+#endif  // FMT_OS_H_

include/fmt/ostream.h

@@ -1,6 +1,6 @@
 // Formatting library for C++ - std::ostream support
 //
-// Copyright (c) 2012 - 2016, Victor Zverovich
+// Copyright (c) 2012 - present, Victor Zverovich
 // All rights reserved.
 //
 // For the license information refer to format.h.
@@ -8,130 +8,184 @@
 #ifndef FMT_OSTREAM_H_
 #define FMT_OSTREAM_H_
 
-#include "format.h"
+#include <fstream>
 #include <ostream>
 
+#include "format.h"
+
 FMT_BEGIN_NAMESPACE
-namespace internal {
 
-template <class Char>
-class formatbuf : public std::basic_streambuf<Char> {
- private:
-  typedef typename std::basic_streambuf<Char>::int_type int_type;
-  typedef typename std::basic_streambuf<Char>::traits_type traits_type;
+template <typename OutputIt, typename Char> class basic_printf_context;
 
-  basic_buffer<Char> &buffer_;
+namespace detail {
 
- public:
-  formatbuf(basic_buffer<Char> &buffer) : buffer_(buffer) {}
-
- protected:
-  // The put-area is actually always empty. This makes the implementation
-  // simpler and has the advantage that the streambuf and the buffer are always
-  // in sync and sputc never writes into uninitialized memory. The obvious
-  // disadvantage is that each call to sputc always results in a (virtual) call
-  // to overflow. There is no disadvantage here for sputn since this always
-  // results in a call to xsputn.
-
-  int_type overflow(int_type ch = traits_type::eof()) FMT_OVERRIDE {
-    if (!traits_type::eq_int_type(ch, traits_type::eof()))
-      buffer_.push_back(static_cast<Char>(ch));
-    return ch;
-  }
-
-  std::streamsize xsputn(const Char *s, std::streamsize count) FMT_OVERRIDE {
-    buffer_.append(s, s + count);
-    return count;
-  }
-};
-
-template <typename Char>
-struct test_stream : std::basic_ostream<Char> {
- private:
-  struct null;
-  // Hide all operator<< from std::basic_ostream<Char>.
-  void operator<<(null);
-};
-
-// Checks if T has a user-defined operator<< (e.g. not a member of std::ostream).
-template <typename T, typename Char>
+// Checks if T has a user-defined operator<<.
+template <typename T, typename Char, typename Enable = void>
 class is_streamable {
  private:
   template <typename U>
-  static decltype(
-    internal::declval<test_stream<Char>&>()
-      << internal::declval<U>(), std::true_type()) test(int);
+  static auto test(int)
+      -> bool_constant<sizeof(std::declval<std::basic_ostream<Char>&>()
+                              << std::declval<U>()) != 0>;
 
-  template <typename>
-  static std::false_type test(...);
+  template <typename> static auto test(...) -> std::false_type;
 
-  typedef decltype(test<T>(0)) result;
+  using result = decltype(test<T>(0));
 
  public:
+  is_streamable() = default;
+
   static const bool value = result::value;
 };
 
+// Formatting of built-in types and arrays is intentionally disabled because
+// it's handled by standard (non-ostream) formatters.
+template <typename T, typename Char>
+struct is_streamable<
+    T, Char,
+    enable_if_t<
+        std::is_arithmetic<T>::value || std::is_array<T>::value ||
+        std::is_pointer<T>::value || std::is_same<T, char8_type>::value ||
+        std::is_convertible<T, fmt::basic_string_view<Char>>::value ||
+        std::is_same<T, std_string_view<Char>>::value ||
+        (std::is_convertible<T, int>::value && !std::is_enum<T>::value)>>
+    : std::false_type {};
+
+template <typename Char> FILE* get_file(std::basic_filebuf<Char>&) {
+  return nullptr;
+}
+
+struct dummy_filebuf {
+  FILE* _Myfile;
+};
+template <typename T, typename U = int> struct ms_filebuf {
+  using type = dummy_filebuf;
+};
+template <typename T> struct ms_filebuf<T, decltype(T::_Myfile, 0)> {
+  using type = T;
+};
+using filebuf_type = ms_filebuf<std::filebuf>::type;
+
+FILE* get_file(filebuf_type& buf);
+
+// Generate a unique explicit instantion in every translation unit using a tag
+// type in an anonymous namespace.
+namespace {
+struct filebuf_access_tag {};
+}  // namespace
+template <typename Tag, typename FileMemberPtr, FileMemberPtr file>
+class filebuf_access {
+  friend FILE* get_file(filebuf_type& buf) { return buf.*file; }
+};
+template class filebuf_access<filebuf_access_tag,
+                              decltype(&filebuf_type::_Myfile),
+                              &filebuf_type::_Myfile>;
+
+inline bool write(std::filebuf& buf, fmt::string_view data) {
+  FILE* f = get_file(buf);
+  if (!f) return false;
+  print(f, data);
+  return true;
+}
+inline bool write(std::wfilebuf&, fmt::basic_string_view<wchar_t>) {
+  return false;
+}
+
 // Write the content of buf to os.
+// It is a separate function rather than a part of vprint to simplify testing.
 template <typename Char>
-void write(std::basic_ostream<Char> &os, basic_buffer<Char> &buf) {
-  const Char *data = buf.data();
-  typedef std::make_unsigned<std::streamsize>::type UnsignedStreamSize;
-  UnsignedStreamSize size = buf.size();
-  UnsignedStreamSize max_size =
-      internal::to_unsigned((std::numeric_limits<std::streamsize>::max)());
+void write_buffer(std::basic_ostream<Char>& os, buffer<Char>& buf) {
+  if (const_check(FMT_MSC_VERSION)) {
+    auto filebuf = dynamic_cast<std::basic_filebuf<Char>*>(os.rdbuf());
+    if (filebuf && write(*filebuf, {buf.data(), buf.size()})) return;
+  }
+  const Char* buf_data = buf.data();
+  using unsigned_streamsize = std::make_unsigned<std::streamsize>::type;
+  unsigned_streamsize size = buf.size();
+  unsigned_streamsize max_size = to_unsigned(max_value<std::streamsize>());
   do {
-    UnsignedStreamSize n = size <= max_size ? size : max_size;
-    os.write(data, static_cast<std::streamsize>(n));
-    data += n;
+    unsigned_streamsize n = size <= max_size ? size : max_size;
+    os.write(buf_data, static_cast<std::streamsize>(n));
+    buf_data += n;
     size -= n;
   } while (size != 0);
 }
 
 template <typename Char, typename T>
-void format_value(basic_buffer<Char> &buffer, const T &value) {
-  internal::formatbuf<Char> format_buf(buffer);
-  std::basic_ostream<Char> output(&format_buf);
-  output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
+void format_value(buffer<Char>& buf, const T& value,
+                  locale_ref loc = locale_ref()) {
+  auto&& format_buf = formatbuf<std::basic_streambuf<Char>>(buf);
+  auto&& output = std::basic_ostream<Char>(&format_buf);
+#if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
+  if (loc) output.imbue(loc.get<std::locale>());
+#endif
   output << value;
-  buffer.resize(buffer.size());
+  output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
 }
-}  // namespace internal
 
-// Disable conversion to int if T has an overloaded operator<< which is a free
-// function (not a member of std::ostream).
-template <typename T, typename Char>
-struct convert_to_int<T, Char, void> {
-  static const bool value =
-    convert_to_int<T, Char, int>::value &&
-    !internal::is_streamable<T, Char>::value;
-};
+template <typename T> struct streamed_view { const T& value; };
+
+}  // namespace detail
 
 // Formats an object of type T that has an overloaded ostream operator<<.
-template <typename T, typename Char>
-struct formatter<T, Char,
-    typename std::enable_if<
-      internal::is_streamable<T, Char>::value &&
-      !internal::format_type<
-        typename buffer_context<Char>::type, T>::value>::type>
-    : formatter<basic_string_view<Char>, Char> {
-
-  template <typename Context>
-  auto format(const T &value, Context &ctx) -> decltype(ctx.out()) {
-    basic_memory_buffer<Char> buffer;
-    internal::format_value(buffer, value);
-    basic_string_view<Char> str(buffer.data(), buffer.size());
-    return formatter<basic_string_view<Char>, Char>::format(str, ctx);
+template <typename Char>
+struct basic_ostream_formatter : formatter<basic_string_view<Char>, Char> {
+  template <typename T, typename OutputIt>
+  auto format(const T& value, basic_format_context<OutputIt, Char>& ctx) const
+      -> OutputIt {
+    auto buffer = basic_memory_buffer<Char>();
+    format_value(buffer, value, ctx.locale());
+    return formatter<basic_string_view<Char>, Char>::format(
+        {buffer.data(), buffer.size()}, ctx);
   }
 };
 
-template <typename Char>
-inline void vprint(std::basic_ostream<Char> &os,
-                   basic_string_view<Char> format_str,
-                   basic_format_args<typename buffer_context<Char>::type> args) {
-  basic_memory_buffer<Char> buffer;
-  vformat_to(buffer, format_str, args);
-  internal::write(os, buffer);
+using ostream_formatter = basic_ostream_formatter<char>;
+
+template <typename T>
+struct formatter<detail::streamed_view<T>> : ostream_formatter {
+  template <typename OutputIt>
+  auto format(detail::streamed_view<T> view,
+              basic_format_context<OutputIt, char>& ctx) const -> OutputIt {
+    return ostream_formatter::format(view.value, ctx);
+  }
+};
+
+/**
+  \rst
+  Returns a view that formats `value` via an ostream ``operator<<``.
+
+  **Example**::
+
+    fmt::print("Current thread id: {}\n",
+               fmt::streamed(std::this_thread::get_id()));
+  \endrst
+ */
+template <typename T>
+auto streamed(const T& value) -> detail::streamed_view<T> {
+  return {value};
 }
+
+namespace detail {
+
+// Formats an object of type T that has an overloaded ostream operator<<.
+template <typename T, typename Char>
+struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
+    : basic_ostream_formatter<Char> {
+  using basic_ostream_formatter<Char>::format;
+};
+
+}  // namespace detail
+
+FMT_MODULE_EXPORT template <typename Char>
+void vprint(std::basic_ostream<Char>& os,
+            basic_string_view<type_identity_t<Char>> format_str,
+            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  auto buffer = basic_memory_buffer<Char>();
+  detail::vformat_to(buffer, format_str, args);
+  detail::write_buffer(os, buffer);
+}
+
 /**
   \rst
   Prints formatted data to the stream *os*.
@@ -141,17 +195,19 @@ inline void vprint(std::basic_ostream<Char> &os,
     fmt::print(cerr, "Don't {}!", "panic");
   \endrst
  */
-template <typename... Args>
-inline void print(std::ostream &os, string_view format_str,
-                  const Args & ... args) {
-  vprint<char>(os, format_str, make_format_args<format_context>(args...));
+FMT_MODULE_EXPORT template <typename... T>
+void print(std::ostream& os, format_string<T...> fmt, T&&... args) {
+  vprint(os, fmt, fmt::make_format_args(args...));
 }
 
+FMT_MODULE_EXPORT
 template <typename... Args>
-inline void print(std::wostream &os, wstring_view format_str,
-                  const Args & ... args) {
-  vprint<wchar_t>(os, format_str, make_format_args<wformat_context>(args...));
+void print(std::wostream& os,
+           basic_format_string<wchar_t, type_identity_t<Args>...> fmt,
+           Args&&... args) {
+  vprint(os, fmt, fmt::make_format_args<buffer_context<wchar_t>>(args...));
 }
+
 FMT_END_NAMESPACE
 
 #endif  // FMT_OSTREAM_H_

include/fmt/posix.h

@@ -1,324 +0,0 @@
-// A C++ interface to POSIX functions.
-//
-// Copyright (c) 2012 - 2016, Victor Zverovich
-// All rights reserved.
-//
-// For the license information refer to format.h.
-
-#ifndef FMT_POSIX_H_
-#define FMT_POSIX_H_
-
-#if defined(__MINGW32__) || defined(__CYGWIN__)
-// Workaround MinGW bug https://sourceforge.net/p/mingw/bugs/2024/.
-# undef __STRICT_ANSI__
-#endif
-
-#include <errno.h>
-#include <fcntl.h>   // for O_RDONLY
-#include <locale.h>  // for locale_t
-#include <stdio.h>
-#include <stdlib.h>  // for strtod_l
-
-#include <cstddef>
-
-#if defined __APPLE__ || defined(__FreeBSD__)
-# include <xlocale.h>  // for LC_NUMERIC_MASK on OS X
-#endif
-
-#include "format.h"
-
-#ifndef FMT_POSIX
-# if defined(_WIN32) && !defined(__MINGW32__)
-// Fix warnings about deprecated symbols.
-#  define FMT_POSIX(call) _##call
-# else
-#  define FMT_POSIX(call) call
-# endif
-#endif
-
-// Calls to system functions are wrapped in FMT_SYSTEM for testability.
-#ifdef FMT_SYSTEM
-# define FMT_POSIX_CALL(call) FMT_SYSTEM(call)
-#else
-# define FMT_SYSTEM(call) call
-# ifdef _WIN32
-// Fix warnings about deprecated symbols.
-#  define FMT_POSIX_CALL(call) ::_##call
-# else
-#  define FMT_POSIX_CALL(call) ::call
-# endif
-#endif
-
-// Retries the expression while it evaluates to error_result and errno
-// equals to EINTR.
-#ifndef _WIN32
-# define FMT_RETRY_VAL(result, expression, error_result) \
-  do { \
-    result = (expression); \
-  } while (result == error_result && errno == EINTR)
-#else
-# define FMT_RETRY_VAL(result, expression, error_result) result = (expression)
-#endif
-
-#define FMT_RETRY(result, expression) FMT_RETRY_VAL(result, expression, -1)
-
-FMT_BEGIN_NAMESPACE
-
-/**
-  \rst
-  A reference to a null-terminated string. It can be constructed from a C
-  string or ``std::string``.
-
-  You can use one of the following typedefs for common character types:
-
-  +---------------+-----------------------------+
-  | Type          | Definition                  |
-  +===============+=============================+
-  | cstring_view  | basic_cstring_view<char>    |
-  +---------------+-----------------------------+
-  | wcstring_view | basic_cstring_view<wchar_t> |
-  +---------------+-----------------------------+
-
-  This class is most useful as a parameter type to allow passing
-  different types of strings to a function, for example::
-
-    template <typename... Args>
-    std::string format(cstring_view format_str, const Args & ... args);
-
-    format("{}", 42);
-    format(std::string("{}"), 42);
-  \endrst
- */
-template <typename Char>
-class basic_cstring_view {
- private:
-  const Char *data_;
-
- public:
-  /** Constructs a string reference object from a C string. */
-  basic_cstring_view(const Char *s) : data_(s) {}
-
-  /**
-    \rst
-    Constructs a string reference from an ``std::string`` object.
-    \endrst
-   */
-  basic_cstring_view(const std::basic_string<Char> &s) : data_(s.c_str()) {}
-
-  /** Returns the pointer to a C string. */
-  const Char *c_str() const { return data_; }
-};
-
-typedef basic_cstring_view<char> cstring_view;
-typedef basic_cstring_view<wchar_t> wcstring_view;
-
-// An error code.
-class error_code {
- private:
-  int value_;
-
- public:
-  explicit error_code(int value = 0) FMT_NOEXCEPT : value_(value) {}
-
-  int get() const FMT_NOEXCEPT { return value_; }
-};
-
-// A buffered file.
-class buffered_file {
- private:
-  FILE *file_;
-
-  friend class file;
-
-  explicit buffered_file(FILE *f) : file_(f) {}
-
- public:
-  // Constructs a buffered_file object which doesn't represent any file.
-  buffered_file() FMT_NOEXCEPT : file_(FMT_NULL) {}
-
-  // Destroys the object closing the file it represents if any.
-  FMT_API ~buffered_file() FMT_DTOR_NOEXCEPT;
-
- private:
-  buffered_file(const buffered_file &) = delete;
-  void operator=(const buffered_file &) = delete;
-
-
- public:
-  buffered_file(buffered_file &&other) FMT_NOEXCEPT : file_(other.file_) {
-    other.file_ = FMT_NULL;
-  }
-
-  buffered_file& operator=(buffered_file &&other) {
-    close();
-    file_ = other.file_;
-    other.file_ = FMT_NULL;
-    return *this;
-  }
-
-  // Opens a file.
-  FMT_API buffered_file(cstring_view filename, cstring_view mode);
-
-  // Closes the file.
-  FMT_API void close();
-
-  // Returns the pointer to a FILE object representing this file.
-  FILE *get() const FMT_NOEXCEPT { return file_; }
-
-  // We place parentheses around fileno to workaround a bug in some versions
-  // of MinGW that define fileno as a macro.
-  FMT_API int (fileno)() const;
-
-  void vprint(string_view format_str, format_args args) {
-    fmt::vprint(file_, format_str, args);
-  }
-
-  template <typename... Args>
-  inline void print(string_view format_str, const Args & ... args) {
-    vprint(format_str, make_format_args(args...));
-  }
-};
-
-// A file. Closed file is represented by a file object with descriptor -1.
-// Methods that are not declared with FMT_NOEXCEPT may throw
-// fmt::system_error in case of failure. Note that some errors such as
-// closing the file multiple times will cause a crash on Windows rather
-// than an exception. You can get standard behavior by overriding the
-// invalid parameter handler with _set_invalid_parameter_handler.
-class file {
- private:
-  int fd_;  // File descriptor.
-
-  // Constructs a file object with a given descriptor.
-  explicit file(int fd) : fd_(fd) {}
-
- public:
-  // Possible values for the oflag argument to the constructor.
-  enum {
-    RDONLY = FMT_POSIX(O_RDONLY), // Open for reading only.
-    WRONLY = FMT_POSIX(O_WRONLY), // Open for writing only.
-    RDWR   = FMT_POSIX(O_RDWR)    // Open for reading and writing.
-  };
-
-  // Constructs a file object which doesn't represent any file.
-  file() FMT_NOEXCEPT : fd_(-1) {}
-
-  // Opens a file and constructs a file object representing this file.
-  FMT_API file(cstring_view path, int oflag);
-
- private:
-  file(const file &) = delete;
-  void operator=(const file &) = delete;
-
- public:
-  file(file &&other) FMT_NOEXCEPT : fd_(other.fd_) {
-    other.fd_ = -1;
-  }
-
-  file& operator=(file &&other) {
-    close();
-    fd_ = other.fd_;
-    other.fd_ = -1;
-    return *this;
-  }
-
-  // Destroys the object closing the file it represents if any.
-  FMT_API ~file() FMT_DTOR_NOEXCEPT;
-
-  // Returns the file descriptor.
-  int descriptor() const FMT_NOEXCEPT { return fd_; }
-
-  // Closes the file.
-  FMT_API void close();
-
-  // Returns the file size. The size has signed type for consistency with
-  // stat::st_size.
-  FMT_API long long size() const;
-
-  // Attempts to read count bytes from the file into the specified buffer.
-  FMT_API std::size_t read(void *buffer, std::size_t count);
-
-  // Attempts to write count bytes from the specified buffer to the file.
-  FMT_API std::size_t write(const void *buffer, std::size_t count);
-
-  // Duplicates a file descriptor with the dup function and returns
-  // the duplicate as a file object.
-  FMT_API static file dup(int fd);
-
-  // Makes fd be the copy of this file descriptor, closing fd first if
-  // necessary.
-  FMT_API void dup2(int fd);
-
-  // 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;
-
-  // Creates a pipe setting up read_end and write_end file objects for reading
-  // and writing respectively.
-  FMT_API static void pipe(file &read_end, file &write_end);
-
-  // Creates a buffered_file object associated with this file and detaches
-  // this file object from the file.
-  FMT_API buffered_file fdopen(const char *mode);
-};
-
-// Returns the memory page size.
-long getpagesize();
-
-#if (defined(LC_NUMERIC_MASK) || defined(_MSC_VER)) && \
-    !defined(__ANDROID__) && !defined(__CYGWIN__) && !defined(__OpenBSD__) && \
-    !defined(__NEWLIB_H__)
-# define FMT_LOCALE
-#endif
-
-#ifdef FMT_LOCALE
-// A "C" numeric locale.
-class Locale {
- private:
-# ifdef _MSC_VER
-  typedef _locale_t locale_t;
-
-  enum { LC_NUMERIC_MASK = LC_NUMERIC };
-
-  static locale_t newlocale(int category_mask, const char *locale, locale_t) {
-    return _create_locale(category_mask, locale);
-  }
-
-  static void freelocale(locale_t locale) {
-    _free_locale(locale);
-  }
-
-  static double strtod_l(const char *nptr, char **endptr, _locale_t locale) {
-    return _strtod_l(nptr, endptr, locale);
-  }
-# endif
-
-  locale_t locale_;
-
-  Locale(const Locale &) = delete;
-  void operator=(const Locale &) = delete;
-
- public:
-  typedef locale_t Type;
-
-  Locale() : locale_(newlocale(LC_NUMERIC_MASK, "C", FMT_NULL)) {
-    if (!locale_)
-      FMT_THROW(system_error(errno, "cannot create locale"));
-  }
-  ~Locale() { freelocale(locale_); }
-
-  Type get() const { return locale_; }
-
-  // Converts string to floating-point number and advances str past the end
-  // of the parsed input.
-  double strtod(const char *&str) const {
-    char *end = FMT_NULL;
-    double result = strtod_l(str, &end, locale_);
-    str = end;
-    return result;
-  }
-};
-#endif  // FMT_LOCALE
-FMT_END_NAMESPACE
-
-#endif  // FMT_POSIX_H_

include/fmt/ranges.h

@@ -1,4 +1,4 @@
-// Formatting library for C++ - the core API
+// Formatting library for C++ - experimental range support
 //
 // Copyright (c) 2012 - present, Victor Zverovich
 // All rights reserved.
@@ -12,143 +12,223 @@
 #ifndef FMT_RANGES_H_
 #define FMT_RANGES_H_
 
-#include "format.h"
+#include <initializer_list>
+#include <tuple>
 #include <type_traits>
 
-// output only up to N items from the range.
-#ifndef FMT_RANGE_OUTPUT_LENGTH_LIMIT
-# define FMT_RANGE_OUTPUT_LENGTH_LIMIT 256
-#endif
+#include "format.h"
 
 FMT_BEGIN_NAMESPACE
 
-template <typename Char>
-struct formatting_base {
-  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 std::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 : 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;
-};
-
-namespace internal {
+namespace detail {
 
 template <typename RangeT, typename OutputIterator>
-void copy(const RangeT &range, OutputIterator out) {
+OutputIterator copy(const RangeT& range, OutputIterator out) {
   for (auto it = range.begin(), end = range.end(); it != end; ++it)
     *out++ = *it;
+  return out;
 }
 
 template <typename OutputIterator>
-void copy(const char *str, OutputIterator out) {
-  const char *p_curr = str;
-  while (*p_curr) {
-    *out++ = *p_curr++;
-  }
+OutputIterator copy(const char* str, OutputIterator out) {
+  while (*str) *out++ = *str++;
+  return out;
 }
 
 template <typename OutputIterator>
-void copy(char ch, OutputIterator out) {
+OutputIterator copy(char 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 OutputIterator>
+OutputIterator copy(wchar_t ch, OutputIterator out) {
+  *out++ = ch;
+  return out;
+}
+
+// Returns true if T has a std::string-like interface, like std::string_view.
+template <typename T> class is_std_string_like {
   template <typename U>
-  static auto check(U *p) ->
-    decltype(p->find('a'), p->length(), p->data(), int());
-  template <typename>
-  static void check(...);
+  static auto check(U* p)
+      -> decltype((void)p->find('a'), p->length(), (void)p->data(), int());
+  template <typename> static void check(...);
 
  public:
-  static FMT_CONSTEXPR_DECL const bool value =
-    !std::is_void<decltype(check<T>(FMT_NULL))>::value;
+  static constexpr const bool value =
+      is_string<T>::value ||
+      std::is_convertible<T, std_string_view<char>>::value ||
+      !std::is_void<decltype(check<T>(nullptr))>::value;
 };
 
-template <typename... Ts>
-struct conditional_helper {};
+template <typename Char>
+struct is_std_string_like<fmt::basic_string_view<Char>> : std::true_type {};
 
-template <typename T, typename _ = void>
-struct is_range_ : std::false_type {};
-
-#if !FMT_MSC_VER || FMT_MSC_VER > 1800
-template <typename T>
-struct is_range_<T, typename std::conditional<
-                    false,
-                    conditional_helper<decltype(internal::declval<T>().begin()),
-                                       decltype(internal::declval<T>().end())>,
-                    void>::type> : std::true_type {};
-#endif
-
-/// tuple_size and tuple_element check.
-template <typename T>
-class is_tuple_like_ {
-  template <typename U>
-  static auto check(U *p) ->
-    decltype(std::tuple_size<U>::value,
-      internal::declval<typename std::tuple_element<0, U>::type>(), int());
-  template <typename>
-  static void check(...);
+template <typename T> class is_map {
+  template <typename U> static auto check(U*) -> typename U::mapped_type;
+  template <typename> static void check(...);
 
  public:
-  static FMT_CONSTEXPR_DECL const bool value =
-    !std::is_void<decltype(check<T>(FMT_NULL))>::value;
+#ifdef FMT_FORMAT_MAP_AS_LIST
+  static constexpr const bool value = false;
+#else
+  static constexpr const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value;
+#endif
+};
+
+template <typename T> class is_set {
+  template <typename U> static auto check(U*) -> typename U::key_type;
+  template <typename> static void check(...);
+
+ public:
+#ifdef FMT_FORMAT_SET_AS_LIST
+  static constexpr const bool value = false;
+#else
+  static constexpr const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value && !is_map<T>::value;
+#endif
+};
+
+template <typename... Ts> struct conditional_helper {};
+
+template <typename T, typename _ = void> struct is_range_ : std::false_type {};
+
+#if !FMT_MSC_VERSION || FMT_MSC_VERSION > 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 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_end(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_end(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)> {};
+#  undef FMT_DECLTYPE_RETURN
+#endif
+
+// tuple_size and tuple_element check.
+template <typename T> class is_tuple_like_ {
+  template <typename U>
+  static auto check(U* p) -> decltype(std::tuple_size<U>::value, int());
+  template <typename> static void check(...);
+
+ public:
+  static constexpr const bool value =
+      !std::is_void<decltype(check<T>(nullptr))>::value;
 };
 
 // Check for integer_sequence
-#if defined(__cpp_lib_integer_sequence) || FMT_MSC_VER >= 1900
+#if defined(__cpp_lib_integer_sequence) || FMT_MSC_VERSION >= 1900
 template <typename T, T... N>
 using integer_sequence = std::integer_sequence<T, N...>;
-template <std::size_t... N>
-using index_sequence = std::index_sequence<N...>;
-template <std::size_t N>
-using make_index_sequence = std::make_index_sequence<N>;
+template <size_t... N> using index_sequence = std::index_sequence<N...>;
+template <size_t N> using make_index_sequence = std::make_index_sequence<N>;
 #else
-template <typename T, T... N>
-struct integer_sequence {
-  typedef T value_type;
+template <typename T, T... N> struct integer_sequence {
+  using value_type = T;
 
-  static FMT_CONSTEXPR std::size_t size() {
-    return sizeof...(N);
-  }
+  static FMT_CONSTEXPR size_t size() { return sizeof...(N); }
 };
 
-template <std::size_t... N>
-using index_sequence = integer_sequence<std::size_t, N...>;
+template <size_t... N> using index_sequence = integer_sequence<size_t, N...>;
 
