Update version

* Allow disabling floating point support

Add FMT_USE_FLOAT, FMT_USE_DOUBLE and FMT_USE_LONG_DOUBLE to allow a
user of the library to configure the float types they want to allow.
This is specially useful in embedded environements where code size is
important.

* Avoid conditional macros to disable float support

* Add is_supported_floating_point constexpr function

* Fix empty-body warning

.gitignore

@@ -1,4 +1,5 @@
 .vscode/
+.vs/
 
 *.iml
 .idea/

.travis.yml

@@ -92,45 +92,6 @@ matrix:
       # g++ 4.8 on Linux with C++11
     - env: COMPILER=g++-4.8 BUILD=Debug STANDARD=11
       compiler: gcc
-    - name: Android NDK (Gradle)
-      language: android
-      addons:
-        apt:
-          update: true
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - ninja-build
-            - curl
-            - tree
-      android:
-        components:
-          - tools
-          - platform-tools
-          - android-25 # 7.0
-          - android-27 # 8.1
-          - android-28 # 9.0
-          - build-tools-28.0.3
-      before_install:
-        # Install Gradle from https://sdkman.io/
-        - curl -s "https://get.sdkman.io" | bash > /dev/null
-        - source "$HOME/.sdkman/bin/sdkman-init.sh"
-        - sdk version
-        - sdk install gradle
-        - sdk use gradle
-        - gradle --version
-      install:
-        # Accept SDK Licenses + Install NDK
-        - yes | sdkmanager --update > /dev/null 2>&1
-        - sdkmanager ndk-bundle > /dev/null 2>&1
-      before_script:
-        - pushd ./support
-      script:
-        - gradle clean
-        - gradle assemble
-      after_success:
-        - popd;
-        - tree ./libs
 
 before_script:
   - if [[ "${TRAVIS_OS_NAME}" == "linux" ]]; then export CXX=${COMPILER}; fi

CMakeLists.txt

@@ -24,13 +24,24 @@ function(join result_var)
   set(${result_var} "${result}" PARENT_SCOPE)
 endfunction()
 
+# 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(SET_VERBOSE "" "" "CACHE" ${ARGN})
+  list(GET SET_VERBOSE_CACHE 0 type)
+  list(REMOVE_AT SET_VERBOSE_CACHE 0)
+  join(doc ${SET_VERBOSE_CACHE})
+  set(${SET_VERBOSE_UNPARSED_ARGUMENTS} 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 (MASTER_PROJECT AND 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})
+  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 ()
 
 option(FMT_PEDANTIC "Enable extra warnings and expensive tests." OFF)
@@ -42,6 +53,7 @@ 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_FUZZ "Generate the fuzz target." OFF)
+option(FMT_CUDA_TEST "Generate the cuda-test target." OFF)
 
 project(FMT CXX)
 
@@ -60,7 +72,9 @@ 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")
@@ -68,7 +82,13 @@ set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH}
 include(cxx14)
 include(CheckCXXCompilerFlag)
 
-set(FMT_REQUIRED_FEATURES cxx_auto_type cxx_variadic_templates)
+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 (CMAKE_CXX_COMPILER_ID MATCHES "GNU")
   set(PEDANTIC_COMPILE_FLAGS -pedantic-errors -Wall -Wextra -pedantic
@@ -78,7 +98,7 @@ if (CMAKE_CXX_COMPILER_ID MATCHES "GNU")
       -Wcast-align -Wnon-virtual-dtor
       -Wctor-dtor-privacy -Wdisabled-optimization
       -Winvalid-pch -Woverloaded-virtual
-      -Wconversion
+      -Wconversion -Wswitch-enum
       -Wno-ctor-dtor-privacy -Wno-format-nonliteral -Wno-shadow)
   if (NOT CMAKE_CXX_COMPILER_VERSION VERSION_LESS 4.6)
       set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS} -Wnoexcept
@@ -98,7 +118,7 @@ endif ()
 
 if (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
   set(PEDANTIC_COMPILE_FLAGS -Wall -Wextra -pedantic -Wconversion
-      -Wno-sign-conversion)
+      -Wno-sign-conversion -Wdeprecated -Wweak-vtables)
   check_cxx_compiler_flag(-Wzero-as-null-pointer-constant HAS_NULLPTR_WARNING)
   if (HAS_NULLPTR_WARNING)
     set(PEDANTIC_COMPILE_FLAGS ${PEDANTIC_COMPILE_FLAGS}
@@ -122,7 +142,9 @@ if (MASTER_PROJECT AND CMAKE_GENERATOR MATCHES "Visual Studio")
     set(MSBUILD_SETUP "call \"${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}\" %*")
@@ -135,10 +157,8 @@ endif ()
 
 include(CheckSymbolExists)
 if (WIN32)
-  check_symbol_exists(open io.h HAVE_OPEN)
   check_symbol_exists(_strtod_l "${strtod_l_headers}" HAVE_STRTOD_L)
 else ()
-  check_symbol_exists(open fcntl.h HAVE_OPEN)
   check_symbol_exists(strtod_l "${strtod_l_headers}" HAVE_STRTOD_L)
 endif ()
 
@@ -152,13 +172,8 @@ endfunction()
 
 # Define the fmt library, its includes and the needed defines.
 add_headers(FMT_HEADERS chrono.h color.h compile.h core.h format.h format-inl.h
-                        locale.h ostream.h printf.h ranges.h
-                        safe-duration-cast.h)
-set(FMT_SOURCES src/format.cc)
-if (HAVE_OPEN)
-  add_headers(FMT_HEADERS posix.h)
-  set(FMT_SOURCES ${FMT_SOURCES} src/posix.cc)
-endif ()
+                        locale.h os.h ostream.h posix.h printf.h ranges.h)
+set(FMT_SOURCES src/format.cc src/os.cc)
 
 add_library(fmt ${FMT_SOURCES} ${FMT_HEADERS} README.rst ChangeLog.rst)
 add_library(fmt::fmt ALIAS fmt)
@@ -180,12 +195,21 @@ target_include_directories(fmt PUBLIC
   $<BUILD_INTERFACE:${PROJECT_SOURCE_DIR}/include>
   $<INSTALL_INTERFACE:include>)
 
+set(FMT_DEBUG_POSTFIX d CACHE STRING "Debug library postfix.")
+
 set_target_properties(fmt PROPERTIES
   VERSION ${FMT_VERSION} SOVERSION ${CPACK_PACKAGE_VERSION_MAJOR}
-  DEBUG_POSTFIX d)
+  DEBUG_POSTFIX "${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")
     # 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)
@@ -200,7 +224,6 @@ 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
@@ -211,8 +234,9 @@ target_include_directories(fmt-header-only INTERFACE
 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 ${CMAKE_INSTALL_LIBDIR}/cmake/fmt CACHE STRING
+              "Installation directory for cmake files, relative to "
+              "${CMAKE_INSTALL_PREFIX}.")
   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)
@@ -223,14 +247,17 @@ if (FMT_INSTALL)
     set(INSTALL_TARGETS ${INSTALL_TARGETS} fmt-header-only)
   endif ()
 
-  set(FMT_LIB_DIR ${CMAKE_INSTALL_LIBDIR} CACHE STRING
-      "Installation directory for libraries, relative to ${CMAKE_INSTALL_PREFIX}.")
+  set_verbose(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_INC_DIR ${CMAKE_INSTALL_INCLUDEDIR}/fmt CACHE STRING
+              "Installation directory for include files, relative to "
+              "${CMAKE_INSTALL_PREFIX}.")
 
-  set(FMT_PKGCONFIG_DIR ${CMAKE_INSTALL_LIBDIR}/pkgconfig CACHE PATH
-      "Installation directory for pkgconfig (.pc) files, relative to ${CMAKE_INSTALL_PREFIX}.")
+  set_verbose(FMT_PKGCONFIG_DIR ${CMAKE_INSTALL_LIBDIR}/pkgconfig CACHE PATH
+              "Installation directory for pkgconfig (.pc) files, relative to "
+              "${CMAKE_INSTALL_PREFIX}.")
 
   # Generate the version, config and target files into the build directory.
   write_basic_package_version_file(
@@ -259,7 +286,9 @@ if (FMT_INSTALL)
 
   # Install the library and headers.
   install(TARGETS ${INSTALL_TARGETS} EXPORT ${targets_export_name}
-          DESTINATION ${FMT_LIB_DIR})
+          LIBRARY DESTINATION ${FMT_LIB_DIR}
+          ARCHIVE DESTINATION ${FMT_LIB_DIR}
+          RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR})
 
   install(FILES $<TARGET_PDB_FILE:${INSTALL_TARGETS}>
           DESTINATION ${FMT_LIB_DIR} OPTIONAL)
@@ -285,7 +314,7 @@ set(gitignore ${PROJECT_SOURCE_DIR}/.gitignore)
 if (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}")

ChangeLog.rst

@@ -1,3 +1,498 @@
+6.2.0 - 2020-04-05
+------------------
+
+* Improved error reporting when trying to format an object of a non-formattable
+  type:
+
+  .. code:: c++
+
+     fmt::format("{}", S());
+
+  now gives::
+
+    include/fmt/core.h:1015:5: error: static_assert failed due to requirement
+    'formattable' "Cannot format argument. To make type T formattable provide a
+    formatter<T> specialization:
+    https://fmt.dev/latest/api.html#formatting-user-defined-types"
+        static_assert(
+        ^
+    ...
+    note: in instantiation of function template specialization
+    'fmt::v6::format<char [3], S, char>' requested here
+      fmt::format("{}", S());
+           ^
+
+  if ``S`` is not formattable.
+
+* Reduced library size by ~10%.
+
+* Always print decimal point if ``#`` is specified
+  (`#1476 <https://github.com/fmtlib/fmt/issues/1476>`_,
+  `#1498 <https://github.com/fmtlib/fmt/issues/1498>`_):
+
+  .. code:: c++
+
+     fmt::print("{:#.0f}", 42.0);
+
+  now prints ``42.``
+
+* Implemented the ``'L'`` specifier for locale-specific numeric formatting to
+  improve compatibility with ``std::format``. The ``'n'`` specifier is now
+  deprecated and will be removed in the next major release.
+
+* Moved OS-specific APIs such as ``windows_error`` from ``fmt/format.h`` to
+  ``fmt/os.h``. You can define ``FMT_DEPRECATED_INCLUDE_OS`` to automatically
+  include ``fmt/os.h`` from ``fmt/format.h`` for compatibility but this will be
+  disabled in the next major release.
+
+* Added precision overflow detection in floating-point formatting.
+
+* Implemented detection of invalid use of ``fmt::arg``.
+
+* Used ``type_identity`` to block unnecessary template argument deduction.
+  Thanks Tim Song.
+
+* Improved UTF-8 handling
+  (`#1109 <https://github.com/fmtlib/fmt/issues/1109>`_):
+
+  .. code:: c++
+
+     fmt::print("┌{0:─^{2}}┐\n"
+                "│{1: ^{2}}│\n"
+                "└{0:─^{2}}┘\n", "", "Привет, мир!", 20);
+
+  now prints::
+
+     ┌────────────────────┐
+     │    Привет, мир!    │
+     └────────────────────┘
+
+  on systems that support Unicode.
+
+* Added experimental dynamic argument storage
+  (`#1170 <https://github.com/fmtlib/fmt/issues/1170>`_,
+  `#1584 <https://github.com/fmtlib/fmt/pull/1584>`_):
+
+  .. code:: c++
+
+     fmt::dynamic_format_arg_store<fmt::format_context> store;
+     store.push_back("answer");
+     store.push_back(42);
+     fmt::vprint("The {} is {}.\n", store);
+  
+  prints::
+
+     The answer is 42.
+
+  Thanks `@vsolontsov-ll (Vladimir Solontsov)
+  <https://github.com/vsolontsov-ll>`_.
+
+* Made ``fmt::join`` accept ``initializer_list``
+  (`#1591 <https://github.com/fmtlib/fmt/pull/1591>`_).
+  Thanks `@Rapotkinnik (Nikolay Rapotkin) <https://github.com/Rapotkinnik>`_.
+
+* Fixed handling of empty tuples
+  (`#1588 <https://github.com/fmtlib/fmt/issues/1588>`_).
+
+* Fixed handling of output iterators in ``format_to_n``
+  (`#1506 <https://github.com/fmtlib/fmt/issues/1506>`_).
+
+* Fixed formatting of ``std::chrono::duration`` types to wide output
+  (`#1533 <https://github.com/fmtlib/fmt/pull/1533>`_).
+  Thanks `@zeffy (pilao) <https://github.com/zeffy>`_.
+
+* Added const ``begin`` and ``end`` overload to buffers
+  (`#1553 <https://github.com/fmtlib/fmt/pull/1553>`_).
+  Thanks `@dominicpoeschko <https://github.com/dominicpoeschko>`_.
+
+* Added the ability to disable floating-point formatting via ``FMT_USE_FLOAT``,
+  ``FMT_USE_DOUBLE`` and ``FMT_USE_LONG_DOUBLE`` macros for extremely
+  memory-constrained embedded system
+  (`#1590 <https://github.com/fmtlib/fmt/pull/1590>`_).
+  Thanks `@albaguirre (Alberto Aguirre) <https://github.com/albaguirre>`_.
+
+* Made ``FMT_STRING`` work with ``constexpr`` ``string_view``
+  (`#1589 <https://github.com/fmtlib/fmt/pull/1589>`_).
+  Thanks `@scramsby (Scott Ramsby) <https://github.com/scramsby>`_.
+
+* Implemented a minor optimization in the format string parser
+  (`#1560 <https://github.com/fmtlib/fmt/pull/1560>`_).
+  Thanks `@IkarusDeveloper <https://github.com/IkarusDeveloper>`_.
+
+* Improved attribute detection
+  (`#1469 <https://github.com/fmtlib/fmt/pull/1469>`_,
+  `#1475 <https://github.com/fmtlib/fmt/pull/1475>`_,
+  `#1576 <https://github.com/fmtlib/fmt/pull/1576>`_).
+  Thanks `@federico-busato (Federico) <https://github.com/federico-busato>`_,
+  `@chronoxor (Ivan Shynkarenka) <https://github.com/chronoxor>`_,
+  `@refnum <https://github.com/refnum>`_.
+
+* Improved documentation
+  (`#1481 <https://github.com/fmtlib/fmt/pull/1481>`_,
+  `#1523 <https://github.com/fmtlib/fmt/pull/1523>`_).
+  Thanks `@JackBoosY (Jack·Boos·Yu) <https://github.com/JackBoosY>`_,
+  `@imba-tjd (谭九鼎) <https://github.com/imba-tjd>`_.
+
+* Fixed symbol visibility on Linux when compiling with ``-fvisibility=hidden``
+  (`#1535 <https://github.com/fmtlib/fmt/pull/1535>`_).
+  Thanks `@milianw (Milian Wolff) <https://github.com/milianw>`_.
+
+* Implemented various build configuration fixes and improvements
+  (`#1264 <https://github.com/fmtlib/fmt/issues/1264>`_,
+  `#1460 <https://github.com/fmtlib/fmt/issues/1460>`_,
+  `#1534 <https://github.com/fmtlib/fmt/pull/1534>`_,
+  `#1536 <https://github.com/fmtlib/fmt/issues/1536>`_,
+  `#1545 <https://github.com/fmtlib/fmt/issues/1545>`_,
+  `#1546 <https://github.com/fmtlib/fmt/pull/1546>`_,
+  `#1566 <https://github.com/fmtlib/fmt/issues/1566>`_,
+  `#1582 <https://github.com/fmtlib/fmt/pull/1582>`_,
+  `#1597 <https://github.com/fmtlib/fmt/issues/1597>`_,
+  `#1598 <https://github.com/fmtlib/fmt/pull/1598>`_).
+  Thanks `@ambitslix (Attila M. Szilagyi) <https://github.com/ambitslix>`_,
+  `@jwillikers (Jordan Williams) <https://github.com/jwillikers>`_,
+  `@stac47 (Laurent Stacul) <https://github.com/stac47>`_.
+
+* Fixed various warnings and compilation issues
+  (`#1433 <https://github.com/fmtlib/fmt/pull/1433>`_,
+  `#1461 <https://github.com/fmtlib/fmt/issues/1461>`_,
+  `#1470 <https://github.com/fmtlib/fmt/pull/1470>`_,
+  `#1480 <https://github.com/fmtlib/fmt/pull/1480>`_,
+  `#1485 <https://github.com/fmtlib/fmt/pull/1485>`_,
+  `#1492 <https://github.com/fmtlib/fmt/pull/1492>`_,
+  `#1493 <https://github.com/fmtlib/fmt/issues/1493>`_,
+  `#1504 <https://github.com/fmtlib/fmt/issues/1504>`_,
+  `#1505 <https://github.com/fmtlib/fmt/pull/1505>`_,
+  `#1512 <https://github.com/fmtlib/fmt/pull/1512>`_,
+  `#1515 <https://github.com/fmtlib/fmt/issues/1515>`_,
+  `#1516 <https://github.com/fmtlib/fmt/pull/1516>`_,
+  `#1518 <https://github.com/fmtlib/fmt/pull/1518>`_,
+  `#1519 <https://github.com/fmtlib/fmt/pull/1519>`_,
+  `#1520 <https://github.com/fmtlib/fmt/pull/1520>`_,
+  `#1521 <https://github.com/fmtlib/fmt/pull/1521>`_,
+  `#1522 <https://github.com/fmtlib/fmt/pull/1522>`_,
+  `#1524 <https://github.com/fmtlib/fmt/issues/1524>`_,
+  `#1530 <https://github.com/fmtlib/fmt/pull/1530>`_,
+  `#1531 <https://github.com/fmtlib/fmt/issues/1531>`_,
+  `#1532 <https://github.com/fmtlib/fmt/pull/1532>`_,
+  `#1539 <https://github.com/fmtlib/fmt/issues/1539>`_,
+  `#1547 <https://github.com/fmtlib/fmt/issues/1547>`_,
+  `#1548 <https://github.com/fmtlib/fmt/issues/1548>`_,
+  `#1554 <https://github.com/fmtlib/fmt/pull/1554>`_,
+  `#1567 <https://github.com/fmtlib/fmt/issues/1567>`_,
+  `#1568 <https://github.com/fmtlib/fmt/pull/1568>`_,
+  `#1569 <https://github.com/fmtlib/fmt/pull/1569>`_,
+  `#1571 <https://github.com/fmtlib/fmt/pull/1571>`_,
+  `#1573 <https://github.com/fmtlib/fmt/pull/1573>`_,
+  `#1575 <https://github.com/fmtlib/fmt/pull/1575>`_,
+  `#1581 <https://github.com/fmtlib/fmt/pull/1581>`_,
+  `#1583 <https://github.com/fmtlib/fmt/issues/1583>`_,
+  `#1586 <https://github.com/fmtlib/fmt/issues/1586>`_,
+  `#1587 <https://github.com/fmtlib/fmt/issues/1587>`_,
+  `#1594 <https://github.com/fmtlib/fmt/issues/1594>`_,
+  `#1596 <https://github.com/fmtlib/fmt/pull/1596>`_,
+  `#1604 <https://github.com/fmtlib/fmt/issues/1604>`_,
+  `#1606 <https://github.com/fmtlib/fmt/pull/1606>`_,
+  `#1607 <https://github.com/fmtlib/fmt/issues/1607>`_,
+  `#1609 <https://github.com/fmtlib/fmt/issues/1609>`_).
+  Thanks `@marti4d (Chris Martin) <https://github.com/marti4d>`_,
+  `@iPherian <https://github.com/iPherian>`_,
+  `@parkertomatoes <https://github.com/parkertomatoes>`_,
+  `@gsjaardema (Greg Sjaardema) <https://github.com/gsjaardema>`_,
+  `@chronoxor (Ivan Shynkarenka) <https://github.com/chronoxor>`_,
+  `@DanielaE (Daniela Engert) <https://github.com/DanielaE>`_,
+  `@torsten48 <https://github.com/torsten48>`_,
+  `@tohammer (Tobias Hammer) <https://github.com/tohammer>`_,
+  `@lefticus (Jason Turner) <https://github.com/lefticus>`_,
+  `@ryusakki (Haise) <https://github.com/ryusakki>`_,
+  `@adnsv (Alex Denisov) <https://github.com/adnsv>`_,
+  `@fghzxm <https://github.com/fghzxm>`_,
+  `@refnum <https://github.com/refnum>`_,
+  `@pramodk (Pramod Kumbhar) <https://github.com/pramodk>`_,
+  `@Spirrwell <https://github.com/Spirrwell>`_,
+  `@scramsby (Scott Ramsby) <https://github.com/scramsby>`_.
+
+6.1.2 - 2019-12-11
+------------------
+
+* Fixed ABI compatibility with ``libfmt.so.6.0.0``
+  (`#1471 <https://github.com/fmtlib/fmt/issues/1471>`_).
+
+* Fixed handling types convertible to ``std::string_view``
+  (`#1451 <https://github.com/fmtlib/fmt/pull/1451>`_).
+  Thanks `@denizevrenci (Deniz Evrenci) <https://github.com/denizevrenci>`_.
+
+* Made CUDA test an opt-in enabled via the ``FMT_CUDA_TEST`` CMake option.
+
+* Fixed sign conversion warnings
+  (`#1440 <https://github.com/fmtlib/fmt/pull/1440>`_).
+  Thanks `@0x8000-0000 (Florin Iucha) <https://github.com/0x8000-0000>`_.
+
+6.1.1 - 2019-12-04
+------------------
+
+* Fixed shared library build on Windows
+  (`#1443 <https://github.com/fmtlib/fmt/pull/1443>`_,
+  `#1445 <https://github.com/fmtlib/fmt/issues/1445>`_,
+  `#1446 <https://github.com/fmtlib/fmt/pull/1446>`_,
+  `#1450 <https://github.com/fmtlib/fmt/issues/1450>`_).
+  Thanks `@egorpugin (Egor Pugin) <https://github.com/egorpugin>`_,
+  `@bbolli (Beat Bolli) <https://github.com/bbolli>`_.
+
+* Added a missing decimal point in exponent notation with trailing zeros.
+
+* Removed deprecated ``format_arg_store::TYPES``.
+
+6.1.0 - 2019-12-01
+------------------
+
+* {fmt} now formats IEEE 754 ``float`` and ``double`` using the shortest decimal
+  representation with correct rounding by default:
+
+  .. code:: c++
+
+     #include <cmath>
+     #include <fmt/core.h>
+
+     int main() {
+       fmt::print("{}", M_PI);
+     }
+
+  prints ``3.141592653589793``.
+
+* Made the fast binary to decimal floating-point formatter the default,
+  simplified it and improved performance. {fmt} is now 15 times faster than
+  libc++'s ``std::ostringstream``, 11 times faster than ``printf`` and 10%
+  faster than double-conversion on `dtoa-benchmark
+  <https://github.com/fmtlib/dtoa-benchmark>`_:
+
+  ==================  =========  =======
+  Function            Time (ns)  Speedup
+  ==================  =========  =======
+  ostringstream        1,346.30    1.00x
+  ostrstream           1,195.74    1.13x
+  sprintf                995.08    1.35x
+  doubleconv              99.10   13.59x
+  fmt                     88.34   15.24x
+  ==================  =========  =======
+
+  .. image:: https://user-images.githubusercontent.com/576385/
+             69767160-cdaca400-112f-11ea-9fc5-347c9f83caad.png
+
+* {fmt} no longer converts ``float`` arguments to ``double``. In particular this
+  improves the default (shortest) representation of floats and makes
+  ``fmt::format`` consistent with ``std::format`` specs
+  (`#1336 <https://github.com/fmtlib/fmt/issues/1336>`_,
+  `#1353 <https://github.com/fmtlib/fmt/issues/1353>`_,
+  `#1360 <https://github.com/fmtlib/fmt/pull/1360>`_,
+  `#1361 <https://github.com/fmtlib/fmt/pull/1361>`_):
+
+  .. code:: c++
+
+     fmt::print("{}", 0.1f);
+
+  prints ``0.1`` instead of ``0.10000000149011612``.
+
+  Thanks `@orivej (Orivej Desh) <https://github.com/orivej>`_.
+
+* Made floating-point formatting output consistent with ``printf``/iostreams
+  (`#1376 <https://github.com/fmtlib/fmt/issues/1376>`_,
+  `#1417 <https://github.com/fmtlib/fmt/issues/1417>`_).
+
+* Added support for 128-bit integers
+  (`#1287 <https://github.com/fmtlib/fmt/pull/1287>`_):
+
+  .. code:: c++
+
+     fmt::print("{}", std::numeric_limits<__int128_t>::max());
+
+  prints ``170141183460469231731687303715884105727``.
+
+  Thanks `@denizevrenci (Deniz Evrenci) <https://github.com/denizevrenci>`_.
+
+* The overload of ``print`` that takes ``text_style`` is now atomic, i.e. the
+  output from different threads doesn't interleave
+  (`#1351 <https://github.com/fmtlib/fmt/pull/1351>`_).
+  Thanks `@tankiJong (Tanki Zhang) <https://github.com/tankiJong>`_.
+
+* Made compile time in the header-only mode ~20% faster by reducing the number
+  of template instantiations. ``wchar_t`` overload of ``vprint`` was moved from
+  ``fmt/core.h`` to ``fmt/format.h``.
+
+* Added an overload of ``fmt::join`` that works with tuples
+  (`#1322 <https://github.com/fmtlib/fmt/issues/1322>`_,
+  `#1330 <https://github.com/fmtlib/fmt/pull/1330>`_):
+
+  .. code:: c++
+
+     #include <tuple>
+     #include <fmt/ranges.h>
+
+     int main() {
+       std::tuple<char, int, float> t{'a', 1, 2.0f};
+       fmt::print("{}", t);
+     }
+
+  prints ``('a', 1, 2.0)``.
+
+  Thanks `@jeremyong (Jeremy Ong) <https://github.com/jeremyong>`_.
+
+* Changed formatting of octal zero with prefix from "00" to "0":
+
+  .. code:: c++
+
+     fmt::print("{:#o}", 0);
+
+  prints ``0``.
+
+* The locale is now passed to ostream insertion (``<<``) operators
+  (`#1406 <https://github.com/fmtlib/fmt/pull/1406>`_):
+
+  .. code:: c++
+
+     #include <fmt/locale.h>
+     #include <fmt/ostream.h>
+
+     struct S {
+       double value;
+     };
+
+     std::ostream& operator<<(std::ostream& os, S s) {
+       return os << s.value;
+     }
+
+     int main() {
+       auto s = fmt::format(std::locale("fr_FR.UTF-8"), "{}", S{0.42});
+       // s == "0,42"
+     }
+
+  Thanks `@dlaugt (Daniel Laügt) <https://github.com/dlaugt>`_.
+
+* Locale-specific number formatting now uses grouping
+  (`#1393 <https://github.com/fmtlib/fmt/issues/1393>`_
+  `#1394 <https://github.com/fmtlib/fmt/pull/1394>`_).
+  Thanks `@skrdaniel <https://github.com/skrdaniel>`_.
+
+* Fixed handling of types with deleted implicit rvalue conversion to
+  ``const char**`` (`#1421 <https://github.com/fmtlib/fmt/issues/1421>`_):
+
+  .. code:: c++
+
+     struct mystring {
+       operator const char*() const&;
+       operator const char*() &;
+       operator const char*() const&& = delete;
+       operator const char*() && = delete;
+     };
+     mystring str;
+     fmt::print("{}", str); // now compiles
+
+* Enums are now mapped to correct underlying types instead of ``int``
+  (`#1286 <https://github.com/fmtlib/fmt/pull/1286>`_).
+  Thanks `@agmt (Egor Seredin) <https://github.com/agmt>`_.
+
+* Enum classes are no longer implicitly converted to ``int``
+  (`#1424 <https://github.com/fmtlib/fmt/issues/1424>`_).
+
+* Added ``basic_format_parse_context`` for consistency with C++20
+  ``std::format`` and deprecated ``basic_parse_context``.
+
+* Fixed handling of UTF-8 in precision
+  (`#1389 <https://github.com/fmtlib/fmt/issues/1389>`_,
+  `#1390 <https://github.com/fmtlib/fmt/pull/1390>`_).
+  Thanks `@tajtiattila (Attila Tajti) <https://github.com/tajtiattila>`_.
+
+* {fmt} can now 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>`__
+  (`#1410 <https://github.com/fmtlib/fmt/pull/1410>`_)::
+
+    conda install -c conda-forge fmt
+
+  Thanks `@tdegeus (Tom de Geus) <https://github.com/tdegeus>`_.
+
+* Added a CUDA test (`#1285 <https://github.com/fmtlib/fmt/pull/1285>`_,
+  `#1317 <https://github.com/fmtlib/fmt/pull/1317>`_).
+  Thanks `@luncliff (Park DongHa) <https://github.com/luncliff>`_ and
+  `@risa2000 <https://github.com/risa2000>`_.
+
+* Improved documentation (`#1276 <https://github.com/fmtlib/fmt/pull/1276>`_,
+  `#1291 <https://github.com/fmtlib/fmt/issues/1291>`_,
+  `#1296 <https://github.com/fmtlib/fmt/issues/1296>`_,
+  `#1315 <https://github.com/fmtlib/fmt/pull/1315>`_,
+  `#1332 <https://github.com/fmtlib/fmt/pull/1332>`_,
+  `#1337 <https://github.com/fmtlib/fmt/pull/1337>`_,
+  `#1395 <https://github.com/fmtlib/fmt/issues/1395>`_
+  `#1418 <https://github.com/fmtlib/fmt/pull/1418>`_).
+  Thanks
+  `@waywardmonkeys (Bruce Mitchener) <https://github.com/waywardmonkeys>`_,
+  `@pauldreik (Paul Dreik) <https://github.com/pauldreik>`_,
+  `@jackoalan (Jack Andersen) <https://github.com/jackoalan>`_.
+
+* Various code improvements
+  (`#1358 <https://github.com/fmtlib/fmt/pull/1358>`_,
+  `#1407 <https://github.com/fmtlib/fmt/pull/1407>`_).
+  Thanks `@orivej (Orivej Desh) <https://github.com/orivej>`_,
+  `@dpacbach (David P. Sicilia) <https://github.com/dpacbach>`_,
+
+* Fixed compile-time format string checks for user-defined types
+  (`#1292 <https://github.com/fmtlib/fmt/issues/1292>`_).
+
+* Worked around a false positive in ``unsigned-integer-overflow`` sanitizer
+  (`#1377 <https://github.com/fmtlib/fmt/issues/1377>`_).
+
+* Fixed various warnings and compilation issues
+  (`#1273 <https://github.com/fmtlib/fmt/issues/1273>`_,
+  `#1278 <https://github.com/fmtlib/fmt/pull/1278>`_,
+  `#1280 <https://github.com/fmtlib/fmt/pull/1280>`_,
+  `#1281 <https://github.com/fmtlib/fmt/issues/1281>`_,
+  `#1288 <https://github.com/fmtlib/fmt/issues/1288>`_,
+  `#1290 <https://github.com/fmtlib/fmt/pull/1290>`_,
+  `#1301 <https://github.com/fmtlib/fmt/pull/1301>`_,
+  `#1305 <https://github.com/fmtlib/fmt/issues/1305>`_,
+  `#1306 <https://github.com/fmtlib/fmt/issues/1306>`_,
+  `#1309 <https://github.com/fmtlib/fmt/issues/1309>`_,
+  `#1312 <https://github.com/fmtlib/fmt/pull/1312>`_,
+  `#1313 <https://github.com/fmtlib/fmt/issues/1313>`_,
+  `#1316 <https://github.com/fmtlib/fmt/issues/1316>`_,
+  `#1319 <https://github.com/fmtlib/fmt/issues/1319>`_,
+  `#1320 <https://github.com/fmtlib/fmt/pull/1320>`_,
+  `#1326 <https://github.com/fmtlib/fmt/pull/1326>`_,
+  `#1328 <https://github.com/fmtlib/fmt/pull/1328>`_,
+  `#1344 <https://github.com/fmtlib/fmt/issues/1344>`_,
+  `#1345 <https://github.com/fmtlib/fmt/pull/1345>`_,
+  `#1347 <https://github.com/fmtlib/fmt/pull/1347>`_,
+  `#1349 <https://github.com/fmtlib/fmt/pull/1349>`_,
+  `#1354 <https://github.com/fmtlib/fmt/issues/1354>`_,
+  `#1362 <https://github.com/fmtlib/fmt/issues/1362>`_,
+  `#1366 <https://github.com/fmtlib/fmt/issues/1366>`_,
+  `#1364 <https://github.com/fmtlib/fmt/pull/1364>`_,
+  `#1370 <https://github.com/fmtlib/fmt/pull/1370>`_,
+  `#1371 <https://github.com/fmtlib/fmt/pull/1371>`_,
+  `#1385 <https://github.com/fmtlib/fmt/issues/1385>`_,
+  `#1388 <https://github.com/fmtlib/fmt/issues/1388>`_,
+  `#1397 <https://github.com/fmtlib/fmt/pull/1397>`_,
+  `#1414 <https://github.com/fmtlib/fmt/pull/1414>`_,
+  `#1416 <https://github.com/fmtlib/fmt/pull/1416>`_,
+  `#1422 <https://github.com/fmtlib/fmt/issues/1422>`_
+  `#1427 <https://github.com/fmtlib/fmt/pull/1427>`_,
+  `#1431 <https://github.com/fmtlib/fmt/issues/1431>`_,
+  `#1433 <https://github.com/fmtlib/fmt/pull/1433>`_).
+  Thanks `@hhb <https://github.com/hhb>`_,
+  `@gsjaardema (Greg Sjaardema) <https://github.com/gsjaardema>`_,
+  `@gabime (Gabi Melman) <https://github.com/gabime>`_,
+  `@neheb (Rosen Penev) <https://github.com/neheb>`_,
+  `@vedranmiletic (Vedran Miletić) <https://github.com/vedranmiletic>`_,
+  `@dkavolis (Daumantas Kavolis) <https://github.com/dkavolis>`_,
+  `@mwinterb <https://github.com/mwinterb>`_,
+  `@orivej (Orivej Desh) <https://github.com/orivej>`_,
+  `@denizevrenci (Deniz Evrenci) <https://github.com/denizevrenci>`_
+  `@leonklingele <https://github.com/leonklingele>`_,
+  `@chronoxor (Ivan Shynkarenka) <https://github.com/chronoxor>`_,
+  `@kent-tri <https://github.com/kent-tri>`_,
+  `@0x8000-0000 (Florin Iucha) <https://github.com/0x8000-0000>`_,
+  `@marti4d (Chris Martin) <https://github.com/marti4d>`_.
+
 6.0.0 - 2019-08-26
 ------------------
 