-template <typename T, std::size_t N, T... Ns>
+template <typename T, size_t N, T... Ns>
 struct make_integer_sequence : make_integer_sequence<T, N - 1, N - 1, Ns...> {};
 template <typename T, T... Ns>
 struct make_integer_sequence<T, 0, Ns...> : integer_sequence<T, Ns...> {};
 
-template <std::size_t N>
-using make_index_sequence = make_integer_sequence<std::size_t, N>;
+template <size_t N>
+using make_index_sequence = make_integer_sequence<size_t, N>;
 #endif
 
+template <typename T>
+using tuple_index_sequence = make_index_sequence<std::tuple_size<T>::value>;
+
+template <typename T, typename C, bool = is_tuple_like_<T>::value>
+class is_tuple_formattable_ {
+ public:
+  static constexpr const bool value = false;
+};
+template <typename T, typename C> class is_tuple_formattable_<T, C, true> {
+  template <std::size_t... I>
+  static std::true_type check2(index_sequence<I...>,
+                               integer_sequence<bool, (I == I)...>);
+  static std::false_type check2(...);
+  template <std::size_t... I>
+  static decltype(check2(
+      index_sequence<I...>{},
+      integer_sequence<
+          bool, (is_formattable<typename std::tuple_element<I, T>::type,
+                                C>::value)...>{})) check(index_sequence<I...>);
+
+ public:
+  static constexpr const bool value =
+      decltype(check(tuple_index_sequence<T>{}))::value;
+};
+
 template <class Tuple, class F, size_t... Is>
-void for_each(index_sequence<Is...>, Tuple &&tup, F &&f) FMT_NOEXCEPT {
+void for_each(index_sequence<Is...>, Tuple&& tup, F&& f) noexcept {
   using std::get;
   // using free function get<I>(T) now.
   const int _[] = {0, ((void)f(get<Is>(tup)), 0)...};
@@ -156,150 +236,396 @@ void for_each(index_sequence<Is...>, Tuple &&tup, F &&f) FMT_NOEXCEPT {
 }
 
 template <class T>
-FMT_CONSTEXPR make_index_sequence<std::tuple_size<T>::value> 
-get_indexes(T const &) { return {}; }
+FMT_CONSTEXPR make_index_sequence<std::tuple_size<T>::value> get_indexes(
+    T const&) {
+  return {};
+}
 
-template <class Tuple, class F>
-void for_each(Tuple &&tup, F &&f) {
+template <class Tuple, class F> void for_each(Tuple&& tup, F&& f) {
   const auto indexes = get_indexes(tup);
   for_each(indexes, std::forward<Tuple>(tup), std::forward<F>(f));
 }
 
-template<typename Arg>
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const Arg&, 
-  typename std::enable_if<
-    !is_like_std_string<typename std::decay<Arg>::type>::value>::type* = nullptr) {
-  return add_space ? " {}" : "{}";
-}
+#if FMT_MSC_VERSION && FMT_MSC_VERSION < 1920
+// Older MSVC doesn't get the reference type correctly for arrays.
+template <typename R> struct range_reference_type_impl {
+  using type = decltype(*detail::range_begin(std::declval<R&>()));
+};
 
-template<typename Arg>
-FMT_CONSTEXPR const char* format_str_quoted(bool add_space, const Arg&, 
-  typename std::enable_if<
-    is_like_std_string<typename std::decay<Arg>::type>::value>::type* = nullptr) {
-  return add_space ? " \"{}\"" : "\"{}\"";
-}
-
-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"\"{}\"";
-}
-
-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"'{}'";
-}
-
-}  // namespace internal
+template <typename T, std::size_t N> struct range_reference_type_impl<T[N]> {
+  using type = T&;
+};
 
 template <typename T>
-struct is_tuple_like {
-  static FMT_CONSTEXPR_DECL const bool value =
-    internal::is_tuple_like_<T>::value && !internal::is_range_<T>::value;
+using range_reference_type = typename range_reference_type_impl<T>::type;
+#else
+template <typename Range>
+using range_reference_type =
+    decltype(*detail::range_begin(std::declval<Range&>()));
+#endif
+
+// We don't use the Range's value_type for anything, but we do need the Range's
+// reference type, with cv-ref stripped.
+template <typename Range>
+using uncvref_type = remove_cvref_t<range_reference_type<Range>>;
+
+template <typename Range>
+using uncvref_first_type = remove_cvref_t<
+    decltype(std::declval<range_reference_type<Range>>().first)>;
+
+template <typename Range>
+using uncvref_second_type = remove_cvref_t<
+    decltype(std::declval<range_reference_type<Range>>().second)>;
+
+template <typename OutputIt> OutputIt write_delimiter(OutputIt out) {
+  *out++ = ',';
+  *out++ = ' ';
+  return out;
+}
+
+template <typename Char, typename OutputIt>
+auto write_range_entry(OutputIt out, basic_string_view<Char> str) -> OutputIt {
+  return write_escaped_string(out, str);
+}
+
+template <typename Char, typename OutputIt, typename T,
+          FMT_ENABLE_IF(std::is_convertible<T, std_string_view<char>>::value)>
+inline auto write_range_entry(OutputIt out, const T& str) -> OutputIt {
+  auto sv = std_string_view<Char>(str);
+  return write_range_entry<Char>(out, basic_string_view<Char>(sv));
+}
+
+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) {
+  return write_escaped_char(out, v);
+}
+
+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 {
+  static constexpr const bool value =
+      detail::is_tuple_like_<T>::value && !detail::is_range_<T>::value;
+};
+
+template <typename T, typename C> struct is_tuple_formattable {
+  static constexpr const bool value =
+      detail::is_tuple_formattable_<T, C>::value;
 };
 
 template <typename TupleT, typename Char>
-struct formatter<TupleT, Char, 
-    typename std::enable_if<fmt::is_tuple_like<TupleT>::value>::type> {
-private:
-  // 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++ = ' ';
-        }
-        internal::copy(formatting.delimiter, out);
-      }
-      format_to(out,
-                internal::format_str_quoted(
-                    (formatting.add_delimiter_spaces && i > 0), v),
-                v);
+struct formatter<TupleT, Char,
+                 enable_if_t<fmt::is_tuple_like<TupleT>::value &&
+                             fmt::is_tuple_formattable<TupleT, Char>::value>> {
+ private:
+  // C++11 generic lambda for format().
+  template <typename FormatContext> struct format_each {
+    template <typename T> void operator()(const T& v) {
+      if (i > 0) out = detail::write_delimiter(out);
+      out = detail::write_range_entry<Char>(out, v);
       ++i;
     }
-
-    formatting_tuple<Char>& formatting;
-    std::size_t& i;
-    typename std::add_lvalue_reference<decltype(std::declval<FormatContext>().out())>::type out;
+    int i;
+    typename FormatContext::iterator& out;
   };
 
-public:
-  formatting_tuple<Char> formatting;
-
+ public:
   template <typename ParseContext>
-  FMT_CONSTEXPR auto parse(ParseContext &ctx) -> decltype(ctx.begin()) {
-    return formatting.parse(ctx);
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
   }
 
   template <typename FormatContext = format_context>
-  auto format(const TupleT &values, FormatContext &ctx) -> decltype(ctx.out()) {
+  auto format(const TupleT& values, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
     auto out = ctx.out();
-    std::size_t i = 0;
-    internal::copy(formatting.prefix, out);
-
-    internal::for_each(values, format_each<FormatContext>{formatting, i, out});
-    if (formatting.add_prepostfix_space) {
-      *out++ = ' ';
-    }
-    internal::copy(formatting.postfix, out);
-
-    return ctx.out();
+    *out++ = '(';
+    detail::for_each(values, format_each<FormatContext>{0, out});
+    *out++ = ')';
+    return out;
   }
 };
 
-template <typename T>
-struct is_range {
-  static FMT_CONSTEXPR_DECL const bool value =
-    internal::is_range_<T>::value && !internal::is_like_std_string<T>::value;
+template <typename T, typename Char> struct is_range {
+  static constexpr const bool value =
+      detail::is_range_<T>::value && !detail::is_std_string_like<T>::value &&
+      !detail::is_map<T>::value &&
+      !std::is_convertible<T, std::basic_string<Char>>::value &&
+      !std::is_constructible<detail::std_string_view<Char>, T>::value;
 };
 
-template <typename RangeT, typename Char>
-struct formatter<RangeT, Char,
-    typename std::enable_if<fmt::is_range<RangeT>::value>::type> {
+namespace detail {
+template <typename Context> struct range_mapper {
+  using mapper = arg_mapper<Context>;
 
-  formatting_range<Char> formatting;
+  template <typename T,
+            FMT_ENABLE_IF(has_formatter<remove_cvref_t<T>, Context>::value)>
+  static auto map(T&& value) -> T&& {
+    return static_cast<T&&>(value);
+  }
+  template <typename T,
+            FMT_ENABLE_IF(!has_formatter<remove_cvref_t<T>, Context>::value)>
+  static auto map(T&& value)
+      -> decltype(mapper().map(static_cast<T&&>(value))) {
+    return mapper().map(static_cast<T&&>(value));
+  }
+};
+
+template <typename Char, typename Element>
+using range_formatter_type = conditional_t<
+    is_formattable<Element, Char>::value,
+    formatter<remove_cvref_t<decltype(range_mapper<buffer_context<Char>>{}.map(
+                  std::declval<Element>()))>,
+              Char>,
+    fallback_formatter<Element, Char>>;
+
+template <typename R>
+using maybe_const_range =
+    conditional_t<has_const_begin_end<R>::value, const R, R>;
+}  // namespace detail
+
+template <typename R, typename Char>
+struct formatter<
+    R, Char,
+    enable_if_t<
+        conjunction<fmt::is_range<R, Char>
+// Workaround a bug in MSVC 2017 and earlier.
+#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1920
+        ,
+        disjunction<
+          is_formattable<detail::uncvref_type<detail::maybe_const_range<R>>,
+                         Char>,
+          detail::has_fallback_formatter<
+             detail::uncvref_type<detail::maybe_const_range<R>>, Char>
+        >
+#endif
+        >::value
+        >> {
+
+  using range_type = detail::maybe_const_range<R>;
+  using formatter_type =
+      detail::range_formatter_type<Char, detail::uncvref_type<range_type>>;
+  formatter_type underlying_;
+  bool custom_specs_ = false;
 
   template <typename ParseContext>
-  FMT_CONSTEXPR auto parse(ParseContext &ctx) -> decltype(ctx.begin()) {
-    return formatting.parse(ctx);
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    auto it = ctx.begin();
+    auto end = ctx.end();
+    if (it == end || *it == '}') return it;
+
+    if (*it != ':')
+      FMT_THROW(format_error("no top-level range formatters supported"));
+
+    custom_specs_ = true;
+    ++it;
+    ctx.advance_to(it);
+    return underlying_.parse(ctx);
   }
 
   template <typename FormatContext>
-  typename FormatContext::iterator format(
-      const RangeT &values, FormatContext &ctx) {
+  auto format(range_type& range, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    Char prefix = detail::is_set<R>::value ? '{' : '[';
+    Char postfix = detail::is_set<R>::value ? '}' : ']';
+    detail::range_mapper<buffer_context<Char>> mapper;
     auto out = ctx.out();
-    internal::copy(formatting.prefix, out);
-    std::size_t i = 0;
-    for (auto it = values.begin(), end = values.end(); it != end; ++it) {
-      if (i > 0) {
-        if (formatting.add_prepostfix_space) {
-          *out++ = ' ';
-        }
-        internal::copy(formatting.delimiter, out);
-      }
-      format_to(out,
-                internal::format_str_quoted(
-                    (formatting.add_delimiter_spaces && i > 0), *it),
-                *it);
-      if (++i > formatting.range_length_limit) {
-        format_to(out, " ... <other elements>");
-        break;
+    *out++ = prefix;
+    int i = 0;
+    auto it = detail::range_begin(range);
+    auto end = detail::range_end(range);
+    for (; it != end; ++it) {
+      if (i > 0) out = detail::write_delimiter(out);
+      if (custom_specs_) {
+        ctx.advance_to(out);
+        out = underlying_.format(mapper.map(*it), ctx);
+      } else {
+        out = detail::write_range_entry<Char>(out, *it);
       }
+      ++i;
     }
-    if (formatting.add_prepostfix_space) {
-      *out++ = ' ';
-    }
-    internal::copy(formatting.postfix, out);
-    return ctx.out();
+    *out++ = postfix;
+    return out;
   }
 };
 
+template <typename T, typename Char>
+struct formatter<
+    T, Char,
+    enable_if_t<conjunction<detail::is_map<T>
+// Workaround a bug in MSVC 2017 and earlier.
+#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1920
+        ,
+        disjunction<
+          is_formattable<detail::uncvref_first_type<T>, Char>,
+          detail::has_fallback_formatter<detail::uncvref_first_type<T>, Char>
+        >,
+        disjunction<
+          is_formattable<detail::uncvref_second_type<T>, Char>,
+          detail::has_fallback_formatter<detail::uncvref_second_type<T>, Char>
+        >
+#endif
+    >::value
+    >> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <
+      typename FormatContext, typename U,
+      FMT_ENABLE_IF(
+          std::is_same<U, conditional_t<detail::has_const_begin_end<T>::value,
+                                        const T, T>>::value)>
+  auto format(U& map, FormatContext& ctx) const -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    *out++ = '{';
+    int i = 0;
+    for (const auto& item : map) {
+      if (i > 0) out = detail::write_delimiter(out);
+      out = detail::write_range_entry<Char>(out, item.first);
+      *out++ = ':';
+      *out++ = ' ';
+      out = detail::write_range_entry<Char>(out, item.second);
+      ++i;
+    }
+    *out++ = '}';
+    return out;
+  }
+};
+
+template <typename Char, typename... T> struct tuple_join_view : detail::view {
+  const std::tuple<T...>& tuple;
+  basic_string_view<Char> sep;
+
+  tuple_join_view(const std::tuple<T...>& t, basic_string_view<Char> s)
+      : tuple(t), sep{s} {}
+};
+
+template <typename Char, typename... T>
+using tuple_arg_join = tuple_join_view<Char, T...>;
+
+// Define FMT_TUPLE_JOIN_SPECIFIERS to enable experimental format specifiers
+// support in tuple_join. It is disabled by default because of issues with
+// the dynamic width and precision.
+#ifndef FMT_TUPLE_JOIN_SPECIFIERS
+#  define FMT_TUPLE_JOIN_SPECIFIERS 0
+#endif
+
+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 do_parse(ctx, std::integral_constant<size_t, sizeof...(T)>());
+  }
+
+  template <typename FormatContext>
+  auto format(const tuple_join_view<Char, T...>& value,
+              FormatContext& ctx) const -> typename FormatContext::iterator {
+    return do_format(value, ctx,
+                     std::integral_constant<size_t, sizeof...(T)>());
+  }
+
+ private:
+  std::tuple<formatter<typename std::decay<T>::type, Char>...> formatters_;
+
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
+                              std::integral_constant<size_t, 0>)
+      -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename ParseContext, size_t N>
+  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
+                              std::integral_constant<size_t, N>)
+      -> decltype(ctx.begin()) {
+    auto end = ctx.begin();
+#if FMT_TUPLE_JOIN_SPECIFIERS
+    end = std::get<sizeof...(T) - N>(formatters_).parse(ctx);
+    if (N > 1) {
+      auto end1 = do_parse(ctx, std::integral_constant<size_t, N - 1>());
+      if (end != end1)
+        FMT_THROW(format_error("incompatible format specs for tuple elements"));
+    }
+#endif
+    return end;
+  }
+
+  template <typename FormatContext>
+  auto do_format(const tuple_join_view<Char, T...>&, FormatContext& ctx,
+                 std::integral_constant<size_t, 0>) const ->
+      typename FormatContext::iterator {
+    return ctx.out();
+  }
+
+  template <typename FormatContext, size_t N>
+  auto do_format(const tuple_join_view<Char, T...>& value, FormatContext& ctx,
+                 std::integral_constant<size_t, N>) const ->
+      typename FormatContext::iterator {
+    auto out = std::get<sizeof...(T) - N>(formatters_)
+                   .format(std::get<sizeof...(T) - N>(value.tuple), ctx);
+    if (N > 1) {
+      out = std::copy(value.sep.begin(), value.sep.end(), out);
+      ctx.advance_to(out);
+      return do_format(value, ctx, std::integral_constant<size_t, N - 1>());
+    }
+    return out;
+  }
+};
+
+FMT_MODULE_EXPORT_BEGIN
+
+/**
+  \rst
+  Returns an object that formats `tuple` with elements separated by `sep`.
+
+  **Example**::
+
+    std::tuple<int, char> t = {1, 'a'};
+    fmt::print("{}", fmt::join(t, ", "));
+    // Output: "1, a"
+  \endrst
+ */
+template <typename... T>
+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 auto join(const std::tuple<T...>& tuple,
+                        basic_string_view<wchar_t> sep)
+    -> tuple_join_view<wchar_t, T...> {
+  return {tuple, sep};
+}
+
+/**
+  \rst
+  Returns an object that formats `initializer_list` with elements separated by
+  `sep`.
+
+  **Example**::
+
+    fmt::print("{}", fmt::join({1, 2, 3}, ", "));
+    // Output: "1, 2, 3"
+  \endrst
+ */
+template <typename T>
+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_
-
+#endif  // FMT_RANGES_H_

include/fmt/std.h

@@ -0,0 +1,176 @@
+// Formatting library for C++ - formatters for standard library types
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#ifndef FMT_STD_H_
+#define FMT_STD_H_
+
+#include <thread>
+#include <type_traits>
+#include <utility>
+
+#include "ostream.h"
+
+#if FMT_HAS_INCLUDE(<version>)
+#  include <version>
+#endif
+// Checking FMT_CPLUSPLUS for warning suppression in MSVC.
+#if FMT_CPLUSPLUS >= 201703L
+#  if FMT_HAS_INCLUDE(<filesystem>)
+#    include <filesystem>
+#  endif
+#  if FMT_HAS_INCLUDE(<variant>)
+#    include <variant>
+#  endif
+#endif
+
+#ifdef __cpp_lib_filesystem
+FMT_BEGIN_NAMESPACE
+
+namespace detail {
+
+template <typename Char>
+void write_escaped_path(basic_memory_buffer<Char>& quoted,
+                        const std::filesystem::path& p) {
+  write_escaped_string<Char>(std::back_inserter(quoted), p.string<Char>());
+}
+#  ifdef _WIN32
+template <>
+inline void write_escaped_path<char>(basic_memory_buffer<char>& quoted,
+                                     const std::filesystem::path& p) {
+  auto s = p.u8string();
+  write_escaped_string<char>(
+      std::back_inserter(quoted),
+      string_view(reinterpret_cast<const char*>(s.c_str()), s.size()));
+}
+#  endif
+template <>
+inline void write_escaped_path<std::filesystem::path::value_type>(
+    basic_memory_buffer<std::filesystem::path::value_type>& quoted,
+    const std::filesystem::path& p) {
+  write_escaped_string<std::filesystem::path::value_type>(
+      std::back_inserter(quoted), p.native());
+}
+
+}  // namespace detail
+
+#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1920
+// For MSVC 2017 and earlier using the partial specialization
+// would cause an ambiguity error, therefore we provide it only
+// conditionally.
+template <typename Char>
+struct formatter<std::filesystem::path, Char>
+    : formatter<basic_string_view<Char>> {
+  template <typename FormatContext>
+  auto format(const std::filesystem::path& p, FormatContext& ctx) const ->
+      typename FormatContext::iterator {
+    basic_memory_buffer<Char> quoted;
+    detail::write_escaped_path(quoted, p);
+    return formatter<basic_string_view<Char>>::format(
+        basic_string_view<Char>(quoted.data(), quoted.size()), ctx);
+  }
+};
+#endif
+FMT_END_NAMESPACE
+#endif
+
+FMT_BEGIN_NAMESPACE
+template <typename Char>
+struct formatter<std::thread::id, Char> : basic_ostream_formatter<Char> {};
+FMT_END_NAMESPACE
+
+#ifdef __cpp_lib_variant
+FMT_BEGIN_NAMESPACE
+template <typename Char> struct formatter<std::monostate, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  auto format(const std::monostate&, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    out = detail::write<Char>(out, "monostate");
+    return out;
+  }
+};
+
+namespace detail {
+
+template <typename T>
+using variant_index_sequence =
+    std::make_index_sequence<std::variant_size<T>::value>;
+
+// variant_size and variant_alternative check.
+template <typename T, typename U = void>
+struct is_variant_like_ : std::false_type {};
+template <typename T>
+struct is_variant_like_<T, std::void_t<decltype(std::variant_size<T>::value)>>
+    : std::true_type {};
+
+// formattable element check
+template <typename T, typename C> class is_variant_formattable_ {
+  template <std::size_t... I>
+  static std::conjunction<
+      is_formattable<std::variant_alternative_t<I, T>, C>...>
+      check(std::index_sequence<I...>);
+
+ public:
+  static constexpr const bool value =
+      decltype(check(variant_index_sequence<T>{}))::value;
+};
+
+template <typename Char, typename OutputIt, typename T>
+auto write_variant_alternative(OutputIt out, const T& v) -> OutputIt {
+  if constexpr (is_string<T>::value)
+    return write_escaped_string<Char>(out, detail::to_string_view(v));
+  else if constexpr (std::is_same_v<T, Char>)
+    return write_escaped_char(out, v);
+  else
+    return write<Char>(out, v);
+}
+
+}  // namespace detail
+
+template <typename T> struct is_variant_like {
+  static constexpr const bool value = detail::is_variant_like_<T>::value;
+};
+
+template <typename T, typename C> struct is_variant_formattable {
+  static constexpr const bool value =
+      detail::is_variant_formattable_<T, C>::value;
+};
+
+template <typename Variant, typename Char>
+struct formatter<
+    Variant, Char,
+    std::enable_if_t<std::conjunction_v<
+        is_variant_like<Variant>, is_variant_formattable<Variant, Char>>>> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  auto format(const Variant& value, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+
+    out = detail::write<Char>(out, "variant(");
+    std::visit(
+        [&](const auto& v) {
+          out = detail::write_variant_alternative<Char>(out, v);
+        },
+        value);
+    *out++ = ')';
+    return out;
+  }
+};
+FMT_END_NAMESPACE
+#endif
+
+#endif  // FMT_STD_H_

include/fmt/time.h

@@ -1,156 +0,0 @@
-// Formatting library for C++ - time formatting
-//
-// Copyright (c) 2012 - 2016, Victor Zverovich
-// All rights reserved.
-//
-// For the license information refer to format.h.
-
-#ifndef FMT_TIME_H_
-#define FMT_TIME_H_
-
-#include "format.h"
-#include <ctime>
-
-FMT_BEGIN_NAMESPACE
-
-// Prevents expansion of a preceding token as a function-style macro.
-// Usage: f FMT_NOMACRO()
-#define FMT_NOMACRO
-
-namespace internal{
-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<>(); }
-}
-
-// Thread-safe replacement for std::localtime
-inline std::tm localtime(std::time_t time) {
-  struct dispatcher {
-    std::time_t time_;
-    std::tm tm_;
-
-    dispatcher(std::time_t t): time_(t) {}
-
-    bool run() {
-      using namespace fmt::internal;
-      return handle(localtime_r(&time_, &tm_));
-    }
-
-    bool handle(std::tm *tm) { return tm != FMT_NULL; }
-
-    bool handle(internal::null<>) {
-      using namespace fmt::internal;
-      return fallback(localtime_s(&tm_, &time_));
-    }
-
-    bool fallback(int res) { return res == 0; }
-
-    bool fallback(internal::null<>) {
-      using namespace fmt::internal;
-      std::tm *tm = std::localtime(&time_);
-      if (tm) tm_ = *tm;
-      return tm != FMT_NULL;
-    }
-  };
-  dispatcher lt(time);
-  if (lt.run())
-    return lt.tm_;
-  // Too big time values may be unsupported.
-  FMT_THROW(format_error("time_t value out of range"));
-}
-
-// Thread-safe replacement for std::gmtime
-inline std::tm gmtime(std::time_t time) {
-  struct dispatcher {
-    std::time_t time_;
-    std::tm tm_;
-
-    dispatcher(std::time_t t): time_(t) {}
-
-    bool run() {
-      using namespace fmt::internal;
-      return handle(gmtime_r(&time_, &tm_));
-    }
-
-    bool handle(std::tm *tm) { return tm != FMT_NULL; }
-
-    bool handle(internal::null<>) {
-      using namespace fmt::internal;
-      return fallback(gmtime_s(&tm_, &time_));
-    }
-
-    bool fallback(int res) { return res == 0; }
-
-    bool fallback(internal::null<>) {
-      std::tm *tm = std::gmtime(&time_);
-      if (tm) tm_ = *tm;
-      return tm != FMT_NULL;
-    }
-  };
-  dispatcher gt(time);
-  if (gt.run())
-    return gt.tm_;
-  // Too big time values may be unsupported.
-  FMT_THROW(format_error("time_t value out of range"));
-}
-
-namespace internal {
-inline std::size_t strftime(char *str, std::size_t count, const char *format,
-                            const std::tm *time) {
-  return std::strftime(str, count, format, time);
-}
-
-inline std::size_t strftime(wchar_t *str, std::size_t count,
-                            const wchar_t *format, const std::tm *time) {
-  return std::wcsftime(str, count, format, time);
-}
-}
-
-template <typename Char>
-struct formatter<std::tm, Char> {
-  template <typename ParseContext>
-  auto parse(ParseContext &ctx) -> decltype(ctx.begin()) {
-    auto it = internal::null_terminating_iterator<Char>(ctx);
-    if (*it == ':')
-      ++it;
-    auto end = it;
-    while (*end && *end != '}')
-      ++end;
-    tm_format.reserve(end - it + 1);
-    using internal::pointer_from;
-    tm_format.append(pointer_from(it), pointer_from(end));
-    tm_format.push_back('\0');
-    return pointer_from(end);
-  }
-
-  template <typename FormatContext>
-  auto format(const std::tm &tm, FormatContext &ctx) -> decltype(ctx.out()) {
-    internal::basic_buffer<Char> &buf = internal::get_container(ctx.out());
-    std::size_t start = buf.size();
-    for (;;) {
-      std::size_t size = buf.capacity() - start;
-      std::size_t count =
-        internal::strftime(&buf[start], size, &tm_format[0], &tm);
-      if (count != 0) {
-        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 std::size_t MIN_GROWTH = 10;
-      buf.reserve(buf.capacity() + (size > MIN_GROWTH ? size : MIN_GROWTH));
-    }
-    return ctx.out();
-  }
-
-  basic_memory_buffer<Char> tm_format;
-};
-FMT_END_NAMESPACE
-
-#endif  // FMT_TIME_H_

include/fmt/xchar.h

@@ -0,0 +1,232 @@
+// 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_XCHAR_H_
+#define FMT_XCHAR_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 {
+#if FMT_USE_USER_DEFINED_LITERALS && !FMT_USE_NONTYPE_TEMPLATE_ARGS
+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);
+}
+
+#if !FMT_GCC_VERSION || FMT_GCC_VERSION >= 409
+template <typename... Args>
+using wformat_string = basic_format_string<wchar_t, type_identity_t<Args>...>;
+#endif
+
+template <typename... T>
+auto format(wformat_string<T...> fmt, T&&... args) -> std::wstring {
+  return vformat(fmt, fmt::make_wformat_args(args...));
+}
+
+// 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> {
+  return vformat(detail::to_string_view(format_str),
+                 fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+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, detail::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, detail::to_string_view(format_str),
+                         fmt::make_format_args<buffer_context<Char>>(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, detail::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 {
+  return vformat_to(out, detail::to_string_view(fmt),
+                    fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+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, detail::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 {
+  return vformat_to(out, loc, to_string_view(format_str),
+                    fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+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> {
+  return vformat_to_n(out, n, detail::to_string_view(fmt),
+                      fmt::make_format_args<buffer_context<Char>>(args...));
+}
+
+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;
+  detail::vformat_to(buf, detail::to_string_view(fmt),
+                     fmt::make_format_args<buffer_context<Char>>(args...));
+  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), fmt::make_wformat_args(args...));
+}
+
+template <typename... T> void print(wformat_string<T...> fmt, T&&... args) {
+  return vprint(wstring_view(fmt), 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_XCHAR_H_

src/fmt.cc

@@ -0,0 +1,99 @@
+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

@@ -8,39 +8,40 @@
 #include "fmt/format-inl.h"
 
 FMT_BEGIN_NAMESPACE
-template struct internal::basic_data<void>;
+namespace detail {
+
+template FMT_API auto dragonbox::to_decimal(float x) noexcept
+    -> dragonbox::decimal_fp<float>;
+template FMT_API auto dragonbox::to_decimal(double x) noexcept
+    -> dragonbox::decimal_fp<double>;
+
+#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+template FMT_API locale_ref::locale_ref(const std::locale& loc);
+template FMT_API auto locale_ref::get<std::locale>() const -> std::locale;
+#endif
 
 // Explicit instantiations for char.
 