@@ -183,6 +678,7 @@
 * Modernized the codebase using more C++11 features and removing workarounds.
   Most importantly, ``buffer_context`` is now an alias template, so
   use ``buffer_context<T>`` instead of ``buffer_context<T>::type``.
+  These features require GCC 4.8 or later.
 
 * ``formatter`` specializations now always take precedence over implicit
   conversions to ``int`` and the undocumented ``convert_to_int`` trait
@@ -298,7 +794,7 @@
   `#1222 <https://github.com/fmtlib/fmt/issues/1222>`_).
   Thanks `@alabuzhev (Alex Alabuzhev) <https://github.com/alabuzhev>`_.
 
-* Fixed bugs discovered by fuzzing or during fuzzing integation
+* Fixed bugs discovered by fuzzing or during fuzzing integration
   (`#1124 <https://github.com/fmtlib/fmt/issues/1124>`_,
   `#1127 <https://github.com/fmtlib/fmt/issues/1127>`_,
   `#1132 <https://github.com/fmtlib/fmt/issues/1132>`_,

README.rst

@@ -7,16 +7,20 @@
 .. image:: https://ci.appveyor.com/api/projects/status/ehjkiefde6gucy1v
    :target: https://ci.appveyor.com/project/vitaut/fmt
 
+.. image:: https://oss-fuzz-build-logs.storage.googleapis.com/badges/libfmt.svg
+   :alt: fmt is continuously fuzzed att oss-fuzz
+   :target: https://bugs.chromium.org/p/oss-fuzz/issues/list?colspec=ID%20Type%20Component%20Status%20Proj%20Reported%20Owner%20Summary&q=proj%3Dlibfmt&can=1
+
 .. image:: https://img.shields.io/badge/stackoverflow-fmt-blue.svg
    :alt: Ask questions at StackOverflow with the tag fmt
-   :target: http://stackoverflow.com/questions/tagged/fmt
+   :target: https://stackoverflow.com/questions/tagged/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.
 
 `Documentation <https://fmt.dev/latest/>`__
 
-Q&A: ask questions on `StackOverflow with the tag fmt <http://stackoverflow.com/questions/tagged/fmt>`_.
+Q&A: ask questions on `StackOverflow with the tag fmt <https://stackoverflow.com/questions/tagged/fmt>`_.
 
 Features
 --------
@@ -24,27 +28,27 @@ Features
 * Replacement-based `format API <https://fmt.dev/dev/api.html>`_ with
   positional arguments for localization.
 * `Format string syntax <https://fmt.dev/dev/syntax.html>`_ similar to the one
-  of `str.format <https://docs.python.org/2/library/stdtypes.html#str.format>`_
+  of `str.format <https://docs.python.org/3/library/stdtypes.html#str.format>`_
   in Python.
 * Safe `printf implementation
   <https://fmt.dev/latest/api.html#printf-formatting>`_ including
   the POSIX extension for positional arguments.
-* Implementation of `C++20 std::format <https://fmt.dev/Text%20Formatting.html>`__.
+* Implementation of `C++20 std::format <https://en.cppreference.com/w/cpp/utility/format>`__.
 * Support for user-defined types.
 * High performance: faster than common standard library implementations of
-  `printf <http://en.cppreference.com/w/cpp/io/c/fprintf>`_ and
+  `printf <https://en.cppreference.com/w/cpp/io/c/fprintf>`_ and
   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://github.com/fmtlib/fmt/tree/master/test>`_ and is continuously fuzzed.
 * Safety: the library is fully type safe, errors in format strings can be
   reported at compile time, automatic memory management prevents buffer overflow
   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 <https://fmt.dev/latest/index.html#portability>`_ with
   consistent output across platforms and support for older compilers.
@@ -77,16 +81,15 @@ Check a format string at compile time:
 .. code:: c++
 
     // test.cc
-    #define FMT_STRING_ALIAS 1
     #include <fmt/format.h>
-    std::string s = format(fmt("{2}"), 42);
+    std::string s = format(FMT_STRING("{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);
+    std::string s = format(FMT_STRING("{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);
@@ -118,11 +121,10 @@ Format objects of user-defined types via a simple `extension API
 
     template <>
     struct fmt::formatter<date> {
-      template <typename ParseContext>
-      constexpr auto parse(ParseContext &ctx) { return ctx.begin(); }
+      constexpr auto parse(format_parse_context& ctx) { return ctx.begin(); }
 
       template <typename FormatContext>
-      auto format(const date &d, FormatContext &ctx) {
+      auto format(const date& d, FormatContext& ctx) {
         return format_to(ctx.out(), "{}-{}-{}", d.year, d.month, d.day);
       }
     };
@@ -138,12 +140,12 @@ 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) {
+    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) {
+    void report_error(const char* format, const Args & ... args) {
       vreport_error(format, fmt::make_format_args(args...));
     }
 
@@ -162,18 +164,17 @@ Speed tests
 ================= ============= ===========
 Library           Method        Run Time, s
 ================= ============= ===========
-libc              printf          1.01
-libc++            std::ostream    3.04
-{fmt} 1632f72     fmt::print      0.86
-tinyformat 2.0.1  tfm::printf     3.23
-Boost Format 1.67 boost::format   7.98
+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
 ================= ============= ===========
 
-{fmt} is the fastest of the benchmarked methods, ~17% faster than ``printf``.
+{fmt} is the fastest of the benchmarked methods, ~35% faster than ``printf``.
 
 The above results were generated by building ``tinyformat_test.cpp`` on macOS
-10.14.3 with ``clang++ -O3 -DSPEED_TEST -DHAVE_FORMAT``, and taking the best of
+10.14.6 with ``clang++ -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 2,000,000 times with output sent to ``/dev/null``; for
 further details refer to the `source
@@ -183,7 +184,7 @@ further details refer to the `source
 formatting (`dtoa-benchmark <https://github.com/fmtlib/dtoa-benchmark>`_)
 and as fast as `double-conversion <https://github.com/google/double-conversion>`_:
 
-.. image:: https://user-images.githubusercontent.com/576385/54883977-9fe8c000-4e28-11e9-8bde-272d122e7c52.jpg
+.. image:: https://user-images.githubusercontent.com/576385/69767160-cdaca400-112f-11ea-9fc5-347c9f83caad.png
    :target: https://fmt.dev/unknown_mac64_clang10.0.html
 
 Compile time and code bloat
@@ -207,7 +208,6 @@ 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
 Boost Format             91.9                  226                203
 Folly Format            115.7                  101                 88
 ============= =============== ==================== ==================
@@ -228,14 +228,13 @@ 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
 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.
+compare formatting function overhead only. Boost Format is a
+header-only library so it doesn't provide any linkage options.
 
 Running the tests
 ~~~~~~~~~~~~~~~~~
@@ -265,7 +264,7 @@ or the bloat test::
 Projects using this library
 ---------------------------
 
-* `0 A.D. <http://play0ad.com/>`_: A free, open-source, cross-platform real-time
+* `0 A.D. <https://play0ad.com/>`_: A free, open-source, cross-platform real-time
   strategy game
 
 * `AMPL/MP <https://github.com/ampl/mp>`_:
@@ -278,21 +277,23 @@ Projects using this library
 
 * `Ceph <https://ceph.com/>`_: A scalable distributed storage system
 
+* `ccache <https://ccache.dev/>`_: A compiler cache
+
 * `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
+* `KBEngine <https://kbengine.org/>`_: An open-source MMOG server engine
 
-* `Keypirinha <http://keypirinha.com/>`_: A semantic launcher for Windows
+* `Keypirinha <https://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
+* `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
@@ -305,10 +306,10 @@ Projects using this library
 * `MongoDB Smasher <https://github.com/duckie/mongo_smasher>`_: A small tool to
   generate randomized datasets
 
-* `OpenSpace <http://openspaceproject.com/>`_: An open-source astrovisualization
+* `OpenSpace <https://openspaceproject.com/>`_: An open-source astrovisualization
   framework
 
-* `PenUltima Online (POL) <http://www.polserver.com/>`_:
+* `PenUltima Online (POL) <https://www.polserver.com/>`_:
   An MMO server, compatible with most Ultima Online clients
 
 * `quasardb <https://www.quasardb.net/>`_: A distributed, high-performance,
@@ -325,10 +326,10 @@ Projects using this library
 * `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/>`_:
+* `Salesforce Analytics Cloud <https://www.salesforce.com/analytics-cloud/overview/>`_:
   Business intelligence software
 
-* `Scylla <http://www.scylladb.com/>`_: A Cassandra-compatible NoSQL data store
+* `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++
@@ -343,7 +344,7 @@ Projects using this library
 * `TrinityCore <https://github.com/TrinityCore/TrinityCore>`_: Open-source
   MMORPG framework
 
-`More... <https://github.com/search?q=cppformat&type=Code>`_
+`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
@@ -367,7 +368,7 @@ 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, ...))
-<http://gcc.gnu.org/onlinedocs/gcc/Function-Attributes.html>`_ in GCC.
+<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
@@ -419,20 +420,6 @@ arguments. However it has significant limitations, citing its author:
 It is also quite big and has a heavy dependency, STLSoft, which might be
 too restrictive for using it in some projects.
 
-Loki SafeFormat
-~~~~~~~~~~~~~~~
-
-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 and
-makes unconventional use of ``operator()`` for passing format arguments.
-
-Tinyformat
-~~~~~~~~~~
-
-This library supports ``printf``-like format strings and is very small .
-It doesn't support positional arguments and wrapping it in C++98 is somewhat
-difficult. Tinyformat relies on iostreams which limits its performance.
-
 Boost Spirit.Karma
 ~~~~~~~~~~~~~~~~~~
 
@@ -469,7 +456,7 @@ A: use ``std::tuple``:
 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
@@ -499,10 +486,10 @@ 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/>`_.
+<https://clang.llvm.org/doxygen/classclang_1_1Diagnostic.html>`_ in
+`Clang <https://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>`_.
+<https://docs.python.org/3/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

doc/_templates/layout.html

@@ -84,7 +84,7 @@
 <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

@@ -10,12 +10,14 @@ The {fmt} library API consists of the following parts:
   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/ranges.h <ranges-api>`: additional formatting support for ranges
+  and tuples
 * :ref:`fmt/chrono.h <chrono-api>`: date and time formatting
 * :ref:`fmt/ostream.h <ostream-api>`: ``std::ostream`` support
 * :ref:`fmt/printf.h <printf-api>`: ``printf`` formatting
 
 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:
 
@@ -23,7 +25,8 @@ Core API
 ========
 
 ``fmt/core.h`` defines the core API which provides argument handling facilities
-and a lightweight subset of formatting functions.
+and a lightweight subset of formatting functions. In the header-only mode
+include ``fmt/format.h`` instead of ``fmt/core.h``.
 
 The following functions use :ref:`format string syntax <syntax>`
 similar to that of Python's `str.format
@@ -49,7 +52,6 @@ participate in an overload resolution if the latter is not a string.
 
 .. doxygenfunction:: print(std::FILE *, const S&, Args&&...)
 .. doxygenfunction:: vprint(std::FILE *, string_view, format_args)
-.. doxygenfunction:: vprint(std::FILE *, wstring_view, wformat_args)
 
 Named Arguments
 ---------------
@@ -83,6 +85,19 @@ Compatibility
 .. doxygentypedef:: fmt::string_view
 .. doxygentypedef:: fmt::wstring_view
 
+Locale
+------
+
+All formatting is locale-independent by default. Use the ``'n'`` 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("{:n}", 1000000);  // s == "1,000,000"
+
 .. _format-api:
 
 Format API
@@ -94,8 +109,11 @@ string checks, output iterator and user-defined type support.
 Compile-time Format String Checks
 ---------------------------------
 
+Compile-time checks are supported for built-in and string types as well as
+user-defined types with ``constexpr`` ``parse`` functions in their ``formatter``
+specializations.
+
 .. doxygendefine:: FMT_STRING
-.. doxygendefine:: fmt
 
 Formatting User-defined Types
 -----------------------------
@@ -107,32 +125,56 @@ template and implement ``parse`` and ``format`` methods::
 
   struct point { double x, y; };
 
-  namespace fmt {
   template <>
-  struct formatter<point> {
-    template <typename ParseContext>
-    constexpr auto parse(ParseContext &ctx) { return ctx.begin(); }
+  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) {
+      // [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 '}'.
+
+      // 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.out(), "({:.1f}, {:.1f})", p.x, p.y);
+    auto format(const point& p, FormatContext& ctx) {
+      // ctx.out() is an output iterator to write to.
+      return format_to(
+          ctx.out(),
+          presentation == 'f' ? "({:.1f}, {:.1f})" : "({:.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/chrono.h` for an advanced example of how to parse the format string and
-customize the formatted output.
-
-You can also reuse existing formatters, for example::
+You can also reuse existing formatters via inheritance or composition, for
+example::
 
   enum class color {red, green, blue};
 
@@ -140,7 +182,7 @@ You can also reuse existing formatters, for example::
   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) {
       string_view name = "unknown";
       switch (c) {
       case color::red:   name = "red"; break;
@@ -180,6 +222,9 @@ You can also write a formatter for a hierarchy of classes::
     fmt::print("{}", a); // prints "B"
   }
 
+.. doxygenclass:: fmt::basic_format_parse_context
+   :members:
+
 Output Iterator Support
 -----------------------
 
@@ -263,7 +308,7 @@ allocator::
     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...));
     }
 
@@ -278,21 +323,21 @@ Custom Formatting of Built-in Types
 It is possible to change the way arguments are formatted by providing a
 custom argument formatter class::
 
-  using arg_formatter =
-    fmt::arg_formatter<fmt::back_insert_range<fmt::internal::buffer>>;
+  using arg_formatter = fmt::arg_formatter<fmt::buffer_range<char>>;
 
   // 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 = nullptr)
-      : arg_formatter(ctx, spec) {}
+    custom_arg_formatter(fmt::format_context& ctx,
+                         fmt::format_parse_context* parse_ctx = nullptr,
+                         fmt::format_specs* spec = nullptr)
+      : arg_formatter(ctx, parse_ctx, spec) {}
 
     using arg_formatter::operator();
 
     auto operator()(int value) {
-      if (spec().type() == 'x')
+      if (specs() && specs()->type == 'x')
         return (*this)(static_cast<unsigned>(value)); // convert to unsigned and format
       return arg_formatter::operator()(value);
     }
@@ -307,7 +352,7 @@ custom argument formatter class::
 
   template <typename ...Args>
   inline std::string custom_format(
-      fmt::string_view format_str, const Args &... args) {
+      fmt::string_view format_str, const Args&... args) {
     return custom_vformat(format_str, fmt::make_format_args(args...));
   }
 
@@ -316,6 +361,31 @@ custom argument formatter class::
 .. doxygenclass:: fmt::arg_formatter
    :members:
 
+.. _ranges-api:
+
+Ranges and Tuple Formatting
+===========================
+
+The library also supports convenient formatting of ranges and tuples::
+
+  #include <fmt/ranges.h>
+
+  std::tuple<char, int, float> t{'a', 1, 2.0f};
+  // Prints "('a', 1, 2.0)"
+  fmt::print("{}", t);
+
+
+NOTE: currently, the overload of ``fmt::join`` for iterables exists in the main
+``format.h`` header, but expect this to change in the future.
+
+Using ``fmt::join``, you can separate tuple elements with a custom separator::
+
+  #include <fmt/ranges.h>
+
+  std::tuple<int, char> t = {1, 'a'};
+  // Prints "1, a"
+  fmt::print("{}", fmt::join(t, ", "));
+
 .. _chrono-api:
 
 Date and Time Formatting
@@ -349,7 +419,7 @@ user-defined types that have overloaded ``operator<<``::
   public:
     date(int year, int month, int day): year_(year), month_(month), day_(day) {}
 
-    friend std::ostream &operator<<(std::ostream &os, const date &d) {
+    friend std::ostream& operator<<(std::ostream& os, const date& d) {
       return os << d.year_ << '-' << d.month_ << '-' << d.day_;
     }
   };

doc/build.py

@@ -6,7 +6,7 @@ import errno, os, shutil, sys, tempfile
 from subprocess import check_call, check_output, CalledProcessError, Popen, PIPE
 from distutils.version import LooseVersion
 
-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']
+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']
 
 def pip_install(package, commit=None, **kwargs):
   "Install package using pip."
@@ -74,7 +74,7 @@ def build_docs(version='dev', **kwargs):
       GENERATE_MAN      = NO
       GENERATE_RTF      = NO
       CASE_SENSE_NAMES  = NO
-      INPUT             = {0}/core.h {0}/format.h {0}/ostream.h \
+      INPUT             = {0}/core.h {0}/format.h {0}/os.h {0}/ostream.h \
                           {0}/printf.h {0}/time.h
       QUIET             = YES
       JAVADOC_AUTOBRIEF = YES

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>
 
@@ -20,12 +21,13 @@ 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 serveral times `faster
+<http://zverovich.net/2013/09/07/integer-to-string-conversion-in-cplusplus.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 <http://docs.python.org/3/library/stdtypes.html#str.format>`_ in
+Python:
 
 .. code:: c++
 
@@ -60,7 +62,7 @@ The Format API also supports positional arguments useful for localization:
   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:
+what goes where when multiple arguments are being formatted:
 
 .. 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
@@ -106,11 +97,10 @@ string", because the argument ``"forty-two"`` is a string while the format 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``. See `here <api.html#c.fmt>`_ for how to enable
-compile-time checks.
+relaxed ``constexpr``. See `here <api.html#c.fmt>`_ for details.
 
 The following code
 
@@ -178,13 +168,13 @@ The library is highly portable and relies only on a small set of C++11 features:
 * alias templates
 
 These are available since GCC 4.8, Clang 3.0 and MSVC 19.0 (2015). For older
-compilers use fmt `version 4.x
+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.
 
 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,
+output of ``printf`` is platform-dependent. For example,
 
 .. code::
 
@@ -197,9 +187,9 @@ always prints ``inf``.
 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.
 
 .. raw:: html

doc/syntax.rst

@@ -76,19 +76,19 @@ 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: "<" | ">" | "=" | "^"
+   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"
+   type: `int_type` | "a" | "A" | "c" | "e" | "E" | "f" | "F" | "g" | "G" | "L" | "p" | "s"
+   int_type: "b" | "B" | "d" | "o" | "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.                                                   |
 +---------+----------------------------------------------------------+
@@ -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
@@ -217,9 +214,9 @@ 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.                             |
+| ``'L'`` | Locale-specific format. This is the same as ``'d'``,     |
+|         | except that it uses the current locale setting to insert |
+|         | the appropriate number separator characters.             |
 +---------+----------------------------------------------------------+
 | none    | The same as ``'d'``.                                     |
 +---------+----------------------------------------------------------+
@@ -264,9 +261,9 @@ 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. |
 +---------+----------------------------------------------------------+
-| ``'%'`` | Fixed point as a percentage. This is similar to ``'f'``, |
-|         | but the argument is multiplied by 100 and a percent sign |
-|         | ``%`` is appended.                                       |
+| ``'L'`` | Locale-specific format. This is the same as ``'g'``,     |
+|         | except that it uses the current locale setting to insert |
+|         | the appropriate number separator characters.             |
 +---------+----------------------------------------------------------+
 | none    | Similar to ``'g'``, except that fixed-point notation,    |
 |         | when used, has at least one digit past the decimal       |
@@ -323,79 +320,94 @@ 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"
 
-As a percentage::
-
-   format("{0:f} or {0:%}", .635);
-   // Result: "0.635000 or 63.500000%"
-   format("{:*^{}.{}%}", 1., 15, 2); // With fill, dynamic width and dynamic precision.
-   // Result: "****100.00%****"
-
 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 = 6;
+   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/locale.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']):

doc/usage.rst

@@ -103,7 +103,33 @@ 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.
+
 Android NDK
 ===========
 

include/fmt/chrono.h

@@ -8,24 +8,299 @@
 #ifndef FMT_CHRONO_H_
 #define FMT_CHRONO_H_
 
-#include "format.h"
-#include "locale.h"
-
 #include <chrono>
 #include <ctime>
 #include <locale>
 #include <sstream>
 
-// enable safe chrono durations, unless explicitly disabled
+#include "format.h"
+#include "locale.h"
+
+FMT_BEGIN_NAMESPACE
+
+// Enable safe chrono durations, unless explicitly disabled.
 #ifndef FMT_SAFE_DURATION_CAST
 #  define FMT_SAFE_DURATION_CAST 1
 #endif
-
 #if FMT_SAFE_DURATION_CAST
-#  include "safe-duration-cast.h"
-#endif
 
-FMT_BEGIN_NAMESPACE
+// For conversion between std::chrono::durations without undefined
+// behaviour or erroneous results.
+// This is a stripped down version of duration_cast, for inclusion in fmt.
+// See https://github.com/pauldreik/safe_duration_cast
+//
+// Copyright Paul Dreik 2019
+namespace safe_duration_cast {
+
+template <typename To, typename From,
+          FMT_ENABLE_IF(!std::is_same<From, To>::value &&
+                        std::numeric_limits<From>::is_signed ==
+                            std::numeric_limits<To>::is_signed)>
+FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
+  ec = 0;
+  using F = std::numeric_limits<From>;
+  using T = std::numeric_limits<To>;
+  static_assert(F::is_integer, "From must be integral");
+  static_assert(T::is_integer, "To must be integral");
+
+  // A and B are both signed, or both unsigned.
+  if (F::digits <= T::digits) {
+    // From fits in To without any problem.
+  } else {
+    // From does not always fit in To, resort to a dynamic check.
+    if (from < T::min() || from > T::max()) {
+      // outside range.
+      ec = 1;
+      return {};
+    }
+  }
+  return static_cast<To>(from);
+}
+
+/**
+ * converts From to To, without loss. If the dynamic value of from
+ * can't be converted to To without loss, ec is set.
+ */
+template <typename To, typename From,
+          FMT_ENABLE_IF(!std::is_same<From, To>::value &&
+                        std::numeric_limits<From>::is_signed !=
+                            std::numeric_limits<To>::is_signed)>
+FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
+  ec = 0;
+  using F = std::numeric_limits<From>;
+  using T = std::numeric_limits<To>;
+  static_assert(F::is_integer, "From must be integral");
+  static_assert(T::is_integer, "To must be integral");
+
+  if (F::is_signed && !T::is_signed) {
+    // From may be negative, not allowed!
+    if (fmt::internal::is_negative(from)) {
+      ec = 1;
+      return {};
+    }
+
+    // From is positive. Can it always fit in To?
+    if (F::digits <= T::digits) {
+      // yes, From always fits in To.
+    } else {
+      // from may not fit in To, we have to do a dynamic check
+      if (from > static_cast<From>(T::max())) {
+        ec = 1;
+        return {};
+      }
+    }
+  }
+
+  if (!F::is_signed && T::is_signed) {
+    // can from be held in To?
+    if (F::digits < T::digits) {
+      // yes, From always fits in To.
+    } else {
+      // from may not fit in To, we have to do a dynamic check
+      if (from > static_cast<From>(T::max())) {
+        // outside range.
+        ec = 1;
+        return {};
+      }
+    }
+  }
+
+  // reaching here means all is ok for lossless conversion.
+  return static_cast<To>(from);
+
+}  // function
+
+template <typename To, typename From,
+          FMT_ENABLE_IF(std::is_same<From, To>::value)>
+FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
+  ec = 0;
+  return from;
+}  // function
+
+// clang-format off
+/**
+ * converts From to To if possible, otherwise ec is set.
+ *
+ * input                            |    output
+ * ---------------------------------|---------------
+ * NaN                              | NaN
+ * Inf                              | Inf
+ * normal, fits in output           | converted (possibly lossy)
+ * normal, does not fit in output   | ec is set
+ * subnormal                        | best effort
+ * -Inf                             | -Inf
+ */
+// clang-format on
+template <typename To, typename From,
+          FMT_ENABLE_IF(!std::is_same<From, To>::value)>
+FMT_CONSTEXPR To safe_float_conversion(const From from, int& ec) {
+  ec = 0;
+  using T = std::numeric_limits<To>;
+  static_assert(std::is_floating_point<From>::value, "From must be floating");
+  static_assert(std::is_floating_point<To>::value, "To must be floating");
+
+  // catch the only happy case
+  if (std::isfinite(from)) {
+    if (from >= T::lowest() && from <= T::max()) {
+      return static_cast<To>(from);
+    }
+    // not within range.
+    ec = 1;
+    return {};
+  }
+
+  // nan and inf will be preserved
+  return static_cast<To>(from);
+}  // function
+
+template <typename To, typename From,
+          FMT_ENABLE_IF(std::is_same<From, To>::value)>
+FMT_CONSTEXPR To safe_float_conversion(const From from, int& ec) {
+  ec = 0;
+  static_assert(std::is_floating_point<From>::value, "From must be floating");
+  return from;
+}
+
+/**
+ * safe duration cast between integral durations
+ */
+template <typename To, typename FromRep, typename FromPeriod,
+          FMT_ENABLE_IF(std::is_integral<FromRep>::value),
+          FMT_ENABLE_IF(std::is_integral<typename To::rep>::value)>
+To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
+                      int& ec) {
+  using From = std::chrono::duration<FromRep, FromPeriod>;
+  ec = 0;
+  // the basic idea is that we need to convert from count() in the from type
+  // to count() in the To type, by multiplying it with this:
+  struct Factor
+      : std::ratio_divide<typename From::period, typename To::period> {};
+
+  static_assert(Factor::num > 0, "num must be positive");
+  static_assert(Factor::den > 0, "den must be positive");
+
+  // the conversion is like this: multiply from.count() with Factor::num
+  // /Factor::den and convert it to To::rep, all this without
+  // overflow/underflow. let's start by finding a suitable type that can hold
+  // both To, From and Factor::num
+  using IntermediateRep =
+      typename std::common_type<typename From::rep, typename To::rep,
+                                decltype(Factor::num)>::type;
+
+  // safe conversion to IntermediateRep
+  IntermediateRep count =
+      lossless_integral_conversion<IntermediateRep>(from.count(), ec);
+  if (ec) {
+    return {};
+  }
+  // multiply with Factor::num without overflow or underflow
+  if (Factor::num != 1) {
+    const auto max1 = internal::max_value<IntermediateRep>() / Factor::num;
+    if (count > max1) {
+      ec = 1;
+      return {};
+    }
+    const auto min1 = std::numeric_limits<IntermediateRep>::min() / Factor::num;
+    if (count < min1) {
+      ec = 1;
+      return {};
+    }
+    count *= Factor::num;
+  }
+
+  // this can't go wrong, right? den>0 is checked earlier.
+  if (Factor::den != 1) {
+    count /= Factor::den;
+  }
+  // convert to the to type, safely
+  using ToRep = typename To::rep;
+  const ToRep tocount = lossless_integral_conversion<ToRep>(count, ec);
+  if (ec) {
+    return {};
+  }
+  return To{tocount};
+}
+
+/**
+ * safe duration_cast between floating point durations
+ */
+template <typename To, typename FromRep, typename FromPeriod,
+          FMT_ENABLE_IF(std::is_floating_point<FromRep>::value),
+          FMT_ENABLE_IF(std::is_floating_point<typename To::rep>::value)>
+To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
+                      int& ec) {
+  using From = std::chrono::duration<FromRep, FromPeriod>;
+  ec = 0;
+  if (std::isnan(from.count())) {
+    // nan in, gives nan out. easy.
+    return To{std::numeric_limits<typename To::rep>::quiet_NaN()};
+  }
+  // maybe we should also check if from is denormal, and decide what to do about
+  // it.
+
+  // +-inf should be preserved.
+  if (std::isinf(from.count())) {
+    return To{from.count()};
+  }
+
+  // the basic idea is that we need to convert from count() in the from type
+  // to count() in the To type, by multiplying it with this:
+  struct Factor
+      : std::ratio_divide<typename From::period, typename To::period> {};
+
+  static_assert(Factor::num > 0, "num must be positive");
+  static_assert(Factor::den > 0, "den must be positive");
+
+  // the conversion is like this: multiply from.count() with Factor::num
+  // /Factor::den and convert it to To::rep, all this without
+  // overflow/underflow. let's start by finding a suitable type that can hold
+  // both To, From and Factor::num
+  using IntermediateRep =
+      typename std::common_type<typename From::rep, typename To::rep,
+                                decltype(Factor::num)>::type;
+
+  // force conversion of From::rep -> IntermediateRep to be safe,
+  // even if it will never happen be narrowing in this context.
+  IntermediateRep count =
+      safe_float_conversion<IntermediateRep>(from.count(), ec);
+  if (ec) {
+    return {};
+  }
+
+  // multiply with Factor::num without overflow or underflow
+  if (Factor::num != 1) {
+    constexpr auto max1 = internal::max_value<IntermediateRep>() /
+                          static_cast<IntermediateRep>(Factor::num);
+    if (count > max1) {
+      ec = 1;
+      return {};
+    }
+    constexpr auto min1 = std::numeric_limits<IntermediateRep>::lowest() /
+                          static_cast<IntermediateRep>(Factor::num);
+    if (count < min1) {
+      ec = 1;
+      return {};
+    }
+    count *= static_cast<IntermediateRep>(Factor::num);
+  }
+
+  // this can't go wrong, right? den>0 is checked earlier.
+  if (Factor::den != 1) {
+    using common_t = typename std::common_type<IntermediateRep, intmax_t>::type;
+    count /= static_cast<common_t>(Factor::den);
+  }
+
+  // convert to the to type, safely
+  using ToRep = typename To::rep;
+
+  const ToRep tocount = safe_float_conversion<ToRep>(count, ec);
+  if (ec) {
+    return {};
+  }
+  return To{tocount};
+}
+}  // namespace safe_duration_cast
+#endif
 
 // Prevents expansion of a preceding token as a function-style macro.
 // Usage: f FMT_NOMACRO()
@@ -220,12 +495,12 @@ FMT_CONSTEXPR const Char* parse_chrono_format(const Char* begin,
       handler.on_text(ptr - 1, ptr);
       break;
     case 'n': {
-      const char newline[] = "\n";
+      const Char newline[] = {'\n'};
       handler.on_text(newline, newline + 1);
       break;
     }
     case 't': {
-      const char tab[] = "\t";
+      const Char tab[] = {'\t'};
       handler.on_text(tab, tab + 1);
       break;
     }
@@ -403,7 +678,7 @@ inline bool isfinite(T value) {
   return std::isfinite(value);
 }
 
-// Convers value to int and checks that it's in the range [0, upper).
+// Converts value to int and checks that it's in the range [0, upper).
 template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
 inline int to_nonnegative_int(T value, int upper) {
   FMT_ASSERT(value >= 0 && value <= upper, "invalid value");
@@ -421,7 +696,7 @@ inline int to_nonnegative_int(T value, int upper) {
 
 template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
 inline T mod(T x, int y) {
-  return x % y;
+  return x % static_cast<T>(y);
 }
 template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
 inline T mod(T x, int y) {
@@ -484,18 +759,30 @@ inline std::chrono::duration<Rep, std::milli> get_milliseconds(
   return std::chrono::duration<Rep, std::milli>(static_cast<Rep>(ms));
 }
 
-template <typename Rep, typename OutputIt>
-OutputIt format_chrono_duration_value(OutputIt out, Rep val, int precision) {
-  if (precision >= 0) return format_to(out, "{:.{}f}", val, precision);
-  return format_to(out, std::is_floating_point<Rep>::value ? "{:g}" : "{}",
+template <typename Char, typename Rep, typename OutputIt>
+OutputIt format_duration_value(OutputIt out, Rep val, int precision) {
+  const Char pr_f[] = {'{', ':', '.', '{', '}', 'f', '}', 0};
+  if (precision >= 0) return format_to(out, pr_f, val, precision);
+  const Char fp_f[] = {'{', ':', 'g', '}', 0};
+  const Char format[] = {'{', '}', 0};
+  return format_to(out, std::is_floating_point<Rep>::value ? fp_f : format,
                    val);
 }
 
-template <typename Period, typename OutputIt>
-static OutputIt format_chrono_duration_unit(OutputIt out) {
-  if (const char* unit = get_units<Period>()) return format_to(out, "{}", unit);
-  if (Period::den == 1) return format_to(out, "[{}]s", Period::num);
-  return format_to(out, "[{}/{}]s", Period::num, Period::den);
+template <typename Char, typename Period, typename OutputIt>
+OutputIt format_duration_unit(OutputIt out) {
+  if (const char* unit = get_units<Period>()) {
+    string_view s(unit);
+    if (const_check(std::is_same<Char, wchar_t>())) {
+      utf8_to_utf16 u(s);
+      return std::copy(u.c_str(), u.c_str() + u.size(), out);
+    }
+    return std::copy(s.begin(), s.end(), out);
+  }
+  const Char num_f[] = {'[', '{', '}', ']', 's', 0};
+  if (Period::den == 1) return format_to(out, num_f, Period::num);
+  const Char num_def_f[] = {'[', '{', '}', '/', '{', '}', ']', 's', 0};
+  return format_to(out, num_def_f, Period::num, Period::den);
 }
 
 template <typename FormatContext, typename OutputIt, typename Rep,
@@ -518,7 +805,10 @@ struct chrono_formatter {
 
   explicit chrono_formatter(FormatContext& ctx, OutputIt o,
                             std::chrono::duration<Rep, Period> d)
-      : context(ctx), out(o), val(d.count()), negative(false) {
+      : context(ctx),
+        out(o),
+        val(static_cast<rep>(d.count())),
+        negative(false) {
     if (d.count() < 0) {
       val = 0 - val;
       negative = true;
@@ -582,8 +872,8 @@ struct chrono_formatter {
   void write(Rep value, int width) {
     write_sign();
     if (isnan(value)) return write_nan();
-    uint32_or_64_t<int> n = to_unsigned(
-        to_nonnegative_int(value, (std::numeric_limits<int>::max)()));
+    uint32_or_64_or_128_t<int> n =
+        to_unsigned(to_nonnegative_int(value, max_value<int>()));
     int num_digits = internal::count_digits(n);
     if (width > num_digits) out = std::fill_n(out, width - num_digits, '0');
     out = format_decimal<char_type>(out, n, num_digits);
@@ -593,13 +883,13 @@ struct chrono_formatter {
   void write_pinf() { std::copy_n("inf", 3, out); }
   void write_ninf() { std::copy_n("-inf", 4, out); }
 
-  void format_localized(const tm& time, const char* format) {
+  void format_localized(const tm& time, char format, char modifier = 0) {
     if (isnan(val)) return write_nan();
     auto locale = context.locale().template get<std::locale>();
     auto& facet = std::use_facet<std::time_put<char_type>>(locale);
     std::basic_ostringstream<char_type> os;
     os.imbue(locale);
-    facet.put(os, os, ' ', &time, format, format + std::strlen(format));
+    facet.put(os, os, ' ', &time, format, modifier);
     auto str = os.str();
     std::copy(str.begin(), str.end(), out);
   }
@@ -629,7 +919,7 @@ struct chrono_formatter {
     if (ns == numeric_system::standard) return write(hour(), 2);
     auto time = tm();
     time.tm_hour = to_nonnegative_int(hour(), 24);
-    format_localized(time, "%OH");
+    format_localized(time, 'H', 'O');
   }
 
   void on_12_hour(numeric_system ns) {
@@ -638,7 +928,7 @@ struct chrono_formatter {
     if (ns == numeric_system::standard) return write(hour12(), 2);
     auto time = tm();
     time.tm_hour = to_nonnegative_int(hour12(), 12);
-    format_localized(time, "%OI");
+    format_localized(time, 'I', 'O');
   }
 
   void on_minute(numeric_system ns) {
@@ -647,7 +937,7 @@ struct chrono_formatter {
     if (ns == numeric_system::standard) return write(minute(), 2);
     auto time = tm();
     time.tm_min = to_nonnegative_int(minute(), 60);
-    format_localized(time, "%OM");
+    format_localized(time, 'M', 'O');
   }
 
   void on_second(numeric_system ns) {
@@ -672,13 +962,12 @@ struct chrono_formatter {
     }
     auto time = tm();
     time.tm_sec = to_nonnegative_int(second(), 60);
-    format_localized(time, "%OS");
+    format_localized(time, 'S', 'O');
   }
 
   void on_12_hour_time() {
     if (handle_nan_inf()) return;
-
-    format_localized(time(), "%r");
+    format_localized(time(), 'r');
   }
 
   void on_24_hour_time() {
@@ -702,16 +991,18 @@ struct chrono_formatter {
 
   void on_am_pm() {
     if (handle_nan_inf()) return;
-    format_localized(time(), "%p");
+    format_localized(time(), 'p');
   }
 
   void on_duration_value() {
     if (handle_nan_inf()) return;
     write_sign();
-    out = format_chrono_duration_value(out, val, precision);
+    out = format_duration_value<char_type>(out, val, precision);
   }
 
-  void on_duration_unit() { out = format_chrono_duration_unit<Period>(out); }
+  void on_duration_unit() {
+    out = format_duration_unit<char_type, Period>(out);
+  }
 };
 }  // namespace internal
 
@@ -728,7 +1019,7 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
 
   struct spec_handler {
     formatter& f;
-    basic_parse_context<Char>& context;
+    basic_format_parse_context<Char>& context;
     basic_string_view<Char> format_str;
 
     template <typename Id> FMT_CONSTEXPR arg_ref_type make_arg_ref(Id arg_id) {
@@ -738,8 +1029,7 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
 
     FMT_CONSTEXPR arg_ref_type make_arg_ref(basic_string_view<Char> arg_id) {
       context.check_arg_id(arg_id);
-      const auto str_val = internal::string_view_metadata(format_str, arg_id);
-      return arg_ref_type(str_val);
+      return arg_ref_type(arg_id);
     }
 
     FMT_CONSTEXPR arg_ref_type make_arg_ref(internal::auto_id) {
@@ -747,10 +1037,10 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
     }
 
     void on_error(const char* msg) { FMT_THROW(format_error(msg)); }
-    void on_fill(Char fill) { f.specs.fill[0] = fill; }
+    void on_fill(basic_string_view<Char> fill) { f.specs.fill = fill; }
     void on_align(align_t align) { f.specs.align = align; }
-    void on_width(unsigned width) { f.specs.width = width; }
-    void on_precision(unsigned precision) { f.precision = precision; }
+    void on_width(int width) { f.specs.width = width; }
+    void on_precision(int _precision) { f.precision = _precision; }
     void end_precision() {}
 
     template <typename Id> void on_dynamic_width(Id arg_id) {
@@ -762,13 +1052,13 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
     }
   };
 
-  using iterator = typename basic_parse_context<Char>::iterator;
+  using iterator = typename basic_format_parse_context<Char>::iterator;
   struct parse_range {
     iterator begin;
     iterator end;
   };
 
-  FMT_CONSTEXPR parse_range do_parse(basic_parse_context<Char>& ctx) {
+  FMT_CONSTEXPR parse_range do_parse(basic_format_parse_context<Char>& ctx) {
     auto begin = ctx.begin(), end = ctx.end();
     if (begin == end || *begin == '}') return {begin, begin};
     spec_handler handler{*this, ctx, format_str};
@@ -789,7 +1079,7 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
  public:
   formatter() : precision(-1) {}
 
-  FMT_CONSTEXPR auto parse(basic_parse_context<Char>& ctx)
+  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
       -> decltype(ctx.begin()) {
     auto range = do_parse(ctx);
     format_str = basic_string_view<Char>(
@@ -806,13 +1096,13 @@ struct formatter<std::chrono::duration<Rep, Period>, Char> {
     auto out = std::back_inserter(buf);
     using range = internal::output_range<decltype(ctx.out()), Char>;
     internal::basic_writer<range> w(range(ctx.out()));
-    internal::handle_dynamic_spec<internal::width_checker>(
-        specs.width, width_ref, ctx, format_str.begin());
+    internal::handle_dynamic_spec<internal::width_checker>(specs.width,
+                                                           width_ref, ctx);
     internal::handle_dynamic_spec<internal::precision_checker>(
-        precision, precision_ref, ctx, format_str.begin());
+        precision, precision_ref, ctx);
     if (begin == end || *begin == '}') {
-      out = internal::format_chrono_duration_value(out, d.count(), precision);
-      internal::format_chrono_duration_unit<Period>(out);
+      out = internal::format_duration_value<Char>(out, d.count(), precision);
+      internal::format_duration_unit<Char, Period>(out);
     } else {
       internal::chrono_formatter<FormatContext, decltype(out), Rep, Period> f(
           ctx, out, d);

include/fmt/color.h

@@ -299,15 +299,15 @@ class text_style {
     return static_cast<uint8_t>(ems) != 0;
   }
   FMT_CONSTEXPR internal::color_type get_foreground() const FMT_NOEXCEPT {
-    assert(has_foreground() && "no foreground specified for this style");
+    FMT_ASSERT(has_foreground(), "no foreground specified for this style");
     return foreground_color;
   }
   FMT_CONSTEXPR internal::color_type get_background() const FMT_NOEXCEPT {
-    assert(has_background() && "no background specified for this style");
+    FMT_ASSERT(has_background(), "no background specified for this style");
     return background_color;
   }
   FMT_CONSTEXPR emphasis get_emphasis() const FMT_NOEXCEPT {
-    assert(has_emphasis() && "no emphasis specified for this style");
+    FMT_ASSERT(has_emphasis(), "no emphasis specified for this style");
     return ems;
   }
 