-template FMT_API char internal::thousands_sep(locale_provider *lp);
+template FMT_API auto thousands_sep_impl(locale_ref)
+    -> thousands_sep_result<char>;
+template FMT_API auto decimal_point_impl(locale_ref) -> char;
 
-template void basic_fixed_buffer<char>::grow(std::size_t);
+template FMT_API void buffer<char>::append(const char*, const char*);
 
-template void internal::arg_map<format_context>::init(
-    const basic_format_args<format_context> &args);
-
-template FMT_API int internal::char_traits<char>::format_float(
-    char *buffer, std::size_t size, const char *format, int precision,
-    double value);
-
-template FMT_API int internal::char_traits<char>::format_float(
-    char *buffer, std::size_t size, const char *format, int precision,
-    long double value);
+// DEPRECATED!
+// There is no correspondent extern template in format.h because of
+// incompatibility between clang and gcc (#2377).
+template FMT_API void vformat_to(buffer<char>&, string_view,
+                                 basic_format_args<FMT_BUFFER_CONTEXT(char)>,
+                                 locale_ref);
 
 // Explicit instantiations for wchar_t.
 
-template FMT_API wchar_t internal::thousands_sep(locale_provider *lp);
+template FMT_API auto thousands_sep_impl(locale_ref)
+    -> thousands_sep_result<wchar_t>;
+template FMT_API auto decimal_point_impl(locale_ref) -> wchar_t;
 
-template void basic_fixed_buffer<wchar_t>::grow(std::size_t);
+template FMT_API void buffer<wchar_t>::append(const wchar_t*, const wchar_t*);
 
-template void internal::arg_map<wformat_context>::init(
-    const basic_format_args<wformat_context> &args);
-
-template FMT_API int internal::char_traits<wchar_t>::format_float(
-    wchar_t *buffer, std::size_t size, const wchar_t *format,
-    int precision, double value);
-
-template FMT_API int internal::char_traits<wchar_t>::format_float(
-    wchar_t *buffer, std::size_t size, const wchar_t *format,
-    int precision, long double value);
+}  // namespace detail
 FMT_END_NAMESPACE

src/os.cc

@@ -0,0 +1,361 @@
+// Formatting library for C++ - optional OS-specific functionality
+//
+// Copyright (c) 2012 - 2016, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+// Disable bogus MSVC warnings.
+#if !defined(_CRT_SECURE_NO_WARNINGS) && defined(_MSC_VER)
+#  define _CRT_SECURE_NO_WARNINGS
+#endif
+
+#include "fmt/os.h"
+
+#include <climits>
+
+#if FMT_USE_FCNTL
+#  include <sys/stat.h>
+#  include <sys/types.h>
+
+#  ifndef _WIN32
+#    include <unistd.h>
+#  else
+#    ifndef WIN32_LEAN_AND_MEAN
+#      define WIN32_LEAN_AND_MEAN
+#    endif
+#    include <io.h>
+
+#    ifndef S_IRUSR
+#      define S_IRUSR _S_IREAD
+#    endif
+#    ifndef S_IWUSR
+#      define S_IWUSR _S_IWRITE
+#    endif
+#    ifndef S_IRGRP
+#      define S_IRGRP 0
+#    endif
+#    ifndef S_IWGRP
+#      define S_IWGRP 0
+#    endif
+#    ifndef S_IROTH
+#      define S_IROTH 0
+#    endif
+#    ifndef S_IWOTH
+#      define S_IWOTH 0
+#    endif
+#  endif  // _WIN32
+#endif    // FMT_USE_FCNTL
+
+#ifdef _WIN32
+#  include <windows.h>
+#endif
+
+namespace {
+#ifdef _WIN32
+// Return type of read and write functions.
+using rwresult = int;
+
+// On Windows the count argument to read and write is unsigned, so convert
+// it from size_t preventing integer overflow.
+inline unsigned convert_rwcount(std::size_t count) {
+  return count <= UINT_MAX ? static_cast<unsigned>(count) : UINT_MAX;
+}
+#elif FMT_USE_FCNTL
+// Return type of read and write functions.
+using rwresult = ssize_t;
+
+inline std::size_t convert_rwcount(std::size_t count) { return count; }
+#endif
+}  // namespace
+
+FMT_BEGIN_NAMESPACE
+
+#ifdef _WIN32
+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(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) {
+    // WideCharToMultiByte does not support zero length, handle separately.
+    buffer_.resize(1);
+    buffer_[0] = 0;
+    return 0;
+  }
+
+  int length = WideCharToMultiByte(CP_UTF8, 0, s.data(), s_size, nullptr, 0,
+                                   nullptr, nullptr);
+  if (length == 0) return GetLastError();
+  buffer_.resize(length + 1);
+  length = WideCharToMultiByte(CP_UTF8, 0, s.data(), s_size, &buffer_[0],
+                               length, nullptr, nullptr);
+  if (length == 0) return GetLastError();
+  buffer_[length] = 0;
+  return 0;
+}
+
+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) 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 noexcept { return result_ != 0; }
+  operator basic_string_view<wchar_t>() const noexcept {
+    return basic_string_view<wchar_t>(message_, result_);
+  }
+};
+
+class utf8_system_category final : public std::error_category {
+ public:
+  const char* name() const 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() 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,
+                                  const char* message) noexcept {
+  FMT_TRY {
+    system_message msg(error_code);
+    if (msg) {
+      utf16_to_utf8 utf8_message;
+      if (utf8_message.convert(msg) == ERROR_SUCCESS) {
+        fmt::format_to(buffer_appender<char>(out), "{}: {}", message, utf8_message);
+        return;
+      }
+    }
+  }
+  FMT_CATCH(...) {}
+  format_error_code(out, error_code, message);
+}
+
+void report_windows_error(int error_code, const char* message) noexcept {
+  report_error(detail::format_windows_error, error_code, message);
+}
+#endif  // _WIN32
+
+buffered_file::~buffered_file() noexcept {
+  if (file_ && FMT_SYSTEM(fclose(file_)) != 0)
+    report_system_error(errno, "cannot close file");
+}
+
+buffered_file::buffered_file(cstring_view filename, cstring_view mode) {
+  FMT_RETRY_VAL(file_, FMT_SYSTEM(fopen(filename.c_str(), mode.c_str())),
+                nullptr);
+  if (!file_)
+    FMT_THROW(system_error(errno, "cannot open file {}", filename.c_str()));
+}
+
+void buffered_file::close() {
+  if (!file_) return;
+  int result = FMT_SYSTEM(fclose(file_));
+  file_ = nullptr;
+  if (result != 0) FMT_THROW(system_error(errno, "cannot close file"));
+}
+
+int buffered_file::descriptor() const {
+  int fd = FMT_POSIX_CALL(fileno(file_));
+  if (fd == -1) FMT_THROW(system_error(errno, "cannot get file descriptor"));
+  return fd;
+}
+
+#if FMT_USE_FCNTL
+file::file(cstring_view path, int oflag) {
+#  ifdef _WIN32
+  using mode_t = int;
+#  endif
+  constexpr mode_t mode =
+      S_IRUSR | S_IWUSR | S_IRGRP | S_IWGRP | S_IROTH | S_IWOTH;
+#  if defined(_WIN32) && !defined(__MINGW32__)
+  fd_ = -1;
+  FMT_POSIX_CALL(sopen_s(&fd_, path.c_str(), oflag, _SH_DENYNO, mode));
+#  else
+  FMT_RETRY(fd_, FMT_POSIX_CALL(open(path.c_str(), oflag, mode)));
+#  endif
+  if (fd_ == -1)
+    FMT_THROW(system_error(errno, "cannot open file {}", path.c_str()));
+}
+
+file::~file() noexcept {
+  // Don't retry close in case of EINTR!
+  // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
+  if (fd_ != -1 && FMT_POSIX_CALL(close(fd_)) != 0)
+    report_system_error(errno, "cannot close file");
+}
+
+void file::close() {
+  if (fd_ == -1) return;
+  // Don't retry close in case of EINTR!
+  // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
+  int result = FMT_POSIX_CALL(close(fd_));
+  fd_ = -1;
+  if (result != 0) FMT_THROW(system_error(errno, "cannot close file"));
+}
+
+long long file::size() const {
+#  ifdef _WIN32
+  // Use GetFileSize instead of GetFileSizeEx for the case when _WIN32_WINNT
+  // is less than 0x0500 as is the case with some default MinGW builds.
+  // Both functions support large file sizes.
+  DWORD size_upper = 0;
+  HANDLE handle = reinterpret_cast<HANDLE>(_get_osfhandle(fd_));
+  DWORD size_lower = FMT_SYSTEM(GetFileSize(handle, &size_upper));
+  if (size_lower == INVALID_FILE_SIZE) {
+    DWORD error = GetLastError();
+    if (error != NO_ERROR)
+      FMT_THROW(windows_error(GetLastError(), "cannot get file size"));
+  }
+  unsigned long long long_size = size_upper;
+  return (long_size << sizeof(DWORD) * CHAR_BIT) | size_lower;
+#  else
+  using Stat = struct stat;
+  Stat file_stat = Stat();
+  if (FMT_POSIX_CALL(fstat(fd_, &file_stat)) == -1)
+    FMT_THROW(system_error(errno, "cannot get file attributes"));
+  static_assert(sizeof(long long) >= sizeof(file_stat.st_size),
+                "return type of file::size is not large enough");
+  return file_stat.st_size;
+#  endif
+}
+
+std::size_t file::read(void* buffer, std::size_t count) {
+  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;
+  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);
+}
+
+file file::dup(int fd) {
+  // Don't retry as dup doesn't return EINTR.
+  // http://pubs.opengroup.org/onlinepubs/009695399/functions/dup.html
+  int new_fd = FMT_POSIX_CALL(dup(fd));
+  if (new_fd == -1)
+    FMT_THROW(system_error(errno, "cannot duplicate file descriptor {}", fd));
+  return file(new_fd);
+}
+
+void file::dup2(int fd) {
+  int result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
+  if (result == -1) {
+    FMT_THROW(system_error(errno, "cannot duplicate file descriptor {} to {}",
+                           fd_, fd));
+  }
+}
+
+void file::dup2(int fd, std::error_code& ec) noexcept {
+  int result = 0;
+  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
+  if (result == -1) ec = std::error_code(errno, std::generic_category());
+}
+
+void file::pipe(file& read_end, file& write_end) {
+  // Close the descriptors first to make sure that assignments don't throw
+  // and there are no leaks.
+  read_end.close();
+  write_end.close();
+  int fds[2] = {};
+#  ifdef _WIN32
+  // Make the default pipe capacity same as on Linux 2.6.11+.
+  enum { DEFAULT_CAPACITY = 65536 };
+  int result = FMT_POSIX_CALL(pipe(fds, DEFAULT_CAPACITY, _O_BINARY));
+#  else
+  // Don't retry as the pipe function doesn't return EINTR.
+  // http://pubs.opengroup.org/onlinepubs/009696799/functions/pipe.html
+  int result = FMT_POSIX_CALL(pipe(fds));
+#  endif
+  if (result != 0) FMT_THROW(system_error(errno, "cannot create pipe"));
+  // The following assignments don't throw because read_fd and write_fd
+  // are closed.
+  read_end = file(fds[0]);
+  write_end = file(fds[1]);
+}
+
+buffered_file file::fdopen(const char* mode) {
+// Don't retry as fdopen doesn't return EINTR.
+#  if defined(__MINGW32__) && defined(_POSIX_)
+  FILE* f = ::fdopen(fd_, mode);
+#  else
+  FILE* f = FMT_POSIX_CALL(fdopen(fd_, mode));
+#  endif
+  if (!f)
+    FMT_THROW(
+        system_error(errno, "cannot associate stream with file descriptor"));
+  buffered_file bf(f);
+  fd_ = -1;
+  return bf;
+}
+
+long getpagesize() {
+#  ifdef _WIN32
+  SYSTEM_INFO si;
+  GetSystemInfo(&si);
+  return si.dwPageSize;
+#  else
+  long size = FMT_POSIX_CALL(sysconf(_SC_PAGESIZE));
+  if (size < 0) FMT_THROW(system_error(errno, "cannot get memory page size"));
+  return size;
+#  endif
+}
+
+FMT_API void ostream::grow(size_t) {
+  if (this->size() == this->capacity()) flush();
+}
+#endif  // FMT_USE_FCNTL
+FMT_END_NAMESPACE

src/posix.cc

@@ -1,244 +0,0 @@
-// A C++ interface to POSIX functions.
-//
-// Copyright (c) 2012 - 2016, Victor Zverovich
-// All rights reserved.
-//
-// For the license information refer to format.h.
-
-// Disable bogus MSVC warnings.
-#if !defined(_CRT_SECURE_NO_WARNINGS) && defined(_MSC_VER)
-# define _CRT_SECURE_NO_WARNINGS
-#endif
-
-#include "fmt/posix.h"
-
-#include <limits.h>
-#include <sys/types.h>
-#include <sys/stat.h>
-
-#ifndef _WIN32
-# include <unistd.h>
-#else
-# ifndef WIN32_LEAN_AND_MEAN
-#  define WIN32_LEAN_AND_MEAN
-# endif
-# include <windows.h>
-# include <io.h>
-
-# define O_CREAT _O_CREAT
-# define O_TRUNC _O_TRUNC
-
-# ifndef S_IRUSR
-#  define S_IRUSR _S_IREAD
-# endif
-
-# ifndef S_IWUSR
-#  define S_IWUSR _S_IWRITE
-# endif
-
-# ifdef __MINGW32__
-#  define _SH_DENYNO 0x40
-# endif
-
-#endif  // _WIN32
-
-#ifdef fileno
-# undef fileno
-#endif
-
-namespace {
-#ifdef _WIN32
-// Return type of read and write functions.
-typedef int RWResult;
-
-// On Windows the count argument to read and write is unsigned, so convert
-// it from size_t preventing integer overflow.
-inline unsigned convert_rwcount(std::size_t count) {
-  return count <= UINT_MAX ? static_cast<unsigned>(count) : UINT_MAX;
-}
-#else
-// Return type of read and write functions.
-typedef ssize_t RWResult;
-
-inline std::size_t convert_rwcount(std::size_t count) { return count; }
-#endif
-}
-
-FMT_BEGIN_NAMESPACE
-
-buffered_file::~buffered_file() FMT_NOEXCEPT {
-  if (file_ && FMT_SYSTEM(fclose(file_)) != 0)
-    report_system_error(errno, "cannot close file");
-}
-
-buffered_file::buffered_file(cstring_view filename, cstring_view mode) {
-  FMT_RETRY_VAL(file_,
-                FMT_SYSTEM(fopen(filename.c_str(), mode.c_str())), FMT_NULL);
-  if (!file_)
-    FMT_THROW(system_error(errno, "cannot open file {}", filename.c_str()));
-}
-
-void buffered_file::close() {
-  if (!file_)
-    return;
-  int result = FMT_SYSTEM(fclose(file_));
-  file_ = FMT_NULL;
-  if (result != 0)
-    FMT_THROW(system_error(errno, "cannot close file"));
-}
-
-// A macro used to prevent expansion of fileno on broken versions of MinGW.
-#define FMT_ARGS
-
-int buffered_file::fileno() const {
-  int fd = FMT_POSIX_CALL(fileno FMT_ARGS(file_));
-  if (fd == -1)
-    FMT_THROW(system_error(errno, "cannot get file descriptor"));
-  return fd;
-}
-
-file::file(cstring_view path, int oflag) {
-  int mode = S_IRUSR | S_IWUSR;
-#if defined(_WIN32) && !defined(__MINGW32__)
-  fd_ = -1;
-  FMT_POSIX_CALL(sopen_s(&fd_, path.c_str(), oflag, _SH_DENYNO, mode));
-#else
-  FMT_RETRY(fd_, FMT_POSIX_CALL(open(path.c_str(), oflag, mode)));
-#endif
-  if (fd_ == -1)
-    FMT_THROW(system_error(errno, "cannot open file {}", path.c_str()));
-}
-
-file::~file() FMT_NOEXCEPT {
-  // Don't retry close in case of EINTR!
-  // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
-  if (fd_ != -1 && FMT_POSIX_CALL(close(fd_)) != 0)
-    report_system_error(errno, "cannot close file");
-}
-
-void file::close() {
-  if (fd_ == -1)
-    return;
-  // Don't retry close in case of EINTR!
-  // See http://linux.derkeiler.com/Mailing-Lists/Kernel/2005-09/3000.html
-  int result = FMT_POSIX_CALL(close(fd_));
-  fd_ = -1;
-  if (result != 0)
-    FMT_THROW(system_error(errno, "cannot close file"));
-}
-
-long long file::size() const {
-#ifdef _WIN32
-  // Use GetFileSize instead of GetFileSizeEx for the case when _WIN32_WINNT
-  // is less than 0x0500 as is the case with some default MinGW builds.
-  // Both functions support large file sizes.
-  DWORD size_upper = 0;
-  HANDLE handle = reinterpret_cast<HANDLE>(_get_osfhandle(fd_));
-  DWORD size_lower = FMT_SYSTEM(GetFileSize(handle, &size_upper));
-  if (size_lower == INVALID_FILE_SIZE) {
-    DWORD error = GetLastError();
-    if (error != NO_ERROR)
-      FMT_THROW(windows_error(GetLastError(), "cannot get file size"));
-  }
-  unsigned long long long_size = size_upper;
-  return (long_size << sizeof(DWORD) * CHAR_BIT) | size_lower;
-#else
-  typedef struct stat Stat;
-  Stat file_stat = Stat();
-  if (FMT_POSIX_CALL(fstat(fd_, &file_stat)) == -1)
-    FMT_THROW(system_error(errno, "cannot get file attributes"));
-  static_assert(sizeof(long long) >= sizeof(file_stat.st_size),
-      "return type of file::size is not large enough");
-  return file_stat.st_size;
-#endif
-}
-
-std::size_t file::read(void *buffer, std::size_t count) {
-  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 internal::to_unsigned(result);
-}
-
-std::size_t file::write(const void *buffer, std::size_t count) {
-  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 internal::to_unsigned(result);
-}
-
-file file::dup(int fd) {
-  // Don't retry as dup doesn't return EINTR.
-  // http://pubs.opengroup.org/onlinepubs/009695399/functions/dup.html
-  int new_fd = FMT_POSIX_CALL(dup(fd));
-  if (new_fd == -1)
-    FMT_THROW(system_error(errno, "cannot duplicate file descriptor {}", fd));
-  return file(new_fd);
-}
-
-void file::dup2(int fd) {
-  int result = 0;
-  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
-  if (result == -1) {
-    FMT_THROW(system_error(errno,
-      "cannot duplicate file descriptor {} to {}", fd_, fd));
-  }
-}
-
-void file::dup2(int fd, error_code &ec) FMT_NOEXCEPT {
-  int result = 0;
-  FMT_RETRY(result, FMT_POSIX_CALL(dup2(fd_, fd)));
-  if (result == -1)
-    ec = error_code(errno);
-}
-
-void file::pipe(file &read_end, file &write_end) {
-  // Close the descriptors first to make sure that assignments don't throw
-  // and there are no leaks.
-  read_end.close();
-  write_end.close();
-  int fds[2] = {};
-#ifdef _WIN32
-  // Make the default pipe capacity same as on Linux 2.6.11+.
-  enum { DEFAULT_CAPACITY = 65536 };
-  int result = FMT_POSIX_CALL(pipe(fds, DEFAULT_CAPACITY, _O_BINARY));
-#else
-  // Don't retry as the pipe function doesn't return EINTR.
-  // http://pubs.opengroup.org/onlinepubs/009696799/functions/pipe.html
-  int result = FMT_POSIX_CALL(pipe(fds));
-#endif
-  if (result != 0)
-    FMT_THROW(system_error(errno, "cannot create pipe"));
-  // The following assignments don't throw because read_fd and write_fd
-  // are closed.
-  read_end = file(fds[0]);
-  write_end = file(fds[1]);
-}
-
-buffered_file file::fdopen(const char *mode) {
-  // Don't retry as fdopen doesn't return EINTR.
-  FILE *f = FMT_POSIX_CALL(fdopen(fd_, mode));
-  if (!f)
-    FMT_THROW(system_error(errno,
-                           "cannot associate stream with file descriptor"));
-  buffered_file bf(f);
-  fd_ = -1;
-  return bf;
-}
-
-long getpagesize() {
-#ifdef _WIN32
-  SYSTEM_INFO si;
-  GetSystemInfo(&si);
-  return si.dwPageSize;
-#else
-  long size = FMT_POSIX_CALL(sysconf(_SC_PAGESIZE));
-  if (size < 0)
-    FMT_THROW(system_error(errno, "cannot get memory page size"));
-  return size;
-#endif
-}
-FMT_END_NAMESPACE
-

support/AndroidManifest.xml

@@ -1 +1 @@
-<manifest package="fmt" />
+<manifest package="net.fmtlib" />

support/README

@@ -2,5 +2,3 @@ This directory contains build support files such as
 
 * CMake modules
 * Build scripts
-* qmake (static build with dynamic libc only)
-

support/Vagrantfile

@@ -0,0 +1,20 @@
+# -*- mode: ruby -*-
+# vi: set ft=ruby :
+
+# A vagrant config for testing against gcc-4.8.
+Vagrant.configure("2") do |config|
+  config.vm.box = "ubuntu/xenial64"
+  config.disksize.size = '15GB'
+
+  config.vm.provider "virtualbox" do |vb|
+    vb.memory = "4096"
+  end
+
+  config.vm.provision "shell", inline: <<-SHELL
+    apt-get update
+    apt-get install -y g++ make wget git
+    wget -q https://github.com/Kitware/CMake/releases/download/v3.14.4/cmake-3.14.4-Linux-x86_64.tar.gz
+    tar xzf cmake-3.14.4-Linux-x86_64.tar.gz
+    ln -s `pwd`/cmake-3.14.4-Linux-x86_64/bin/cmake /usr/local/bin
+  SHELL
+end

support/appveyor-build.py

@@ -23,14 +23,17 @@ else:
     # Add MSBuild 14.0 to PATH as described in
     # http://help.appveyor.com/discussions/problems/2229-v140-not-found-on-vs2105rc.
     os.environ['PATH'] = r'C:\Program Files (x86)\MSBuild\15.0\Bin;' + path
-    if image == 'Visual Studio 2013':
-        generator = 'Visual Studio 12 2013'
-    elif image == 'Visual Studio 2015':
-        generator = 'Visual Studio 14 2015'
-    elif image == 'Visual Studio 2017':
-        generator = 'Visual Studio 15 2017'
-    if platform == 'x64':
-        generator += ' Win64'
+    if image == 'Visual Studio 2019':
+        generator = 'Visual Studio 16 2019'
+        if platform == 'x64':
+            cmake_command.extend(['-A', 'x64'])
+    else:
+        if image == 'Visual Studio 2015':
+            generator = 'Visual Studio 14 2015'
+        elif image == 'Visual Studio 2017':
+            generator = 'Visual Studio 15 2017'
+        if platform == 'x64':
+            generator += ' Win64'
     cmake_command.append('-G' + generator)
     build_command = ['cmake', '--build', '.', '--config', config, '--', '/m:4']
     test_command = ['ctest', '-C', config]

support/appveyor.yml

@@ -4,14 +4,11 @@ configuration:
 
 clone_depth: 1
 
-platform:
-  - Win32
-  - x64
-
 image:
-  - Visual Studio 2013
   - Visual Studio 2015
-  - Visual Studio 2017
+
+platform:
+  - x64
 
 environment:
   CTEST_OUTPUT_ON_FAILURE: 1

support/bazel/.bazelrc

@@ -0,0 +1 @@
+build --symlink_prefix=/ # Out of source build

support/bazel/.bazelversion

@@ -0,0 +1 @@
+5.1.1

support/bazel/BUILD.bazel

@@ -0,0 +1,28 @@
+cc_library(
+    name = "fmt",
+    srcs = [
+        #"src/fmt.cc", # No C++ module support
+        "src/format.cc",
+        "src/os.cc",
+    ],
+    hdrs = [
+        "include/fmt/args.h",
+        "include/fmt/chrono.h",
+        "include/fmt/color.h",
+        "include/fmt/compile.h",
+        "include/fmt/core.h",
+        "include/fmt/format-inl.h",
+        "include/fmt/format.h",
+        "include/fmt/os.h",
+        "include/fmt/ostream.h",
+        "include/fmt/printf.h",
+        "include/fmt/ranges.h",
+        "include/fmt/std.h",
+        "include/fmt/xchar.h",
+    ],
+    includes = [
+        "include",        
+    ],
+    strip_include_prefix = "include",
+    visibility = ["//visibility:public"],
+)

support/bazel/README.md

@@ -0,0 +1,73 @@
+# Bazel support
+
+To get [Bazel](https://bazel.build/) working with {fmt} you can copy the files `BUILD.bazel`, `WORKSPACE.bazel`, `.bazelrc`, and `.bazelversion` from this folder (`support/bazel`) to the root folder of this project. This way {fmt} gets bazelized and can be used with Bazel (e.g. doing a `bazel build //...` on {fmt}). 
+
+## Using {fmt} as a dependency
+
+The following minimal example shows how to use {fmt} as a dependency within a Bazel project.
+
+The following file structure is assumed:
+
+```
+example
+├── BUILD.bazel
+├── main.cpp
+└── WORKSPACE.bazel
+```
+
+*main.cpp*:
+
+```c++
+#include "fmt/core.h"
+
+int main() {
+  fmt::print("The answer is {}\n", 42);
+}
+```
+
+The expected output of this example is `The answer is 42`.
+
+*WORKSPACE.bazel*:
+
+```python
+load("@bazel_tools//tools/build_defs/repo:git.bzl", "git_repository")
+
+git_repository(
+    name = "fmt",
+    branch = "master",
+    remote = "https://github.com/fmtlib/fmt",
+    patch_cmds = [
+        "mv support/bazel/.bazelrc .bazelrc",
+        "mv support/bazel/.bazelversion .bazelversion",
+        "mv support/bazel/BUILD.bazel BUILD.bazel",
+        "mv support/bazel/WORKSPACE.bazel WORKSPACE.bazel",
+    ],
+    # Windows-related patch commands are only needed in the case MSYS2 is not installed.
+    # More details about the installation process of MSYS2 on Windows systems can be found here:
+    # https://docs.bazel.build/versions/main/install-windows.html#installing-compilers-and-language-runtimes
+    # Even if MSYS2 is installed the Windows related patch commands can still be used.
+    patch_cmds_win = [
+        "Move-Item -Path support/bazel/.bazelrc -Destination .bazelrc",
+        "Move-Item -Path support/bazel/.bazelversion -Destination .bazelversion",
+        "Move-Item -Path support/bazel/BUILD.bazel -Destination BUILD.bazel",
+        "Move-Item -Path support/bazel/WORKSPACE.bazel -Destination WORKSPACE.bazel",
+    ],
+)
+```
+
+In the *WORKSPACE* file, the {fmt} GitHub repository is fetched. Using the attribute `patch_cmds` the  files `BUILD.bazel`, `WORKSPACE.bazel`, `.bazelrc`, and `.bazelversion` are moved to the root of the {fmt} repository. This way the {fmt} repository is recognized as a bazelized workspace. 
+
+*BUILD.bazel*:
+
+```python
+cc_binary(
+    name = "Demo",
+    srcs = ["main.cpp"],
+    deps = ["@fmt"],
+)
+```
+
+The *BUILD* file defines a binary named `Demo` that has a dependency to {fmt}.
+
+To execute the binary you can run `bazel run //:Demo`.
+

support/bazel/WORKSPACE.bazel

@@ -0,0 +1 @@
+workspace(name = "fmt")