@@ -412,7 +412,7 @@ template <typename Char> struct ansi_color_escape {
 
   FMT_CONSTEXPR const Char* begin() const FMT_NOEXCEPT { return buffer; }
   FMT_CONSTEXPR const Char* end() const FMT_NOEXCEPT {
-    return buffer + std::strlen(buffer);
+    return buffer + std::char_traits<Char>::length(buffer);
   }
 
  private:
@@ -470,58 +470,39 @@ inline void reset_color(basic_memory_buffer<Char>& buffer) FMT_NOEXCEPT {
 }
 
 template <typename Char>
-std::basic_string<Char> vformat(const text_style& ts,
-                                basic_string_view<Char> format_str,
-                                basic_format_args<buffer_context<Char> > args) {
-  basic_memory_buffer<Char> buffer;
+void vformat_to(basic_memory_buffer<Char>& buf, const text_style& ts,
+                basic_string_view<Char> format_str,
+                basic_format_args<buffer_context<Char>> args) {
   bool has_style = false;
   if (ts.has_emphasis()) {
     has_style = true;
-    ansi_color_escape<Char> escape = make_emphasis<Char>(ts.get_emphasis());
-    buffer.append(escape.begin(), escape.end());
+    auto emphasis = internal::make_emphasis<Char>(ts.get_emphasis());
+    buf.append(emphasis.begin(), emphasis.end());
   }
   if (ts.has_foreground()) {
     has_style = true;
-    ansi_color_escape<Char> escape =
-        make_foreground_color<Char>(ts.get_foreground());
-    buffer.append(escape.begin(), escape.end());
+    auto foreground =
+        internal::make_foreground_color<Char>(ts.get_foreground());
+    buf.append(foreground.begin(), foreground.end());
   }
   if (ts.has_background()) {
     has_style = true;
-    ansi_color_escape<Char> escape =
-        make_background_color<Char>(ts.get_background());
-    buffer.append(escape.begin(), escape.end());
+    auto background =
+        internal::make_background_color<Char>(ts.get_background());
+    buf.append(background.begin(), background.end());
   }
-  internal::vformat_to(buffer, format_str, args);
-  if (has_style) {
-    reset_color<Char>(buffer);
-  }
-  return fmt::to_string(buffer);
+  internal::vformat_to(buf, format_str, args);
+  if (has_style) internal::reset_color<Char>(buf);
 }
 }  // namespace internal
 
-template <typename S, typename Char = char_t<S> >
+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<Char> > args) {
-  bool has_style = false;
-  if (ts.has_emphasis()) {
-    has_style = true;
-    internal::fputs<Char>(internal::make_emphasis<Char>(ts.get_emphasis()), f);
-  }
-  if (ts.has_foreground()) {
-    has_style = true;
-    internal::fputs<Char>(
-        internal::make_foreground_color<Char>(ts.get_foreground()), f);
-  }
-  if (ts.has_background()) {
-    has_style = true;
-    internal::fputs<Char>(
-        internal::make_background_color<Char>(ts.get_background()), f);
-  }
-  vprint(f, format, args);
-  if (has_style) {
-    internal::reset_color<Char>(f);
-  }
+            basic_format_args<buffer_context<Char>> args) {
+  basic_memory_buffer<Char> buf;
+  internal::vformat_to(buf, ts, to_string_view(format), args);
+  buf.push_back(Char(0));
+  internal::fputs(buf.data(), f);
 }
 
 /**
@@ -536,7 +517,7 @@ template <typename S, typename... Args,
 void print(std::FILE* f, const text_style& ts, const S& format_str,
            const Args&... args) {
   internal::check_format_string<Args...>(format_str);
-  using context = buffer_context<char_t<S> >;
+  using context = buffer_context<char_t<S>>;
   format_arg_store<context, Args...> as{args...};
   vprint(f, ts, format_str, basic_format_args<context>(as));
 }
@@ -554,11 +535,13 @@ void print(const text_style& ts, const S& format_str, const Args&... args) {
   return print(stdout, ts, format_str, args...);
 }
 
-template <typename S, typename Char = char_t<S> >
+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<Char> > args) {
-  return internal::vformat(ts, to_string_view(format_str), args);
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  basic_memory_buffer<Char> buf;
+  internal::vformat_to(buf, ts, to_string_view(format_str), args);
+  return fmt::to_string(buf);
 }
 
 /**
@@ -573,11 +556,11 @@ inline std::basic_string<Char> vformat(
                                       "The answer is {}", 42);
   \endrst
 */
-template <typename S, typename... Args, typename Char = char_t<S> >
+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 internal::vformat(ts, to_string_view(format_str),
-                           {internal::make_args_checked(format_str, args...)});
+  return vformat(ts, to_string_view(format_str),
+                 internal::make_args_checked<Args...>(format_str, args...));
 }
 
 FMT_END_NAMESPACE

include/fmt/compile.h

@@ -9,255 +9,50 @@
 #define FMT_COMPILE_H_
 
 #include <vector>
+
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
 namespace internal {
 
+// Part of a compiled format string. It can be either literal text or a
+// replacement field.
 template <typename Char> struct format_part {
- public:
-  struct named_argument_id {
-    FMT_CONSTEXPR named_argument_id(internal::string_view_metadata id)
-        : id(id) {}
-    internal::string_view_metadata id;
+  enum class kind { arg_index, arg_name, text, replacement };
+
+  struct replacement {
+    arg_ref<Char> arg_id;
+    dynamic_format_specs<Char> specs;
   };
 
-  struct argument_id {
-    FMT_CONSTEXPR argument_id() : argument_id(0u) {}
-
-    FMT_CONSTEXPR argument_id(unsigned id)
-        : which(which_arg_id::index), val(id) {}
-
-    FMT_CONSTEXPR argument_id(internal::string_view_metadata id)
-        : which(which_arg_id::named_index), val(id) {}
-
-    enum class which_arg_id { index, named_index };
-
-    which_arg_id which;
-
-    union value {
-      FMT_CONSTEXPR value() : index(0u) {}
-      FMT_CONSTEXPR value(unsigned id) : index(id) {}
-      FMT_CONSTEXPR value(internal::string_view_metadata id)
-          : named_index(id) {}
-
-      unsigned index;
-      internal::string_view_metadata named_index;
-    } val;
-  };
-
-  struct specification {
-    FMT_CONSTEXPR specification() : arg_id(0u) {}
-    FMT_CONSTEXPR specification(unsigned id) : arg_id(id) {}
-
-    FMT_CONSTEXPR specification(internal::string_view_metadata id)
-        : arg_id(id) {}
-
-    argument_id arg_id;
-    internal::dynamic_format_specs<Char> parsed_specs;
-  };
-
-  FMT_CONSTEXPR format_part()
-      : which(kind::argument_id), end_of_argument_id(0u), val(0u) {}
-
-  FMT_CONSTEXPR format_part(internal::string_view_metadata text)
-      : which(kind::text), end_of_argument_id(0u), val(text) {}
-
-  FMT_CONSTEXPR format_part(unsigned id)
-      : which(kind::argument_id), end_of_argument_id(0u), val(id) {}
-
-  FMT_CONSTEXPR format_part(named_argument_id arg_id)
-      : which(kind::named_argument_id), end_of_argument_id(0u), val(arg_id) {}
-
-  FMT_CONSTEXPR format_part(specification spec)
-      : which(kind::specification), end_of_argument_id(0u), val(spec) {}
-
-  enum class kind { argument_id, named_argument_id, text, specification };
-
-  kind which;
-  std::size_t end_of_argument_id;
+  kind part_kind;
   union value {
-    FMT_CONSTEXPR value() : arg_id(0u) {}
-    FMT_CONSTEXPR value(unsigned id) : arg_id(id) {}
-    FMT_CONSTEXPR value(named_argument_id named_id)
-        : named_arg_id(named_id.id) {}
-    FMT_CONSTEXPR value(internal::string_view_metadata t) : text(t) {}
-    FMT_CONSTEXPR value(specification s) : spec(s) {}
-    unsigned arg_id;
-    internal::string_view_metadata named_arg_id;
-    internal::string_view_metadata text;
-    specification spec;
+    int arg_index;
+    basic_string_view<Char> str;
+    replacement repl;
+
+    FMT_CONSTEXPR value(int index = 0) : arg_index(index) {}
+    FMT_CONSTEXPR value(basic_string_view<Char> s) : str(s) {}
+    FMT_CONSTEXPR value(replacement r) : repl(r) {}
   } val;
-};
+  // Position past the end of the argument id.
+  const Char* arg_id_end = nullptr;
 
-template <typename Char, typename PartsContainer>
-class format_preparation_handler : public internal::error_handler {
- private:
-  using part = format_part<Char>;
+  FMT_CONSTEXPR format_part(kind k = kind::arg_index, value v = {})
+      : part_kind(k), val(v) {}
 
- public:
-  using iterator = typename basic_string_view<Char>::iterator;
-
-  FMT_CONSTEXPR format_preparation_handler(basic_string_view<Char> format,
-                                           PartsContainer& parts)
-      : parts_(parts), format_(format), parse_context_(format) {}
-
-  FMT_CONSTEXPR void on_text(const Char* begin, const Char* end) {
-    if (begin == end) return;
-    const auto offset = begin - format_.data();
-    const auto size = end - begin;
-    parts_.push_back(part(string_view_metadata(offset, size)));
+  static FMT_CONSTEXPR format_part make_arg_index(int index) {
+    return format_part(kind::arg_index, index);
   }
-
-  FMT_CONSTEXPR void on_arg_id() {
-    parts_.push_back(part(parse_context_.next_arg_id()));
+  static FMT_CONSTEXPR format_part make_arg_name(basic_string_view<Char> name) {
+    return format_part(kind::arg_name, name);
   }
-
-  FMT_CONSTEXPR void on_arg_id(unsigned id) {
-    parse_context_.check_arg_id(id);
-    parts_.push_back(part(id));
+  static FMT_CONSTEXPR format_part make_text(basic_string_view<Char> text) {
+    return format_part(kind::text, text);
   }
-
-  FMT_CONSTEXPR void on_arg_id(basic_string_view<Char> id) {
-    const auto view = string_view_metadata(format_, id);
-    const auto arg_id = typename part::named_argument_id(view);
-    parts_.push_back(part(arg_id));
+  static FMT_CONSTEXPR format_part make_replacement(replacement repl) {
+    return format_part(kind::replacement, repl);
   }
-
-  FMT_CONSTEXPR void on_replacement_field(const Char* ptr) {
-    parts_.back().end_of_argument_id = ptr - format_.begin();
-  }
-
-  FMT_CONSTEXPR const Char* on_format_specs(const Char* begin,
-                                            const Char* end) {
-    const auto specs_offset = to_unsigned(begin - format_.begin());
-
-    using parse_context = basic_parse_context<Char>;
-    internal::dynamic_format_specs<Char> parsed_specs;
-    dynamic_specs_handler<parse_context> handler(parsed_specs, parse_context_);
-    begin = parse_format_specs(begin, end, handler);
-
-    if (*begin != '}') on_error("missing '}' in format string");
-
-    auto& last_part = parts_.back();
-    auto specs = last_part.which == part::kind::argument_id
-                     ? typename part::specification(last_part.val.arg_id)
-                     : typename part::specification(last_part.val.named_arg_id);
-    specs.parsed_specs = parsed_specs;
-    last_part = part(specs);
-    last_part.end_of_argument_id = specs_offset;
-    return begin;
-  }
-
- private:
-  PartsContainer& parts_;
-  basic_string_view<Char> format_;
-  basic_parse_context<Char> parse_context_;
-};
-
-template <typename Format, typename PreparedPartsProvider, typename... Args>
-class prepared_format {
- public:
-  using char_type = char_t<Format>;
-  using format_part_t = format_part<char_type>;
-
-  constexpr prepared_format(Format f)
-      : format_(std::move(f)), parts_provider_(to_string_view(format_)) {}
-
-  prepared_format() = delete;
-
-  using context = buffer_context<char_type>;
-
-  template <typename Range, typename Context>
-  auto vformat_to(Range out, basic_format_args<Context> args) const ->
-      typename Context::iterator {
-    const auto format_view = internal::to_string_view(format_);
-    basic_parse_context<char_type> parse_ctx(format_view);
-    Context ctx(out.begin(), args);
-
-    const auto& parts = parts_provider_.parts();
-    for (auto part_it = parts.begin(); part_it != parts.end(); ++part_it) {
-      const auto& part = *part_it;
-      const auto& value = part.val;
-
-      switch (part.which) {
-      case format_part_t::kind::text: {
-        const auto text = value.text.to_view(format_view.data());
-        auto output = ctx.out();
-        auto&& it = internal::reserve(output, text.size());
-        it = std::copy_n(text.begin(), text.size(), it);
-        ctx.advance_to(output);
-      } break;
-
-      case format_part_t::kind::argument_id: {
-        advance_parse_context_to_specification(parse_ctx, part);
-        format_arg<Range>(parse_ctx, ctx, value.arg_id);
-      } break;
-
-      case format_part_t::kind::named_argument_id: {
-        advance_parse_context_to_specification(parse_ctx, part);
-        const auto named_arg_id =
-            value.named_arg_id.to_view(format_view.data());
-        format_arg<Range>(parse_ctx, ctx, named_arg_id);
-      } break;
-      case format_part_t::kind::specification: {
-        const auto& arg_id_value = value.spec.arg_id.val;
-        const auto arg = value.spec.arg_id.which ==
-                                 format_part_t::argument_id::which_arg_id::index
-                             ? ctx.arg(arg_id_value.index)
-                             : ctx.arg(arg_id_value.named_index.to_view(
-                                   to_string_view(format_).data()));
-
-        auto specs = value.spec.parsed_specs;
-
-        handle_dynamic_spec<internal::width_checker>(
-            specs.width, specs.width_ref, ctx, format_view.begin());
-        handle_dynamic_spec<internal::precision_checker>(
-            specs.precision, specs.precision_ref, ctx, format_view.begin());
-
-        check_prepared_specs(specs, arg.type());
-        advance_parse_context_to_specification(parse_ctx, part);
-        ctx.advance_to(
-            visit_format_arg(arg_formatter<Range>(ctx, nullptr, &specs), arg));
-      } break;
-      }
-    }
-
-    return ctx.out();
-  }
-
- private:
-  void advance_parse_context_to_specification(
-      basic_parse_context<char_type>& parse_ctx,
-      const format_part_t& part) const {
-    const auto view = to_string_view(format_);
-    const auto specification_begin = view.data() + part.end_of_argument_id;
-    advance_to(parse_ctx, specification_begin);
-  }
-
-  template <typename Range, typename Context, typename Id>
-  void format_arg(basic_parse_context<char_type>& parse_ctx, Context& ctx,
-                  Id arg_id) const {
-    parse_ctx.check_arg_id(arg_id);
-    const auto stopped_at =
-        visit_format_arg(arg_formatter<Range>(ctx), ctx.arg(arg_id));
-    ctx.advance_to(stopped_at);
-  }
-
-  template <typename Char>
-  void check_prepared_specs(const basic_format_specs<Char>& specs,
-                            internal::type arg_type) const {
-    internal::error_handler h;
-    numeric_specs_checker<internal::error_handler> checker(h, arg_type);
-    if (specs.align == align::numeric) checker.require_numeric_argument();
-    if (specs.sign != sign::none) checker.check_sign();
-    if (specs.alt) checker.require_numeric_argument();
-    if (specs.precision >= 0) checker.check_precision();
-  }
-
- private:
-  Format format_;
-  PreparedPartsProvider parts_provider_;
 };
 
 template <typename Char> struct part_counter {
@@ -268,7 +63,7 @@ template <typename Char> struct part_counter {
   }
 
   FMT_CONSTEXPR void on_arg_id() { ++num_parts; }
-  FMT_CONSTEXPR void on_arg_id(unsigned) { ++num_parts; }
+  FMT_CONSTEXPR void on_arg_id(int) { ++num_parts; }
   FMT_CONSTEXPR void on_arg_id(basic_string_view<Char>) { ++num_parts; }
 
   FMT_CONSTEXPR void on_replacement_field(const Char*) {}
@@ -276,13 +71,13 @@ template <typename Char> struct part_counter {
   FMT_CONSTEXPR const Char* on_format_specs(const Char* begin,
                                             const Char* end) {
     // Find the matching brace.
-    unsigned braces_counter = 0;
+    unsigned brace_counter = 0;
     for (; begin != end; ++begin) {
       if (*begin == '{') {
-        ++braces_counter;
+        ++brace_counter;
       } else if (*begin == '}') {
-        if (braces_counter == 0u) break;
-        --braces_counter;
+        if (brace_counter == 0u) break;
+        --brace_counter;
       }
     }
     return begin;
@@ -291,156 +86,493 @@ template <typename Char> struct part_counter {
   FMT_CONSTEXPR void on_error(const char*) {}
 };
 
-template <typename Format> class compiletime_prepared_parts_type_provider {
- private:
-  using char_type = char_t<Format>;
+// Counts the number of parts in a format string.
+template <typename Char>
+FMT_CONSTEXPR unsigned count_parts(basic_string_view<Char> format_str) {
+  part_counter<Char> counter;
+  parse_format_string<true>(format_str, counter);
+  return counter.num_parts;
+}
 
-  static FMT_CONSTEXPR unsigned count_parts() {
-    FMT_CONSTEXPR_DECL const auto text = to_string_view(Format{});
-    part_counter<char_type> counter;
-    internal::parse_format_string</*IS_CONSTEXPR=*/true>(text, counter);
-    return counter.num_parts;
+template <typename Char, typename PartHandler>
+class format_string_compiler : public error_handler {
+ private:
+  using part = format_part<Char>;
+
+  PartHandler handler_;
+  part part_;
+  basic_string_view<Char> format_str_;
+  basic_format_parse_context<Char> parse_context_;
+
+ public:
+  FMT_CONSTEXPR format_string_compiler(basic_string_view<Char> format_str,
+                                       PartHandler handler)
+      : handler_(handler),
+        format_str_(format_str),
+        parse_context_(format_str) {}
+
+  FMT_CONSTEXPR void on_text(const Char* begin, const Char* end) {
+    if (begin != end)
+      handler_(part::make_text({begin, to_unsigned(end - begin)}));
   }
 
-// Workaround for old compilers. Compiletime parts preparation will not be
-// performed with them anyway.
+  FMT_CONSTEXPR void on_arg_id() {
+    part_ = part::make_arg_index(parse_context_.next_arg_id());
+  }
+
+  FMT_CONSTEXPR void on_arg_id(int id) {
+    parse_context_.check_arg_id(id);
+    part_ = part::make_arg_index(id);
+  }
+
+  FMT_CONSTEXPR void on_arg_id(basic_string_view<Char> id) {
+    part_ = part::make_arg_name(id);
+  }
+
+  FMT_CONSTEXPR void on_replacement_field(const Char* ptr) {
+    part_.arg_id_end = ptr;
+    handler_(part_);
+  }
+
+  FMT_CONSTEXPR const Char* on_format_specs(const Char* begin,
+                                            const Char* end) {
+    auto repl = typename part::replacement();
+    dynamic_specs_handler<basic_format_parse_context<Char>> handler(
+        repl.specs, parse_context_);
+    auto it = parse_format_specs(begin, end, handler);
+    if (*it != '}') on_error("missing '}' in format string");
+    repl.arg_id = part_.part_kind == part::kind::arg_index
+                      ? arg_ref<Char>(part_.val.arg_index)
+                      : arg_ref<Char>(part_.val.str);
+    auto part = part::make_replacement(repl);
+    part.arg_id_end = begin;
+    handler_(part);
+    return it;
+  }
+};
+
+// Compiles a format string and invokes handler(part) for each parsed part.
+template <bool IS_CONSTEXPR, typename Char, typename PartHandler>
+FMT_CONSTEXPR void compile_format_string(basic_string_view<Char> format_str,
+                                         PartHandler handler) {
+  parse_format_string<IS_CONSTEXPR>(
+      format_str,
+      format_string_compiler<Char, PartHandler>(format_str, handler));
+}
+
+template <typename Range, typename Context, typename Id>
+void format_arg(
+    basic_format_parse_context<typename Range::value_type>& parse_ctx,
+    Context& ctx, Id arg_id) {
+  ctx.advance_to(
+      visit_format_arg(arg_formatter<Range>(ctx, &parse_ctx), ctx.arg(arg_id)));
+}
+
+// vformat_to is defined in a subnamespace to prevent ADL.
+namespace cf {
+template <typename Context, typename Range, typename CompiledFormat>
+auto vformat_to(Range out, CompiledFormat& cf, basic_format_args<Context> args)
+    -> typename Context::iterator {
+  using char_type = typename Context::char_type;
+  basic_format_parse_context<char_type> parse_ctx(
+      to_string_view(cf.format_str_));
+  Context ctx(out.begin(), args);
+
+  const auto& parts = cf.parts();
+  for (auto part_it = std::begin(parts); part_it != std::end(parts);
+       ++part_it) {
+    const auto& part = *part_it;
+    const auto& value = part.val;
+
+    using format_part_t = format_part<char_type>;
+    switch (part.part_kind) {
+    case format_part_t::kind::text: {
+      const auto text = value.str;
+      auto output = ctx.out();
+      auto&& it = reserve(output, text.size());
+      it = std::copy_n(text.begin(), text.size(), it);
+      ctx.advance_to(output);
+      break;
+    }
+
+    case format_part_t::kind::arg_index:
+      advance_to(parse_ctx, part.arg_id_end);
+      internal::format_arg<Range>(parse_ctx, ctx, value.arg_index);
+      break;
+
+    case format_part_t::kind::arg_name:
+      advance_to(parse_ctx, part.arg_id_end);
+      internal::format_arg<Range>(parse_ctx, ctx, value.str);
+      break;
+
+    case format_part_t::kind::replacement: {
+      const auto& arg_id_value = value.repl.arg_id.val;
+      const auto arg = value.repl.arg_id.kind == arg_id_kind::index
+                           ? ctx.arg(arg_id_value.index)
+                           : ctx.arg(arg_id_value.name);
+
+      auto specs = value.repl.specs;
+
+      handle_dynamic_spec<width_checker>(specs.width, specs.width_ref, ctx);
+      handle_dynamic_spec<precision_checker>(specs.precision,
+                                             specs.precision_ref, ctx);
+
+      error_handler h;
+      numeric_specs_checker<error_handler> checker(h, arg.type());
+      if (specs.align == align::numeric) checker.require_numeric_argument();
+      if (specs.sign != sign::none) checker.check_sign();
+      if (specs.alt) checker.require_numeric_argument();
+      if (specs.precision >= 0) checker.check_precision();
+
+      advance_to(parse_ctx, part.arg_id_end);
+      ctx.advance_to(
+          visit_format_arg(arg_formatter<Range>(ctx, nullptr, &specs), arg));
+      break;
+    }
+    }
+  }
+  return ctx.out();
+}
+}  // namespace cf
+
+struct basic_compiled_format {};
+
+template <typename S, typename = void>
+struct compiled_format_base : basic_compiled_format {
+  using char_type = char_t<S>;
+  using parts_container = std::vector<internal::format_part<char_type>>;
+
+  parts_container compiled_parts;
+
+  explicit compiled_format_base(basic_string_view<char_type> format_str) {
+    compile_format_string<false>(format_str,
+                                 [this](const format_part<char_type>& part) {
+                                   compiled_parts.push_back(part);
+                                 });
+  }
+
+  const parts_container& parts() const { return compiled_parts; }
+};
+
+template <typename Char, unsigned N> struct format_part_array {
+  format_part<Char> data[N] = {};
+  FMT_CONSTEXPR format_part_array() = default;
+};
+
+template <typename Char, unsigned N>
+FMT_CONSTEXPR format_part_array<Char, N> compile_to_parts(
+    basic_string_view<Char> format_str) {
+  format_part_array<Char, N> parts;
+  unsigned counter = 0;
+  // This is not a lambda for compatibility with older compilers.
+  struct {
+    format_part<Char>* parts;
+    unsigned* counter;
+    FMT_CONSTEXPR void operator()(const format_part<Char>& part) {
+      parts[(*counter)++] = part;
+    }
+  } collector{parts.data, &counter};
+  compile_format_string<true>(format_str, collector);
+  if (counter < N) {
+    parts.data[counter] =
+        format_part<Char>::make_text(basic_string_view<Char>());
+  }
+  return parts;
+}
+
+template <typename T> constexpr const T& constexpr_max(const T& a, const T& b) {
+  return (a < b) ? b : a;
+}
+
+template <typename S>
+struct compiled_format_base<S, enable_if_t<is_compile_string<S>::value>>
+    : basic_compiled_format {
+  using char_type = char_t<S>;
+
+  FMT_CONSTEXPR explicit compiled_format_base(basic_string_view<char_type>) {}
+
+// Workaround for old compilers. Format string compilation will not be
+// performed there anyway.
 #if FMT_USE_CONSTEXPR
-  static FMT_CONSTEXPR_DECL const unsigned number_of_format_parts =
-      compiletime_prepared_parts_type_provider::count_parts();
+  static FMT_CONSTEXPR_DECL const unsigned num_format_parts =
+      constexpr_max(count_parts(to_string_view(S())), 1u);
 #else
-  static const unsigned number_of_format_parts = 0u;
+  static const unsigned num_format_parts = 1;
 #endif
 
- public:
-  template <unsigned N> struct format_parts_array {
-    using value_type = format_part<char_type>;
+  using parts_container = format_part<char_type>[num_format_parts];
 
-    FMT_CONSTEXPR format_parts_array() : arr{} {}
-
-    FMT_CONSTEXPR value_type& operator[](unsigned ind) { return arr[ind]; }
-
-    FMT_CONSTEXPR const value_type* begin() const { return arr; }
-    FMT_CONSTEXPR const value_type* end() const { return begin() + N; }
-
-   private:
-    value_type arr[N];
-  };
-
-  struct empty {
-    // Parts preparator will search for it
-    using value_type = format_part<char_type>;
-  };
-
-  using type = conditional_t<number_of_format_parts != 0,
-                             format_parts_array<number_of_format_parts>, empty>;
-};
-
-template <typename Parts> class compiletime_prepared_parts_collector {
- private:
-  using format_part = typename Parts::value_type;
-
- public:
-  FMT_CONSTEXPR explicit compiletime_prepared_parts_collector(Parts& parts)
-      : parts_{parts}, counter_{0u} {}
-
-  FMT_CONSTEXPR void push_back(format_part part) { parts_[counter_++] = part; }
-
-  FMT_CONSTEXPR format_part& back() { return parts_[counter_ - 1]; }
-
- private:
-  Parts& parts_;
-  unsigned counter_;
-};
-
-template <typename PartsContainer, typename Char>
-FMT_CONSTEXPR PartsContainer prepare_parts(basic_string_view<Char> format) {
-  PartsContainer parts;
-  internal::parse_format_string</*IS_CONSTEXPR=*/false>(
-      format, format_preparation_handler<Char, PartsContainer>(format, parts));
-  return parts;
-}
-
-template <typename PartsContainer, typename Char>
-FMT_CONSTEXPR PartsContainer
-prepare_compiletime_parts(basic_string_view<Char> format) {
-  using collector = compiletime_prepared_parts_collector<PartsContainer>;
-
-  PartsContainer parts;
-  collector c(parts);
-  internal::parse_format_string</*IS_CONSTEXPR=*/true>(
-      format, format_preparation_handler<Char, collector>(format, c));
-  return parts;
-}
-
-template <typename PartsContainer> class runtime_parts_provider {
- public:
-  runtime_parts_provider() = delete;
-  template <typename Char>
-  runtime_parts_provider(basic_string_view<Char> format)
-      : parts_(prepare_parts<PartsContainer>(format)) {}
-
-  const PartsContainer& parts() const { return parts_; }
-
- private:
-  PartsContainer parts_;
-};
-
-template <typename Format, typename PartsContainer>
-struct compiletime_parts_provider {
-  compiletime_parts_provider() = delete;
-  template <typename Char>
-  FMT_CONSTEXPR compiletime_parts_provider(basic_string_view<Char>) {}
-
-  const PartsContainer& parts() const {
-    static FMT_CONSTEXPR_DECL const PartsContainer prepared_parts =
-        prepare_compiletime_parts<PartsContainer>(
-            internal::to_string_view(Format{}));
-
-    return prepared_parts;
+  const parts_container& parts() const {
+    static FMT_CONSTEXPR_DECL const auto compiled_parts =
+        compile_to_parts<char_type, num_format_parts>(
+            internal::to_string_view(S()));
+    return compiled_parts.data;
   }
 };
+
+template <typename S, typename... Args>
+class compiled_format : private compiled_format_base<S> {
+ public:
+  using typename compiled_format_base<S>::char_type;
+
+ private:
+  basic_string_view<char_type> format_str_;
+
+  template <typename Context, typename Range, typename CompiledFormat>
+  friend auto cf::vformat_to(Range out, CompiledFormat& cf,
+                             basic_format_args<Context> args) ->
+      typename Context::iterator;
+
+ public:
+  compiled_format() = delete;
+  explicit constexpr compiled_format(basic_string_view<char_type> format_str)
+      : compiled_format_base<S>(format_str), format_str_(format_str) {}
+};
+
+#ifdef __cpp_if_constexpr
+template <typename... Args> struct type_list {};
+
+// Returns a reference to the argument at index N from [first, rest...].
+template <int N, typename T, typename... Args>
+constexpr const auto& get(const T& first, const Args&... rest) {
+  static_assert(N < 1 + sizeof...(Args), "index is out of bounds");
+  if constexpr (N == 0)
+    return first;
+  else
+    return get<N - 1>(rest...);
+}
+
+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(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>
+  OutputIt format(OutputIt out, const Args&...) const {
+    // TODO: reserve
+    return copy_str<Char>(data.begin(), data.end(), out);
+  }
+};
+
+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, typename OutputIt, typename T,
+          std::enable_if_t<std::is_integral_v<T>, int> = 0>
+OutputIt format_default(OutputIt out, T value) {
+  // TODO: reserve
+  format_int fi(value);
+  return std::copy(fi.data(), fi.data() + fi.size(), out);
+}
+
+template <typename Char, typename OutputIt>
+OutputIt format_default(OutputIt out, double value) {
+  writer w(out);
+  w.write(value);
+  return w.out();
+}
+
+template <typename Char, typename OutputIt>
+OutputIt format_default(OutputIt out, Char value) {
+  *out++ = value;
+  return out;
+}
+
+template <typename Char, typename OutputIt>
+OutputIt format_default(OutputIt out, const Char* value) {
+  auto length = std::char_traits<Char>::length(value);
+  return copy_str<Char>(value, value + length, out);
+}
+
+// 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>
+  OutputIt format(OutputIt out, const Args&... args) const {
+    // This ensures that the argument type is convertile to `const T&`.
+    const T& arg = get<N>(args...);
+    return format_default<Char>(out, arg);
+  }
+};
+
+template <typename Char, typename T, int N>
+struct is_compiled_format<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>
+  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 != to_string_view(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;
+  }
+}
+
+// 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 basic_string_view<char_type> str = format_str;
+  if constexpr (str[POS] == '{') {
+    if (POS + 1 == str.size())
+      throw format_error("unmatched '{' in format string");
+    if constexpr (str[POS + 1] == '{') {
+      return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+    } else if constexpr (str[POS + 1] == '}') {
+      using type = get_type<ID, Args>;
+      if constexpr (std::is_same<type, int>::value) {
+        return parse_tail<Args, POS + 2, ID + 1>(field<char_type, type, ID>(),
+                                                 format_str);
+      } else {
+        return unknown_format();
+      }
+    } else {
+      return unknown_format();
+    }
+  } else if constexpr (str[POS] == '}') {
+    if (POS + 1 == str.size())
+      throw format_error("unmatched '}' in format string");
+    return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+  } else {
+    constexpr auto end = parse_text(str, POS + 1);
+    return parse_tail<Args, end, ID>(make_text(str, POS, end - POS),
+                                     format_str);
+  }
+}
+#endif  // __cpp_if_constexpr
 }  // namespace internal
 
 #if FMT_USE_CONSTEXPR
+#  ifdef __cpp_if_constexpr
 template <typename... Args, typename S,
           FMT_ENABLE_IF(is_compile_string<S>::value)>
-FMT_CONSTEXPR auto compile(S format_str) -> internal::prepared_format<
-    S,
-    internal::compiletime_parts_provider<
-        S,
-        typename internal::compiletime_prepared_parts_type_provider<S>::type>,
-    Args...> {
-  return format_str;
-}
-#endif
-
-template <typename... Args, typename Char, size_t N>
-auto compile(const Char (&format_str)[N]) -> internal::prepared_format<
-    std::basic_string<Char>,
-    internal::runtime_parts_provider<std::vector<internal::format_part<Char>>>,
-    Args...> {
-  return std::basic_string<Char>(format_str, N - 1);
+constexpr auto compile(S format_str) {
+  constexpr basic_string_view<typename S::char_type> str = format_str;
+  if constexpr (str.size() == 0) {
+    return internal::make_text(str, 0, 0);
+  } else {
+    constexpr auto result =
+        internal::compile_format_string<internal::type_list<Args...>, 0, 0>(
+            format_str);
+    if constexpr (std::is_same<remove_cvref_t<decltype(result)>,
+                               internal::unknown_format>()) {
+      return internal::compiled_format<S, Args...>(to_string_view(format_str));
+    } else {
+      return result;
+    }
+  }
 }
 
 template <typename CompiledFormat, typename... Args,
-          typename Char = typename CompiledFormat::char_type>
+          typename Char = typename CompiledFormat::char_type,
+          FMT_ENABLE_IF(internal::is_compiled_format<CompiledFormat>::value)>
 std::basic_string<Char> format(const CompiledFormat& cf, const Args&... args) {
   basic_memory_buffer<Char> buffer;
-  using range = internal::buffer_range<Char>;
-  using context = buffer_context<Char>;
-  cf.template vformat_to<range, context>(range(buffer),
-                                         {make_format_args<context>(args...)});
+  cf.format(std::back_inserter(buffer), args...);
   return to_string(buffer);
 }
 
-template <typename OutputIt, typename CompiledFormat, typename... Args>
+template <typename OutputIt, typename CompiledFormat, typename... Args,
+          FMT_ENABLE_IF(internal::is_compiled_format<CompiledFormat>::value)>
+OutputIt format_to(OutputIt out, const CompiledFormat& cf,
+                   const Args&... args) {
+  return cf.format(out, args...);
+}
+#  else
+template <typename... Args, typename S,
+          FMT_ENABLE_IF(is_compile_string<S>::value)>
+constexpr auto compile(S format_str) -> internal::compiled_format<S, Args...> {
+  return internal::compiled_format<S, Args...>(to_string_view(format_str));
+}
+#  endif  // __cpp_if_constexpr
+#endif    // FMT_USE_CONSTEXPR
+
+// Compiles the format string which must be a string literal.
+template <typename... Args, typename Char, size_t N>
+auto compile(const Char (&format_str)[N])
+    -> internal::compiled_format<const Char*, Args...> {
+  return internal::compiled_format<const Char*, Args...>(
+      basic_string_view<Char>(format_str, N - 1));
+}
+
+template <typename CompiledFormat, typename... Args,
+          typename Char = typename CompiledFormat::char_type,
+          FMT_ENABLE_IF(std::is_base_of<internal::basic_compiled_format,
+                                        CompiledFormat>::value)>
+std::basic_string<Char> format(const CompiledFormat& cf, const Args&... args) {
+  basic_memory_buffer<Char> buffer;
+  using range = buffer_range<Char>;
+  using context = buffer_context<Char>;
+  internal::cf::vformat_to<context>(range(buffer), cf,
+                                    make_format_args<context>(args...));
+  return to_string(buffer);
+}
+
+template <typename OutputIt, typename CompiledFormat, typename... Args,
+          FMT_ENABLE_IF(std::is_base_of<internal::basic_compiled_format,
+                                        CompiledFormat>::value)>
 OutputIt format_to(OutputIt out, const CompiledFormat& cf,
                    const Args&... args) {
   using char_type = typename CompiledFormat::char_type;
   using range = internal::output_range<OutputIt, char_type>;
   using context = format_context_t<OutputIt, char_type>;
-  return cf.template vformat_to<range, context>(
-      range(out), {make_format_args<context>(args...)});
+  return internal::cf::vformat_to<context>(range(out), cf,
+                                           make_format_args<context>(args...));
 }
 
 template <typename OutputIt, typename CompiledFormat, typename... Args,
@@ -455,10 +587,7 @@ format_to_n_result<OutputIt> format_to_n(OutputIt out, size_t n,
 
 template <typename CompiledFormat, typename... Args>
 std::size_t formatted_size(const CompiledFormat& cf, const Args&... args) {
-  return fmt::format_to(
-             internal::counting_iterator<typename CompiledFormat::char_type>(),
-             cf, args...)
-      .count();
+  return format_to(internal::counting_iterator(), cf, args...).count();
 }
 
 FMT_END_NAMESPACE

include/fmt/locale.h

@@ -9,6 +9,7 @@
 #define FMT_LOCALE_H_
 
 #include <locale>
+
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
@@ -18,16 +19,16 @@ template <typename Char>
 typename buffer_context<Char>::iterator vformat_to(
     const std::locale& loc, buffer<Char>& buf,
     basic_string_view<Char> format_str,
-    basic_format_args<buffer_context<Char>> args) {
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
   using range = buffer_range<Char>;
   return vformat_to<arg_formatter<range>>(buf, to_string_view(format_str), args,
                                           internal::locale_ref(loc));
 }
 
 template <typename Char>
-std::basic_string<Char> vformat(const std::locale& loc,
-                                basic_string_view<Char> format_str,
-                                basic_format_args<buffer_context<Char>> args) {
+std::basic_string<Char> vformat(
+    const std::locale& loc, basic_string_view<Char> format_str,
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
   basic_memory_buffer<Char> buffer;
   internal::vformat_to(loc, buffer, format_str, args);
   return fmt::to_string(buffer);
@@ -37,7 +38,7 @@ std::basic_string<Char> vformat(const std::locale& loc,
 template <typename S, typename Char = char_t<S>>
 inline std::basic_string<Char> vformat(
     const std::locale& loc, const S& format_str,
-    basic_format_args<buffer_context<Char>> args) {
+    basic_format_args<buffer_context<type_identity_t<Char>>> args) {
   return internal::vformat(loc, to_string_view(format_str), args);
 }
 
@@ -46,15 +47,15 @@ inline std::basic_string<Char> format(const std::locale& loc,
                                       const S& format_str, Args&&... args) {
   return internal::vformat(
       loc, to_string_view(format_str),
-      {internal::make_args_checked<Args...>(format_str, args...)});
+      internal::make_args_checked<Args...>(format_str, args...));
 }
 
 template <typename S, typename OutputIt, typename... Args,
           typename Char = enable_if_t<
               internal::is_output_iterator<OutputIt>::value, char_t<S>>>
-inline OutputIt vformat_to(OutputIt out, const std::locale& loc,
-                           const S& format_str,
-                           format_args_t<OutputIt, Char> args) {
+inline OutputIt vformat_to(
+    OutputIt out, const std::locale& loc, const S& format_str,
+    format_args_t<type_identity_t<OutputIt>, Char> args) {
   using range = internal::output_range<OutputIt, Char>;
   return vformat_to<arg_formatter<range>>(
       range(out), to_string_view(format_str), args, internal::locale_ref(loc));

include/fmt/os.h

@@ -0,0 +1,392 @@
+// 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_
+
+#if defined(__MINGW32__) || defined(__CYGWIN__)
+// Workaround MinGW bug https://sourceforge.net/p/mingw/bugs/2024/.
+#  undef __STRICT_ANSI__
+#endif
+
+#include <cerrno>
+#include <clocale>  // for locale_t
+#include <cstddef>
+#include <cstdio>
+#include <cstdlib>  // for strtod_l
+
+#if defined __APPLE__ || defined(__FreeBSD__)
+#  include <xlocale.h>  // for LC_NUMERIC_MASK on OS X
+#endif
+
+#include "format.h"
+
+// UWP doesn't provide _pipe.
+#if FMT_HAS_INCLUDE("winapifamily.h")
+#  include <winapifamily.h>
+#endif
+#if FMT_HAS_INCLUDE("fcntl.h") && \
+    (!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
+
+#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 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>;
+
+// 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_; }
+};
+
+#ifdef _WIN32
+namespace internal {
+// 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(wstring_view 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(wstring_view s);
+};
+
+FMT_API void format_windows_error(buffer<char>& out, int error_code,
+                                  string_view message) FMT_NOEXCEPT;
+}  // namespace internal
+
+/** A Windows error. */
+class windows_error : public system_error {
+ private:
+  FMT_API void init(int error_code, string_view format_str, format_args args);
+
+ public:
+  /**
+   \rst
+   Constructs a :class:`fmt::windows_error` object with the description
+   of the form
+
+   .. 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 windows_error with the description
+     //   cannot open file 'madeup': The system cannot find the file specified.
+     // or similar (system message may vary).
+     const char *filename = "madeup";
+     LPOFSTRUCT of = LPOFSTRUCT();
+     HFILE file = OpenFile(filename, &of, OF_READ);
+     if (file == HFILE_ERROR) {
+       throw fmt::windows_error(GetLastError(),
+                                "cannot open file '{}'", filename);
+     }
+   \endrst
+  */
+  template <typename... Args>
+  windows_error(int error_code, string_view message, const Args&... args) {
+    init(error_code, message, make_format_args(args...));
+  }
+};
+
+// Reports a Windows error without throwing an exception.
+// Can be used to report errors from destructors.
+FMT_API void report_windows_error(int error_code,
+                                  string_view message) FMT_NOEXCEPT;
+#endif  // _WIN32
+
+// 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() FMT_NOEXCEPT : file_(nullptr) {}
+
+  // Destroys the object closing the file it represents if any.
+  FMT_API ~buffered_file() FMT_NOEXCEPT;
+
+ public:
+  buffered_file(buffered_file&& other) FMT_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 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...));
+  }
+};
+
+#if FMT_USE_FCNTL
+// 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);
+
+ public:
+  file(const file&) = delete;
+  void operator=(const file&) = delete;
+
+  file(file&& other) FMT_NOEXCEPT : fd_(other.fd_) { other.fd_ = -1; }
+
+  file& operator=(file&& other) FMT_NOEXCEPT {
+    close();
+    fd_ = other.fd_;
+    other.fd_ = -1;
+    return *this;
+  }
+
+  // Destroys the object closing the file it represents if any.
+  FMT_API ~file() FMT_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();
+#endif  // FMT_USE_FCNTL
+
+#ifdef FMT_LOCALE
+// A "C" numeric locale.
+class locale {
+ private:
+#  ifdef _WIN32
+  using locale_t = _locale_t;
+
+  static void freelocale(locale_t loc) { _free_locale(loc); }
+
+  static double strtod_l(const char* nptr, char** endptr, _locale_t loc) {
+    return _strtod_l(nptr, endptr, loc);
+  }
+#  endif
+
+  locale_t locale_;
+
+ public:
+  using type = locale_t;
+  locale(const locale&) = delete;
+  void operator=(const locale&) = delete;
+
+  locale() {
+#  ifndef _WIN32
+    locale_ = FMT_SYSTEM(newlocale(LC_NUMERIC_MASK, "C", nullptr));
+#  else
+    locale_ = _create_locale(LC_NUMERIC, "C");
+#  endif
+    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 = nullptr;
+    double result = strtod_l(str, &end, locale_);
+    str = end;
+    return result;
+  }
+};
+using Locale FMT_DEPRECATED_ALIAS = locale;
+#endif  // FMT_LOCALE
+FMT_END_NAMESPACE
+
+#endif  // FMT_OS_H_

include/fmt/ostream.h

@@ -46,9 +46,13 @@ template <class Char> class formatbuf : public std::basic_streambuf<Char> {
 
 template <typename Char> struct test_stream : std::basic_ostream<Char> {
  private:
-  struct null;
   // Hide all operator<< from std::basic_ostream<Char>.
-  void operator<<(null);
+  void_t<> operator<<(null<>);
+  void_t<> operator<<(const Char*);
+
+  template <typename T, FMT_ENABLE_IF(std::is_convertible<T, int>::value &&
+                                      !std::is_enum<T>::value)>
+  void_t<> operator<<(T);
 };
 
 // Checks if T has a user-defined operator<< (e.g. not a member of
@@ -56,9 +60,9 @@ template <typename Char> struct test_stream : std::basic_ostream<Char> {
 template <typename T, typename Char> class is_streamable {
  private:
   template <typename U>
-  static decltype((void)(std::declval<test_stream<Char>&>()
-                         << std::declval<U>()),
-                  std::true_type())
+  static bool_constant<!std::is_same<decltype(std::declval<test_stream<Char>&>()
+                                              << std::declval<U>()),
+                                     void_t<>>::value>
   test(int);
 
   template <typename> static std::false_type test(...);
@@ -75,8 +79,7 @@ void write(std::basic_ostream<Char>& os, buffer<Char>& buf) {
   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((std::numeric_limits<std::streamsize>::max)());
+  unsigned_streamsize max_size = to_unsigned(max_value<std::streamsize>());
   do {
     unsigned_streamsize n = size <= max_size ? size : max_size;
     os.write(buf_data, static_cast<std::streamsize>(n));
@@ -86,9 +89,13 @@ void write(std::basic_ostream<Char>& os, buffer<Char>& buf) {
 }
 
 template <typename Char, typename T>
-void format_value(buffer<Char>& buf, const T& value) {
+void format_value(buffer<Char>& buf, const T& value,
+                  locale_ref loc = locale_ref()) {
   formatbuf<Char> format_buf(buf);
   std::basic_ostream<Char> output(&format_buf);
+  #if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
+  if (loc) output.imbue(loc.get<std::locale>());
+  #endif
   output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
   output << value;
   buf.resize(buf.size());
@@ -101,7 +108,7 @@ struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
   template <typename Context>
   auto format(const T& value, Context& ctx) -> decltype(ctx.out()) {
     basic_memory_buffer<Char> buffer;
-    format_value(buffer, value);
+    format_value(buffer, value, ctx.locale());
     basic_string_view<Char> str(buffer.data(), buffer.size());
     return formatter<basic_string_view<Char>, Char>::format(str, ctx);
   }
@@ -110,7 +117,7 @@ struct fallback_formatter<T, Char, enable_if_t<is_streamable<T, Char>::value>>
 
 template <typename Char>
 void vprint(std::basic_ostream<Char>& os, basic_string_view<Char> format_str,
-            basic_format_args<buffer_context<Char>> args) {
+            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
   basic_memory_buffer<Char> buffer;
   internal::vformat_to(buffer, format_str, args);
   internal::write(os, buffer);
@@ -129,7 +136,7 @@ template <typename S, typename... Args,
           typename Char = enable_if_t<internal::is_string<S>::value, char_t<S>>>
 void print(std::basic_ostream<Char>& os, const S& format_str, Args&&... args) {
   vprint(os, to_string_view(format_str),
-         {internal::make_args_checked<Args...>(format_str, args...)});
+         internal::make_args_checked<Args...>(format_str, args...));
 }
 FMT_END_NAMESPACE
 

include/fmt/posix.h

@@ -1,311 +1,2 @@
-// 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 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>;
-
-// 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_(nullptr) {}
-
-  // Destroys the object closing the file it represents if any.
-  FMT_API ~buffered_file() FMT_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_ = 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 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_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();
-
-#ifdef FMT_LOCALE
-// A "C" numeric locale.
-class Locale {
- private:
-#  ifdef _WIN32
-  using 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:
-  using type = locale_t;
-
-  Locale() : locale_(newlocale(LC_NUMERIC_MASK, "C", nullptr)) {
-    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 = nullptr;
-    double result = strtod_l(str, &end, locale_);
-    str = end;
-    return result;
-  }
-};
-#endif  // FMT_LOCALE
-FMT_END_NAMESPACE
-
-#endif  // FMT_POSIX_H_
+#include "os.h"
+#warning "fmt/posix.h is deprecated; use fmt/os.h instead"

include/fmt/printf.h

@@ -1,4 +1,4 @@
-// Formatting library for C++
+// Formatting library for C++ - legacy printf implementation
 //
 // Copyright (c) 2012 - 2016, Victor Zverovich
 // All rights reserved.
@@ -8,7 +8,7 @@
 #ifndef FMT_PRINTF_H_
 #define FMT_PRINTF_H_
 
-#include <algorithm>  // std::fill_n
+#include <algorithm>  // std::max
 #include <limits>     // std::numeric_limits
 
 #include "ostream.h"
@@ -16,15 +16,11 @@
 FMT_BEGIN_NAMESPACE
 namespace internal {
 