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

@@ -1,18 +1,32 @@
+import java.nio.file.Paths
+
 // General gradle arguments for root project
 buildscript {    
     repositories {
         google()
         jcenter()
     }
-
     dependencies {
-        classpath 'com.android.tools.build:gradle:3.0.1'
+        //
+        // https://developer.android.com/studio/releases/gradle-plugin#updating-gradle
+        //
+        // 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
+        //
+        classpath "com.android.tools.build:gradle:4.1.1"
     }
 }
+repositories {
+    google()
+    jcenter()
+}
+
+// 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'
-
+apply plugin: "com.android.library"
 android {
     compileSdkVersion 25    // Android 7.0
 
@@ -24,21 +38,18 @@ android {
     splits {
         abi {
             enable true
-            // Be general, as much as possible ...
-            // universalApk true 
-
             // Specify platforms for Application
             reset()
-            include "x86", "x86_64", "armeabi-v7a", "arm64-v8a"
+            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 16      // Follow release count
-        versionName "4.1.0" // Follow Official version
-        testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
+        versionCode 34      // Follow release count
+        versionName "7.1.2" // Follow Official version
         
         externalNativeBuild {
             cmake {
@@ -46,10 +57,10 @@ android {
                 arguments "-DBUILD_SHARED_LIBS=true"    // Build shared object
                 arguments "-DFMT_TEST=false"            // Skip test
                 arguments "-DFMT_DOC=false"             // Skip document
-                cppFlags  "-std=c++14"
+                cppFlags  "-std=c++17"
+                targets   "fmt"
             }
         }
-        println("Gradle CMake Plugin: ")
         println(externalNativeBuild.cmake.cppFlags)
         println(externalNativeBuild.cmake.arguments)
     }
@@ -60,16 +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 "${rootDir}/include"
         }
     }
 }
@@ -79,20 +101,32 @@ assemble.doLast
     // Instead of `ninja install`, Gradle will deploy the files.
     // We are doing this since FMT is dependent to the ANDROID_STL after build
     copy {
-        from 'build/intermediates/cmake'
-        into '../libs'
+        from "build/intermediates/cmake"
+        into "${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/cmake/JoinPaths.cmake

@@ -0,0 +1,26 @@
+# This module provides function for joining paths
+# known from from most languages
+#
+# Original license:
+# SPDX-License-Identifier: (MIT OR CC0-1.0)
+# Explicit permission given to distribute this module under
+# the terms of the project as described in /LICENSE.rst.
+# Copyright 2020 Jan Tojnar
+# https://github.com/jtojnar/cmake-snips
+#
+# Modelled after Python’s os.path.join
+# https://docs.python.org/3.7/library/os.path.html#os.path.join
+# Windows not supported
+function(join_paths joined_path first_path_segment)
+    set(temp_path "${first_path_segment}")
+    foreach(current_segment IN LISTS ARGN)
+        if(NOT ("${current_segment}" STREQUAL ""))
+            if(IS_ABSOLUTE "${current_segment}")
+                set(temp_path "${current_segment}")
+            else()
+                set(temp_path "${temp_path}/${current_segment}")
+            endif()
+        endif()
+    endforeach()
+    set(${joined_path} "${temp_path}" PARENT_SCOPE)
+endfunction()

support/cmake/cxx14.cmake

@@ -1,7 +1,11 @@
 # C++14 feature support detection
 
-include(CheckCXXSourceCompiles)
 include(CheckCXXCompilerFlag)
+function (fmt_check_cxx_compiler_flag flag result)
+  if (NOT MSVC)
+    check_cxx_compiler_flag("${flag}" ${result})
+  endif ()
+endfunction ()
 
 if (NOT CMAKE_CXX_STANDARD)
   set(CMAKE_CXX_STANDARD 11)
@@ -9,35 +13,38 @@ endif()
 message(STATUS "CXX_STANDARD: ${CMAKE_CXX_STANDARD}")
 
 if (CMAKE_CXX_STANDARD EQUAL 20)
-  check_cxx_compiler_flag(-std=c++20 has_std_20_flag)
-  check_cxx_compiler_flag(-std=c++2a has_std_2a_flag)
+  fmt_check_cxx_compiler_flag(-std=c++20 has_std_20_flag)
+  fmt_check_cxx_compiler_flag(-std=c++2a has_std_2a_flag)
 
   if (has_std_20_flag)
     set(CXX_STANDARD_FLAG -std=c++20)
   elseif (has_std_2a_flag)
     set(CXX_STANDARD_FLAG -std=c++2a)
   endif ()
+
 elseif (CMAKE_CXX_STANDARD EQUAL 17)
-  check_cxx_compiler_flag(-std=c++17 has_std_17_flag)
-  check_cxx_compiler_flag(-std=c++1z has_std_1z_flag)
+  fmt_check_cxx_compiler_flag(-std=c++17 has_std_17_flag)
+  fmt_check_cxx_compiler_flag(-std=c++1z has_std_1z_flag)
 
   if (has_std_17_flag)
     set(CXX_STANDARD_FLAG -std=c++17)
   elseif (has_std_1z_flag)
     set(CXX_STANDARD_FLAG -std=c++1z)
   endif ()
+
 elseif (CMAKE_CXX_STANDARD EQUAL 14)
-  check_cxx_compiler_flag(-std=c++14 has_std_14_flag)
-  check_cxx_compiler_flag(-std=c++1y has_std_1y_flag)
+  fmt_check_cxx_compiler_flag(-std=c++14 has_std_14_flag)
+  fmt_check_cxx_compiler_flag(-std=c++1y has_std_1y_flag)
 
   if (has_std_14_flag)
     set(CXX_STANDARD_FLAG -std=c++14)
   elseif (has_std_1y_flag)
     set(CXX_STANDARD_FLAG -std=c++1y)
   endif ()
+
 elseif (CMAKE_CXX_STANDARD EQUAL 11)
-  check_cxx_compiler_flag(-std=c++11 has_std_11_flag)
-  check_cxx_compiler_flag(-std=c++0x has_std_0x_flag)
+  fmt_check_cxx_compiler_flag(-std=c++11 has_std_11_flag)
+  fmt_check_cxx_compiler_flag(-std=c++0x has_std_0x_flag)
 
   if (has_std_11_flag)
     set(CXX_STANDARD_FLAG -std=c++11)
@@ -45,53 +52,3 @@ elseif (CMAKE_CXX_STANDARD EQUAL 11)
     set(CXX_STANDARD_FLAG -std=c++0x)
   endif ()
 endif ()
-
-set(CMAKE_REQUIRED_FLAGS ${CXX_STANDARD_FLAG})
-
-# Check if variadic templates are working and not affected by GCC bug 39653:
-# https://gcc.gnu.org/bugzilla/show_bug.cgi?id=39653
-check_cxx_source_compiles("
-  template <class T, class ...Types>
-  struct S { typedef typename S<Types...>::type type; };
-  int main() {}" SUPPORTS_VARIADIC_TEMPLATES)
-if (NOT SUPPORTS_VARIADIC_TEMPLATES)
-  set (SUPPORTS_VARIADIC_TEMPLATES OFF)
-endif ()
-
-# Check if initializer lists are supported.
-check_cxx_source_compiles("
-  #include <initializer_list>
-  int main() {}" SUPPORTS_INITIALIZER_LIST)
-if (NOT SUPPORTS_INITIALIZER_LIST)
-  set (SUPPORTS_INITIALIZER_LIST OFF)
-endif ()
-
-# Check if enum bases are available
-check_cxx_source_compiles("
-  enum C : char {A};
-  int main() {}"
-  SUPPORTS_ENUM_BASE)
-if (NOT SUPPORTS_ENUM_BASE)
-  set (SUPPORTS_ENUM_BASE OFF)
-endif ()
-
-# Check if type traits are available
-check_cxx_source_compiles("
-  #include <type_traits>
-  class C { void operator=(const C&); };
-  int main() { static_assert(!std::is_copy_assignable<C>::value, \"\"); }"
-  SUPPORTS_TYPE_TRAITS)
-if (NOT SUPPORTS_TYPE_TRAITS)
-  set (SUPPORTS_TYPE_TRAITS OFF)
-endif ()
-
-# Check if user-defined literals are available
-check_cxx_source_compiles("
-  void operator\"\" _udl(long double);
-  int main() {}"
-  SUPPORTS_USER_DEFINED_LITERALS)
-if (NOT SUPPORTS_USER_DEFINED_LITERALS)
-  set (SUPPORTS_USER_DEFINED_LITERALS OFF)
-endif ()
-
-set(CMAKE_REQUIRED_FLAGS )

support/cmake/fmt-config.cmake.in

@@ -1,4 +1,7 @@
 @PACKAGE_INIT@
 
-include(${CMAKE_CURRENT_LIST_DIR}/@targets_export_name@.cmake)
+if (NOT TARGET fmt::fmt)
+  include(${CMAKE_CURRENT_LIST_DIR}/@targets_export_name@.cmake)
+endif ()
+
 check_required_components(fmt)

support/cmake/fmt.pc.in

@@ -0,0 +1,11 @@
+prefix=@CMAKE_INSTALL_PREFIX@
+exec_prefix=@CMAKE_INSTALL_PREFIX@
+libdir=@libdir_for_pc_file@
+includedir=@includedir_for_pc_file@
+
+Name: fmt
+Description: A modern formatting library
+Version: @FMT_VERSION@
+Libs: -L${libdir} -l@FMT_LIB_NAME@
+Cflags: -I${includedir}
+

support/cmake/run-cmake.bat

@@ -1,11 +0,0 @@
-@echo on
-rem This scripts configures build environment and runs CMake.
-rem Use it instead of running CMake directly when building with
-rem the Microsoft SDK toolchain rather than Visual Studio.
-rem It is used in the same way as cmake, for example:
-rem
-rem   run-cmake -G "Visual Studio 10 Win64" .
-
-for /F "delims=" %%i IN ('cmake "-DPRINT_PATH=1" -P %~dp0/FindSetEnv.cmake') DO set setenv=%%i
-if NOT "%setenv%" == "" call "%setenv%"
-cmake %*

support/fmt.pro

@@ -1,27 +0,0 @@
-# Staticlib configuration for qmake builds
-# For some reason qmake 3.1 fails to identify source dependencies and excludes format.cc and printf.cc
-# from compilation so it _MUST_ be called as qmake -nodepend
-# A workaround is implemented below: a custom compiler is defined which does not track dependencies
-
-TEMPLATE = lib
-
-TARGET = fmt
-
-QMAKE_EXT_CPP = .cc
-
-CONFIG = staticlib warn_on c++11
-
-FMT_SOURCES = \
-    ../src/format.cc \
-    ../src/posix.cc
-
-fmt.name = libfmt
-fmt.input = FMT_SOURCES
-fmt.output = ${QMAKE_FILE_BASE}$$QMAKE_EXT_OBJ
-fmt.clean = ${QMAKE_FILE_BASE}$$QMAKE_EXT_OBJ
-fmt.depends = ${QMAKE_FILE_IN}
-# QMAKE_RUN_CXX will not be expanded
-fmt.commands = $$QMAKE_CXX -c $$QMAKE_CXXFLAGS $$QMAKE_CXXFLAGS_WARN_ON $$QMAKE_CXXFLAGS_RELEASE_WITH_DEBUGINFO $$QMAKE_CXXFLAGS_CXX11 ${QMAKE_FILE_IN}
-fmt.variable_out = OBJECTS
-fmt.CONFIG = no_dependencies no_link
-QMAKE_EXTRA_COMPILERS += fmt

support/manage.py

@@ -1,10 +1,13 @@
-#!/usr/bin/env python
+#!/usr/bin/env python3
 
 """Manage site and releases.
 
 Usage:
   manage.py release [<branch>]
   manage.py site
+
+For the release command $FMT_TOKEN should contain a GitHub personal access token
+obtained from https://github.com/settings/tokens.
 """
 
 from __future__ import print_function
@@ -134,14 +137,47 @@ def update_site(env):
         if not os.path.exists(contents):
             os.rename(os.path.join(target_doc_dir, 'index.rst'), contents)
         # Fix issues in reference.rst/api.rst.
-        for filename in ['reference.rst', 'api.rst']:
+        for filename in ['reference.rst', 'api.rst', 'index.rst']:
             pattern = re.compile('doxygenfunction.. (bin|oct|hexu|hex)$', re.M)
             with rewrite(os.path.join(target_doc_dir, filename)) as b:
                 b.data = b.data.replace('std::ostream &', 'std::ostream&')
                 b.data = re.sub(pattern, r'doxygenfunction:: \1(int)', b.data)
                 b.data = b.data.replace('std::FILE*', 'std::FILE *')
                 b.data = b.data.replace('unsigned int', 'unsigned')
-                b.data = b.data.replace('operator""_', 'operator"" _')
+                #b.data = b.data.replace('operator""_', 'operator"" _')
+                b.data = b.data.replace(
+                    'format_to_n(OutputIt, size_t, string_view, Args&&',
+                    'format_to_n(OutputIt, size_t, const S&, const Args&')
+                b.data = b.data.replace(
+                    'format_to_n(OutputIt, std::size_t, string_view, Args&&',
+                    'format_to_n(OutputIt, std::size_t, const S&, const Args&')
+                if version == ('3.0.2'):
+                    b.data = b.data.replace(
+                        'fprintf(std::ostream&', 'fprintf(std::ostream &')
+                if version == ('5.3.0'):
+                    b.data = b.data.replace(
+                        'format_to(OutputIt, const S&, const Args&...)',
+                        'format_to(OutputIt, const S &, const Args &...)')
+                if version.startswith('5.') or version.startswith('6.'):
+                    b.data = b.data.replace(', size_t', ', std::size_t')
+                if version.startswith('7.'):
+                    b.data = b.data.replace(', std::size_t', ', size_t')
+                    b.data = b.data.replace('join(It, It', 'join(It, Sentinel')
+                if version.startswith('7.1.'):
+                    b.data = b.data.replace(', std::size_t', ', size_t')
+                    b.data = b.data.replace('join(It, It', 'join(It, Sentinel')
+                    b.data = b.data.replace(
+                        'fmt::format_to(OutputIt, const S&, Args&&...)',
+                        'fmt::format_to(OutputIt, const S&, Args&&...) -> ' +
+                        'typename std::enable_if<enable, OutputIt>::type')
+                b.data = b.data.replace('aa long', 'a long')
+                b.data = b.data.replace('serveral', 'several')
+                if version.startswith('6.2.'):
+                    b.data = b.data.replace(
+                        'vformat(const S&, basic_format_args<' +
+                        'buffer_context<Char>>)',
+                        'vformat(const S&, basic_format_args<' +
+                        'buffer_context<type_identity_t<Char>>>)')
         # Fix a broken link in index.rst.
         index = os.path.join(target_doc_dir, 'index.rst')
         with rewrite(index) as b:
@@ -204,7 +240,7 @@ def release(args):
     # Update the version in the changelog.
     title_len = 0
     for line in fileinput.input(changelog_path, inplace=True):
-        if line.decode('utf-8').startswith(version + ' - TBD'):
+        if line.startswith(version + ' - TBD'):
             line = version + ' - ' + datetime.date.today().isoformat()
             title_len = len(line)
             line += '\n'
@@ -234,9 +270,9 @@ def release(args):
 
     # Create a release on GitHub.
     fmt_repo.push('origin', 'release')
-    params = {'access_token': os.getenv('FMT_TOKEN')}
+    auth_headers = {'Authorization': 'token ' + os.getenv('FMT_TOKEN')}
     r = requests.post('https://api.github.com/repos/fmtlib/fmt/releases',
-                      params=params,
+                      headers=auth_headers,
                       data=json.dumps({'tag_name': version,
                                        'target_commitish': 'release',
                                        'body': changes, 'draft': True}))
@@ -247,8 +283,8 @@ def release(args):
     package = 'fmt-{}.zip'.format(version)
     r = requests.post(
         '{}/{}/assets?name={}'.format(uploads_url, id, package),
-        headers={'Content-Type': 'application/zip'},
-        params=params, data=open('build/fmt/' + package, 'rb'))
+        headers={'Content-Type': 'application/zip'} | auth_headers,
+        data=open('build/fmt/' + package, 'rb'))
     if r.status_code != 201:
         raise Exception('Failed to upload an asset ' + str(r))
 

support/printable.py

@@ -0,0 +1,201 @@
+#!/usr/bin/env python3
+
+# This script is based on
+# https://github.com/rust-lang/rust/blob/master/library/core/src/unicode/printable.py
+# distributed under https://github.com/rust-lang/rust/blob/master/LICENSE-MIT.
+
+# This script uses the following Unicode tables:
+# - UnicodeData.txt
+
+
+from collections import namedtuple
+import csv
+import os
+import subprocess
+
+NUM_CODEPOINTS=0x110000
+
+def to_ranges(iter):
+    current = None
+    for i in iter:
+        if current is None or i != current[1] or i in (0x10000, 0x20000):
+            if current is not None:
+                yield tuple(current)
+            current = [i, i + 1]
+        else:
+            current[1] += 1
+    if current is not None:
+        yield tuple(current)
+
+def get_escaped(codepoints):
+    for c in codepoints:
+        if (c.class_ or "Cn") in "Cc Cf Cs Co Cn Zl Zp Zs".split() and c.value != ord(' '):
+            yield c.value
+
+def get_file(f):
+    try:
+        return open(os.path.basename(f))
+    except FileNotFoundError:
+        subprocess.run(["curl", "-O", f], check=True)
+        return open(os.path.basename(f))
+
+Codepoint = namedtuple('Codepoint', 'value class_')
+
+def get_codepoints(f):
+    r = csv.reader(f, delimiter=";")
+    prev_codepoint = 0
+    class_first = None
+    for row in r:
+        codepoint = int(row[0], 16)
+        name = row[1]
+        class_ = row[2]
+
+        if class_first is not None:
+            if not name.endswith("Last>"):
+                raise ValueError("Missing Last after First")
+
+        for c in range(prev_codepoint + 1, codepoint):
+            yield Codepoint(c, class_first)
+
+        class_first = None
+        if name.endswith("First>"):
+            class_first = class_
+
+        yield Codepoint(codepoint, class_)
+        prev_codepoint = codepoint
+
+    if class_first is not None:
+        raise ValueError("Missing Last after First")
+
+    for c in range(prev_codepoint + 1, NUM_CODEPOINTS):
+        yield Codepoint(c, None)
+
+def compress_singletons(singletons):
+    uppers = [] # (upper, # items in lowers)
+    lowers = []
+
+    for i in singletons:
+        upper = i >> 8
+        lower = i & 0xff
+        if len(uppers) == 0 or uppers[-1][0] != upper:
+            uppers.append((upper, 1))
+        else:
+            upper, count = uppers[-1]
+            uppers[-1] = upper, count + 1
+        lowers.append(lower)
+
+    return uppers, lowers
+
+def compress_normal(normal):
+    # lengths 0x00..0x7f are encoded as 00, 01, ..., 7e, 7f
+    # lengths 0x80..0x7fff are encoded as 80 80, 80 81, ..., ff fe, ff ff
+    compressed = [] # [truelen, (truelenaux), falselen, (falselenaux)]
+
+    prev_start = 0
+    for start, count in normal:
+        truelen = start - prev_start
+        falselen = count
+        prev_start = start + count
+
+        assert truelen < 0x8000 and falselen < 0x8000
+        entry = []
+        if truelen > 0x7f:
+            entry.append(0x80 | (truelen >> 8))
+            entry.append(truelen & 0xff)
+        else:
+            entry.append(truelen & 0x7f)
+        if falselen > 0x7f:
+            entry.append(0x80 | (falselen >> 8))
+            entry.append(falselen & 0xff)
+        else:
+            entry.append(falselen & 0x7f)
+
+        compressed.append(entry)
+
+    return compressed
+
+def print_singletons(uppers, lowers, uppersname, lowersname):
+    print("  static constexpr singleton {}[] = {{".format(uppersname))
+    for u, c in uppers:
+        print("    {{{:#04x}, {}}},".format(u, c))
+    print("  };")
+    print("  static constexpr unsigned char {}[] = {{".format(lowersname))
+    for i in range(0, len(lowers), 8):
+        print("    {}".format(" ".join("{:#04x},".format(l) for l in lowers[i:i+8])))
+    print("  };")
+
+def print_normal(normal, normalname):
+    print("  static constexpr unsigned char {}[] = {{".format(normalname))
+    for v in normal:
+        print("    {}".format(" ".join("{:#04x},".format(i) for i in v)))
+    print("  };")
+
+def main():
+    file = get_file("https://www.unicode.org/Public/UNIDATA/UnicodeData.txt")
+
+    codepoints = get_codepoints(file)
+
+    CUTOFF=0x10000
+    singletons0 = []
+    singletons1 = []
+    normal0 = []
+    normal1 = []
+    extra = []
+
+    for a, b in to_ranges(get_escaped(codepoints)):
+        if a > 2 * CUTOFF:
+            extra.append((a, b - a))
+        elif a == b - 1:
+            if a & CUTOFF:
+                singletons1.append(a & ~CUTOFF)
+            else:
+                singletons0.append(a)
+        elif a == b - 2:
+            if a & CUTOFF:
+                singletons1.append(a & ~CUTOFF)
+                singletons1.append((a + 1) & ~CUTOFF)
+            else:
+                singletons0.append(a)
+                singletons0.append(a + 1)
+        else:
+            if a >= 2 * CUTOFF:
+                extra.append((a, b - a))
+            elif a & CUTOFF:
+                normal1.append((a & ~CUTOFF, b - a))
+            else:
+                normal0.append((a, b - a))
+
+    singletons0u, singletons0l = compress_singletons(singletons0)
+    singletons1u, singletons1l = compress_singletons(singletons1)
+    normal0 = compress_normal(normal0)
+    normal1 = compress_normal(normal1)
+
+    print("""\
+FMT_FUNC auto is_printable(uint32_t cp) -> bool {\
+""")
+    print_singletons(singletons0u, singletons0l, 'singletons0', 'singletons0_lower')
+    print_singletons(singletons1u, singletons1l, 'singletons1', 'singletons1_lower')
+    print_normal(normal0, 'normal0')
+    print_normal(normal1, 'normal1')
+    print("""\
+  auto lower = static_cast<uint16_t>(cp);
+  if (cp < 0x10000) {
+    return is_printable(lower, singletons0,
+                        sizeof(singletons0) / sizeof(*singletons0),
+                        singletons0_lower, normal0, sizeof(normal0));
+  }
+  if (cp < 0x20000) {
+    return is_printable(lower, singletons1,
+                        sizeof(singletons1) / sizeof(*singletons1),
+                        singletons1_lower, normal1, sizeof(normal1));
+  }\
+""")
+    for a, b in extra:
+        print("  if (0x{:x} <= cp && cp < 0x{:x}) return false;".format(a, a + b))
+    print("""\
+  return cp < 0x{:x};
+}}\
+""".format(NUM_CODEPOINTS))
+
+if __name__ == '__main__':
+    main()

support/rst2md.py

@@ -1,6 +1,7 @@
+#!/usr/bin/env python
 # reStructuredText (RST) to GitHub-flavored Markdown converter
 
-import re
+import re, sys
 from docutils import core, nodes, writers
 
 
@@ -35,6 +36,9 @@ class Translator(nodes.NodeVisitor):
         self.version = re.match(r'(\d+\.\d+\.\d+).*', node.children[0]).group(1)
         raise nodes.SkipChildren
 
+    def visit_title_reference(self, node):
+        raise Exception(node)
+
     def depart_title(self, node):
         pass
 
@@ -61,7 +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
@@ -109,6 +113,30 @@ class Translator(nodes.NodeVisitor):
     def depart_image(self, node):
         pass
 
+    def write_row(self, row, widths):
+        for i, entry in enumerate(row):
+            text = entry[0][0] if len(entry) > 0 else ''
+            if i != 0:
+                self.write('|')
+            self.write('{:{}}'.format(text, widths[i]))
+        self.write('\n')
+
+    def visit_table(self, node):
+        table = node.children[0]
+        colspecs = table[:-2]
+        thead = table[-2]
+        tbody = table[-1]
+        widths = [int(cs['colwidth']) for cs in colspecs]
+        sep = '|'.join(['-' * w for w in widths]) + '\n'
+        self.write('\n\n')
+        self.write_row(thead[0], widths)
+        self.write(sep)
+        for row in tbody:
+            self.write_row(row, widths)
+        raise nodes.SkipChildren
+
+    def depart_table(self, node):
+        pass
 
 class MDWriter(writers.Writer):
     """GitHub-flavored markdown writer"""
@@ -125,3 +153,7 @@ class MDWriter(writers.Writer):
 def convert(rst_path):
     """Converts RST file to Markdown."""
     return core.publish_file(source_path=rst_path, writer=MDWriter())
+
+
+if __name__ == '__main__':
+    convert(sys.argv[1])

support/rtd/index.rst

@@ -1,2 +1,2 @@
 If you are not redirected automatically, follow the
-`link to the fmt documentation <http://fmtlib.net/latest/>`_.
+`link to the fmt documentation <https://fmt.dev/latest/>`_.

support/rtd/theme/layout.html

@@ -2,15 +2,15 @@
 
 {% block extrahead %}
 <meta charset="UTF-8">
-<meta http-equiv="refresh" content="1;url=http://fmtlib.net/latest/">
+<meta http-equiv="refresh" content="1;url=https://fmt.dev/latest/">
 <script type="text/javascript">
-    window.location.href = "http://fmtlib.net/latest/"
+    window.location.href = "https://fmt.dev/latest/"
 </script>
 <title>Page Redirection</title>
 {% endblock %}
 
 {% block document %}
-If you are not redirected automatically, follow the <a href='http://fmtlib.net/latest/'>link to the fmt documentation</a>.
+If you are not redirected automatically, follow the <a href='https://fmt.dev/latest/'>link to the fmt documentation</a>.
 {% endblock %}
 