-// A helper function to suppress bogus "conditional expression is constant"
-// warnings.
-template <typename T> inline T const_check(T value) { return value; }
-
 // Checks if a value fits in int - used to avoid warnings about comparing
 // signed and unsigned integers.
 template <bool IsSigned> struct int_checker {
   template <typename T> static bool fits_in_int(T value) {
-    unsigned max = std::numeric_limits<int>::max();
+    unsigned max = max_value<int>();
     return value <= max;
   }
   static bool fits_in_int(bool) { return true; }
@@ -32,8 +28,8 @@ template <bool IsSigned> struct int_checker {
 
 template <> struct int_checker<true> {
   template <typename T> static bool fits_in_int(T value) {
-    return value >= std::numeric_limits<int>::min() &&
-           value <= std::numeric_limits<int>::max();
+    return value >= (std::numeric_limits<int>::min)() &&
+           value <= max_value<int>();
   }
   static bool fits_in_int(int) { return true; }
 };
@@ -158,12 +154,12 @@ template <typename Char> class printf_width_handler {
 
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
   unsigned operator()(T value) {
-    auto width = static_cast<uint32_or_64_t<T>>(value);
+    auto width = static_cast<uint32_or_64_or_128_t<T>>(value);
     if (internal::is_negative(value)) {
       specs_.align = align::left;
       width = 0 - width;
     }
-    unsigned int_max = std::numeric_limits<int>::max();
+    unsigned int_max = max_value<int>();
     if (width > int_max) FMT_THROW(format_error("number is too big"));
     return static_cast<unsigned>(width);
   }
@@ -235,7 +231,7 @@ class printf_arg_formatter : public internal::arg_formatter_base<Range> {
   printf_arg_formatter(iterator iter, format_specs& specs, context_type& ctx)
       : base(Range(iter), &specs, internal::locale_ref()), context_(ctx) {}
 
-  template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
+  template <typename T, FMT_ENABLE_IF(fmt::internal::is_integral<T>::value)>
   iterator operator()(T value) {
     // MSVC2013 fails to compile separate overloads for bool and char_type so
     // use std::is_same instead.
@@ -307,6 +303,8 @@ class printf_arg_formatter : public internal::arg_formatter_base<Range> {
 };
 
 template <typename T> struct printf_formatter {
+  printf_formatter() = delete;
+
   template <typename ParseContext>
   auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
@@ -324,6 +322,7 @@ template <typename OutputIt, typename Char> class basic_printf_context {
  public:
   /** The character type for the output. */
   using char_type = Char;
+  using iterator = OutputIt;
   using format_arg = basic_format_arg<basic_printf_context>;
   template <typename T> using formatter_type = printf_formatter<T>;
 
@@ -332,17 +331,17 @@ template <typename OutputIt, typename Char> class basic_printf_context {
 
   OutputIt out_;
   basic_format_args<basic_printf_context> args_;
-  basic_parse_context<Char> parse_ctx_;
+  basic_format_parse_context<Char> parse_ctx_;
 
   static void parse_flags(format_specs& specs, const Char*& it,
                           const Char* end);
 
-  // Returns the argument with specified index or, if arg_index is equal
-  // to the maximum unsigned value, the next argument.
-  format_arg get_arg(unsigned arg_index = std::numeric_limits<unsigned>::max());
+  // Returns the argument with specified index or, if arg_index is -1, the next
+  // argument.
+  format_arg get_arg(int arg_index = -1);
 
   // Parses argument index, flags and width and returns the argument index.
-  unsigned parse_header(const Char*& it, const Char* end, format_specs& specs);
+  int parse_header(const Char*& it, const Char* end, format_specs& specs);
 
  public:
   /**
@@ -359,17 +358,18 @@ template <typename OutputIt, typename Char> class basic_printf_context {
   OutputIt out() { return out_; }
   void advance_to(OutputIt it) { out_ = it; }
 
-  format_arg arg(unsigned id) const { return args_.get(id); }
+  internal::locale_ref locale() { return {}; }
 
-  basic_parse_context<Char>& parse_context() { return parse_ctx_; }
+  format_arg arg(int id) const { return args_.get(id); }
+
+  basic_format_parse_context<Char>& parse_context() { return parse_ctx_; }
 
   FMT_CONSTEXPR void on_error(const char* message) {
     parse_ctx_.on_error(message);
   }
 
   /** Formats stored arguments and writes the output to the range. */
-  template <typename ArgFormatter =
-                printf_arg_formatter<internal::buffer_range<Char>>>
+  template <typename ArgFormatter = printf_arg_formatter<buffer_range<Char>>>
   OutputIt format();
 };
 
@@ -402,8 +402,8 @@ void basic_printf_context<OutputIt, Char>::parse_flags(format_specs& specs,
 
 template <typename OutputIt, typename Char>
 typename basic_printf_context<OutputIt, Char>::format_arg
-basic_printf_context<OutputIt, Char>::get_arg(unsigned arg_index) {
-  if (arg_index == std::numeric_limits<unsigned>::max())
+basic_printf_context<OutputIt, Char>::get_arg(int arg_index) {
+  if (arg_index < 0)
     arg_index = parse_ctx_.next_arg_id();
   else
     parse_ctx_.check_arg_id(--arg_index);
@@ -411,15 +411,16 @@ basic_printf_context<OutputIt, Char>::get_arg(unsigned arg_index) {
 }
 
 template <typename OutputIt, typename Char>
-unsigned basic_printf_context<OutputIt, Char>::parse_header(
-    const Char*& it, const Char* end, format_specs& specs) {
-  unsigned arg_index = std::numeric_limits<unsigned>::max();
+int basic_printf_context<OutputIt, Char>::parse_header(const Char*& it,
+                                                       const Char* end,
+                                                       format_specs& specs) {
+  int arg_index = -1;
   char_type c = *it;
   if (c >= '0' && c <= '9') {
     // Parse an argument index (if followed by '$') or a width possibly
     // preceded with '0' flag(s).
     internal::error_handler eh;
-    unsigned value = parse_nonnegative_int(it, end, eh);
+    int value = parse_nonnegative_int(it, end, eh);
     if (it != end && *it == '$') {  // value is an argument index
       ++it;
       arg_index = value;
@@ -441,8 +442,8 @@ unsigned basic_printf_context<OutputIt, Char>::parse_header(
       specs.width = parse_nonnegative_int(it, end, eh);
     } else if (*it == '*') {
       ++it;
-      specs.width = visit_format_arg(
-          internal::printf_width_handler<char_type>(specs), get_arg());
+      specs.width = static_cast<int>(visit_format_arg(
+          internal::printf_width_handler<char_type>(specs), get_arg()));
     }
   }
   return arg_index;
@@ -469,7 +470,8 @@ OutputIt basic_printf_context<OutputIt, Char>::format() {
     specs.align = align::right;
 
     // Parse argument index, flags and width.
-    unsigned arg_index = parse_header(it, end, specs);
+    int arg_index = parse_header(it, end, specs);
+    if (arg_index == 0) on_error("argument index out of range");
 
     // Parse precision.
     if (it != end && *it == '.') {
@@ -477,11 +479,11 @@ OutputIt basic_printf_context<OutputIt, Char>::format() {
       c = it != end ? *it : 0;
       if ('0' <= c && c <= '9') {
         internal::error_handler eh;
-        specs.precision = static_cast<int>(parse_nonnegative_int(it, end, eh));
+        specs.precision = parse_nonnegative_int(it, end, eh);
       } else if (c == '*') {
         ++it;
-        specs.precision =
-            visit_format_arg(internal::printf_precision_handler(), get_arg());
+        specs.precision = static_cast<int>(
+            visit_format_arg(internal::printf_precision_handler(), get_arg()));
       } else {
         specs.precision = 0;
       }
@@ -600,7 +602,8 @@ inline format_arg_store<wprintf_context, Args...> make_wprintf_args(
 
 template <typename S, typename Char = char_t<S>>
 inline std::basic_string<Char> vsprintf(
-    const S& format, basic_format_args<basic_printf_context_t<Char>> args) {
+    const S& format,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
   basic_memory_buffer<Char> buffer;
   printf(buffer, to_string_view(format), args);
   return to_string(buffer);
@@ -619,12 +622,13 @@ template <typename S, typename... Args,
           typename Char = enable_if_t<internal::is_string<S>::value, char_t<S>>>
 inline std::basic_string<Char> sprintf(const S& format, const Args&... args) {
   using context = basic_printf_context_t<Char>;
-  return vsprintf(to_string_view(format), {make_format_args<context>(args...)});
+  return vsprintf(to_string_view(format), make_format_args<context>(args...));
 }
 
 template <typename S, typename Char = char_t<S>>
-inline int vfprintf(std::FILE* f, const S& format,
-                    basic_format_args<basic_printf_context_t<Char>> args) {
+inline int vfprintf(
+    std::FILE* f, const S& format,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
   basic_memory_buffer<Char> buffer;
   printf(buffer, to_string_view(format), args);
   std::size_t size = buffer.size();
@@ -647,12 +651,13 @@ template <typename S, typename... Args,
 inline int fprintf(std::FILE* f, const S& format, const Args&... args) {
   using context = basic_printf_context_t<Char>;
   return vfprintf(f, to_string_view(format),
-                  {make_format_args<context>(args...)});
+                  make_format_args<context>(args...));
 }
 
 template <typename S, typename Char = char_t<S>>
-inline int vprintf(const S& format,
-                   basic_format_args<basic_printf_context_t<Char>> args) {
+inline int vprintf(
+    const S& format,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
   return vfprintf(stdout, to_string_view(format), args);
 }
 
@@ -670,12 +675,13 @@ template <typename S, typename... Args,
 inline int printf(const S& format_str, const Args&... args) {
   using context = basic_printf_context_t<char_t<S>>;
   return vprintf(to_string_view(format_str),
-                 {make_format_args<context>(args...)});
+                 make_format_args<context>(args...));
 }
 
 template <typename S, typename Char = char_t<S>>
-inline int vfprintf(std::basic_ostream<Char>& os, const S& format,
-                    basic_format_args<basic_printf_context_t<Char>> args) {
+inline int vfprintf(
+    std::basic_ostream<Char>& os, const S& format,
+    basic_format_args<basic_printf_context_t<type_identity_t<Char>>> args) {
   basic_memory_buffer<Char> buffer;
   printf(buffer, to_string_view(format), args);
   internal::write(os, buffer);
@@ -686,9 +692,9 @@ inline int vfprintf(std::basic_ostream<Char>& os, const S& format,
 template <typename ArgFormatter, typename Char,
           typename Context =
               basic_printf_context<typename ArgFormatter::iterator, Char>>
-typename ArgFormatter::iterator vprintf(internal::buffer<Char>& out,
-                                        basic_string_view<Char> format_str,
-                                        basic_format_args<Context> args) {
+typename ArgFormatter::iterator vprintf(
+    internal::buffer<Char>& out, basic_string_view<Char> format_str,
+    basic_format_args<type_identity_t<Context>> args) {
   typename ArgFormatter::iterator iter(out);
   Context(iter, format_str, args).template format<ArgFormatter>();
   return iter;
@@ -708,7 +714,7 @@ inline int fprintf(std::basic_ostream<Char>& os, const S& format_str,
                    const Args&... args) {
   using context = basic_printf_context_t<Char>;
   return vfprintf(os, to_string_view(format_str),
-                  {make_format_args<context>(args...)});
+                  make_format_args<context>(args...));
 }
 FMT_END_NAMESPACE
 

include/fmt/ranges.h

@@ -12,7 +12,9 @@
 #ifndef FMT_RANGES_H_
 #define FMT_RANGES_H_
 
+#include <initializer_list>
 #include <type_traits>
+
 #include "format.h"
 
 // output only up to N items from the range.
@@ -104,10 +106,7 @@ struct is_range_<
 /// 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,
-                  (void)std::declval<typename std::tuple_element<0, U>::type>(),
-                  int());
+  static auto check(U* p) -> decltype(std::tuple_size<U>::value, int());
   template <typename> static void check(...);
 
  public:
@@ -246,7 +245,8 @@ template <typename T, typename Char> struct is_range {
   static FMT_CONSTEXPR_DECL const bool value =
       internal::is_range_<T>::value &&
       !internal::is_like_std_string<T>::value &&
-      !std::is_convertible<T, std::basic_string<Char>>::value;
+      !std::is_convertible<T, std::basic_string<Char>>::value &&
+      !std::is_constructible<internal::std_string_view<Char>, T>::value;
 };
 
 template <typename RangeT, typename Char>
@@ -283,6 +283,105 @@ struct formatter<RangeT, Char,
   }
 };
 
+template <typename Char, typename... T> struct tuple_arg_join : internal::view {
+  const std::tuple<T...>& tuple;
+  basic_string_view<Char> sep;
+
+  tuple_arg_join(const std::tuple<T...>& t, basic_string_view<Char> s)
+      : tuple{t}, sep{s} {}
+};
+
+template <typename Char, typename... T>
+struct formatter<tuple_arg_join<Char, T...>, Char> {
+  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+
+  template <typename FormatContext>
+  typename FormatContext::iterator format(
+      const tuple_arg_join<Char, T...>& value, FormatContext& ctx) {
+    return format(value, ctx, internal::make_index_sequence<sizeof...(T)>{});
+  }
+
+ private:
+  template <typename FormatContext, size_t... N>
+  typename FormatContext::iterator format(
+      const tuple_arg_join<Char, T...>& value, FormatContext& ctx,
+      internal::index_sequence<N...>) {
+    return format_args(value, ctx, std::get<N>(value.tuple)...);
+  }
+
+  template <typename FormatContext>
+  typename FormatContext::iterator format_args(
+      const tuple_arg_join<Char, T...>&, FormatContext& ctx) {
+    // NOTE: for compilers that support C++17, this empty function instantiation
+    // can be replaced with a constexpr branch in the variadic overload.
+    return ctx.out();
+  }
+
+  template <typename FormatContext, typename Arg, typename... Args>
+  typename FormatContext::iterator format_args(
+      const tuple_arg_join<Char, T...>& value, FormatContext& ctx,
+      const Arg& arg, const Args&... args) {
+    using base = formatter<typename std::decay<Arg>::type, Char>;
+    auto out = ctx.out();
+    out = base{}.format(arg, ctx);
+    if (sizeof...(Args) > 0) {
+      out = std::copy(value.sep.begin(), value.sep.end(), out);
+      ctx.advance_to(out);
+      return format_args(value, ctx, args...);
+    }
+    return out;
+  }
+};
+
+/**
+  \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 tuple_arg_join<char, T...> join(const std::tuple<T...>& tuple,
+                                              string_view sep) {
+  return {tuple, sep};
+}
+
+template <typename... T>
+FMT_CONSTEXPR tuple_arg_join<wchar_t, T...> join(const std::tuple<T...>& tuple,
+                                                 wstring_view sep) {
+  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>
+arg_join<internal::iterator_t<const std::initializer_list<T>>, char> join(
+    std::initializer_list<T> list, string_view sep) {
+  return join(std::begin(list), std::end(list), sep);
+}
+
+template <typename T>
+arg_join<internal::iterator_t<const std::initializer_list<T>>, wchar_t> join(
+    std::initializer_list<T> list, wstring_view sep) {
+  return join(std::begin(list), std::end(list), sep);
+}
+
 FMT_END_NAMESPACE
 
 #endif  // FMT_RANGES_H_

include/fmt/safe-duration-cast.h

@@ -1,293 +0,0 @@
-/*
- * For conversion between std::chrono::durations without undefined
- * behaviour or erroneous results.
- * This is a stripped down version of duration_cast, for inclusion in fmt.
- * See https://github.com/pauldreik/safe_duration_cast
- *
- * Copyright Paul Dreik 2019
- *
- * This file is licensed under the fmt license, see format.h
- */
-
-#include <chrono>
-#include <cmath>
-#include <limits>
-#include <type_traits>
-
-#include "format.h"
-
-FMT_BEGIN_NAMESPACE
-
-namespace safe_duration_cast {
-
-template <typename To, typename From,
-          FMT_ENABLE_IF(!std::is_same<From, To>::value &&
-                        std::numeric_limits<From>::is_signed ==
-                            std::numeric_limits<To>::is_signed)>
-FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
-  ec = 0;
-  using F = std::numeric_limits<From>;
-  using T = std::numeric_limits<To>;
-  static_assert(F::is_integer, "From must be integral");
-  static_assert(T::is_integer, "To must be integral");
-
-  // A and B are both signed, or both unsigned.
-  if (F::digits <= T::digits) {
-    // From fits in To without any problem.
-  } else {
-    // From does not always fit in To, resort to a dynamic check.
-    if (from < T::min() || from > T::max()) {
-      // outside range.
-      ec = 1;
-      return {};
-    }
-  }
-  return static_cast<To>(from);
-}
-
-/**
- * converts From to To, without loss. If the dynamic value of from
- * can't be converted to To without loss, ec is set.
- */
-template <typename To, typename From,
-          FMT_ENABLE_IF(!std::is_same<From, To>::value &&
-                        std::numeric_limits<From>::is_signed !=
-                            std::numeric_limits<To>::is_signed)>
-FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
-  ec = 0;
-  using F = std::numeric_limits<From>;
-  using T = std::numeric_limits<To>;
-  static_assert(F::is_integer, "From must be integral");
-  static_assert(T::is_integer, "To must be integral");
-
-  if (F::is_signed && !T::is_signed) {
-    // From may be negative, not allowed!
-    if (from < 0) {
-      ec = 1;
-      return {};
-    }
-
-    // From is positive. Can it always fit in To?
-    if (F::digits <= T::digits) {
-      // yes, From always fits in To.
-    } else {
-      // from may not fit in To, we have to do a dynamic check
-      if (from > static_cast<From>(T::max())) {
-        ec = 1;
-        return {};
-      }
-    }
-  }
-
-  if (!F::is_signed && T::is_signed) {
-    // can from be held in To?
-    if (F::digits < T::digits) {
-      // yes, From always fits in To.
-    } else {
-      // from may not fit in To, we have to do a dynamic check
-      if (from > static_cast<From>(T::max())) {
-        // outside range.
-        ec = 1;
-        return {};
-      }
-    }
-  }
-
-  // reaching here means all is ok for lossless conversion.
-  return static_cast<To>(from);
-
-}  // function
-
-template <typename To, typename From,
-          FMT_ENABLE_IF(std::is_same<From, To>::value)>
-FMT_CONSTEXPR To lossless_integral_conversion(const From from, int& ec) {
-  ec = 0;
-  return from;
-}  // function
-
-// clang-format off
-/**
- * converts From to To if possible, otherwise ec is set.
- *
- * input                            |    output
- * ---------------------------------|---------------
- * NaN                              | NaN
- * Inf                              | Inf
- * normal, fits in output           | converted (possibly lossy)
- * normal, does not fit in output   | ec is set
- * subnormal                        | best effort
- * -Inf                             | -Inf
- */
-// clang-format on
-template <typename To, typename From,
-          FMT_ENABLE_IF(!std::is_same<From, To>::value)>
-FMT_CONSTEXPR To safe_float_conversion(const From from, int& ec) {
-  ec = 0;
-  using T = std::numeric_limits<To>;
-  static_assert(std::is_floating_point<From>::value, "From must be floating");
-  static_assert(std::is_floating_point<To>::value, "To must be floating");
-
-  // catch the only happy case
-  if (std::isfinite(from)) {
-    if (from >= T::lowest() && from <= T::max()) {
-      return static_cast<To>(from);
-    }
-    // not within range.
-    ec = 1;
-    return {};
-  }
-
-  // nan and inf will be preserved
-  return static_cast<To>(from);
-}  // function
-
-template <typename To, typename From,
-          FMT_ENABLE_IF(std::is_same<From, To>::value)>
-FMT_CONSTEXPR To safe_float_conversion(const From from, int& ec) {
-  ec = 0;
-  static_assert(std::is_floating_point<From>::value, "From must be floating");
-  return from;
-}
-
-/**
- * safe duration cast between integral durations
- */
-template <typename To, typename FromRep, typename FromPeriod,
-          FMT_ENABLE_IF(std::is_integral<FromRep>::value),
-          FMT_ENABLE_IF(std::is_integral<typename To::rep>::value)>
-To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
-                      int& ec) {
-  using From = std::chrono::duration<FromRep, FromPeriod>;
-  ec = 0;
-  // the basic idea is that we need to convert from count() in the from type
-  // to count() in the To type, by multiplying it with this:
-  using Factor = std::ratio_divide<typename From::period, typename To::period>;
-
-  static_assert(Factor::num > 0, "num must be positive");
-  static_assert(Factor::den > 0, "den must be positive");
-
-  // the conversion is like this: multiply from.count() with Factor::num
-  // /Factor::den and convert it to To::rep, all this without
-  // overflow/underflow. let's start by finding a suitable type that can hold
-  // both To, From and Factor::num
-  using IntermediateRep =
-      typename std::common_type<typename From::rep, typename To::rep,
-                                decltype(Factor::num)>::type;
-
-  // safe conversion to IntermediateRep
-  IntermediateRep count =
-      lossless_integral_conversion<IntermediateRep>(from.count(), ec);
-  if (ec) {
-    return {};
-  }
-  // multiply with Factor::num without overflow or underflow
-  if (Factor::num != 1) {
-    constexpr auto max1 =
-        std::numeric_limits<IntermediateRep>::max() / Factor::num;
-    if (count > max1) {
-      ec = 1;
-      return {};
-    }
-    constexpr auto min1 =
-        std::numeric_limits<IntermediateRep>::min() / Factor::num;
-    if (count < min1) {
-      ec = 1;
-      return {};
-    }
-    count *= Factor::num;
-  }
-
-  // this can't go wrong, right? den>0 is checked earlier.
-  if (Factor::den != 1) {
-    count /= Factor::den;
-  }
-  // convert to the to type, safely
-  using ToRep = typename To::rep;
-  const ToRep tocount = lossless_integral_conversion<ToRep>(count, ec);
-  if (ec) {
-    return {};
-  }
-  return To{tocount};
-}
-
-/**
- * safe duration_cast between floating point durations
- */
-template <typename To, typename FromRep, typename FromPeriod,
-          FMT_ENABLE_IF(std::is_floating_point<FromRep>::value),
-          FMT_ENABLE_IF(std::is_floating_point<typename To::rep>::value)>
-To safe_duration_cast(std::chrono::duration<FromRep, FromPeriod> from,
-                      int& ec) {
-  using From = std::chrono::duration<FromRep, FromPeriod>;
-  ec = 0;
-  if (std::isnan(from.count())) {
-    // nan in, gives nan out. easy.
-    return To{std::numeric_limits<typename To::rep>::quiet_NaN()};
-  }
-  // maybe we should also check if from is denormal, and decide what to do about
-  // it.
-
-  // +-inf should be preserved.
-  if (std::isinf(from.count())) {
-    return To{from.count()};
-  }
-
-  // the basic idea is that we need to convert from count() in the from type
-  // to count() in the To type, by multiplying it with this:
-  using Factor = std::ratio_divide<typename From::period, typename To::period>;
-
-  static_assert(Factor::num > 0, "num must be positive");
-  static_assert(Factor::den > 0, "den must be positive");
-
-  // the conversion is like this: multiply from.count() with Factor::num
-  // /Factor::den and convert it to To::rep, all this without
-  // overflow/underflow. let's start by finding a suitable type that can hold
-  // both To, From and Factor::num
-  using IntermediateRep =
-      typename std::common_type<typename From::rep, typename To::rep,
-                                decltype(Factor::num)>::type;
-
-  // force conversion of From::rep -> IntermediateRep to be safe,
-  // even if it will never happen be narrowing in this context.
-  IntermediateRep count =
-      safe_float_conversion<IntermediateRep>(from.count(), ec);
-  if (ec) {
-    return {};
-  }
-
-  // multiply with Factor::num without overflow or underflow
-  if (Factor::num != 1) {
-    constexpr auto max1 = std::numeric_limits<IntermediateRep>::max() /
-                          static_cast<IntermediateRep>(Factor::num);
-    if (count > max1) {
-      ec = 1;
-      return {};
-    }
-    constexpr auto min1 = std::numeric_limits<IntermediateRep>::lowest() /
-                          static_cast<IntermediateRep>(Factor::num);
-    if (count < min1) {
-      ec = 1;
-      return {};
-    }
-    count *= static_cast<IntermediateRep>(Factor::num);
-  }
-
-  // this can't go wrong, right? den>0 is checked earlier.
-  if (Factor::den != 1) {
-    using common_t = typename std::common_type<IntermediateRep, intmax_t>::type;
-    count /= static_cast<common_t>(Factor::den);
-  }
-
-  // convert to the to type, safely
-  using ToRep = typename To::rep;
-
-  const ToRep tocount = safe_float_conversion<ToRep>(count, ec);
-  if (ec) {
-    return {};
-  }
-  return To{tocount};
-}
-
-}  // namespace safe_duration_cast
-
-FMT_END_NAMESPACE

src/format.cc

@@ -8,11 +8,125 @@
 #include "fmt/format-inl.h"
 
 FMT_BEGIN_NAMESPACE
-template struct FMT_API internal::basic_data<void>;
+namespace internal {
 