 {% block footer %}

support/travis-build.py

@@ -1,113 +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 library.
-makedirs_if_not_exist(build_dir)
-cmake_flags = [
-    '-DCMAKE_INSTALL_PREFIX=' + install_dir, '-DCMAKE_BUILD_TYPE=' + build,
-    '-DCMAKE_CXX_STANDARD=' + standard
-]
-check_call(['cmake', '-DFMT_DOC=OFF', '-DFMT_PEDANTIC=ON', '-DFMT_WERROR=ON', fmt_dir] +
-           cmake_flags, cwd=build_dir)
-
-# Build library.
-check_call(['make', '-j4'], cwd=build_dir)
-
-# Test 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 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)

support/update-coverity-branch.py

@@ -1,30 +0,0 @@
-#!/usr/bin/env python
-# Update the coverity branch from the master branch.
-# It is not done automatically because Coverity Scan limits
-# the number of submissions per day.
-
-from __future__ import print_function
-import shutil, tempfile
-from subprocess import check_output, STDOUT
-
-class Git:
-    def __init__(self, dir):
-        self.dir = dir
-
-    def __call__(self, *args):
-        output = check_output(['git'] + list(args), cwd=self.dir, stderr=STDOUT)
-        print(output)
-        return output
-
-dir = tempfile.mkdtemp()
-try:
-    git = Git(dir)
-    git('clone', '-b', 'coverity', 'git@github.com:fmtlib/fmt.git', dir)
-    output = git('merge', '-X', 'theirs', '--no-commit', 'origin/master')
-    if 'Fast-forward' not in output:
-        git('reset', 'HEAD', '.travis.yml')
-        git('checkout', '--', '.travis.yml')
-        git('commit', '-m', 'Update coverity branch')
-    git('push')
-finally:
-    shutil.rmtree(dir)

test/CMakeLists.txt

@@ -1,172 +1,185 @@
-#------------------------------------------------------------------------------
-# 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 ()
-
-if (NOT SUPPORTS_VARIADIC_TEMPLATES OR NOT SUPPORTS_INITIALIZER_LIST)
-  target_compile_definitions(gmock PUBLIC GTEST_LANG_CXX11=0)
-endif ()
-
-# Workaround a bug in implementation of variadic templates in MSVC11.
-if (MSVC)
-  target_compile_definitions(gmock PUBLIC _VARIADIC_MAX=10)
-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=0)
-
-#------------------------------------------------------------------------------
-# 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 ${TEST_MAIN_SRC})
-target_compile_definitions(test-main PUBLIC
-  FMT_USE_FILE_DESCRIPTORS=$<BOOL:${HAVE_OPEN}>)
-target_include_directories(test-main SYSTEM PUBLIC gtest gmock)
-target_link_libraries(test-main gmock fmt)
-
-include(CheckCXXCompilerFlag)
-
-# Workaround GTest bug https://github.com/google/googletest/issues/705.
-check_cxx_compiler_flag(
-  -fno-delete-null-pointer-checks HAVE_FNO_DELETE_NULL_POINTER_CHECKS)
-if (HAVE_FNO_DELETE_NULL_POINTER_CHECKS)
-  target_compile_options(test-main PUBLIC -fno-delete-null-pointer-checks)
-endif ()
-
-# Use less strict pedantic flags for the tests because GMock doesn't compile
-# cleanly with -pedantic and -std=c++98.
-if (CMAKE_COMPILER_IS_GNUCXX OR (CMAKE_CXX_COMPILER_ID MATCHES "Clang"))
-    #set(PEDANTIC_COMPILE_FLAGS -Wall -Wextra -Wno-long-long -Wno-variadic-macros)
-endif ()
+target_include_directories(test-main PUBLIC
+  $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>)
+target_link_libraries(test-main gtest fmt)
 
 function(add_fmt_executable name)
   add_executable(${name} ${ARGN})
   if (MINGW)
     target_link_libraries(${name} -static-libgcc -static-libstdc++)
   endif ()
+  # (Wstringop-overflow) - [meta-bug] bogus/missing -Wstringop-overflow warnings
+  #   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88443
+  # Bogus -Wstringop-overflow warning
+  #   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100395
+  # [10 Regression] spurious -Wstringop-overflow writing to a trailing array plus offset
+  #   https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95353
+  if (CMAKE_CXX_COMPILER_ID MATCHES "GNU" AND
+      NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 7.0)
+    target_link_libraries(${name} -Wno-stringop-overflow)
+  endif ()
 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 ${PEDANTIC_COMPILE_FLAGS} -Wno-weak-vtables)
+    endif ()
+  elseif (ADD_FMT_TEST_MODULE)
+    set(libs gtest test-module)
+    set_source_files_properties(${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.
-  target_compile_definitions(${name} PRIVATE
-    FMT_USE_TYPE_TRAITS=$<BOOL:${SUPPORTS_TYPE_TRAITS}>
-    FMT_USE_ENUM_BASE=$<BOOL:${SUPPORTS_ENUM_BASE}>)
   if (FMT_PEDANTIC)
     target_compile_options(${name} PRIVATE ${PEDANTIC_COMPILE_FLAGS})
   endif ()
-  target_include_directories(${name} SYSTEM PUBLIC gtest gmock)
+  if (FMT_WERROR)
+    target_compile_options(${name} PRIVATE ${WERROR_FLAG})
+  endif ()
   add_test(NAME ${name} COMMAND ${name})
 endfunction()
 
+add_fmt_test(args-test)
 add_fmt_test(assert-test)
-add_fmt_test(core-test mock-allocator.h)
+add_fmt_test(chrono-test)
+add_fmt_test(color-test)
+add_fmt_test(core-test)
 add_fmt_test(gtest-extra-test)
-add_fmt_test(format-test)
-add_fmt_test(format-impl-test)
+add_fmt_test(format-test mock-allocator.h)
+if (MSVC)
+  target_compile_options(format-test PRIVATE /bigobj)
+endif ()
+if (NOT (MSVC AND BUILD_SHARED_LIBS))
+  add_fmt_test(format-impl-test HEADER_ONLY header-only-test.cc)
+endif ()
 add_fmt_test(ostream-test)
+add_fmt_test(compile-test)
+add_fmt_test(compile-fp-test HEADER_ONLY)
+if (MSVC)
+  # Without this option, MSVC returns 199711L for the __cplusplus macro.
+  target_compile_options(compile-fp-test PRIVATE /Zc:__cplusplus)
+endif()
 add_fmt_test(printf-test)
-add_fmt_test(time-test)
-add_fmt_test(custom-formatter-test)
-add_fmt_test(ranges-test)
+add_fmt_test(ranges-test ranges-odr-test.cc)
+add_fmt_test(scan-test)
+add_fmt_test(std-test)
+try_compile(compile_result_unused
+            ${CMAKE_CURRENT_BINARY_DIR}
+            SOURCES ${CMAKE_CURRENT_LIST_DIR}/detect-stdfs.cc
+            OUTPUT_VARIABLE RAWOUTPUT)
+string(REGEX REPLACE ".*libfound \"([^\"]*)\".*" "\\1" STDLIBFS "${RAWOUTPUT}")
+if (STDLIBFS)
+  target_link_libraries(std-test ${STDLIBFS})
+endif ()
+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 (HAVE_OPEN)
+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 test-main.cc)
+  if (MSVC)
+    target_compile_options(test-module PRIVATE /utf-8 /Zc:__cplusplus
+                           /Zc:externConstexpr /Zc:inline)
+    target_compile_options(module-test PRIVATE /utf-8 /Zc:__cplusplus
+                           /Zc:externConstexpr /Zc:inline)
+  endif ()
+endif ()
+
+if (NOT DEFINED MSVC_STATIC_RUNTIME AND MSVC)
+  foreach (flag_var
+			 CMAKE_CXX_FLAGS CMAKE_CXX_FLAGS_DEBUG CMAKE_CXX_FLAGS_RELEASE
+			 CMAKE_CXX_FLAGS_MINSIZEREL CMAKE_CXX_FLAGS_RELWITHDEBINFO)
+	if (${flag_var} MATCHES "^(/|-)(MT|MTd)")
+	  set(MSVC_STATIC_RUNTIME ON)
+	  break()
+	endif()
+  endforeach()
+endif()
+
+if (NOT MSVC_STATIC_RUNTIME)
   add_fmt_executable(posix-mock-test
     posix-mock-test.cc ../src/format.cc ${TEST_MAIN_SRC})
   target_include_directories(
     posix-mock-test PRIVATE ${PROJECT_SOURCE_DIR}/include)
-  target_compile_definitions(posix-mock-test PRIVATE FMT_USE_FILE_DESCRIPTORS=1)
-  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 ()
   add_test(NAME posix-mock-test COMMAND posix-mock-test)
-  add_fmt_test(posix-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 ()
-
-# Test that the library can be compiled with exceptions disabled.
-# -fno-exception is broken in icc: https://github.com/fmtlib/fmt/issues/822.
-if (NOT CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
-  check_cxx_compiler_flag(-fno-exceptions HAVE_FNO_EXCEPTIONS_FLAG)
-endif ()
-if (HAVE_FNO_EXCEPTIONS_FLAG)
-  add_library(noexception-test ../src/format.cc)
-  target_include_directories(
-    noexception-test PRIVATE ${PROJECT_SOURCE_DIR}/include)
-  target_compile_options(noexception-test PRIVATE -fno-exceptions)
-  if (FMT_PEDANTIC)
-    target_compile_options(noexception-test PRIVATE ${PEDANTIC_COMPILE_FLAGS})
-  endif ()
-  target_include_directories(noexception-test SYSTEM PUBLIC gtest gmock)
+  add_fmt_test(os-test)
 endif ()
 
 message(STATUS "FMT_PEDANTIC: ${FMT_PEDANTIC}")
 
 if (FMT_PEDANTIC)
-  # Test that the library compiles without windows.h.
-  if (CMAKE_SYSTEM_NAME STREQUAL "Windows")
-    add_library(no-windows-h-test ../src/format.cc)
+  # Test that the library can be compiled with exceptions disabled.
+  # -fno-exception is broken in icc: https://github.com/fmtlib/fmt/issues/822.
+  if (NOT CMAKE_CXX_COMPILER_ID STREQUAL "Intel")
+    check_cxx_compiler_flag(-fno-exceptions HAVE_FNO_EXCEPTIONS_FLAG)
+  endif ()
+  if (HAVE_FNO_EXCEPTIONS_FLAG)
+    add_library(noexception-test ../src/format.cc noexception-test.cc)
     target_include_directories(
-      no-windows-h-test PRIVATE ${PROJECT_SOURCE_DIR}/include)
-    target_compile_definitions(no-windows-h-test PRIVATE FMT_USE_WINDOWS_H=0)
-    if (FMT_PEDANTIC)
-      target_compile_options(no-windows-h-test PRIVATE ${PEDANTIC_COMPILE_FLAGS})
-    endif ()
-    target_include_directories(no-windows-h-test SYSTEM PUBLIC gtest gmock)
+      noexception-test PRIVATE ${PROJECT_SOURCE_DIR}/include)
+    target_compile_options(noexception-test PRIVATE -fno-exceptions)
+    target_compile_options(noexception-test PRIVATE ${PEDANTIC_COMPILE_FLAGS})
   endif ()
 
-  add_test(compile-test ${CMAKE_CTEST_COMMAND}
+  # Test that the library compiles without locale.
+  add_library(nolocale-test ../src/format.cc)
+  target_include_directories(
+    nolocale-test PRIVATE ${PROJECT_SOURCE_DIR}/include)
+  target_compile_definitions(
+    nolocale-test PRIVATE FMT_STATIC_THOUSANDS_SEPARATOR=1)
+endif ()
+
+# These tests are disabled on Windows because they take too long.
+if (FMT_PEDANTIC AND NOT WIN32)
+  # Test if incorrect API usages produce compilation error.
+  add_test(compile-error-test ${CMAKE_CTEST_COMMAND}
     --build-and-test
-    "${CMAKE_CURRENT_SOURCE_DIR}/compile-test"
-    "${CMAKE_CURRENT_BINARY_DIR}/compile-test"
+    "${CMAKE_CURRENT_SOURCE_DIR}/compile-error-test"
+    "${CMAKE_CURRENT_BINARY_DIR}/compile-error-test"
     --build-generator ${CMAKE_GENERATOR}
     --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}"
     "-DCXX_STANDARD_FLAG=${CXX_STANDARD_FLAG}"
-    "-DPEDANTIC_COMPILE_FLAGS=${PEDANTIC_COMPILE_FLAGS}"
-    "-DSUPPORTS_USER_DEFINED_LITERALS=${SUPPORTS_USER_DEFINED_LITERALS}")
+    "-DFMT_DIR=${CMAKE_SOURCE_DIR}")
 
-  # test if the targets are findable from the build directory
+  # Test if the targets are found from the build directory.
   add_test(find-package-test ${CMAKE_CTEST_COMMAND}
     -C ${CMAKE_BUILD_TYPE}
     --build-and-test
@@ -176,12 +189,13 @@ if (FMT_PEDANTIC)
     --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}"
     "-DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}")
 
-  # test if the targets are findable when add_subdirectory is used
+  # Test if the targets are found when add_subdirectory is used.
   add_test(add-subdirectory-test ${CMAKE_CTEST_COMMAND}
     -C ${CMAKE_BUILD_TYPE}
     --build-and-test
@@ -195,3 +209,38 @@ if (FMT_PEDANTIC)
     "-DPEDANTIC_COMPILE_FLAGS=${PEDANTIC_COMPILE_FLAGS}"
     "-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)
+  if (${CMAKE_VERSION} VERSION_LESS 3.15)
+    find_package(CUDA 9.0)
+  else ()
+    include(CheckLanguage)
+    check_language(CUDA)
+    if (CMAKE_CUDA_COMPILER)
+      enable_language(CUDA OPTIONAL)
+      set(CUDA_FOUND TRUE)
+    endif ()
+  endif ()
+
+  if (CUDA_FOUND)
+    add_subdirectory(cuda-test)
+    add_test(NAME cuda-test COMMAND fmt-in-cuda-test)
+  endif ()
+endif ()

test/add-subdirectory-test/CMakeLists.txt

@@ -1,17 +1,17 @@
-cmake_minimum_required(VERSION 3.1.0)
+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 +1,186 @@
+// 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 <memory>
+
+#include "gtest/gtest.h"
+
+TEST(args_test, basic) {
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+  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.
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+  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) {
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+  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) {
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+  auto s = to_stringable();
+  store.push_back(s);
+  store.push_back(std::cref(s));
+  fmt::vformat("", store);
+}
+
+TEST(args_test, named_int) {
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+  store.push_back(fmt::arg("a1", 42));
+  EXPECT_EQ("42", fmt::vformat("{a1}", store));
+}
+
+TEST(args_test, named_strings) {
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+  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) {
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+  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) {
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+  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) {
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+  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) {
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+  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) {
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+  store.push_back(std::string("foo"));
+  try {
+    store.push_back(copy_throwable());
+  } catch (...) {
+  }
+  EXPECT_EQ(fmt::vformat("{}", store), "foo");
+}
+
+TEST(args_test, move_constructor) {
+  using store_type = fmt::dynamic_format_arg_store<fmt::format_context>;
+  auto store = std::unique_ptr<store_type>(new store_type());
+  store->push_back(42);
+  store->push_back(std::string("foo"));
+  store->push_back(fmt::arg("a1", "foo"));
+  auto moved_store = std::move(*store);
+  store.reset();
+  EXPECT_EQ(fmt::vformat("{} {} {a1}", moved_store), "42 foo foo");
+}

test/assert-test.cc

@@ -1,4 +1,8 @@
-// Formatting library for C++ - assertion tests
+// Formatting library for C++ - FMT_ASSERT test
+//
+// It is a separate test to minimize the number of EXPECT_DEBUG_DEATH checks
+// which are slow on some platforms. In other tests FMT_ASSERT is made to throw
+// an exception which is much faster and easier to check.
 //
 // Copyright (c) 2012 - present, Victor Zverovich
 // All rights reserved.
@@ -6,17 +10,22 @@
 // For the license information refer to format.h.
 
 #include "fmt/core.h"
-#include "gtest.h"
+#include "gtest/gtest.h"
 
+TEST(assert_test, fail) {
 #if GTEST_HAS_DEATH_TEST
-# define EXPECT_DEBUG_DEATH_IF_SUPPORTED(statement, regex) \
-    EXPECT_DEBUG_DEATH(statement, regex)
+  EXPECT_DEBUG_DEATH(FMT_ASSERT(false, "don't panic!"), "don't panic!");
 #else
-# define EXPECT_DEBUG_DEATH_IF_SUPPORTED(statement, regex) \
-    GTEST_UNSUPPORTED_DEATH_TEST_(statement, regex, )
+  fmt::print("warning: death tests are not supported\n");
 #endif
-
-TEST(AssertTest, Fail) {
-  EXPECT_DEBUG_DEATH_IF_SUPPORTED(
-      FMT_ASSERT(false, "don't panic!"), "don't panic!");
+}
+
+TEST(assert_test, dangling_else) {
+  bool test_condition = false;
+  bool executed_else = false;
+  if (test_condition)
+    FMT_ASSERT(true, "");
+  else
+    executed_else = true;
+  EXPECT_TRUE(executed_else);
 }