-// Workaround a bug in MSVC2013 that prevents instantiation of grisu_format.
-bool (*instantiate_grisu_format)(double, internal::buffer<char>&, int, unsigned,
-                                 int&) = internal::grisu_format;
+template <typename T>
+int format_float(char* buf, std::size_t size, const char* format, int precision,
+                 T value) {
+#ifdef FUZZING_BUILD_MODE_UNSAFE_FOR_PRODUCTION
+  if (precision > 100000)
+    throw std::runtime_error(
+        "fuzz mode - avoid large allocation inside snprintf");
+#endif
+  // Suppress the warning about nonliteral format string.
+  int (*snprintf_ptr)(char*, size_t, const char*, ...) = FMT_SNPRINTF;
+  return precision < 0 ? snprintf_ptr(buf, size, format, value)
+                       : snprintf_ptr(buf, size, format, precision, value);
+}
+struct sprintf_specs {
+  int precision;
+  char type;
+  bool alt : 1;
+
+  template <typename Char>
+  constexpr sprintf_specs(basic_format_specs<Char> specs)
+      : precision(specs.precision), type(specs.type), alt(specs.alt) {}
+
+  constexpr bool has_precision() const { return precision >= 0; }
+};
+
+// This is deprecated and is kept only to preserve ABI compatibility.
+template <typename Double>
+char* sprintf_format(Double value, internal::buffer<char>& buf,
+                     sprintf_specs specs) {
+  // Buffer capacity must be non-zero, otherwise MSVC's vsnprintf_s will fail.
+  FMT_ASSERT(buf.capacity() != 0, "empty buffer");
+
+  // Build format string.
+  enum { max_format_size = 10 };  // longest format: %#-*.*Lg
+  char format[max_format_size];
+  char* format_ptr = format;
+  *format_ptr++ = '%';
+  if (specs.alt || !specs.type) *format_ptr++ = '#';
+  if (specs.precision >= 0) {
+    *format_ptr++ = '.';
+    *format_ptr++ = '*';
+  }
+  if (std::is_same<Double, long double>::value) *format_ptr++ = 'L';
+
+  char type = specs.type;
+
+  if (type == '%')
+    type = 'f';
+  else if (type == 0 || type == 'n')
+    type = 'g';
+#if FMT_MSC_VER
+  if (type == 'F') {
+    // MSVC's printf doesn't support 'F'.
+    type = 'f';
+  }
+#endif
+  *format_ptr++ = type;
+  *format_ptr = '\0';
+
+  // Format using snprintf.
+  char* start = nullptr;
+  char* decimal_point_pos = nullptr;
+  for (;;) {
+    std::size_t buffer_size = buf.capacity();
+    start = &buf[0];
+    int result =
+        format_float(start, buffer_size, format, specs.precision, value);
+    if (result >= 0) {
+      unsigned n = internal::to_unsigned(result);
+      if (n < buf.capacity()) {
+        // Find the decimal point.
+        auto p = buf.data(), end = p + n;
+        if (*p == '+' || *p == '-') ++p;
+        if (specs.type != 'a' && specs.type != 'A') {
+          while (p < end && *p >= '0' && *p <= '9') ++p;
+          if (p < end && *p != 'e' && *p != 'E') {
+            decimal_point_pos = p;
+            if (!specs.type) {
+              // Keep only one trailing zero after the decimal point.
+              ++p;
+              if (*p == '0') ++p;
+              while (p != end && *p >= '1' && *p <= '9') ++p;
+              char* where = p;
+              while (p != end && *p == '0') ++p;
+              if (p == end || *p < '0' || *p > '9') {
+                if (p != end) std::memmove(where, p, to_unsigned(end - p));
+                n -= static_cast<unsigned>(p - where);
+              }
+            }
+          }
+        }
+        buf.resize(n);
+        break;  // The buffer is large enough - continue with formatting.
+      }
+      buf.reserve(n + 1);
+    } else {
+      // If result is negative we ask to increase the capacity by at least 1,
+      // but as std::vector, the buffer grows exponentially.
+      buf.reserve(buf.capacity() + 1);
+    }
+  }
+  return decimal_point_pos;
+}
+}  // namespace internal
+
+template FMT_API char* internal::sprintf_format(double, internal::buffer<char>&,
+                                                sprintf_specs);
+template FMT_API char* internal::sprintf_format(long double,
+                                                internal::buffer<char>&,
+                                                sprintf_specs);
+
+template struct FMT_INSTANTIATION_DEF_API internal::basic_data<void>;
+
+// Workaround a bug in MSVC2013 that prevents instantiation of format_float.
+int (*instantiate_format_float)(double, int, internal::float_specs,
+                                internal::buffer<char>&) =
+    internal::format_float;
 
 #ifndef FMT_STATIC_THOUSANDS_SEPARATOR
 template FMT_API internal::locale_ref::locale_ref(const std::locale& loc);
@@ -21,6 +135,7 @@ template FMT_API std::locale internal::locale_ref::get<std::locale>() const;
 
 // Explicit instantiations for char.
 
+template FMT_API std::string internal::grouping_impl<char>(locale_ref);
 template FMT_API char internal::thousands_sep_impl(locale_ref);
 template FMT_API char internal::decimal_point_impl(locale_ref);
 
@@ -35,23 +150,27 @@ template FMT_API std::string internal::vformat<char>(
 template FMT_API format_context::iterator internal::vformat_to(
     internal::buffer<char>&, string_view, basic_format_args<format_context>);
 
-template FMT_API char* internal::sprintf_format(double, internal::buffer<char>&,
-                                                sprintf_specs);
-template FMT_API char* internal::sprintf_format(long double,
-                                                internal::buffer<char>&,
-                                                sprintf_specs);
+template FMT_API int internal::snprintf_float(double, int,
+                                              internal::float_specs,
+                                              internal::buffer<char>&);
+template FMT_API int internal::snprintf_float(long double, int,
+                                              internal::float_specs,
+                                              internal::buffer<char>&);
+template FMT_API int internal::format_float(double, int, internal::float_specs,
+                                            internal::buffer<char>&);
+template FMT_API int internal::format_float(long double, int,
+                                            internal::float_specs,
+                                            internal::buffer<char>&);
 
 // Explicit instantiations for wchar_t.
 
+template FMT_API std::string internal::grouping_impl<wchar_t>(locale_ref);
 template FMT_API wchar_t internal::thousands_sep_impl(locale_ref);
 template FMT_API wchar_t internal::decimal_point_impl(locale_ref);
 
 template FMT_API void internal::buffer<wchar_t>::append(const wchar_t*,
                                                         const wchar_t*);
 
-template FMT_API void internal::arg_map<wformat_context>::init(
-    const basic_format_args<wformat_context>&);
-
 template FMT_API std::wstring internal::vformat<wchar_t>(
     wstring_view, basic_format_args<wformat_context>);
 FMT_END_NAMESPACE

src/os.cc

@@ -1,4 +1,4 @@
-// A C++ interface to POSIX functions.
+// Formatting library for C++ - optional OS-specific functionality
 //
 // Copyright (c) 2012 - 2016, Victor Zverovich
 // All rights reserved.
@@ -10,37 +10,43 @@
 #  define _CRT_SECURE_NO_WARNINGS
 #endif
 
-#include "fmt/posix.h"
+#include "fmt/os.h"
 
-#include <limits.h>
-#include <sys/stat.h>
-#include <sys/types.h>
+#include <climits>
 
-#ifndef _WIN32
-#  include <unistd.h>
-#else
-#  ifndef WIN32_LEAN_AND_MEAN
-#    define WIN32_LEAN_AND_MEAN
-#  endif
-#  include <io.h>
+#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>
+#    include <windows.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
+#endif    // FMT_USE_FCNTL
+
+#ifdef _WIN32
 #  include <windows.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
+#endif
 
 #ifdef fileno
 #  undef fileno
@@ -49,7 +55,7 @@
 namespace {
 #ifdef _WIN32
 // Return type of read and write functions.
-typedef int RWResult;
+using RWResult = int;
 
 // On Windows the count argument to read and write is unsigned, so convert
 // it from size_t preventing integer overflow.
@@ -58,7 +64,7 @@ inline unsigned convert_rwcount(std::size_t count) {
 }
 #else
 // Return type of read and write functions.
-typedef ssize_t RWResult;
+using RWResult = ssize_t;
 
 inline std::size_t convert_rwcount(std::size_t count) { return count; }
 #endif
@@ -66,6 +72,81 @@ inline std::size_t convert_rwcount(std::size_t count) { return count; }
 
 FMT_BEGIN_NAMESPACE
 
+#ifdef _WIN32
+internal::utf16_to_utf8::utf16_to_utf8(wstring_view s) {
+  if (int error_code = convert(s)) {
+    FMT_THROW(windows_error(error_code,
+                            "cannot convert string from UTF-16 to UTF-8"));
+  }
+}
+
+int internal::utf16_to_utf8::convert(wstring_view 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;
+}
+
+void windows_error::init(int err_code, string_view format_str,
+                         format_args args) {
+  error_code_ = err_code;
+  memory_buffer buffer;
+  internal::format_windows_error(buffer, err_code, vformat(format_str, args));
+  std::runtime_error& base = *this;
+  base = std::runtime_error(to_string(buffer));
+}
+
+void internal::format_windows_error(internal::buffer<char>& out, int error_code,
+                                    string_view message) FMT_NOEXCEPT {
+  FMT_TRY {
+    wmemory_buffer buf;
+    buf.resize(inline_buffer_size);
+    for (;;) {
+      wchar_t* system_message = &buf[0];
+      int result = FormatMessageW(
+          FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS, nullptr,
+          error_code, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), system_message,
+          static_cast<uint32_t>(buf.size()), nullptr);
+      if (result != 0) {
+        utf16_to_utf8 utf8_message;
+        if (utf8_message.convert(system_message) == ERROR_SUCCESS) {
+          internal::writer w(out);
+          w.write(message);
+          w.write(": ");
+          w.write(utf8_message);
+          return;
+        }
+        break;
+      }
+      if (GetLastError() != ERROR_INSUFFICIENT_BUFFER)
+        break;  // Can't get error message, report error code instead.
+      buf.resize(buf.size() * 2);
+    }
+  }
+  FMT_CATCH(...) {}
+  format_error_code(out, error_code, message);
+}
+
+void report_windows_error(int error_code,
+                          fmt::string_view message) FMT_NOEXCEPT {
+  report_error(internal::format_windows_error, error_code, message);
+}
+#endif  // _WIN32
+
 buffered_file::~buffered_file() FMT_NOEXCEPT {
   if (file_ && FMT_SYSTEM(fclose(file_)) != 0)
     report_system_error(errno, "cannot close file");
@@ -94,14 +175,15 @@ int buffered_file::fileno() const {
   return fd;
 }
 
+#if FMT_USE_FCNTL
 file::file(cstring_view path, int oflag) {
   int mode = S_IRUSR | S_IWUSR;
-#if defined(_WIN32) && !defined(__MINGW32__)
+#  if defined(_WIN32) && !defined(__MINGW32__)
   fd_ = -1;
   FMT_POSIX_CALL(sopen_s(&fd_, path.c_str(), oflag, _SH_DENYNO, mode));
-#else
+#  else
   FMT_RETRY(fd_, FMT_POSIX_CALL(open(path.c_str(), oflag, mode)));
-#endif
+#  endif
   if (fd_ == -1)
     FMT_THROW(system_error(errno, "cannot open file {}", path.c_str()));
 }
@@ -123,7 +205,7 @@ void file::close() {
 }
 
 long long file::size() const {
-#ifdef _WIN32
+#  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.
@@ -137,15 +219,15 @@ long long file::size() const {
   }
   unsigned long long long_size = size_upper;
   return (long_size << sizeof(DWORD) * CHAR_BIT) | size_lower;
-#else
-  typedef struct stat Stat;
+#  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
+#  endif
 }
 
 std::size_t file::read(void* buffer, std::size_t count) {
@@ -192,15 +274,15 @@ void file::pipe(file& read_end, file& write_end) {
   read_end.close();
   write_end.close();
   int fds[2] = {};
-#ifdef _WIN32
+#  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
+#  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
+#  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.
@@ -220,14 +302,15 @@ buffered_file file::fdopen(const char* mode) {
 }
 
 long getpagesize() {
-#ifdef _WIN32
+#  ifdef _WIN32
   SYSTEM_INFO si;
   GetSystemInfo(&si);
   return si.dwPageSize;
-#else
+#  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
+#  endif
 }
+#endif  // FMT_USE_FCNTL
 FMT_END_NAMESPACE

support/Vagrantfile

@@ -3,7 +3,7 @@
 
 # A vagrant config for testing against gcc-4.8.
 Vagrant.configure("2") do |config|
-  config.vm.box = "ubuntu/trusty64"
+  config.vm.box = "ubuntu/xenial64"
 
   config.vm.provider "virtualbox" do |vb|
     vb.memory = "4096"

support/cmake/cxx14.cmake

@@ -48,17 +48,6 @@ 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
-# Can be removed once gcc 4.4 support is dropped.
-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 user-defined literals are available
 check_cxx_source_compiles("
   void operator\"\" _udl(long double);

support/cmake/fmt.pc.in

@@ -1,11 +1,11 @@
 prefix=@CMAKE_INSTALL_PREFIX@
 exec_prefix=@CMAKE_INSTALL_PREFIX@
-libdir=@CMAKE_INSTALL_FULL_LIBDIR@
-includedir=@CMAKE_INSTALL_FULL_INCLUDEDIR@
+libdir=${exec_prefix}/@CMAKE_INSTALL_LIBDIR@
+includedir=${prefix}/@CMAKE_INSTALL_INCLUDEDIR@
 
 Name: fmt
 Description: A modern formatting library
 Version: @FMT_VERSION@
-Libs: -L${libdir} -lfmt
+Libs: -L${libdir} -l@FMT_LIB_NAME@
 Cflags: -I${includedir}
 

support/manage.py

@@ -137,7 +137,7 @@ 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&')
@@ -146,6 +146,7 @@ def update_site(env):
                 b.data = b.data.replace('unsigned int', 'unsigned')
                 b.data = b.data.replace('operator""_', 'operator"" _')
                 b.data = b.data.replace(', size_t', ', std::size_t')
+                b.data = b.data.replace('aa long', 'a long')
         # Fix a broken link in index.rst.
         index = os.path.join(target_doc_dir, 'index.rst')
         with rewrite(index) as b:

test/CMakeLists.txt

@@ -17,9 +17,7 @@ else ()
   target_compile_definitions(gmock PUBLIC GTEST_HAS_PTHREAD=0)
 endif ()
 
-if (NOT SUPPORTS_VARIADIC_TEMPLATES)
-  target_compile_definitions(gmock PUBLIC GTEST_LANG_CXX11=0)
-endif ()
+target_compile_definitions(gmock PUBLIC GTEST_LANG_CXX11=0)
 
 if (MSVC)
   # Workaround a bug in implementation of variadic templates in MSVC11.
@@ -47,8 +45,6 @@ target_compile_definitions(gmock
 
 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)
 
@@ -84,6 +80,9 @@ function(add_fmt_test name)
   if (FMT_PEDANTIC)
     target_compile_options(${name} PRIVATE ${PEDANTIC_COMPILE_FLAGS})
   endif ()
+  if (FMT_WERROR)
+    target_compile_options(${name} PRIVATE ${WERROR_FLAG})
+  endif ()
   target_include_directories(${name} SYSTEM PUBLIC gtest gmock)
   add_test(NAME ${name} COMMAND ${name})
 endfunction()
@@ -96,6 +95,9 @@ add_fmt_test(grisu-test)
 target_compile_definitions(grisu-test PRIVATE FMT_USE_GRISU=1)
 add_fmt_test(gtest-extra-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)
 endif ()
@@ -107,12 +109,11 @@ add_fmt_test(custom-formatter-test)
 add_fmt_test(ranges-test)
 add_fmt_test(scan-test)
 
-if (HAVE_OPEN)
+if (NOT MSVC_BUILD_STATIC)
   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)
   if (FMT_PEDANTIC)
@@ -122,7 +123,7 @@ if (HAVE_OPEN)
     target_compile_definitions(posix-mock-test PRIVATE FMT_LOCALE)
   endif ()
   add_test(NAME posix-mock-test COMMAND posix-mock-test)
-  add_fmt_test(posix-test)
+  add_fmt_test(os-test)
 endif ()
 
 add_fmt_executable(header-only-test
@@ -168,18 +169,6 @@ if (FMT_PEDANTIC)
   target_compile_definitions(
     nolocale-test PRIVATE FMT_STATIC_THOUSANDS_SEPARATOR=1)
 
-  # Test that the library compiles without windows.h.
-  if (CMAKE_SYSTEM_NAME STREQUAL "Windows")
-    add_library(no-windows-h-test ../src/format.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)
-  endif ()
-
   add_test(compile-error-test ${CMAKE_CTEST_COMMAND}
     --build-and-test
     "${CMAKE_CURRENT_SOURCE_DIR}/compile-error-test"
@@ -225,3 +214,23 @@ if (FMT_PEDANTIC AND NOT WIN32)
     "-DPEDANTIC_COMPILE_FLAGS=${PEDANTIC_COMPILE_FLAGS}"
     "-DCMAKE_BUILD_TYPE=${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/assert-test.cc

@@ -8,15 +8,21 @@
 #include "fmt/core.h"
 #include "gtest.h"
 
-#if GTEST_HAS_DEATH_TEST
-#  define EXPECT_DEBUG_DEATH_IF_SUPPORTED(statement, regex) \
-    EXPECT_DEBUG_DEATH(statement, regex)
-#else
-#  define EXPECT_DEBUG_DEATH_IF_SUPPORTED(statement, regex) \
-    GTEST_UNSUPPORTED_DEATH_TEST_(statement, regex, )
-#endif
-
 TEST(AssertTest, Fail) {
-  EXPECT_DEBUG_DEATH_IF_SUPPORTED(FMT_ASSERT(false, "don't panic!"),
-                                  "don't panic!");
+#if GTEST_HAS_DEATH_TEST
+  EXPECT_DEBUG_DEATH(FMT_ASSERT(false, "don't panic!"), "don't panic!");
+#else
+  fmt::print("warning: death tests are not supported\n");
+#endif
+}
+
+bool test_condition = false;
+
+TEST(AssertTest, DanglingElse) {
+  bool executed_else = false;
+  if (test_condition)
+    FMT_ASSERT(true, "");
+  else
+    executed_else = true;
+  EXPECT_TRUE(executed_else);
 }

test/chrono-test.cc

@@ -145,6 +145,48 @@ TEST(ChronoTest, FormatDefault) {
       fmt::format("{}", std::chrono::duration<int, std::ratio<15, 4>>(42)));
 }
 
+TEST(ChronoTest, FormatWide) {
+  EXPECT_EQ(L"42s", fmt::format(L"{}", std::chrono::seconds(42)));
+  EXPECT_EQ(L"42as",
+            fmt::format(L"{}", std::chrono::duration<int, std::atto>(42)));
+  EXPECT_EQ(L"42fs",
+            fmt::format(L"{}", std::chrono::duration<int, std::femto>(42)));
+  EXPECT_EQ(L"42ps",
+            fmt::format(L"{}", std::chrono::duration<int, std::pico>(42)));
+  EXPECT_EQ(L"42ns", fmt::format(L"{}", std::chrono::nanoseconds(42)));
+  EXPECT_EQ(L"42\u00B5s", fmt::format(L"{}", std::chrono::microseconds(42)));
+  EXPECT_EQ(L"42ms", fmt::format(L"{}", std::chrono::milliseconds(42)));
+  EXPECT_EQ(L"42cs",
+            fmt::format(L"{}", std::chrono::duration<int, std::centi>(42)));
+  EXPECT_EQ(L"42ds",
+            fmt::format(L"{}", std::chrono::duration<int, std::deci>(42)));
+  EXPECT_EQ(L"42s", fmt::format(L"{}", std::chrono::seconds(42)));
+  EXPECT_EQ(L"42das",
+            fmt::format(L"{}", std::chrono::duration<int, std::deca>(42)));
+  EXPECT_EQ(L"42hs",
+            fmt::format(L"{}", std::chrono::duration<int, std::hecto>(42)));
+  EXPECT_EQ(L"42ks",
+            fmt::format(L"{}", std::chrono::duration<int, std::kilo>(42)));
+  EXPECT_EQ(L"42Ms",
+            fmt::format(L"{}", std::chrono::duration<int, std::mega>(42)));
+  EXPECT_EQ(L"42Gs",
+            fmt::format(L"{}", std::chrono::duration<int, std::giga>(42)));
+  EXPECT_EQ(L"42Ts",
+            fmt::format(L"{}", std::chrono::duration<int, std::tera>(42)));
+  EXPECT_EQ(L"42Ps",
+            fmt::format(L"{}", std::chrono::duration<int, std::peta>(42)));
+  EXPECT_EQ(L"42Es",
+            fmt::format(L"{}", std::chrono::duration<int, std::exa>(42)));
+  EXPECT_EQ(L"42m", fmt::format(L"{}", std::chrono::minutes(42)));
+  EXPECT_EQ(L"42h", fmt::format(L"{}", std::chrono::hours(42)));
+  EXPECT_EQ(
+      L"42[15]s",
+      fmt::format(L"{}", std::chrono::duration<int, std::ratio<15, 1>>(42)));
+  EXPECT_EQ(
+      L"42[15/4]s",
+      fmt::format(L"{}", std::chrono::duration<int, std::ratio<15, 4>>(42)));
+}
+
 TEST(ChronoTest, Align) {
   auto s = std::chrono::seconds(42);
   EXPECT_EQ("42s  ", fmt::format("{:5}", s));

test/color-test.cc

@@ -47,9 +47,11 @@ TEST(ColorsTest, ColorsPrint) {
                "\x1b[105mtbmagenta\x1b[0m");
 }
 
-TEST(ColorsTest, ColorsFormat) {
+TEST(ColorsTest, Format) {
   EXPECT_EQ(fmt::format(fg(fmt::rgb(255, 20, 30)), "rgb(255,20,30)"),
             "\x1b[38;2;255;020;030mrgb(255,20,30)\x1b[0m");
+  EXPECT_EQ(fmt::format(fg(fmt::rgb(255, 20, 30)), L"rgb(255,20,30) wide"),
+            L"\x1b[38;2;255;020;030mrgb(255,20,30) wide\x1b[0m");
   EXPECT_EQ(fmt::format(fg(fmt::color::blue), "blue"),
             "\x1b[38;2;000;000;255mblue\x1b[0m");
   EXPECT_EQ(
@@ -78,4 +80,6 @@ TEST(ColorsTest, ColorsFormat) {
             "\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");
 }

test/compile-test.cc

@@ -34,205 +34,17 @@
 using testing::Return;
 using testing::StrictMock;
 