test/chrono-test.cc

@@ -0,0 +1,632 @@
+// Formatting library for C++ - time formatting tests
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#include "fmt/chrono.h"
+
+#include <ctime>
+#include <vector>
+
+#include "gtest-extra.h"  // EXPECT_THROW_MSG
+#include "util.h"         // get_locale
+
+using fmt::runtime;
+
+using testing::Contains;
+
+auto make_tm() -> std::tm {
+  auto time = std::tm();
+  time.tm_mday = 1;
+  return time;
+}
+
+auto make_hour(int h) -> std::tm {
+  auto time = make_tm();
+  time.tm_hour = h;
+  return time;
+}
+
+auto make_minute(int m) -> std::tm {
+  auto time = make_tm();
+  time.tm_min = m;
+  return time;
+}
+
+auto make_second(int s) -> std::tm {
+  auto time = make_tm();
+  time.tm_sec = s;
+  return time;
+}
+
+std::string system_strftime(const std::string& format, const std::tm* timeptr,
+                            std::locale* locptr = nullptr) {
+  auto loc = locptr ? *locptr : std::locale::classic();
+  auto& facet = std::use_facet<std::time_put<char>>(loc);
+  std::ostringstream os;
+  os.imbue(loc);
+  facet.put(os, os, ' ', timeptr, format.c_str(),
+            format.c_str() + format.size());
+#ifdef _WIN32
+  // Workaround a bug in older versions of Universal CRT.
+  auto str = os.str();
+  if (str == "-0000") str = "+0000";
+  return str;
+#else
+  return os.str();
+#endif
+}
+
+FMT_CONSTEXPR std::tm make_tm(int year, int mon, int mday, int hour, int min,
+                              int sec) {
+  auto tm = std::tm();
+  tm.tm_sec = sec;
+  tm.tm_min = min;
+  tm.tm_hour = hour;
+  tm.tm_mday = mday;
+  tm.tm_mon = mon - 1;
+  tm.tm_year = year - 1900;
+  return tm;
+}
+
+TEST(chrono_test, format_tm) {
+  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(fmt::format("{:%Y}", tm), "2016");
+  EXPECT_EQ(fmt::format("{:%C}", tm), "20");
+  EXPECT_EQ(fmt::format("{:%C%y}", tm), fmt::format("{:%Y}", tm));
+  EXPECT_EQ(fmt::format("{:%e}", tm), "25");
+  EXPECT_EQ(fmt::format("{:%D}", tm), "04/25/16");
+  EXPECT_EQ(fmt::format("{:%F}", tm), "2016-04-25");
+  EXPECT_EQ(fmt::format("{:%T}", tm), "11:22:33");
+
+  // Short year
+  tm.tm_year = 999 - 1900;
+  tm.tm_mon = 0;   // for %G
+  tm.tm_mday = 2;  // for %G
+  tm.tm_wday = 3;  // for %G
+  tm.tm_yday = 1;  // for %G
+  EXPECT_EQ(fmt::format("{:%Y}", tm), "0999");
+  EXPECT_EQ(fmt::format("{:%C%y}", tm), "0999");
+  EXPECT_EQ(fmt::format("{:%G}", tm), "0999");
+
+  tm.tm_year = 27 - 1900;
+  EXPECT_EQ(fmt::format("{:%Y}", tm), "0027");
+  EXPECT_EQ(fmt::format("{:%C%y}", tm), "0027");
+
+  // Overflow year
+  tm.tm_year = 2147483647;
+  EXPECT_EQ(fmt::format("{:%Y}", tm), "2147485547");
+
+  tm.tm_year = -2147483648;
+  EXPECT_EQ(fmt::format("{:%Y}", tm), "-2147481748");
+
+  // for week on the year
+  // https://www.cl.cam.ac.uk/~mgk25/iso-time.html
+  std::vector<std::tm> tm_list = {
+      make_tm(1975, 12, 29, 12, 14, 16),  // W01
+      make_tm(1977, 1, 2, 12, 14, 16),    // W53
+      make_tm(1999, 12, 27, 12, 14, 16),  // W52
+      make_tm(1999, 12, 31, 12, 14, 16),  // W52
+      make_tm(2000, 1, 1, 12, 14, 16),    // W52
+      make_tm(2000, 1, 2, 12, 14, 16),    // W52
+      make_tm(2000, 1, 3, 12, 14, 16)     // W1
+  };
+  const std::string iso_week_spec = "%Y-%m-%d: %G %g %V";
+  for (auto ctm : tm_list) {
+    // Calculate tm_yday, tm_wday, etc.
+    std::time_t t = std::mktime(&ctm);
+    tm = *std::localtime(&t);
+
+    auto fmt_spec = fmt::format("{{:{}}}", iso_week_spec);
+    EXPECT_EQ(system_strftime(iso_week_spec, &tm),
+              fmt::format(fmt::runtime(fmt_spec), tm));
+  }
+
+  // Every day from 1970-01-01
+  std::time_t time_now = std::time(nullptr);
+  for (std::time_t t = 6 * 3600; t < time_now; t += 86400) {
+    tm = *std::localtime(&t);
+
+    auto fmt_spec = fmt::format("{{:{}}}", iso_week_spec);
+    EXPECT_EQ(system_strftime(iso_week_spec, &tm),
+              fmt::format(fmt::runtime(fmt_spec), tm));
+  }
+}
+
+// MSVC:
+//  minkernel\crts\ucrt\src\appcrt\time\wcsftime.cpp(971) : Assertion failed:
+//  timeptr->tm_year >= -1900 && timeptr->tm_year <= 8099
+#ifndef _WIN32
+TEST(chrono_test, format_tm_future) {
+  auto tm = std::tm();
+  tm.tm_year = 10445;  // 10000+ years
+  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 12345-04-25 11:22:33.");
+  EXPECT_EQ(fmt::format("{:%Y}", tm), "12345");
+  EXPECT_EQ(fmt::format("{:%C}", tm), "123");
+  EXPECT_EQ(fmt::format("{:%C%y}", tm), fmt::format("{:%Y}", tm));
+  EXPECT_EQ(fmt::format("{:%D}", tm), "04/25/45");
+  EXPECT_EQ(fmt::format("{:%F}", tm), "12345-04-25");
+  EXPECT_EQ(fmt::format("{:%T}", tm), "11:22:33");
+}
+
+TEST(chrono_test, format_tm_past) {
+  auto tm = std::tm();
+  tm.tm_year = -2001;
+  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 -101-04-25 11:22:33.");
+  EXPECT_EQ(fmt::format("{:%Y}", tm), "-101");
+
+  // macOS  %C - "-1"
+  // Linux  %C - "-2"
+  // fmt    %C - "-1"
+  EXPECT_EQ(fmt::format("{:%C}", tm), "-1");
+  EXPECT_EQ(fmt::format("{:%C%y}", tm), fmt::format("{:%Y}", tm));
+
+  // macOS  %D - "04/25/01" (%y)
+  // Linux  %D - "04/25/99" (%y)
+  // fmt    %D - "04/25/01" (%y)
+  EXPECT_EQ(fmt::format("{:%D}", tm), "04/25/01");
+
+  EXPECT_EQ(fmt::format("{:%F}", tm), "-101-04-25");
+  EXPECT_EQ(fmt::format("{:%T}", tm), "11:22:33");
+
+  tm.tm_year = -1901;  // -1
+  EXPECT_EQ(fmt::format("{:%Y}", tm), "-001");
+  EXPECT_EQ(fmt::format("{:%C%y}", tm), fmt::format("{:%Y}", tm));
+
+  tm.tm_year = -1911;  // -11
+  EXPECT_EQ(fmt::format("{:%Y}", tm), "-011");
+  EXPECT_EQ(fmt::format("{:%C%y}", tm), fmt::format("{:%Y}", tm));
+}
+#endif
+
+TEST(chrono_test, grow_buffer) {
+  auto s = std::string("{:");
+  for (int i = 0; i < 30; ++i) s += "%c";
+  s += "}\n";
+  auto t = std::time(nullptr);
+  (void)fmt::format(fmt::runtime(s), *std::localtime(&t));
+}
+
+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(chrono_test, empty_result) { EXPECT_EQ(fmt::format("{}", std::tm()), ""); }
+
+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 &&
+         lhs.tm_wday == rhs.tm_wday && lhs.tm_yday == rhs.tm_yday &&
+         lhs.tm_isdst == rhs.tm_isdst;
+}
+
+TEST(chrono_test, localtime) {
+  auto t = std::time(nullptr);
+  auto tm = *std::localtime(&t);
+  EXPECT_TRUE(equal(tm, fmt::localtime(t)));
+}
+
+TEST(chrono_test, gmtime) {
+  auto t = std::time(nullptr);
+  auto tm = *std::gmtime(&t);
+  EXPECT_TRUE(equal(tm, fmt::gmtime(t)));
+}
+
+template <typename TimePoint> auto strftime_full(TimePoint tp) -> std::string {
+  auto t = std::chrono::system_clock::to_time_t(tp);
+  auto tm = *std::localtime(&t);
+  return system_strftime("%Y-%m-%d %H:%M:%S", &tm);
+}
+
+TEST(chrono_test, time_point) {
+  auto t1 = std::chrono::system_clock::now();
+  EXPECT_EQ(strftime_full(t1), fmt::format("{:%Y-%m-%d %H:%M:%S}", t1));
+  EXPECT_EQ(strftime_full(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_full(t2), fmt::format("{:%Y-%m-%d %H:%M:%S}", t2));
+
+  std::vector<std::string> spec_list = {
+      "%%",  "%n",  "%t",  "%Y",  "%EY", "%y",  "%Oy", "%Ey", "%C",
+      "%EC", "%G",  "%g",  "%b",  "%h",  "%B",  "%m",  "%Om", "%U",
+      "%OU", "%W",  "%OW", "%V",  "%OV", "%j",  "%d",  "%Od", "%e",
+      "%Oe", "%a",  "%A",  "%w",  "%Ow", "%u",  "%Ou", "%H",  "%OH",
+      "%I",  "%OI", "%M",  "%OM", "%S",  "%OS", "%x",  "%Ex", "%X",
+      "%EX", "%D",  "%F",  "%R",  "%T",  "%p",  "%z",  "%Z"};
+  spec_list.push_back("%Y-%m-%d %H:%M:%S");
+#ifndef _WIN32
+  // Disabled on Windows because these formats are not consistent among
+  // platforms.
+  spec_list.insert(spec_list.end(), {"%c", "%Ec", "%r"});
+#endif
+
+  for (const auto& spec : spec_list) {
+    auto t = std::chrono::system_clock::to_time_t(t1);
+    auto tm = *std::localtime(&t);
+
+    auto sys_output = system_strftime(spec, &tm);
+
+    auto fmt_spec = fmt::format("{{:{}}}", spec);
+    EXPECT_EQ(sys_output, fmt::format(fmt::runtime(fmt_spec), t1));
+    EXPECT_EQ(sys_output, fmt::format(fmt::runtime(fmt_spec), tm));
+  }
+}
+
+#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+
+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)));
+  EXPECT_EQ("42fs",
+            fmt::format("{}", std::chrono::duration<int, std::femto>(42)));
+  EXPECT_EQ("42ps",
+            fmt::format("{}", std::chrono::duration<int, std::pico>(42)));
+  EXPECT_EQ("42ns", fmt::format("{}", std::chrono::nanoseconds(42)));
+  EXPECT_EQ("42µs", fmt::format("{}", std::chrono::microseconds(42)));
+  EXPECT_EQ("42ms", fmt::format("{}", std::chrono::milliseconds(42)));
+  EXPECT_EQ("42cs",
+            fmt::format("{}", std::chrono::duration<int, std::centi>(42)));
+  EXPECT_EQ("42ds",
+            fmt::format("{}", std::chrono::duration<int, std::deci>(42)));
+  EXPECT_EQ("42s", fmt::format("{}", std::chrono::seconds(42)));
+  EXPECT_EQ("42das",
+            fmt::format("{}", std::chrono::duration<int, std::deca>(42)));
+  EXPECT_EQ("42hs",
+            fmt::format("{}", std::chrono::duration<int, std::hecto>(42)));
+  EXPECT_EQ("42ks",
+            fmt::format("{}", std::chrono::duration<int, std::kilo>(42)));
+  EXPECT_EQ("42Ms",
+            fmt::format("{}", std::chrono::duration<int, std::mega>(42)));
+  EXPECT_EQ("42Gs",
+            fmt::format("{}", std::chrono::duration<int, std::giga>(42)));
+  EXPECT_EQ("42Ts",
+            fmt::format("{}", std::chrono::duration<int, std::tera>(42)));
+  EXPECT_EQ("42Ps",
+            fmt::format("{}", std::chrono::duration<int, std::peta>(42)));
+  EXPECT_EQ("42Es",
+            fmt::format("{}", std::chrono::duration<int, std::exa>(42)));
+  EXPECT_EQ("42m", fmt::format("{}", std::chrono::minutes(42)));
+  EXPECT_EQ("42h", fmt::format("{}", std::chrono::hours(42)));
+  EXPECT_EQ(
+      "42[15]s",
+      fmt::format("{}", std::chrono::duration<int, std::ratio<15, 1>>(42)));
+  EXPECT_EQ(
+      "42[15/4]s",
+      fmt::format("{}", std::chrono::duration<int, std::ratio<15, 4>>(42)));
+}
+
+TEST(chrono_test, align) {
+  auto s = std::chrono::seconds(42);
+  EXPECT_EQ("42s  ", fmt::format("{:5}", s));
+  EXPECT_EQ("42s  ", fmt::format("{:{}}", s, 5));
+  EXPECT_EQ("  42s", fmt::format("{:>5}", s));
+  EXPECT_EQ("**42s**", fmt::format("{:*^7}", s));
+  EXPECT_EQ("03:25:45    ",
+            fmt::format("{:12%H:%M:%S}", std::chrono::seconds(12345)));
+  EXPECT_EQ("    03:25:45",
+            fmt::format("{:>12%H:%M:%S}", std::chrono::seconds(12345)));
+  EXPECT_EQ("~~03:25:45~~",
+            fmt::format("{:~^12%H:%M:%S}", std::chrono::seconds(12345)));
+  EXPECT_EQ("03:25:45    ",
+            fmt::format("{:{}%H:%M:%S}", std::chrono::seconds(12345), 12));
+}
+
+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)));
+  EXPECT_EQ("00", fmt::format("{:%S}", std::chrono::seconds(0)));
+  EXPECT_EQ("00", fmt::format("{:%S}", std::chrono::seconds(60)));
+  EXPECT_EQ("42", fmt::format("{:%S}", std::chrono::seconds(42)));
+  EXPECT_EQ("01.234", fmt::format("{:%S}", std::chrono::milliseconds(1234)));
+  EXPECT_EQ("00", fmt::format("{:%M}", std::chrono::minutes(0)));
+  EXPECT_EQ("00", fmt::format("{:%M}", std::chrono::minutes(60)));
+  EXPECT_EQ("42", fmt::format("{:%M}", std::chrono::minutes(42)));
+  EXPECT_EQ("01", fmt::format("{:%M}", std::chrono::seconds(61)));
+  EXPECT_EQ("00", fmt::format("{:%H}", std::chrono::hours(0)));
+  EXPECT_EQ("00", fmt::format("{:%H}", std::chrono::hours(24)));
+  EXPECT_EQ("14", fmt::format("{:%H}", std::chrono::hours(14)));
+  EXPECT_EQ("01", fmt::format("{:%H}", std::chrono::minutes(61)));
+  EXPECT_EQ("12", fmt::format("{:%I}", std::chrono::hours(0)));
+  EXPECT_EQ("12", fmt::format("{:%I}", std::chrono::hours(12)));
+  EXPECT_EQ("12", fmt::format("{:%I}", std::chrono::hours(24)));
+  EXPECT_EQ("04", fmt::format("{:%I}", std::chrono::hours(4)));
+  EXPECT_EQ("02", fmt::format("{:%I}", std::chrono::hours(14)));
+  EXPECT_EQ("03:25:45",
+            fmt::format("{:%H:%M:%S}", std::chrono::seconds(12345)));
+  EXPECT_EQ("03:25", fmt::format("{:%R}", std::chrono::seconds(12345)));
+  EXPECT_EQ("03:25:45", fmt::format("{:%T}", std::chrono::seconds(12345)));
+  EXPECT_EQ("12345", fmt::format("{:%Q}", std::chrono::seconds(12345)));
+  EXPECT_EQ("s", fmt::format("{:%q}", std::chrono::seconds(12345)));
+}
+
+TEST(chrono_test, invalid_specs) {
+  auto sec = std::chrono::seconds(0);
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%a}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%A}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%c}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%x}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%Ex}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%X}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%EX}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%D}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%F}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%Ec}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%w}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%u}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%b}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%B}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%z}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%Z}"), sec), fmt::format_error,
+                   "no date");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%Eq}"), sec), fmt::format_error,
+                   "invalid format");
+  EXPECT_THROW_MSG((void)fmt::format(runtime("{:%Oq}"), sec), fmt::format_error,
+                   "invalid format");
+}
+
+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));
+  EXPECT_TIME("%OS", make_second(42), std::chrono::seconds(42));
+  auto time = make_tm();
+  time.tm_hour = 3;
+  time.tm_min = 25;
+  time.tm_sec = 45;
+  auto sec = std::chrono::seconds(12345);
+  EXPECT_TIME("%r", time, sec);
+  EXPECT_TIME("%p", time, sec);
+}
+
+using dms = std::chrono::duration<double, std::milli>;
+
+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;
+  EXPECT_EQ("1.234ms", fmt::format("{}", fms(1.234)));
+  typedef std::chrono::duration<double> ds;
+  EXPECT_EQ("1.234s", fmt::format("{}", ds(1.234)));
+  EXPECT_EQ("1.234ms", fmt::format("{}", dms(1.234)));
+}
+
+TEST(chrono_test, format_precision) {
+  EXPECT_THROW_MSG(
+      (void)fmt::format(runtime("{:.2}"), std::chrono::seconds(42)),
+      fmt::format_error, "precision not allowed for this argument type");
+  EXPECT_EQ("1ms", fmt::format("{:.0}", dms(1.234)));
+  EXPECT_EQ("1.2ms", fmt::format("{:.1}", dms(1.234)));
+  EXPECT_EQ("1.23ms", fmt::format("{:.{}}", dms(1.234), 2));
+
+  EXPECT_EQ("13ms", fmt::format("{:.0}", dms(12.56)));
+  EXPECT_EQ("12.6ms", fmt::format("{:.1}", dms(12.56)));
+  EXPECT_EQ("12.56ms", fmt::format("{:.2}", dms(12.56)));
+}
+
+TEST(chrono_test, format_full_specs) {
+  EXPECT_EQ("1ms   ", fmt::format("{:6.0}", dms(1.234)));
+  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));
+  EXPECT_EQ(" 1.23ms ", fmt::format("{0:^{2}.{1}}", dms(1.234), 2, 8));
+  EXPECT_EQ("=1.234ms=", fmt::format("{:=^{}.{}}", dms(1.234), 9, 3));
+  EXPECT_EQ("*1.2340ms*", fmt::format("{:*^10.4}", dms(1.234)));
+
+  EXPECT_EQ("13ms  ", fmt::format("{:6.0}", dms(12.56)));
+  EXPECT_EQ("    13ms", fmt::format("{:>8.{}}", dms(12.56), 0));
+  EXPECT_EQ(" 13ms ", fmt::format("{:^{}.{}}", dms(12.56), 6, 0));
+  EXPECT_EQ("  13ms  ", fmt::format("{0:^{2}.{1}}", dms(12.56), 0, 8));
+  EXPECT_EQ("==13ms===", fmt::format("{:=^{}.{}}", dms(12.56), 9, 0));
+  EXPECT_EQ("***13ms***", fmt::format("{:*^10.0}", dms(12.56)));
+}
+
+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;
+  EXPECT_EQ("1.234 ms", fmt::format("{:%Q %q}", fms(1.234)));
+  typedef std::chrono::duration<double> ds;
+  EXPECT_EQ("1.234 s", fmt::format("{:%Q %q}", ds(1.234)));
+  EXPECT_EQ("1.234 ms", fmt::format("{:%Q %q}", dms(1.234)));
+}
+
+TEST(chrono_test, format_precision_q) {
+  EXPECT_THROW_MSG(
+      (void)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(chrono_test, format_full_specs_q) {
+  EXPECT_EQ("1 ms   ", fmt::format("{:7.0%Q %q}", dms(1.234)));
+  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));
+  EXPECT_EQ(" 1.23 ms ", fmt::format("{0:^{2}.{1}%Q %q}", dms(1.234), 2, 9));
+  EXPECT_EQ("=1.234 ms=", fmt::format("{:=^{}.{}%Q %q}", dms(1.234), 10, 3));
+  EXPECT_EQ("*1.2340 ms*", fmt::format("{:*^11.4%Q %q}", dms(1.234)));
+
+  EXPECT_EQ("13 ms  ", fmt::format("{:7.0%Q %q}", dms(12.56)));
+  EXPECT_EQ("   13 ms", fmt::format("{:>8.{}%Q %q}", dms(12.56), 0));
+  EXPECT_EQ(" 13 ms  ", fmt::format("{:^{}.{}%Q %q}", dms(12.56), 8, 0));
+  EXPECT_EQ("  13 ms  ", fmt::format("{0:^{2}.{1}%Q %q}", dms(12.56), 0, 9));
+  EXPECT_EQ("==13 ms==", fmt::format("{:=^{}.{}%Q %q}", dms(12.56), 9, 0));
+  EXPECT_EQ("***13 ms***", fmt::format("{:*^11.0%Q %q}", dms(12.56)));
+}
+
+TEST(chrono_test, invalid_width_id) {
+  EXPECT_THROW((void)fmt::format(runtime("{:{o}"), std::chrono::seconds(0)),
+               fmt::format_error);
+}
+
+TEST(chrono_test, invalid_colons) {
+  EXPECT_THROW((void)fmt::format(runtime("{0}=:{0::"), std::chrono::seconds(0)),
+               fmt::format_error);
+}
+
+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)));
+  EXPECT_EQ("-00:01",
+            fmt::format("{:%M:%S}", std::chrono::duration<double>(-1)));
+  EXPECT_EQ("s", fmt::format("{:%q}", std::chrono::seconds(-12345)));
+  EXPECT_EQ("-00.127",
+            fmt::format("{:%S}",
+                        std::chrono::duration<signed char, std::milli>{-127}));
+  auto min = std::numeric_limits<int>::min();
+  EXPECT_EQ(fmt::format("{}", min),
+            fmt::format("{:%Q}", std::chrono::duration<int>(min)));
+}
+
+TEST(chrono_test, special_durations) {
+  auto value = fmt::format("{:%S}", std::chrono::duration<double>(1e20));
+  EXPECT_EQ(value, "40");
+  auto nan = std::numeric_limits<double>::quiet_NaN();
+  EXPECT_EQ(
+      "nan nan nan nan nan:nan nan",
+      fmt::format("{:%I %H %M %S %R %r}", std::chrono::duration<double>(nan)));
+  EXPECT_EQ(fmt::format("{}", std::chrono::duration<float, std::exa>(1)),
+            "1Es");
+  EXPECT_EQ(fmt::format("{}", std::chrono::duration<float, std::atto>(1)),
+            "1as");
+  EXPECT_EQ(fmt::format("{:%R}", std::chrono::duration<char, std::mega>{2}),
+            "03:33");
+  EXPECT_EQ(fmt::format("{:%T}", std::chrono::duration<char, std::mega>{2}),
+            "03:33:20");
+  EXPECT_EQ("44.000000000000",
+            fmt::format("{:%S}", std::chrono::duration<float, std::pico>(
+                                     1.54213895E+26)));
+}
+
+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);
+
+  auto tm = std::tm();
+  tm.tm_wday = static_cast<int>(mon.c_encoding());
+
+  EXPECT_EQ(fmt::format("{}", mon), "Mon");
+  EXPECT_EQ(fmt::format("{:%a}", tm), "Mon");
+
+  if (loc != std::locale::classic()) {
+    EXPECT_THAT((std::vector<std::string>{"пн", "Пн", "пнд", "Пнд"}),
+                Contains(fmt::format(loc, "{:L}", mon)));
+    EXPECT_THAT((std::vector<std::string>{"пн", "Пн", "пнд", "Пнд"}),
+                Contains(fmt::format(loc, "{:%a}", tm)));
+  }
+}
+
+TEST(chrono_test, cpp20_duration_subsecond_support) {
+  using attoseconds = std::chrono::duration<long long, std::atto>;
+  // Check that 18 digits of subsecond precision are supported.
+  EXPECT_EQ(fmt::format("{:%S}", attoseconds{999999999999999999}),
+            "00.999999999999999999");
+  EXPECT_EQ(fmt::format("{:%S}", attoseconds{673231113420148734}),
+            "00.673231113420148734");
+  EXPECT_EQ(fmt::format("{:%S}", attoseconds{-673231113420148734}),
+            "-00.673231113420148734");
+  EXPECT_EQ(fmt::format("{:%S}", std::chrono::nanoseconds{13420148734}),
+            "13.420148734");
+  EXPECT_EQ(fmt::format("{:%S}", std::chrono::nanoseconds{-13420148734}),
+            "-13.420148734");
+  EXPECT_EQ(fmt::format("{:%S}", std::chrono::milliseconds{1234}), "01.234");
+  {
+    // Check that {:%H:%M:%S} is equivalent to {:%T}.
+    auto dur = std::chrono::milliseconds{3601234};
+    auto formatted_dur = fmt::format("{:%T}", dur);
+    EXPECT_EQ(formatted_dur, "01:00:01.234");
+    EXPECT_EQ(fmt::format("{:%H:%M:%S}", dur), formatted_dur);
+  }
+  using nanoseconds_dbl = std::chrono::duration<double, std::nano>;
+  EXPECT_EQ(fmt::format("{:%S}", nanoseconds_dbl{-123456789}), "-00.123456789");
+  EXPECT_EQ(fmt::format("{:%S}", nanoseconds_dbl{9123456789}), "09.123456789");
+  // Verify that only the seconds part is extracted and printed.
+  EXPECT_EQ(fmt::format("{:%S}", nanoseconds_dbl{99123456789}), "39.123456789");
+  EXPECT_EQ(fmt::format("{:%S}", nanoseconds_dbl{99123000000}), "39.123000000");
+  {
+    // Now the hour is printed, and we also test if negative doubles work.
+    auto dur = nanoseconds_dbl{-99123456789};
+    auto formatted_dur = fmt::format("{:%T}", dur);
+    EXPECT_EQ(formatted_dur, "-00:01:39.123456789");
+    EXPECT_EQ(fmt::format("{:%H:%M:%S}", dur), formatted_dur);
+  }
+  // Check that durations with precision greater than std::chrono::seconds have
+  // fixed precision, and print zeros even if there is no fractional part.
+  EXPECT_EQ(fmt::format("{:%S}", std::chrono::microseconds{7000000}),
+            "07.000000");
+  EXPECT_EQ(fmt::format("{:%S}", std::chrono::duration<long long, std::ratio<1, 3>>(1)),
+            "00.333333");
+  EXPECT_EQ(fmt::format("{:%S}", std::chrono::duration<long long, std::ratio<1, 7>>(1)),
+            "00.142857");
+}
+
+#endif  // FMT_STATIC_THOUSANDS_SEPARATOR

test/color-test.cc

@@ -0,0 +1,72 @@
+// Formatting library for C++ - color tests
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#include "fmt/color.h"
+
+#include <iterator>  // std::back_inserter
+
+#include "gtest-extra.h"  // EXPECT_WRITE
+
+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::color::blue), "blue"),
+            "\x1b[38;2;000;000;255mblue\x1b[0m");
+  EXPECT_EQ(
+      fmt::format(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_EQ(fmt::format(fmt::emphasis::bold, "bold"), "\x1b[1mbold\x1b[0m");
+  EXPECT_EQ(fmt::format(fmt::emphasis::faint, "faint"), "\x1b[2mfaint\x1b[0m");
+  EXPECT_EQ(fmt::format(fmt::emphasis::italic, "italic"),
+            "\x1b[3mitalic\x1b[0m");
+  EXPECT_EQ(fmt::format(fmt::emphasis::underline, "underline"),
+            "\x1b[4munderline\x1b[0m");
+  EXPECT_EQ(fmt::format(fmt::emphasis::blink, "blink"), "\x1b[5mblink\x1b[0m");
+  EXPECT_EQ(fmt::format(fmt::emphasis::reverse, "reverse"),
+            "\x1b[7mreverse\x1b[0m");
+  EXPECT_EQ(fmt::format(fmt::emphasis::conceal, "conceal"),
+            "\x1b[8mconceal\x1b[0m");
+  EXPECT_EQ(fmt::format(fmt::emphasis::strikethrough, "strikethrough"),
+            "\x1b[9mstrikethrough\x1b[0m");
+  EXPECT_EQ(
+      fmt::format(fg(fmt::color::blue) | fmt::emphasis::bold, "blue/bold"),
+      "\x1b[1m\x1b[38;2;000;000;255mblue/bold\x1b[0m");
+  EXPECT_EQ(fmt::format(fmt::emphasis::bold, "bold error"),
+            "\x1b[1mbold error\x1b[0m");
+  EXPECT_EQ(fmt::format(fg(fmt::color::blue), "blue log"),
+            "\x1b[38;2;000;000;255mblue log\x1b[0m");
+  EXPECT_EQ(fmt::format(fmt::text_style(), "hi"), "hi");
+  EXPECT_EQ(fmt::format(fg(fmt::terminal_color::red), "tred"),
+            "\x1b[31mtred\x1b[0m");
+  EXPECT_EQ(fmt::format(bg(fmt::terminal_color::cyan), "tcyan"),
+            "\x1b[46mtcyan\x1b[0m");
+  EXPECT_EQ(fmt::format(fg(fmt::terminal_color::bright_green), "tbgreen"),
+            "\x1b[92mtbgreen\x1b[0m");
+  EXPECT_EQ(fmt::format(bg(fmt::terminal_color::bright_magenta), "tbmagenta"),
+            "\x1b[105mtbmagenta\x1b[0m");
+  EXPECT_EQ(fmt::format(fg(fmt::terminal_color::red), "{}", "foo"),
+            "\x1b[31mfoo\x1b[0m");
+  EXPECT_EQ(fmt::format("{}{}", fmt::styled("red", fg(fmt::color::red)),
+                        fmt::styled("bold", fmt::emphasis::bold)),
+            "\x1b[38;2;255;000;000mred\x1b[0m\x1b[1mbold\x1b[0m");
+  EXPECT_EQ(fmt::format("{}", fmt::styled("bar", fg(fmt::color::blue) |
+                                                     fmt::emphasis::underline)),
+            "\x1b[4m\x1b[38;2;000;000;255mbar\x1b[0m");
+}
+
+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-error-test/CMakeLists.txt

@@ -0,0 +1,241 @@
+# Test if compile errors are produced where necessary.
+
+cmake_minimum_required(VERSION 3.1...3.18)
+project(compile-error-test CXX)
+
+set(fmt_headers "
+  #include <fmt/format.h>
+  #include <fmt/xchar.h>
+  #include <fmt/ostream.h>
+  #include <iostream>
+")
+
+set(error_test_names "")
+set(non_error_test_content "")
+
+# For error tests (we expect them to produce compilation error):
+#  * adds a name of test into `error_test_names` list
+#  * generates a single source file (with the same name) for each test
+# For non-error tests (we expect them to compile successfully):
+#  * adds a code segment as separate function to `non_error_test_content`
+function (expect_compile name code_fragment)
+  cmake_parse_arguments(EXPECT_COMPILE "ERROR" "" "" ${ARGN})
+  string(MAKE_C_IDENTIFIER "${name}" test_name)
+
+  if (EXPECT_COMPILE_ERROR)
+    file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/test/${test_name}.cc" "
+      ${fmt_headers}
+      void ${test_name}() {
+        ${code_fragment}
+      }
+    ")
+    set(error_test_names_copy "${error_test_names}")
+    list(APPEND error_test_names_copy "${test_name}")
+    set(error_test_names "${error_test_names_copy}" PARENT_SCOPE)
+  else()
+    set(non_error_test_content "
+      ${non_error_test_content}
+      void ${test_name}() {
+        ${code_fragment}
+      }" PARENT_SCOPE)
+  endif()
+endfunction ()
+
+# Generates a source file for non-error test with `non_error_test_content` and
+# CMake project file with all error and single non-error test targets.
+function (run_tests)
+  set(cmake_targets "")
+  foreach(test_name IN LISTS error_test_names)
+    set(cmake_targets "
+      ${cmake_targets}
+      add_library(test-${test_name} ${test_name}.cc)
+      target_link_libraries(test-${test_name} PRIVATE fmt::fmt)
+    ")
+  endforeach()
+
+  file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/test/non_error_test.cc" "
+    ${fmt_headers}
+    ${non_error_test_content}
+  ")
+  set(cmake_targets "
+    ${cmake_targets}
+    add_library(non-error-test non_error_test.cc)
+    target_link_libraries(non-error-test PRIVATE fmt::fmt)
+  ")
+
+  file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/test/CMakeLists.txt" "
+    cmake_minimum_required(VERSION 3.1...3.18)
+    project(tests CXX)
+    add_subdirectory(${FMT_DIR} fmt)
+    ${cmake_targets}
+  ")
+
+  set(build_directory "${CMAKE_CURRENT_BINARY_DIR}/test/build")
+  file(MAKE_DIRECTORY "${build_directory}")
+  execute_process(
+    COMMAND
+      "${CMAKE_COMMAND}"
+      "-DCMAKE_CXX_COMPILER=${CMAKE_CXX_COMPILER}"
+      "-DCMAKE_CXX_FLAGS=${CMAKE_CXX_FLAGS}"
+      "-DCMAKE_CXX_STANDARD=${CMAKE_CXX_STANDARD}"
+      "-DCMAKE_GENERATOR=${CMAKE_GENERATOR}"
+      "-DCMAKE_MAKE_PROGRAM=${CMAKE_MAKE_PROGRAM}"
+      "-DFMT_DIR=${FMT_DIR}"
+      "${CMAKE_CURRENT_BINARY_DIR}/test"
+    WORKING_DIRECTORY "${build_directory}"
+    RESULT_VARIABLE result_var
+    OUTPUT_VARIABLE output_var
+    ERROR_VARIABLE output_var)
+  if (NOT result_var EQUAL 0)
+    message(FATAL_ERROR "Unable to configure:\n${output_var}")
+  endif()
+
+  foreach(test_name IN LISTS error_test_names)
+    execute_process(
+      COMMAND
+        "${CMAKE_COMMAND}" --build "${build_directory}" --target "test-${test_name}"
+      WORKING_DIRECTORY "${build_directory}"
+      RESULT_VARIABLE result_var
+      OUTPUT_VARIABLE output_var
+      ERROR_QUIET)
+    if (result_var EQUAL 0)
+      message(SEND_ERROR "No compile error for \"${test_name}\":\n${output_var}")
+    endif ()
+  endforeach()
+
+  execute_process(
+    COMMAND
+      "${CMAKE_COMMAND}" --build "${build_directory}" --target "non-error-test"
+    WORKING_DIRECTORY "${build_directory}"
+    RESULT_VARIABLE result_var
+    OUTPUT_VARIABLE output_var
+    ERROR_VARIABLE output_var)
+  if (NOT result_var EQUAL 0)
+    message(SEND_ERROR "Compile error for combined non-error test:\n${output_var}")
+  endif ()
+endfunction ()
+
+
+# check if the source file skeleton compiles
+expect_compile(check "")
+expect_compile(check-error "compilation_error" ERROR)
+
+# Formatting a wide character with a narrow format string is forbidden.
+expect_compile(wide-character-narrow-format-string "fmt::format(L\"{}\", L'a');")
+expect_compile(wide-character-narrow-format-string-error "fmt::format(\"{}\", L'a');" ERROR)
+
+# Formatting a wide string with a narrow format string is forbidden.
+expect_compile(wide-string-narrow-format-string "fmt::format(L\"{}\", L\"foo\");")
+expect_compile(wide-string-narrow-format-string-error "fmt::format(\"{}\", L\"foo\");" ERROR)
+
+# Formatting a narrow string with a wide format string is forbidden because
+# mixing UTF-8 with UTF-16/32 can result in an invalid output.
+expect_compile(narrow-string-wide-format-string "fmt::format(L\"{}\", L\"foo\");")
+expect_compile(narrow-string-wide-format-string-error "fmt::format(L\"{}\", \"foo\");" ERROR)
+
+expect_compile(cast-to-string "
+  struct S {
+    operator std::string() const { return std::string(); }
+  };
+  fmt::format(\"{}\", std::string(S()));
+")
+expect_compile(cast-to-string-error "
+  struct S {
+    operator std::string() const { return std::string(); }
+  };
+  fmt::format(\"{}\", S());
+" ERROR)
+
+# Formatting a function
+expect_compile(format-function "
+  void (*f)();
+  fmt::format(\"{}\", fmt::ptr(f));
+")
+expect_compile(format-function-error "
+  void (*f)();
+  fmt::format(\"{}\", f);
+" ERROR)
+
+# Formatting an unformattable argument should always be a compile time error
+expect_compile(format-lots-of-arguments-with-unformattable "
+  struct E {};
+  fmt::format(\"\", 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, E());
+" ERROR)
+expect_compile(format-lots-of-arguments-with-function "
+  void (*f)();
+  fmt::format(\"\", 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, f);
+" ERROR)
+
+# Check if user-defined literals are available
+include(CheckCXXSourceCompiles)
+set(CMAKE_REQUIRED_FLAGS ${CXX_STANDARD_FLAG})
+check_cxx_source_compiles("
+  void operator\"\" _udl(long double);
+  int main() {}"
+  SUPPORTS_USER_DEFINED_LITERALS)
+set(CMAKE_REQUIRED_FLAGS )
+if (NOT SUPPORTS_USER_DEFINED_LITERALS)
+  set (SUPPORTS_USER_DEFINED_LITERALS OFF)
+endif ()
+
+# Make sure that compiler features detected in the header
+# match the features detected in CMake.
+if (SUPPORTS_USER_DEFINED_LITERALS)
+  set(supports_udl 1)
+else ()
+  set(supports_udl 0)
+endif ()
+expect_compile(udl-check "
+  #if FMT_USE_USER_DEFINED_LITERALS != ${supports_udl}
+  # error
+  #endif
+")
+
+if (CMAKE_CXX_STANDARD GREATER_EQUAL 20)
+  # Compile-time argument type check
+  expect_compile(format-string-number-spec "
+    #ifdef FMT_HAS_CONSTEVAL
+      fmt::format(\"{:d}\", 42);
+    #endif
+  ")
+  expect_compile(format-string-number-spec-error "
+    #ifdef FMT_HAS_CONSTEVAL
+      fmt::format(\"{:d}\", \"I am not a number\");
+    #else
+      #error
+    #endif
+  " ERROR)
+  expect_compile(print-string-number-spec-error "
+    #ifdef FMT_HAS_CONSTEVAL
+      fmt::print(\"{:d}\", \"I am not a number\");
+    #else
+      #error
+    #endif
+  " ERROR)
+  expect_compile(print-stream-string-number-spec-error "
+  #ifdef FMT_HAS_CONSTEVAL
+    fmt::print(std::cout, \"{:d}\", \"I am not a number\");
+  #else
+    #error
+  #endif
+  " ERROR)
+
+  # Compile-time argument name check
+  expect_compile(format-string-name "
+    #if defined(FMT_HAS_CONSTEVAL) && FMT_USE_NONTYPE_TEMPLATE_ARGS
+      using namespace fmt::literals;
+      fmt::print(\"{foo}\", \"foo\"_a=42);
+    #endif
+  ")
+  expect_compile(format-string-name-error "
+    #if defined(FMT_HAS_CONSTEVAL) && FMT_USE_NONTYPE_TEMPLATE_ARGS
+      using namespace fmt::literals;
+      fmt::print(\"{foo}\", \"bar\"_a=42);
+    #else
+      #error
+    #endif
+  " ERROR)
+endif ()
+
+# Run all tests
+run_tests()

test/compile-fp-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 "fmt/compile.h"
+#include "gmock/gmock.h"
+
+#if defined(__cpp_lib_bit_cast) && __cpp_lib_bit_cast >= 201806 && \
+    defined(__cpp_constexpr) && __cpp_constexpr >= 201907 &&       \
+    defined(__cpp_constexpr_dynamic_alloc) &&                      \
+    __cpp_constexpr_dynamic_alloc >= 201907 && FMT_CPLUSPLUS >= 202002L
+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, floating_point) {
+  EXPECT_EQ("0", test_format<2>(FMT_COMPILE("{}"), 0.0f));
+  EXPECT_EQ("392.500000", test_format<11>(FMT_COMPILE("{0:f}"), 392.5f));
+
+  EXPECT_EQ("0", test_format<2>(FMT_COMPILE("{:}"), 0.0));
+  EXPECT_EQ("0.000000", test_format<9>(FMT_COMPILE("{:f}"), 0.0));
+  EXPECT_EQ("0", test_format<2>(FMT_COMPILE("{:g}"), 0.0));
+  EXPECT_EQ("392.65", test_format<7>(FMT_COMPILE("{:}"), 392.65));
+  EXPECT_EQ("392.65", test_format<7>(FMT_COMPILE("{:g}"), 392.65));
+  EXPECT_EQ("392.65", test_format<7>(FMT_COMPILE("{:G}"), 392.65));
+  EXPECT_EQ("4.9014e+06", test_format<11>(FMT_COMPILE("{:g}"), 4.9014e6));
+  EXPECT_EQ("-392.650000", test_format<12>(FMT_COMPILE("{:f}"), -392.65));
+  EXPECT_EQ("-392.650000", test_format<12>(FMT_COMPILE("{:F}"), -392.65));
+
+  EXPECT_EQ("3.926500e+02", test_format<13>(FMT_COMPILE("{0:e}"), 392.65));
+  EXPECT_EQ("3.926500E+02", test_format<13>(FMT_COMPILE("{0:E}"), 392.65));
+  EXPECT_EQ("+0000392.6", test_format<11>(FMT_COMPILE("{0:+010.4g}"), 392.65));
+  EXPECT_EQ("9223372036854775808.000000",
+            test_format<27>(FMT_COMPILE("{:f}"), 9223372036854775807.0));
+
+  constexpr double nan = std::numeric_limits<double>::quiet_NaN();
+  EXPECT_EQ("nan", test_format<4>(FMT_COMPILE("{}"), nan));
+  EXPECT_EQ("+nan", test_format<5>(FMT_COMPILE("{:+}"), nan));
+  if (std::signbit(-nan))
+    EXPECT_EQ("-nan", test_format<5>(FMT_COMPILE("{}"), -nan));
+  else
+    fmt::print("Warning: compiler doesn't handle negative NaN correctly");
+
+  constexpr double inf = std::numeric_limits<double>::infinity();
+  EXPECT_EQ("inf", test_format<4>(FMT_COMPILE("{}"), inf));
+  EXPECT_EQ("+inf", test_format<5>(FMT_COMPILE("{:+}"), inf));
+  EXPECT_EQ("-inf", test_format<5>(FMT_COMPILE("{}"), -inf));
+}
+#endif

test/compile-test.cc

@@ -0,0 +1,388 @@
+// 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/compile.h"
+
+#include <type_traits>
+
+#include "fmt/chrono.h"
+#include "gmock/gmock.h"
+#include "gtest-extra.h"
+
+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(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);
+}
+
+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(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(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));
+}
+
+struct type_with_get {
+  template <int> friend void get(type_with_get);
+};
+
+FMT_BEGIN_NAMESPACE
+template <> struct formatter<type_with_get> : formatter<int> {
+  template <typename FormatContext>
+  auto format(type_with_get, FormatContext& ctx) -> decltype(ctx.out()) {
+    return formatter<int>::format(42, ctx);
+  }
+};
+FMT_END_NAMESPACE
+
+TEST(compile_test, compile_type_with_get) {
+  EXPECT_EQ("42", fmt::format(FMT_COMPILE("{}"), type_with_get()));
+}
+
+#if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
+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>
+  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(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));
+  EXPECT_EQ("42", fmt::format(FMT_COMPILE("{}"), 42ull));
+  EXPECT_EQ("true", fmt::format(FMT_COMPILE("{}"), true));
+  EXPECT_EQ("x", fmt::format(FMT_COMPILE("{}"), 'x'));
+  EXPECT_EQ("4.2", fmt::format(FMT_COMPILE("{}"), 4.2));
+  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(compile_test, format_wide_string) {
+  EXPECT_EQ(L"42", fmt::format(FMT_COMPILE(L"{}"), 42));
+}
+
+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(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(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_ARGS
+  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, join) {
+  unsigned char data[] = {0x1, 0x2, 0xaf};
+  EXPECT_EQ("0102af", fmt::format(FMT_COMPILE("{:02x}"), fmt::join(data, "")));
+}
+
+TEST(compile_test, format_to) {
+  char buf[8];
+  auto end = fmt::format_to(buf, FMT_COMPILE("{}"), 42);
+  *end = '\0';
+  EXPECT_STREQ("42", buf);
+  end = fmt::format_to(buf, FMT_COMPILE("{:x}"), 42);
+  *end = '\0';
+  EXPECT_STREQ("2a", buf);
+}
+
+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);
+  *res.out = '\0';
+  EXPECT_STREQ("42", buffer);
+  res = fmt::format_to_n(buffer, buffer_size, FMT_COMPILE("{:x}"), 42);
+  *res.out = '\0';
+  EXPECT_STREQ("2a", buffer);
+}
+
+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_ARGS
+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
+
+// MSVS 2019 19.29.30145.0 - Support C++20 and OK.
+// MSVS 2022 19.32.31332.0 - compile-test.cc(362,3): fatal error C1001: Internal
+// compiler error.
+//  (compiler file
+//  'D:\a\_work\1\s\src\vctools\Compiler\CxxFE\sl\p1\c\constexpr\constexpr.cpp',
+//  line 8635)
+#if ((FMT_CPLUSPLUS >= 202002L) &&                    \
+     (!FMT_MSC_VERSION || FMT_MSC_VERSION < 1930)) || \
+    (FMT_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/compile-test/CMakeLists.txt

@@ -1,79 +0,0 @@
-# Test if compile errors are produced where necessary.
-
-cmake_minimum_required(VERSION 3.1.0)
-
-include(CheckCXXSourceCompiles)
-include(CheckCXXCompilerFlag)
-
-set(CMAKE_REQUIRED_INCLUDES ${CMAKE_CURRENT_SOURCE_DIR}/../../include)
-set(CMAKE_REQUIRED_FLAGS ${CXX_STANDARD_FLAG} ${PEDANTIC_COMPILE_FLAGS})
-
-function (generate_source result fragment)
-  set(${result} "
-  #define FMT_HEADER_ONLY 1
-  #include \"fmt/format.h\"
-  int main() {
-    ${fragment}
-  }
-  " PARENT_SCOPE)
-endfunction ()
-
-function (expect_compile code)
-  generate_source(source "${code}")
-  check_cxx_source_compiles("${source}" compiles)
-  if (NOT compiles)
-    set(error_msg "Compile error for: ${code}")
-  endif ()
-  # Unset the CMake cache variable compiles. Otherwise the compile test will
-  # just use cached information next time it runs.
-  unset(compiles CACHE)
-  if (error_msg)
-    message(FATAL_ERROR ${error_msg})
-  endif ()
-endfunction ()
-
-function (expect_compile_error code)
-  generate_source(source "${code}")
-  check_cxx_source_compiles("${source}" compiles)
-  if (compiles)
-    set(error_msg "No compile error for: ${code}")
-  endif ()
-  # Unset the CMake cache variable compiles. Otherwise the compile test will
-  # just use cached information next time it runs.
-  unset(compiles CACHE)
-  if (error_msg)
-    message(FATAL_ERROR ${error_msg})
-  endif ()
-endfunction ()
-
-# check if the source file skeleton compiles
-expect_compile("")
-
-# Formatting a wide character with a narrow format string is forbidden.
-expect_compile_error("fmt::format(\"{}\", L'a');")
-
-# Formatting a wide string with a narrow format string is forbidden.
-expect_compile_error("fmt::format(\"{}\", L\"foo\");")
-
-# Formatting a narrow string with a wide format string is forbidden because
-# mixing UTF-8 with UTF-16/32 can result in an invalid output.
-expect_compile_error("fmt::format(L\"{}\", \"foo\");")
-
-# Formatting a wide string with a narrow format string is forbidden.
-expect_compile_error("
-  struct S {
-    operator std::string() const { return std::string(); }
-  };
-  fmt::format(\"{}\", S());
-")
-
-# Make sure that compiler features detected in the header
-# match the features detected in CMake.
-if (SUPPORTS_USER_DEFINED_LITERALS)
-  set(supports_udl 1)
-else ()
-  set(supports_udl 0)
-endif ()
-expect_compile("#if FMT_USE_USER_DEFINED_LITERALS != ${supports_udl}
-                # error
-                #endif")

test/cuda-test/CMakeLists.txt

@@ -0,0 +1,73 @@
+# We can find some usecases which follow the guide of CMake which uses
+# `enable_language(CUDA)` instead of `find_package(CUDA)` and let the CMake
+# built-in functions use NVCC.
+
+# See: https://cmake.org/cmake/help/latest/module/FindCUDA.html#replacement
+#
+# However, this requires CMake version 3.10 or higher and we can't be sure most
+# of the CUDA projects are using those.
+#
+# This test relies on `find_package(CUDA)` in the parent CMake config.
+
+# These can be updated when NVCC becomes ready for C++ 17 features
+# https://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html#cpp14-language-features
+set(CMAKE_CUDA_STANDARD 14)
+set(CMAKE_CUDA_STANDARD_REQUIRED 14)
+
+# In this test, we assume that the user is going to compile CUDA source code
+# with some libraries (fmt in this case).
+#
+# In addition to that, this test invokes both the C++ host compiler and NVCC
+# by providing another (non-CUDA) C++ source code.
+if (${CMAKE_VERSION} VERSION_LESS 3.15)
+  # https://docs.nvidia.com/cuda/cuda-compiler-driver-nvcc/index.html
+  list(APPEND CUDA_NVCC_FLAGS "-std=c++14")
+  if (MSVC)
+    # This is the solution of pytorch:
+    # https://github.com/pytorch/pytorch/pull/7118
+    list(APPEND CUDA_NVCC_FLAGS "-Xcompiler" "/std:c++14")
+    list(APPEND CUDA_NVCC_FLAGS "-Xcompiler" "/Zc:__cplusplus")
+    # for the reason of this -Xcompiler options, see below.
+  endif ()
+  cuda_add_executable(fmt-in-cuda-test cuda-cpp14.cu cpp14.cc)
+  target_compile_features(fmt-in-cuda-test PRIVATE cxx_std_14)
+  if (MSVC)
+    # This part is for (non-CUDA) C++ code. MSVC can define incorrect
+    # `__cplusplus` macro. Fix for the issue is to use additional compiler flag. 
+    #
+    # See Also:
+    # https://devblogs.microsoft.com/cppblog/msvc-now-correctly-reports-__cplusplus/
+    # https://github.com/Microsoft/vscode-cpptools/issues/2595
+    target_compile_options(fmt-in-cuda-test PRIVATE /Zc:__cplusplus /permissive-)
+  endif ()
+else()
+  # now using a "new" way of handling CUDA
+  add_executable(fmt-in-cuda-test cuda-cpp14.cu cpp14.cc)
+  set_target_properties(fmt-in-cuda-test PROPERTIES CUDA_SEPARABLE_COMPILATION ON)
+  target_compile_features(fmt-in-cuda-test PRIVATE cxx_std_14)
+  if (MSVC)
+    # with MSVC, 'cxx_std_14' will only propagate to the host code (MSVC), but will
+    # not set __cplusplus correctly anyway, while nvcc will ignore it.
+    # If specified for nvcc on the command line as '-std=c++14' nvcc will emit this
+    # message instead:
+    # nvcc warning : The -std=c++14 flag is not supported with the configured host
+    #                compiler. Flag will be ignored.
+    set_property(SOURCE cuda-cpp14.cu APPEND PROPERTY
+      COMPILE_OPTIONS -Xcompiler /std:c++14 -Xcompiler /Zc:__cplusplus)
+    set_property(SOURCE cpp14.cc APPEND PROPERTY
+      COMPILE_OPTIONS /std:c++14 /Zc:__cplusplus)
+  endif()
+endif()
+
+get_target_property(IN_USE_CUDA_STANDARD fmt-in-cuda-test CUDA_STANDARD)
+message(STATUS "cuda_standard:          ${IN_USE_CUDA_STANDARD}")
+
+get_target_property(IN_USE_CUDA_STANDARD_REQUIRED
+    fmt-in-cuda-test CUDA_STANDARD_REQUIRED)
+message(STATUS "cuda_standard_required: ${IN_USE_CUDA_STANDARD_REQUIRED}")
+
+# We don't use PUBLIC or other keyword for reasons explained in the
+# CUDA_LINK_LIBRARIES_KEYWORD section in
+# https://cmake.org/cmake/help/latest/module/FindCUDA.html
+target_link_libraries(fmt-in-cuda-test fmt::fmt)
+

test/cuda-test/cpp14.cc

@@ -0,0 +1,11 @@
+#include <fmt/core.h>
+
+// The purpose of this part is to ensure NVCC's host compiler also supports
+// the standard version. See 'cuda-cpp14.cu'.
+//
+// https://en.cppreference.com/w/cpp/preprocessor/replace#Predefined_macros
+static_assert(__cplusplus >= 201402L, "expect C++ 2014 for host compiler");
+
+auto make_message_cpp() -> std::string {
+  return fmt::format("host compiler \t: __cplusplus == {}", __cplusplus);
+}

test/cuda-test/cuda-cpp14.cu

@@ -0,0 +1,28 @@
+//  Direct NVCC command line example:
+//
+//  nvcc ./cuda-cpp14.cu -x cu -I"../include" -l"fmtd" -L"../build/Debug" \
+//       -std=c++14 -Xcompiler /std:c++14 -Xcompiler /Zc:__cplusplus
+
+// Ensure that we are using the latest C++ standard for NVCC
+// The version is C++14
+//
+// https://docs.nvidia.com/cuda/cuda-c-programming-guide/index.html#c-cplusplus-language-support
+// https://en.cppreference.com/w/cpp/preprocessor/replace#Predefined_macros
+static_assert(__cplusplus >= 201402L, "expect C++ 2014 for nvcc");
+
+#include <fmt/core.h>
+
+#include <cuda.h>
+#include <iostream>
+
+extern auto make_message_cpp() -> std::string;
+extern auto make_message_cuda() -> std::string;
+
+int main() {
+  std::cout << make_message_cuda() << std::endl;
+  std::cout << make_message_cpp() << std::endl;
+}
+
+auto make_message_cuda() -> std::string {
+  return fmt::format("nvcc compiler \t: __cplusplus == {}", __cplusplus);
+}

test/custom-formatter-test.cc

@@ -1,52 +0,0 @@
-// Formatting library for C++ - custom argument formatter tests
-//
-// Copyright (c) 2012 - present, Victor Zverovich
-// All rights reserved.
-//
-// For the license information refer to format.h.
-
-#include "fmt/format.h"
-#include "gtest-extra.h"
-
-// MSVC 2013 is known to be broken.
-#if !FMT_MSC_VER || FMT_MSC_VER > 1800
-
-// A custom argument formatter that doesn't print `-` for floating-point values
-// rounded to 0.
-class custom_arg_formatter :
-    public fmt::arg_formatter<fmt::back_insert_range<fmt::internal::buffer>> {
- public:
-  typedef fmt::back_insert_range<fmt::internal::buffer> range;
-  typedef fmt::arg_formatter<range> base;
-
-  custom_arg_formatter(
-      fmt::format_context &ctx, fmt::format_specs *s = FMT_NULL)
-  : base(ctx, s) {}
-
-  using base::operator();
-
-  iterator operator()(double value) {
-    // Comparing a float to 0.0 is safe
-    if (round(value * pow(10, spec()->precision())) == 0.0)
-      value = 0;
-    return base::operator()(value);
-  }
-};
-
-std::string custom_vformat(fmt::string_view format_str, fmt::format_args args) {
-  fmt::memory_buffer buffer;
-  // Pass custom argument formatter as a template arg to vwrite.
-  fmt::vformat_to<custom_arg_formatter>(buffer, format_str, args);
-  return std::string(buffer.data(), buffer.size());
-}
-
-template <typename... Args>
-std::string custom_format(const char *format_str, const Args & ... args) {
-  auto va = fmt::make_format_args(args...);
-  return custom_vformat(format_str, va);
-}
-
-TEST(CustomFormatterTest, Format) {
-  EXPECT_EQ("0.00", custom_format("{:.2f}", -.00001));
-}
-#endif

test/detect-stdfs.cc

@@ -0,0 +1,18 @@
+// Formatting library for C++ - tests of formatters for standard library types
+//
+// Copyright (c) 2012 - present, Victor Zverovich
+// All rights reserved.
+//
+// For the license information refer to format.h.
+
+#include <exception>  // _GLIBCXX_RELEASE & _LIBCPP_VERSION
+
+#if defined(_GLIBCXX_RELEASE) && _GLIBCXX_RELEASE == 8
+#  error libfound "stdc++fs"
+#elif !defined(__apple_build_version__) && defined(_LIBCPP_VERSION) && \
+    _LIBCPP_VERSION >= 7000 && _LIBCPP_VERSION < 9000
+#  error libfound "c++fs"
+#else
+// none if std::filesystem does not require additional libraries
+#  error libfound ""
+#endif

test/enforce-checks-test.cc

@@ -0,0 +1,63 @@
+// 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() {
+  (void)fmt::format(FMT_STRING("{}"), 42);
+  (void)fmt::format(FMT_STRING(L"{}"), 42);
+  (void)fmt::format(FMT_STRING("noop"));
+
+  (void)fmt::to_string(42);
+  (void)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() {
+  (void)fmt::format(FMT_STRING("{}"), std::chrono::seconds(42));
+  (void)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)");
+  (void)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'};
+  (void)fmt::format(FMT_STRING("{}"), hello);
+}
+
+int main() {
+  test_format_api();
+  test_chrono();
+  test_text_style();
+  test_range();
+}

test/find-package-test/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.1.0)
+cmake_minimum_required(VERSION 3.1...3.18)
 
 project(fmt-test)
 

test/find-package-test/main.cc

@@ -1,6 +1,5 @@
 #include "fmt/format.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/folly/Range.h

@@ -1,17 +0,0 @@
-// A folly::StringPiece stub.
-
-#include <cstring>
-
-namespace folly {
-class StringPiece {
- public:
-  explicit StringPiece(const char *s) : data_(s), size_(std::strlen(s)) {}
-
-  const char* data() const { return "foo"; }
-  size_t size() const { return 3; }
-
- private:
-  const char *data_;
-  size_t size_;
-};
-}

test/format-impl-test.cc

@@ -5,77 +5,189 @@
 //
 // 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 "../src/format.cc"
-#include "fmt/color.h"
-#include "fmt/printf.h"
-
 #include <algorithm>
 #include <cstring>
 
-#include "gmock.h"
-#include "gtest-extra.h"
+// clang-format off
+#include "test-assert.h"
+// clang-format on
+
+#include "fmt/format.h"
+#include "gmock/gmock.h"
 #include "util.h"
 
-#undef min
-#undef max
+using fmt::detail::bigint;
+using fmt::detail::fp;
+using fmt::detail::max_value;
 
-using fmt::internal::fp;
+static_assert(!std::is_copy_constructible<bigint>::value, "");
+static_assert(!std::is_copy_assignable<bigint>::value, "");
 
-template <bool is_iec559>
-void test_construct_from_double() {
+TEST(bigint_test, construct) {
+  EXPECT_EQ(fmt::to_string(bigint()), "");
+  EXPECT_EQ(fmt::to_string(bigint(0x42)), "42");
+  EXPECT_EQ(fmt::to_string(bigint(0x123456789abcedf0)), "123456789abcedf0");
+}
+
+TEST(bigint_test, compare) {
+  bigint n1(42);
+  bigint n2(42);
+  EXPECT_EQ(compare(n1, n2), 0);
+  n2 <<= 32;
+  EXPECT_LT(compare(n1, n2), 0);
+  bigint n3(43);
+  EXPECT_LT(compare(n1, n3), 0);
+  EXPECT_GT(compare(n3, n1), 0);
+  bigint n4(42 * 0x100000001);
+  EXPECT_LT(compare(n2, n4), 0);
+  EXPECT_GT(compare(n4, n2), 0);
+}
+
+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);
+  EXPECT_GT(add_compare(bigint(1) <<= 32, bigint(0), bigint(0xffffffff)), 0);
+  EXPECT_GT(add_compare(bigint(0), bigint(1) <<= 32, bigint(0xffffffff)), 0);
+  EXPECT_GT(add_compare(bigint(42), bigint(1), bigint(42)), 0);
+  EXPECT_GT(add_compare(bigint(0xffffffff), bigint(1), bigint(0xffffffff)), 0);
+  EXPECT_LT(add_compare(bigint(10), bigint(10), bigint(22)), 0);
+  EXPECT_LT(add_compare(bigint(0x100000010), bigint(0x100000010),
+                        bigint(0x300000010)),
+            0);
+  EXPECT_GT(add_compare(bigint(0x1ffffffff), bigint(0x100000002),
+                        bigint(0x300000000)),
+            0);
+  EXPECT_EQ(add_compare(bigint(0x1ffffffff), bigint(0x100000002),
+                        bigint(0x300000001)),
+            0);
+  EXPECT_LT(add_compare(bigint(0x1ffffffff), bigint(0x100000002),
+                        bigint(0x300000002)),
+            0);
+  EXPECT_LT(add_compare(bigint(0x1ffffffff), bigint(0x100000002),
+                        bigint(0x300000003)),
+            0);
+}
+
+TEST(bigint_test, shift_left) {
+  bigint n(0x42);
+  n <<= 0;
+  EXPECT_EQ(fmt::to_string(n), "42");
+  n <<= 1;
+  EXPECT_EQ(fmt::to_string(n), "84");
+  n <<= 25;
+  EXPECT_EQ(fmt::to_string(n), "108000000");
+}
+
+TEST(bigint_test, multiply) {
+  bigint n(0x42);
+  EXPECT_THROW(n *= 0, assertion_failure);
+  n *= 1;
+  EXPECT_EQ(fmt::to_string(n), "42");
+
+  n *= 2;
+  EXPECT_EQ(fmt::to_string(n), "84");
+  n *= 0x12345678;
+  EXPECT_EQ(fmt::to_string(n), "962fc95e0");
+
+  bigint bigmax(max_value<uint32_t>());
+  bigmax *= max_value<uint32_t>();
+  EXPECT_EQ(fmt::to_string(bigmax), "fffffffe00000001");
+
+  const auto max64 = max_value<uint64_t>();
+  bigmax = max64;
+  bigmax *= max64;
+  EXPECT_EQ(fmt::to_string(bigmax), "fffffffffffffffe0000000000000001");
+
+  const auto max128 = (fmt::detail::uint128_t(max64) << 64) | max64;
+  bigmax = max128;
+  bigmax *= max128;
+  EXPECT_EQ(fmt::to_string(bigmax),
+            "fffffffffffffffffffffffffffffffe00000000000000000000000000000001");
+}
+
+TEST(bigint_test, square) {
+  bigint n0(0);
+  n0.square();
+  EXPECT_EQ(fmt::to_string(n0), "0");
+  bigint n1(0x100);
+  n1.square();
+  EXPECT_EQ(fmt::to_string(n1), "10000");
+  bigint n2(0xfffffffff);
+  n2.square();
+  EXPECT_EQ(fmt::to_string(n2), "ffffffffe000000001");
+  bigint n3(max_value<uint64_t>());
+  n3.square();
+  EXPECT_EQ(fmt::to_string(n3), "fffffffffffffffe0000000000000001");
+  bigint n4;
+  n4.assign_pow10(10);
+  EXPECT_EQ(fmt::to_string(n4), "2540be400");
+}
+
+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(bigint_test, divmod_assign_self) {
+  bigint n(100);
+  EXPECT_THROW(n.divmod_assign(n), assertion_failure);
+}
+
+TEST(bigint_test, divmod_assign_unaligned) {
+  // (42 << 340) / pow(10, 100):
+  bigint n1(42);
+  n1 <<= 340;
+  bigint n2;
+  n2.assign_pow10(100);
+  int result = n1.divmod_assign(n2);
+  EXPECT_EQ(result, 9406);
+  EXPECT_EQ(fmt::to_string(n1),
+            "10f8353019583bfc29ffc8f564e1b9f9d819dbb4cf783e4507eca1539220p96");
+}
+
+TEST(bigint_test, divmod_assign) {
+  // 100 / 10:
+  bigint n1(100);
+  int result = n1.divmod_assign(bigint(10));
+  EXPECT_EQ(result, 10);
+  EXPECT_EQ(fmt::to_string(n1), "0");
+  // pow(10, 100) / (42 << 320):
+  n1.assign_pow10(100);
+  result = n1.divmod_assign(bigint(42) <<= 320);
+  EXPECT_EQ(result, 111);
+  EXPECT_EQ(fmt::to_string(n1),
+            "13ad2594c37ceb0b2784c4ce0bf38ace408e211a7caab24308a82e8f10p96");
+  // 42 / 100:
+  bigint n2(42);
+  n1.assign_pow10(2);
+  result = n2.divmod_assign(n1);
+  EXPECT_EQ(result, 0);
+  EXPECT_EQ(fmt::to_string(n2), "2a");
+}
+
+template <bool is_iec559> void run_double_tests() {
   fmt::print("warning: double is not IEC559, skipping FP tests\n");
 }
 
-template <>
-void test_construct_from_double<true>() {
-  auto v = fp(1.23);
-  EXPECT_EQ(v.f, 0x13ae147ae147aeu);
-  EXPECT_EQ(v.e, -52);
+template <> void run_double_tests<true>() {
+  // Construct from double.
+  EXPECT_EQ(fp(1.23), fp(0x13ae147ae147aeu, -52));
 }
 
-TEST(FPTest, ConstructFromDouble) {
-  test_construct_from_double<std::numeric_limits<double>::is_iec559>();
+TEST(fp_test, double_tests) {
+  run_double_tests<std::numeric_limits<double>::is_iec559>();
 }
 
-TEST(FPTest, Normalize) {
-  auto v = fp(0xbeef, 42);
-  v.normalize();
-  EXPECT_EQ(0xbeef000000000000, v.f);
-  EXPECT_EQ(-6, v.e);
+TEST(fp_test, normalize) {
+  const auto v = fp(0xbeef, 42);
+  auto normalized = normalize(v);
+  EXPECT_EQ(normalized.f, 0xbeef000000000000);
+  EXPECT_EQ(normalized.e, -6);
 }
 
-TEST(FPTest, ComputeBoundariesSubnormal) {
-  auto v = fp(0xbeef, 42);
-  fp lower, upper;
-  v.compute_boundaries(lower, upper);
-  EXPECT_EQ(0xbeee800000000000, lower.f);
-  EXPECT_EQ(-6, lower.e);
-  EXPECT_EQ(0xbeef800000000000, upper.f);
-  EXPECT_EQ(-6, upper.e);
-}
-
-TEST(FPTest, ComputeBoundaries) {
-  auto v = fp(0x10000000000000, 42);
-  fp lower, upper;
-  v.compute_boundaries(lower, upper);
-  EXPECT_EQ(0x7ffffffffffffe00, lower.f);
-  EXPECT_EQ(31, lower.e);
-  EXPECT_EQ(0x8000000000000400, upper.f);
-  EXPECT_EQ(31, upper.e);
-}
-
-TEST(FPTest, Subtract) {
-  auto v = fp(123, 1) - fp(102, 1);
-  EXPECT_EQ(v.f, 21u);
-  EXPECT_EQ(v.e, 1);
-}
-
-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);
@@ -84,119 +196,208 @@ TEST(FPTest, Multiply) {
   EXPECT_EQ(v.e, 4 + 8 + 64);
 }
 
-TEST(FPTest, GetCachedPower) {
-  typedef std::numeric_limits<double> limits;
+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;
-    auto fp = fmt::internal::get_cached_power(exp, dec_exp);
-    EXPECT_LE(exp, fp.e);
-    int dec_exp_step = 8;
-    EXPECT_LE(fp.e, exp + dec_exp_step * log2(10));
-    EXPECT_DOUBLE_EQ(pow(10, dec_exp), ldexp(fp.f, fp.e));
+    auto power = fmt::detail::get_cached_power(exp, dec_exp);
+    bigint exact, cache(power.f);
+    if (dec_exp >= 0) {
+      exact.assign_pow10(dec_exp);
+      if (power.e <= 0)
+        exact <<= -power.e;
+      else
+        cache <<= power.e;
+      exact.align(cache);
+      cache.align(exact);
+      auto exact_str = fmt::to_string(exact);
+      auto cache_str = fmt::to_string(cache);
+      EXPECT_EQ(exact_str.size(), cache_str.size());
+      EXPECT_EQ(exact_str.substr(0, 15), cache_str.substr(0, 15));
+      int diff = cache_str[15] - exact_str[15];
+      if (diff == 1)
+        EXPECT_GT(exact_str[16], '8');
+      else
+        EXPECT_EQ(diff, 0);
+    } else {
+      cache.assign_pow10(-dec_exp);
+      cache *= power.f + 1;  // Inexact check.
+      exact = 1;
+      exact <<= -power.e;
+      exact.align(cache);
+      auto exact_str = fmt::to_string(exact);
+      auto cache_str = fmt::to_string(cache);
+      EXPECT_EQ(exact_str.size(), cache_str.size());
+      EXPECT_EQ(exact_str.substr(0, 16), cache_str.substr(0, 16));
+    }
   }
 }
 
-template <typename T>
-struct ValueExtractor: fmt::internal::function<T> {
-  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()));
-  }
-};
-
-TEST(FormatTest, ArgConverter) {
-  long long value = std::numeric_limits<long long>::max();
-  auto arg = fmt::internal::make_arg<fmt::format_context>(value);
-  visit(fmt::internal::arg_converter<long long, fmt::format_context>(arg, 'd'),
-        arg);
-  EXPECT_EQ(value, visit(ValueExtractor<long long>(), arg));
+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),
+      float_info::kappa -
+          floor_log10_pow2(std::numeric_limits<float>::min_exponent -
+                           fmt::detail::num_significand_bits<float>() - 1));
+  using double_info = fmt::detail::dragonbox::float_info<double>;
+  EXPECT_EQ(
+      fmt::detail::const_check(double_info::max_k),
+      double_info::kappa -
+          floor_log10_pow2(std::numeric_limits<double>::min_exponent -
+                           fmt::detail::num_significand_bits<double>() - 1));
 }
 
-TEST(FormatTest, FormatNegativeNaN) {
-  double nan = std::numeric_limits<double>::quiet_NaN();
-  if (fmt::internal::fputil::isnegative(-nan))
-    EXPECT_EQ("-nan", fmt::format("{}", -nan));
-  else
-    fmt::print("Warning: compiler doesn't handle negative NaN correctly");
+TEST(fp_test, get_round_direction) {
+  using fmt::detail::get_round_direction;
+  using fmt::detail::round_direction;
+  EXPECT_EQ(get_round_direction(100, 50, 0), round_direction::down);
+  EXPECT_EQ(get_round_direction(100, 51, 0), round_direction::up);
+  EXPECT_EQ(get_round_direction(100, 40, 10), round_direction::down);
+  EXPECT_EQ(get_round_direction(100, 60, 10), round_direction::up);
+  for (size_t i = 41; i < 60; ++i)
+    EXPECT_EQ(get_round_direction(100, i, 10), round_direction::unknown);
+  uint64_t max = max_value<uint64_t>();
+  EXPECT_THROW(get_round_direction(100, 100, 0), assertion_failure);
+  EXPECT_THROW(get_round_direction(100, 0, 100), assertion_failure);
+  EXPECT_THROW(get_round_direction(100, 0, 50), assertion_failure);
+  // Check that remainder + error doesn't overflow.
+  EXPECT_EQ(get_round_direction(max, max - 1, 2), round_direction::up);
+  // Check that 2 * (remainder + error) doesn't overflow.
+  EXPECT_EQ(get_round_direction(max, max / 2 + 1, max / 2),
+            round_direction::unknown);
+  // Check that remainder - error doesn't overflow.
+  EXPECT_EQ(get_round_direction(100, 40, 41), round_direction::unknown);
+  // Check that 2 * (remainder - error) doesn't overflow.
+  EXPECT_EQ(get_round_direction(max, max - 1, 1), round_direction::up);
 }
 
-TEST(FormatTest, StrError) {
-  char *message = nullptr;
-  char buffer[BUFFER_SIZE];
-  EXPECT_ASSERT(fmt::safe_strerror(EDOM, message = nullptr, 0), "invalid buffer");
-  EXPECT_ASSERT(fmt::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::safe_strerror(error_code, message = buffer, BUFFER_SIZE);
-  EXPECT_EQ(0, result);
-  std::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.
-#ifndef __MINGW32__
-  result = fmt::safe_strerror(error_code, message = buffer, message_size);
-  EXPECT_EQ(ERANGE, result);
-  result = fmt::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(fp_test, fixed_handler) {
+  struct handler : fmt::detail::gen_digits_handler {
+    char buffer[10];
+    handler(int prec = 0) : fmt::detail::gen_digits_handler() {
+      buf = buffer;
+      precision = prec;
+    }
+  };
+  handler().on_digit('0', 100, 99, 0, false);
+  EXPECT_THROW(handler().on_digit('0', 100, 100, 0, false), assertion_failure);
+  namespace digits = fmt::detail::digits;
+  EXPECT_EQ(handler(1).on_digit('0', 100, 10, 10, false), digits::error);
+  // Check that divisor - error doesn't overflow.
+  EXPECT_EQ(handler(1).on_digit('0', 100, 10, 101, false), digits::error);
+  // Check that 2 * error doesn't overflow.
+  uint64_t max = max_value<uint64_t>();
+  EXPECT_EQ(handler(1).on_digit('0', max, 10, max - 1, false), digits::error);
 }
 
-TEST(FormatTest, FormatErrorCode) {
+TEST(fp_test, grisu_format_compiles_with_on_ieee_double) {
+  auto buf = fmt::memory_buffer();
+  format_float(0.42, -1, fmt::detail::float_specs(), buf);
+}
+
+TEST(format_impl_test, format_error_code) {
   std::string msg = "error 42", sep = ": ";
   {
-    fmt::memory_buffer buffer;
-    format_to(buffer, "garbage");
-    fmt::format_error_code(buffer, 42, "test");
-    EXPECT_EQ("test: " + msg, to_string(buffer));
+    auto buffer = fmt::memory_buffer();
+    format_to(fmt::appender(buffer), "garbage");
+    fmt::detail::format_error_code(buffer, 42, "test");
+    EXPECT_EQ(to_string(buffer), "test: " + msg);
   }
   {
-    fmt::memory_buffer buffer;
-    std::string prefix(
-        fmt::inline_buffer_size - msg.size() - sep.size() + 1, 'x');
-    fmt::format_error_code(buffer, 42, prefix);
+    auto buffer = fmt::memory_buffer();
+    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));
   }
   int codes[] = {42, -1};
-  for (std::size_t i = 0, n = sizeof(codes) / sizeof(*codes); i < n; ++i) {
+  for (size_t i = 0, n = sizeof(codes) / sizeof(*codes); i < n; ++i) {
     // 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');
-    fmt::format_error_code(buffer, codes[i], prefix);
+    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));
-    std::size_t size = fmt::inline_buffer_size;
+    size_t size = fmt::inline_buffer_size;
     EXPECT_EQ(size, buffer.size());
     buffer.resize(0);
     // Test with a message that doesn't fit into the buffer.
     prefix += 'x';
-    fmt::format_error_code(buffer, codes[i], prefix);
-    EXPECT_EQ(msg, to_string(buffer));
+    fmt::detail::format_error_code(buffer, codes[i], prefix);
+    EXPECT_EQ(to_string(buffer), msg);
   }
 }
 
-TEST(FormatTest, CountCodePoints) {
-  EXPECT_EQ(4, fmt::internal::count_code_points(fmt::u8string_view("ёжик")));
+TEST(format_impl_test, compute_width) {
+  EXPECT_EQ(4,
+            fmt::detail::compute_width(
+                fmt::basic_string_view<fmt::detail::char8_type>(
+                    reinterpret_cast<const fmt::detail::char8_type*>("ёжик"))));
 }
 
-TEST(ColorsTest, Colors) {
-  EXPECT_WRITE(stdout, fmt::print(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(fmt::color::blue, "blue"),
-               "\x1b[38;2;000;000;255mblue\x1b[0m");
+// Tests fmt::detail::count_digits for integer type Int.
+template <typename Int> void test_count_digits() {
+  for (Int i = 0; i < 10; ++i) EXPECT_EQ(1u, fmt::detail::count_digits(i));
+  for (Int i = 1, n = 1, end = max_value<Int>() / 10; n <= end; ++i) {
+    n *= 10;
+    EXPECT_EQ(fmt::detail::count_digits(n - 1), i);
+    EXPECT_EQ(fmt::detail::count_digits(n), i + 1);
+  }
 }
+
+TEST(format_impl_test, count_digits) {
+  test_count_digits<uint32_t>();
+  test_count_digits<uint64_t>();
+}
+
+#if FMT_USE_FLOAT128
+TEST(format_impl_test, write_float128) {
+  auto s = std::string();
+  fmt::detail::write<char>(std::back_inserter(s), __float128(42));
+  EXPECT_EQ(s, "42");
+}
+#endif
+
+struct double_double {
+  double a;
+  double b;
+
+  explicit constexpr double_double(double a_val = 0, double b_val = 0)
+      : a(a_val), b(b_val) {}
+
+  operator double() const { return a + b; }
+  auto operator-() const -> double_double { return double_double(-a, -b); }
+};
+
+bool operator>=(const double_double& lhs, const double_double& rhs) {
+  return lhs.a + lhs.b >= rhs.a + rhs.b;
+}
+
+namespace std {
+template <> struct is_floating_point<double_double> : std::true_type {};
+template <> struct numeric_limits<double_double> {
+  // is_iec559 is true for double-double in libstdc++.
+  static constexpr bool is_iec559 = true;
+  static constexpr int digits = 106;
+};
+}  // namespace std
+
+TEST(format_impl_test, write_double_double) {
+  auto s = std::string();
+  fmt::detail::write<char>(std::back_inserter(s), double_double(42), {});
+#ifndef _MSC_VER  // MSVC has an issue with specializing is_floating_point.
+  EXPECT_EQ(s, "42");
+#endif
+}
+
+#ifdef _WIN32
+#  include <windows.h>
+
+TEST(format_impl_test, write_console_signature) {
+  decltype(::WriteConsoleW)* p = fmt::detail::WriteConsoleW;
+  (void)p;
+}
+#endif

test/fuzzing/.gitignore

@@ -0,0 +1,3 @@
+# ignore artifacts from the build.sh script
+build-*/
+

test/fuzzing/CMakeLists.txt

@@ -0,0 +1,30 @@
+# Copyright (c) 2019, Paul Dreik
+# License: see LICENSE.rst in the fmt root directory
+
+# Link in the main function. Useful for reproducing, kcov, gdb, afl, valgrind.
+# (Note that libFuzzer can also reproduce, just pass it the files.)
+option(FMT_FUZZ_LINKMAIN "Enables the reproduce mode, instead of libFuzzer" On)
+
+# For oss-fuzz - insert $LIB_FUZZING_ENGINE into the link flags, but only for
+# the fuzz targets, otherwise the CMake configuration step fails.
+set(FMT_FUZZ_LDFLAGS "" CACHE STRING "LDFLAGS for the fuzz targets")
+
+# Adds a binary for reproducing, i.e. no fuzzing, just enables replaying data
+# through the fuzzers.
+function(add_fuzzer source)
+  get_filename_component(basename ${source} NAME_WE)
+  set(name ${basename}-fuzzer)
+  add_executable(${name} ${source} fuzzer-common.h)
+  if (FMT_FUZZ_LINKMAIN)
+    target_sources(${name} PRIVATE main.cc)
+  endif ()
+  target_link_libraries(${name} PRIVATE fmt)
+  if (FMT_FUZZ_LDFLAGS)
+    target_link_libraries(${name} PRIVATE ${FMT_FUZZ_LDFLAGS})
+  endif ()
+  target_compile_features(${name} PRIVATE cxx_generic_lambdas)
+endfunction()
+
+foreach (source chrono-duration.cc chrono-timepoint.cc float.cc named-arg.cc one-arg.cc two-args.cc)
+  add_fuzzer(${source})
+endforeach ()

test/fuzzing/README.md

@@ -0,0 +1,25 @@
+# Running the fuzzers locally
+
+There is a [helper script](build.sh) to build the fuzzers, which has only been
+tested on Debian and Ubuntu linux so far. There should be no problems fuzzing on
+Windows (using clang>=8) or on Mac, but the script will probably not work out of
+the box.
+
+Something along
+```sh
+mkdir build
+cd build
+export CXX=clang++
+export CXXFLAGS="-fsanitize=fuzzer-no-link -DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION= -g"
+cmake .. -DFMT_SAFE_DURATION_CAST=On -DFMT_FUZZ=On -DFMT_FUZZ_LINKMAIN=Off -DFMT_FUZZ_LDFLAGS="-fsanitize=fuzzer"
+cmake --build .
+```
+should work to build the fuzzers for all platforms which clang supports.
+
+Execute a fuzzer with for instance
+```sh
+cd build
+export UBSAN_OPTIONS=halt_on_error=1
+mkdir out_chrono
+bin/fuzzer_chrono_duration out_chrono
+```

test/fuzzing/build.sh

@@ -0,0 +1,90 @@
+#!/bin/sh
+#
+# Creates fuzzer builds of various kinds
+# - oss-fuzz emulated mode (makes sure a simulated invocation by oss-fuzz works)
+# - libFuzzer build (you will need clang)
+# - afl build (you will need afl)
+#
+#
+# Copyright (c) 2019 Paul Dreik
+#
+# For the license information refer to format.h.
+
+set -e
+me=$(basename $0)
+root=$(readlink -f "$(dirname "$0")/../..")
+
+
+echo $me: root=$root
+
+here=$(pwd)
+
+CXXFLAGSALL="-DFUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION= -g"
+CMAKEFLAGSALL="$root -GNinja -DCMAKE_BUILD_TYPE=Debug -DFMT_DOC=Off -DFMT_TEST=Off -DFMT_FUZZ=On -DCMAKE_CXX_STANDARD=17"
+
+CLANG=clang++-11
+
+# For performance analysis of the fuzzers.
+builddir=$here/build-fuzzers-perfanalysis
+mkdir -p $builddir
+cd $builddir
+CXX="ccache g++" CXXFLAGS="$CXXFLAGSALL -g" cmake \
+$CMAKEFLAGSALL \
+-DFMT_FUZZ_LINKMAIN=On \
+-DCMAKE_BUILD_TYPE=Release
+
+cmake --build $builddir
+
+# Builds the fuzzers as oss-fuzz does.
+builddir=$here/build-fuzzers-ossfuzz
+mkdir -p $builddir
+cd $builddir
+CXX=$CLANG \
+CXXFLAGS="$CXXFLAGSALL -fsanitize=fuzzer-no-link" cmake \
+cmake $CMAKEFLAGSALL \
+-DFMT_FUZZ_LINKMAIN=Off \
+-DFMT_FUZZ_LDFLAGS="-fsanitize=fuzzer"
+
+cmake --build $builddir
+
+
+# Builds fuzzers for local fuzzing with libfuzzer with asan+usan.
+builddir=$here/build-fuzzers-libfuzzer
+mkdir -p $builddir
+cd $builddir
+CXX=$CLANG \
+CXXFLAGS="$CXXFLAGSALL -fsanitize=fuzzer-no-link,address,undefined" cmake \
+cmake $CMAKEFLAGSALL \
+-DFMT_FUZZ_LINKMAIN=Off \
+-DFMT_FUZZ_LDFLAGS="-fsanitize=fuzzer"
+
+cmake --build $builddir
+
+# Builds a fast fuzzer for making coverage fast.
+builddir=$here/build-fuzzers-fast
+mkdir -p $builddir
+cd $builddir
+CXX=$CLANG \
+CXXFLAGS="$CXXFLAGSALL -fsanitize=fuzzer-no-link -O3" cmake \
+cmake $CMAKEFLAGSALL \
+-DFMT_FUZZ_LINKMAIN=Off \
+-DFMT_FUZZ_LDFLAGS="-fsanitize=fuzzer" \
+ -DCMAKE_BUILD_TYPE=Release
+
+cmake --build $builddir
+
+
+# Builds fuzzers for local fuzzing with afl.
+builddir=$here/build-fuzzers-afl
+mkdir -p $builddir
+cd $builddir
+CXX="afl-g++" \
+CXXFLAGS="$CXXFLAGSALL -fsanitize=address,undefined" \
+cmake $CMAKEFLAGSALL \
+-DFMT_FUZZ_LINKMAIN=On
+
+cmake --build $builddir
+
+
+echo $me: all good
+

test/fuzzing/chrono-duration.cc

@@ -0,0 +1,136 @@
+// Copyright (c) 2019, Paul Dreik
+// For the license information refer to format.h.
+
+#include <fmt/chrono.h>
+
+#include <cstdint>
+
+#include "fuzzer-common.h"
+
+template <typename Period, typename Rep>
+void invoke_inner(fmt::string_view format_str, Rep rep) {
+  auto value = std::chrono::duration<Rep, Period>(rep);
+  try {
+#if FMT_FUZZ_FORMAT_TO_STRING
+    std::string message = fmt::format(format_str, value);
+#else
+    auto buf = fmt::memory_buffer();
+    fmt::format_to(std::back_inserter(buf), format_str, value);
+#endif
+  } catch (std::exception&) {
+  }
+}
+
+// Rep is a duration's representation type.
+template <typename Rep>
+void invoke_outer(const uint8_t* data, size_t size, int period) {
+  // Always use a fixed location of the data.
+  static_assert(sizeof(Rep) <= fixed_size, "fixed size is too small");
+  if (size <= fixed_size + 1) return;
+
+  const Rep rep = assign_from_buf<Rep>(data);
+  data += fixed_size;
+  size -= fixed_size;
+
+  // data is already allocated separately in libFuzzer so reading past the end
+  // will most likely be detected anyway.
+  const auto format_str = fmt::string_view(as_chars(data), size);
+
+  // yocto, zepto, zetta and yotta are not handled.
+  switch (period) {
+  case 1:
+    invoke_inner<std::atto>(format_str, rep);
+    break;
+  case 2:
+    invoke_inner<std::femto>(format_str, rep);
+    break;
+  case 3:
+    invoke_inner<std::pico>(format_str, rep);
+    break;
+  case 4:
+    invoke_inner<std::nano>(format_str, rep);
+    break;
+  case 5:
+    invoke_inner<std::micro>(format_str, rep);
+    break;
+  case 6:
+    invoke_inner<std::milli>(format_str, rep);
+    break;
+  case 7:
+    invoke_inner<std::centi>(format_str, rep);
+    break;
+  case 8:
+    invoke_inner<std::deci>(format_str, rep);
+    break;
+  case 9:
+    invoke_inner<std::deca>(format_str, rep);
+    break;
+  case 10:
+    invoke_inner<std::kilo>(format_str, rep);
+    break;
+  case 11:
+    invoke_inner<std::mega>(format_str, rep);
+    break;
+  case 12:
+    invoke_inner<std::giga>(format_str, rep);
+    break;
+  case 13:
+    invoke_inner<std::tera>(format_str, rep);
+    break;
+  case 14:
+    invoke_inner<std::peta>(format_str, rep);
+    break;
+  case 15:
+    invoke_inner<std::exa>(format_str, rep);
+    break;
+  }
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  if (size <= 4) return 0;
+
+  const auto representation = data[0];
+  const auto period = data[1];
+  data += 2;
+  size -= 2;
+
+  switch (representation) {
+  case 1:
+    invoke_outer<char>(data, size, period);
+    break;
+  case 2:
+    invoke_outer<signed char>(data, size, period);
+    break;
+  case 3:
+    invoke_outer<unsigned char>(data, size, period);
+    break;
+  case 4:
+    invoke_outer<short>(data, size, period);
+    break;
+  case 5:
+    invoke_outer<unsigned short>(data, size, period);
+    break;
+  case 6:
+    invoke_outer<int>(data, size, period);
+    break;
+  case 7:
+    invoke_outer<unsigned int>(data, size, period);
+    break;
+  case 8:
+    invoke_outer<long>(data, size, period);
+    break;
+  case 9:
+    invoke_outer<unsigned long>(data, size, period);
+    break;
+  case 10:
+    invoke_outer<float>(data, size, period);
+    break;
+  case 11:
+    invoke_outer<double>(data, size, period);
+    break;
+  case 12:
+    invoke_outer<long double>(data, size, period);
+    break;
+  }
+  return 0;
+}

test/fuzzing/chrono-timepoint.cc

@@ -0,0 +1,32 @@
+// Copyright (c) 2021, Paul Dreik
+// For license information refer to format.h.
+#include <fmt/chrono.h>
+
+#include "fuzzer-common.h"
+
+/*
+ * a fuzzer for the chrono timepoints formatters
+ * C is a clock (std::chrono::system_clock etc)
+ */
+template <typename C> void doit(const uint8_t* data, size_t size) {
+  using Rep = typename C::time_point::rep;
+  constexpr auto N = sizeof(Rep);
+  if (size < N) return;
+
+  const auto x = assign_from_buf<Rep>(data);
+  typename C::duration dur{x};
+  typename C::time_point timepoint{dur};
+  data += N;
+  size -= N;
+  data_to_string format_str(data, size);
+
+  std::string message = fmt::format(format_str.get(), timepoint);
+}
+
+extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
+  try {
+    doit<std::chrono::system_clock>(data, size);
+  } catch (...) {
+  }
+  return 0;
+}

test/fuzzing/float.cc

@@ -0,0 +1,39 @@
+// A fuzzer for floating-point formatter.
+// For the license information refer to format.h.
+
+#include <fmt/format.h>
+
+#include <cstdint>
+#include <cstdlib>
+#include <limits>
+#include <stdexcept>
+
+#include "fuzzer-common.h"
+
+void check_round_trip(fmt::string_view format_str, double value) {
+  auto buffer = fmt::memory_buffer();
+  fmt::format_to(std::back_inserter(buffer), format_str, value);
+
+  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;
+  }
+
+  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/fuzzing/fuzzer-common.h

@@ -0,0 +1,77 @@
+// Copyright (c) 2019, Paul Dreik
+// For the license information refer to format.h.
+
+#ifndef FUZZER_COMMON_H
+#define FUZZER_COMMON_H
+
+#include <fmt/core.h>
+
+#include <cstdint>  // std::uint8_t
+#include <cstring>  // memcpy
+#include <vector>
+
+// One can format to either a string, or a buffer. The latter is faster, but
+// one may be interested in formatting to a string instead to verify it works
+// as intended. To avoid a combinatoric explosion, select this at compile time
+// instead of dynamically from the fuzz data.
+#define FMT_FUZZ_FORMAT_TO_STRING 0
+
+// If {fmt} is given a buffer that is separately allocated, chances that address
+// sanitizer detects out of bound reads is much higher. However, it slows down
+// the fuzzing.
+#define FMT_FUZZ_SEPARATE_ALLOCATION 1
+
+// The size of the largest possible type in use.
+// To let the the fuzzer mutation be efficient at cross pollinating between
+// different types, use a fixed size format. The same bit pattern, interpreted
+// as another type, is likely interesting.
+constexpr auto fixed_size = 16;
+
+// Casts data to a char pointer.
+template <typename T> inline const char* as_chars(const T* data) {
+  return reinterpret_cast<const char*>(data);
+}
+
+// Casts data to a byte pointer.
+template <typename T> inline const std::uint8_t* as_bytes(const T* data) {
+  return reinterpret_cast<const std::uint8_t*>(data);
+}
+
+// Blits bytes from data to form an (assumed trivially constructible) object
+// of type Item.
+template <class Item> inline Item assign_from_buf(const std::uint8_t* data) {
+  auto item = Item();
+  std::memcpy(&item, data, sizeof(Item));
+  return item;
+}
+
+// Reads a boolean value by looking at the first byte from data.
+template <> inline bool assign_from_buf<bool>(const std::uint8_t* data) {
+  return *data != 0;
+}
+
+struct data_to_string {
+#if FMT_FUZZ_SEPARATE_ALLOCATION
+  std::vector<char> buffer;
+
+  data_to_string(const uint8_t* data, size_t size, bool add_terminator = false)
+      : buffer(size + (add_terminator ? 1 : 0)) {
+    if (size) {
+      std::memcpy(buffer.data(), data, size);
+    }
+  }
+
+  fmt::string_view get() const { return {buffer.data(), buffer.size()}; }
+#else
+  fmt::string_view sv;
+
+  data_to_string(const uint8_t* data, size_t size, bool = false)
+      : str(as_chars(data), size) {}
+
+  fmt::string_view get() const { return sv; }
+#endif
+
+  const char* data() const { return get().data(); }
+};
+
+#endif  // FUZZER_COMMON_H