-FMT_BEGIN_NAMESPACE
-namespace internal {
-bool operator==(const internal::string_view_metadata& lhs,
-                const internal::string_view_metadata& rhs) {
-  return std::tie(lhs.offset_, lhs.size_) == std::tie(rhs.offset_, rhs.size_);
-}
-bool operator!=(const internal::string_view_metadata& lhs,
-                const internal::string_view_metadata& rhs) {
-  return !(lhs == rhs);
-}
-
-bool operator==(const format_part<char>::specification& lhs,
-                const format_part<char>::specification& rhs) {
-  if (lhs.arg_id.which != rhs.arg_id.which) {
-    return false;
-  }
-
-  typedef format_part<char>::argument_id::which_arg_id which_arg_id;
-  switch (lhs.arg_id.which) {
-  case which_arg_id::index: {
-    if (lhs.arg_id.val.index != rhs.arg_id.val.index) {
-      return false;
-    }
-  } break;
-  case which_arg_id::named_index: {
-    if (lhs.arg_id.val.named_index != rhs.arg_id.val.named_index) {
-      return false;
-    }
-  } break;
-  }
-
-  return std::tie(lhs.parsed_specs.width, lhs.parsed_specs.fill[0],
-                  lhs.parsed_specs.align, lhs.parsed_specs.precision,
-                  lhs.parsed_specs.sign, lhs.parsed_specs.type) ==
-         std::tie(rhs.parsed_specs.width, rhs.parsed_specs.fill[0],
-                  rhs.parsed_specs.align, rhs.parsed_specs.precision,
-                  rhs.parsed_specs.sign, rhs.parsed_specs.type);
-}
-
-bool operator!=(const format_part<char>::specification& lhs,
-                const format_part<char>::specification& rhs) {
-  return !(lhs == rhs);
-}
-
-bool operator==(const format_part<char>& lhs,
-                const fmt::internal::format_part<char>& rhs) {
-  typedef format_part<char>::kind kind;
-
-  if (lhs.which != rhs.which ||
-      lhs.end_of_argument_id != rhs.end_of_argument_id) {
-    return false;
-  }
-
-  switch (lhs.which) {
-  case kind::argument_id: {
-    return lhs.val.arg_id == rhs.val.arg_id;
-  }
-
-  case kind::named_argument_id: {
-    return lhs.val.named_arg_id == rhs.val.named_arg_id;
-  }
-
-  case kind::text: {
-    return lhs.val.text == rhs.val.text;
-  }
-
-  case kind::specification: {
-    return lhs.val.spec == rhs.val.spec;
-  }
-  }
-
-  return false;
-}
-
-bool operator!=(const fmt::internal::format_part<char>& lhs,
-                const fmt::internal::format_part<char>& rhs) {
-  return !(lhs == rhs);
-}
-}
-FMT_END_NAMESPACE
-
-TEST(CompileTest, FormatPart_ComparisonOperators) {
-  typedef fmt::internal::format_part<char> format_part;
-  typedef fmt::internal::dynamic_format_specs<char> prepared_specs;
-
-  {
-    const auto part = format_part(0u);
-    const auto other = format_part(0u);
-    EXPECT_EQ(part, other);
-  }
-  {
-    const auto lhs = format_part(0u);
-    const auto rhs = format_part(1u);
-    EXPECT_NE(lhs, rhs);
-  }
-  {
-    const auto lhs = format_part(fmt::internal::string_view_metadata(0, 42));
-    const auto rhs = format_part(fmt::internal::string_view_metadata(0, 42));
-    EXPECT_EQ(lhs, rhs);
-  }
-  {
-    const auto lhs = format_part(fmt::internal::string_view_metadata(0, 42));
-    const auto rhs = format_part(fmt::internal::string_view_metadata(0, 4422));
-    EXPECT_NE(lhs, rhs);
-  }
-  {
-    auto lhs = format_part(0u);
-    auto rhs = format_part(fmt::internal::string_view_metadata(0, 42));
-    EXPECT_NE(lhs, rhs);
-    rhs = format_part(fmt::internal::string_view_metadata(0, 0));
-    EXPECT_NE(lhs, rhs);
-  }
-  {
-    auto lhs = format_part(0u);
-    lhs.end_of_argument_id = 42;
-    auto rhs = format_part(0u);
-    rhs.end_of_argument_id = 42;
-    EXPECT_EQ(lhs, rhs);
-    rhs.end_of_argument_id = 13;
-    EXPECT_NE(lhs, rhs);
-  }
-  {
-    const auto specs_argument_id = 0u;
-    const auto specs_named_argument_id =
-        fmt::internal::string_view_metadata(0, 42);
-    auto specs = format_part::specification(0u);
-    auto lhs = format_part(specs);
-    auto rhs = format_part(specs);
-    EXPECT_EQ(lhs, rhs);
-
-    specs.parsed_specs = prepared_specs();
-    lhs = format_part(specs);
-    rhs = format_part(specs);
-    EXPECT_EQ(lhs, rhs);
-
-    specs = format_part::specification(specs_named_argument_id);
-    lhs = format_part(specs);
-    rhs = format_part(specs);
-    EXPECT_EQ(lhs, rhs);
-
-    specs.parsed_specs = prepared_specs();
-    lhs = format_part(specs);
-    rhs = format_part(specs);
-    EXPECT_EQ(lhs, rhs);
-
-    auto lhs_spec = format_part::specification(specs_argument_id);
-    auto rhs_spec = format_part::specification(specs_named_argument_id);
-    lhs = format_part(lhs_spec);
-    rhs = format_part(rhs_spec);
-    EXPECT_NE(lhs, rhs);
-
-    lhs_spec = format_part::specification(specs_argument_id);
-    rhs_spec = format_part::specification(specs_argument_id);
-    lhs_spec.parsed_specs.precision = 1;
-    rhs_spec.parsed_specs.precision = 2;
-    lhs = format_part(lhs_spec);
-    rhs = format_part(rhs_spec);
-    EXPECT_NE(lhs, rhs);
-  }
-  {
-    const auto specs_argument_id = 0u;
-    const auto specs_named_argument_id =
-        fmt::internal::string_view_metadata(0, 42);
-    auto specs = format_part::specification(specs_argument_id);
-    auto lhs = format_part(specs);
-    auto rhs = format_part(0u);
-    auto rhs2 = format_part(fmt::internal::string_view_metadata(0, 42));
-    EXPECT_NE(lhs, rhs);
-    EXPECT_NE(lhs, rhs2);
-
-    specs.parsed_specs = prepared_specs();
-    lhs = format_part{specs};
-    EXPECT_NE(lhs, rhs);
-    EXPECT_NE(lhs, rhs2);
-
-    specs = format_part::specification(specs_named_argument_id);
-    EXPECT_NE(lhs, rhs);
-    EXPECT_NE(lhs, rhs2);
-
-    specs.parsed_specs = prepared_specs();
-    lhs = format_part(specs);
-    EXPECT_NE(lhs, rhs);
-    EXPECT_NE(lhs, rhs2);
-  }
-}
-
 // compiletime_prepared_parts_type_provider is useful only with relaxed
 // constexpr.
 #if FMT_USE_CONSTEXPR
 template <unsigned EXPECTED_PARTS_COUNT, typename Format>
 void check_prepared_parts_type(Format format) {
-  typedef fmt::internal::compiletime_prepared_parts_type_provider<decltype(
-      format)>
-      provider;
-  typedef typename provider::template format_parts_array<EXPECTED_PARTS_COUNT>
-      expected_parts_type;
-  static_assert(
-      std::is_same<typename provider::type, expected_parts_type>::value,
-      "CompileTimePreparedPartsTypeProvider test failed");
+  typedef fmt::internal::compiled_format_base<decltype(format)> provider;
+  typedef fmt::internal::format_part<char>
+      expected_parts_type[EXPECTED_PARTS_COUNT];
+  static_assert(std::is_same<typename provider::parts_container,
+                             expected_parts_type>::value,
+                "CompileTimePreparedPartsTypeProvider test failed");
 }
 
 TEST(CompileTest, CompileTimePreparedPartsTypeProvider) {
@@ -253,40 +65,6 @@ TEST(CompileTest, CompileTimePreparedPartsTypeProvider) {
 }
 #endif
 
-class custom_parts_container {
- public:
-  typedef fmt::internal::format_part<char> format_part_type;
-
- private:
-  typedef std::deque<format_part_type> parts;
-
- public:
-  void add(format_part_type part) { parts_.push_back(std::move(part)); }
-
-  void substitute_last(format_part_type part) {
-    parts_.back() = std::move(part);
-  }
-
-  format_part_type last() { return parts_.back(); }
-
-  auto begin() -> decltype(std::declval<parts>().begin()) {
-    return parts_.begin();
-  }
-
-  auto begin() const -> decltype(std::declval<const parts>().begin()) {
-    return parts_.begin();
-  }
-
-  auto end() -> decltype(std::declval<parts>().begin()) { return parts_.end(); }
-
-  auto end() const -> decltype(std::declval<const parts>().begin()) {
-    return parts_.end();
-  }
-
- private:
-  parts parts_;
-};
-
 TEST(CompileTest, PassStringLiteralFormat) {
   const auto prepared = fmt::compile<int>("test {}");
   EXPECT_EQ("test 42", fmt::format(prepared, 42));
@@ -338,3 +116,28 @@ TEST(CompileTest, FormattedSize) {
   auto f = fmt::compile<int>("{:10}");
   EXPECT_EQ(fmt::formatted_size(f, 42), 10);
 }
+
+TEST(CompileTest, MultipleTypes) {
+  auto f = fmt::compile<int, int>("{} {}");
+  EXPECT_EQ(fmt::format(f, 42, 42), "42 42");
+}
+
+struct formattable {};
+
+FMT_BEGIN_NAMESPACE
+template <> struct formatter<formattable> : formatter<const char*> {
+  auto format(formattable, format_context& ctx) -> decltype(ctx.out()) {
+    return formatter<const char*>::format("foo", ctx);
+  }
+};
+FMT_END_NAMESPACE
+
+TEST(CompileTest, FormatUserDefinedType) {
+  auto f = fmt::compile<formattable>("{}");
+  EXPECT_EQ(fmt::format(f, formattable()), "foo");
+}
+
+TEST(CompileTest, EmptyFormatString) {
+  auto f = fmt::compile<>("");
+  EXPECT_EQ(fmt::format(f), "");
+}

test/core-test.cc

@@ -15,9 +15,8 @@
 #include <string>
 #include <type_traits>
 
-#include "test-assert.h"
-
 #include "gmock.h"
+#include "test-assert.h"
 
 // Check if fmt/core.h compiles with windows.h included before it.
 #ifdef _WIN32
@@ -103,7 +102,7 @@ template <typename T> struct mock_buffer : buffer<T> {
 TEST(BufferTest, Ctor) {
   {
     mock_buffer<int> buffer;
-    EXPECT_EQ(nullptr, &buffer[0]);
+    EXPECT_EQ(nullptr, buffer.data());
     EXPECT_EQ(static_cast<size_t>(0), buffer.size());
     EXPECT_EQ(static_cast<size_t>(0), buffer.capacity());
   }
@@ -127,8 +126,13 @@ TEST(BufferTest, Ctor) {
 struct dying_buffer : test_buffer<int> {
   MOCK_METHOD0(die, void());
   ~dying_buffer() { die(); }
+
+ private:
+  virtual void avoid_weak_vtable();
 };
 
+void dying_buffer::avoid_weak_vtable() {}
+
 TEST(BufferTest, VirtualDtor) {
   typedef StrictMock<dying_buffer> stict_mock_buffer;
   stict_mock_buffer* mock_buffer = new stict_mock_buffer();
@@ -285,8 +289,6 @@ VISIT_TYPE(long, long long);
 VISIT_TYPE(unsigned long, unsigned long long);
 #endif
 
-VISIT_TYPE(float, double);
-
 #define CHECK_ARG_(Char, expected, value)                                     \
   {                                                                           \
     testing::StrictMock<mock_visitor<decltype(expected)>> visitor;            \
@@ -399,8 +401,114 @@ TEST(ArgTest, VisitInvalidArg) {
   fmt::visit_format_arg(visitor, arg);
 }
 
+TEST(FormatDynArgsTest, Basic) {
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+  store.push_back(42);
+  store.push_back("abc1");
+  store.push_back(1.5f);
+
+  std::string result = fmt::vformat("{} and {} and {}", store);
+  EXPECT_EQ("42 and abc1 and 1.5", result);
+}
+
+TEST(FormatDynArgsTest, StringsAndRefs) {
+  // 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';
+
+  std::string 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(FormatDynArgsTest, CustomFormat) {
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+  custom_type c{};
+  store.push_back(c);
+  ++c.i;
+  store.push_back(c);
+  ++c.i;
+  store.push_back(std::cref(c));
+  ++c.i;
+
+  std::string result = fmt::vformat("{} and {} and {}", store);
+  EXPECT_EQ("cust=0 and cust=1 and cust=3", result);
+}
+
+TEST(FormatDynArgsTest, NamedArgByRef) {
+  fmt::dynamic_format_arg_store<fmt::format_context> store;
+
+  // Note: fmt::arg() constructs an object which holds a reference
+  // to its value. It's not an aggregate, so it doesn't extend the
+  // reference lifetime. As a result, it's a very bad idea passing temporary
+  // as a named argument value. Only GCC with optimization level >0
+  // complains about this.
+  //
+  // A real life usecase is when you have both name and value alive
+  // guarantee their lifetime and thus don't want them to be copied into
+  // storages.
+  int a1_val{42};
+  auto a1 = fmt::arg("a1_", a1_val);
+  store.push_back(std::cref(a1));
+
+  std::string result = fmt::vformat("{a1_}",  // and {} and {}",
+                                    store);
+
+  EXPECT_EQ("42", 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(FormatDynArgsTest, ThrowOnCopy) {
+  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(StringViewTest, ValueType) {
+  static_assert(std::is_same<string_view::value_type, char>::value, "");
+}
+
 TEST(StringViewTest, Length) {
-  // Test that StringRef::size() returns string length, not buffer size.
+  // Test that string_view::size() returns string length, not buffer size.
   char str[100] = "some string";
   EXPECT_EQ(std::strlen(str), string_view(str).size());
   EXPECT_LT(std::strlen(str), sizeof(str));
@@ -450,17 +558,22 @@ template <> struct formatter<enabled_formatter> {
 FMT_END_NAMESPACE
 
 TEST(CoreTest, HasFormatter) {
-  using fmt::internal::has_formatter;
+  using fmt::has_formatter;
   using context = fmt::format_context;
-  EXPECT_TRUE((has_formatter<enabled_formatter, context>::value));
-  EXPECT_FALSE((has_formatter<disabled_formatter, context>::value));
-  EXPECT_FALSE((has_formatter<disabled_formatter_convertible, context>::value));
+  static_assert(has_formatter<enabled_formatter, context>::value, "");
+  static_assert(!has_formatter<disabled_formatter, context>::value, "");
+  static_assert(!has_formatter<disabled_formatter_convertible, context>::value,
+                "");
 }
 
 struct convertible_to_int {
   operator int() const { return 42; }
 };
 
+struct convertible_to_c_string {
+  operator const char*() const { return "foo"; }
+};
+
 FMT_BEGIN_NAMESPACE
 template <> struct formatter<convertible_to_int> {
   auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
@@ -470,10 +583,21 @@ template <> struct formatter<convertible_to_int> {
     return std::copy_n("foo", 3, ctx.out());
   }
 };
+
+template <> struct formatter<convertible_to_c_string> {
+  auto parse(format_parse_context& ctx) -> decltype(ctx.begin()) {
+    return ctx.begin();
+  }
+  auto format(convertible_to_c_string, format_context& ctx)
+      -> decltype(ctx.out()) {
+    return std::copy_n("bar", 3, ctx.out());
+  }
+};
 FMT_END_NAMESPACE
 
 TEST(CoreTest, FormatterOverridesImplicitConversion) {
   EXPECT_EQ(fmt::format("{}", convertible_to_int()), "foo");
+  EXPECT_EQ(fmt::format("{}", convertible_to_c_string()), "bar");
 }
 
 namespace my_ns {
@@ -569,13 +693,13 @@ TEST(CoreTest, ToStringViewForeignStrings) {
   fmt::internal::type type =
       fmt::internal::mapped_type_constant<my_string<char>,
                                           fmt::format_context>::value;
-  EXPECT_EQ(type, fmt::internal::string_type);
+  EXPECT_EQ(type, fmt::internal::type::string_type);
   type = fmt::internal::mapped_type_constant<my_string<wchar_t>,
                                              fmt::wformat_context>::value;
-  EXPECT_EQ(type, fmt::internal::string_type);
+  EXPECT_EQ(type, fmt::internal::type::string_type);
   type =
       fmt::internal::mapped_type_constant<QString, fmt::wformat_context>::value;
-  EXPECT_EQ(type, fmt::internal::string_type);
+  EXPECT_EQ(type, fmt::internal::type::string_type);
   // Does not compile: only wide format contexts are compatible with QString!
   // type = fmt::internal::mapped_type_constant<QString,
   // fmt::format_context>::value;
@@ -613,6 +737,17 @@ TEST(FormatterTest, FormatExplicitlyConvertibleToStringView) {
   EXPECT_EQ("foo", fmt::format("{}", explicitly_convertible_to_string_view()));
 }
 
+#  ifdef FMT_USE_STRING_VIEW
+struct explicitly_convertible_to_std_string_view {
+  explicit operator std::string_view() const { return "foo"; }
+};
+
+TEST(FormatterTest, FormatExplicitlyConvertibleToStdStringView) {
+  EXPECT_EQ("foo",
+            fmt::format("{}", explicitly_convertible_to_std_string_view()));
+}
+#  endif
+
 struct explicitly_convertible_to_wstring_view {
   explicit operator fmt::wstring_view() const { return L"foo"; }
 };
@@ -621,17 +756,15 @@ TEST(FormatterTest, FormatExplicitlyConvertibleToWStringView) {
   EXPECT_EQ(L"foo",
             fmt::format(L"{}", explicitly_convertible_to_wstring_view()));
 }
+#endif
 
-struct explicitly_convertible_to_string_like {
-  template <typename String,
-            typename = typename std::enable_if<std::is_constructible<
-                String, const char*, std::size_t>::value>::type>
-  explicit operator String() const {
-    return String("foo", 3u);
-  }
+struct disabled_rvalue_conversion {
+  operator const char*() const& { return "foo"; }
+  operator const char*() & { return "foo"; }
+  operator const char*() const&& = delete;
+  operator const char*() && = delete;
 };
 
-TEST(FormatterTest, FormatExplicitlyConvertibleToStringLike) {
-  EXPECT_EQ("foo", fmt::format("{}", explicitly_convertible_to_string_like()));
+TEST(FormatterTest, DisabledRValueConversion) {
+  EXPECT_EQ("foo", fmt::format("{}", disabled_rvalue_conversion()));
 }
-#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

@@ -18,9 +18,9 @@
 // A custom argument formatter that doesn't print `-` for floating-point values
 // rounded to 0.
 class custom_arg_formatter
-    : public fmt::arg_formatter<fmt::internal::buffer_range<char>> {
+    : public fmt::arg_formatter<fmt::buffer_range<char>> {
  public:
-  using range = fmt::internal::buffer_range<char>;
+  using range = fmt::buffer_range<char>;
   typedef fmt::arg_formatter<range> base;
 
   custom_arg_formatter(fmt::format_context& ctx,

test/format

@@ -8,6 +8,7 @@
 #ifndef FMT_FORMAT_
 #define FMT_FORMAT_
 
+#include <cassert>
 #include <variant>
 #include "fmt/format.h"
 
@@ -82,9 +83,9 @@ namespace std {
     Out format_to(Out out, wstring_view fmt, const Args&... args);
 
   template<class Out>
-    Out vformat_to(Out out, string_view fmt, format_args_t<Out, char> args);
+    Out vformat_to(Out out, string_view fmt, format_args_t<fmt::type_identity_t<Out>, char> args);
   template<class Out>
-    Out vformat_to(Out out, wstring_view fmt, format_args_t<Out, wchar_t> args);
+    Out vformat_to(Out out, wstring_view fmt, format_args_t<fmt::type_identity_t<Out>, wchar_t> args);
 
   template<class Out>
     struct format_to_n_result {
@@ -533,31 +534,31 @@ inline fmt::internal::type get_type(basic_format_arg<Context> arg) {
     using char_type = typename Context::char_type;
     using T = decltype(val);
     if (std::is_same_v<T, monostate>)
-      return fmt::internal::none_type;
+      return fmt::internal::type::none_type;
     if (std::is_same_v<T, bool>)
-      return fmt::internal::bool_type;
+      return fmt::internal::type::bool_type;
     if (std::is_same_v<T, char_type>)
-      return fmt::internal::char_type;
+      return fmt::internal::type::char_type;
     if (std::is_same_v<T, int>)
-      return fmt::internal::int_type;
+      return fmt::internal::type::int_type;
     if (std::is_same_v<T, unsigned int>)
-      return fmt::internal::uint_type;
+      return fmt::internal::type::uint_type;
     if (std::is_same_v<T, long long int>)
-      return fmt::internal::long_long_type;
+      return fmt::internal::type::long_long_type;
     if (std::is_same_v<T, unsigned long long int>)
-      return fmt::internal::ulong_long_type;
+      return fmt::internal::type::ulong_long_type;
     if (std::is_same_v<T, double>)
-      return fmt::internal::double_type;
+      return fmt::internal::type::double_type;
     if (std::is_same_v<T, long double>)
-      return fmt::internal::long_double_type;
+      return fmt::internal::type::long_double_type;
     if (std::is_same_v<T, const char_type*>)
-      return fmt::internal::cstring_type;
+      return fmt::internal::type::cstring_type;
     if (std::is_same_v<T, basic_string_view<char_type>>)
-      return fmt::internal::string_type;
+      return fmt::internal::type::string_type;
     if (std::is_same_v<T, const void*>)
-      return fmt::internal::pointer_type;
+      return fmt::internal::type::pointer_type;
     assert(get_value(arg).index() == 12);
-    return fmt::internal::custom_type;
+    return fmt::internal::type::custom_type;
   }, arg);
 }
 
@@ -648,38 +649,37 @@ struct formatter {
     auto type_spec = specs_.type;
     auto eh = ctx.error_handler();
     switch (type) {
-    case internal::none_type:
-    case internal::named_arg_type:
+    case internal::type::none_type:
+    case internal::type::named_arg_type:
       FMT_ASSERT(false, "invalid argument type");
       break;
-    case internal::int_type:
-    case internal::uint_type:
-    case internal::long_long_type:
-    case internal::ulong_long_type:
-    case internal::bool_type:
+    case internal::type::int_type:
+    case internal::type::uint_type:
+    case internal::type::long_long_type:
+    case internal::type::ulong_long_type:
+    case internal::type::bool_type:
       handle_int_type_spec(type_spec,
                            internal::int_type_checker<decltype(eh)>(eh));
       break;
-    case internal::char_type:
+    case internal::type::char_type:
       handle_char_specs(
           &specs_, internal::char_specs_checker<decltype(eh)>(type_spec, eh));
       break;
-    case internal::double_type:
-    case internal::long_double_type:
-      handle_float_type_spec(type_spec,
-                             internal::float_type_checker<decltype(eh)>(eh));
+    case internal::type::double_type:
+    case internal::type::long_double_type:
+      internal::parse_float_type_spec(specs_, eh);
       break;
-    case internal::cstring_type:
+    case internal::type::cstring_type:
       internal::handle_cstring_type_spec(
           type_spec, internal::cstring_type_checker<decltype(eh)>(eh));
       break;
-    case internal::string_type:
+    case internal::type::string_type:
       internal::check_string_type_spec(type_spec, eh);
       break;
-    case internal::pointer_type:
+    case internal::type::pointer_type:
       internal::check_pointer_type_spec(type_spec, eh);
       break;
-    case internal::custom_type:
+    case internal::type::custom_type:
       // Custom format specifiers should be checked in parse functions of
       // formatter specializations.
       break;
@@ -690,9 +690,9 @@ struct formatter {
   template <typename FormatContext>
   auto format(const T& val, FormatContext& ctx) -> decltype(ctx.out()) {
     fmt::internal::handle_dynamic_spec<fmt::internal::width_checker>(
-        specs_.width, specs_.width_ref, ctx, nullptr);
+        specs_.width, specs_.width_ref, ctx);
     fmt::internal::handle_dynamic_spec<fmt::internal::precision_checker>(
-        specs_.precision, specs_.precision_ref, ctx, nullptr);
+        specs_.precision, specs_.precision_ref, ctx);
     using range_type = fmt::internal::output_range<typename FormatContext::iterator,
                          typename FormatContext::char_type>;
     return visit_format_arg(arg_formatter<range_type>(ctx, nullptr, &specs_),
@@ -718,7 +718,7 @@ template<class... Args>
 string vformat(string_view fmt, format_args args) {
   fmt::memory_buffer mbuf;
   fmt::internal::buffer<char>& buf = mbuf;
-  using range = fmt::internal::buffer_range<char>;
+  using range = fmt::buffer_range<char>;
   detail::format_handler<detail::arg_formatter<range>, char, format_context>
     h(range(std::back_inserter(buf)), fmt, args, {});
   fmt::internal::parse_format_string<false>(fmt::to_string_view(fmt), h);
@@ -730,17 +730,17 @@ wstring vformat(wstring_view fmt, wformat_args args);
 template<class Out, class... Args>
   Out format_to(Out out, string_view fmt, const Args&... args) {
     using context = basic_format_context<Out, decltype(fmt)::value_type>;
-    return vformat_to(out, fmt, {make_format_args<context>(args...)});
+    return vformat_to(out, fmt, make_format_args<context>(args...));
   }
 
 template<class Out, class... Args>
   Out format_to(Out out, wstring_view fmt, const Args&... args) {
     using context = basic_format_context<Out, decltype(fmt)::value_type>;
-    return vformat_to(out, fmt, {make_format_args<context>(args...)});
+    return vformat_to(out, fmt, make_format_args<context>(args...));
   }
 
 template<class Out>
-  Out vformat_to(Out out, string_view fmt, format_args_t<Out, char> args) {
+  Out vformat_to(Out out, string_view fmt, format_args_t<fmt::type_identity_t<Out>, char> args) {
     using range = fmt::internal::output_range<Out, char>;
     detail::format_handler<detail::arg_formatter<range>, char, basic_format_context<Out, char>>
       h(range(out), fmt, args, {});
@@ -749,7 +749,7 @@ template<class Out>
   }
 
 template<class Out>
-  Out vformat_to(Out out, wstring_view fmt, format_args_t<Out, wchar_t> args);
+  Out vformat_to(Out out, wstring_view fmt, format_args_t<fmt::type_identity_t<Out>, wchar_t> args);
 
 template<class Out, class... Args>
   format_to_n_result<Out> format_to_n(Out out, iter_difference_t<Out> n,

test/format-dyn-args-test.cc

@@ -0,0 +1,6 @@
+// Copyright (c) 2020 Vladimir Solontsov
+// SPDX-License-Identifier: MIT Licence
+
+#include <fmt/core.h>
+
+#include "gtest-extra.h"

test/format-impl-test.cc

@@ -10,65 +10,243 @@
 #include "test-assert.h"
 
 // Include format.cc instead of format.h to test implementation.
-#include "../src/format.cc"
-#include "fmt/printf.h"
-
 #include <algorithm>
 #include <cstring>
 
+#include "../src/format.cc"
+#include "fmt/printf.h"
 #include "gmock.h"
 #include "gtest-extra.h"
 #include "util.h"
 
 #undef max
 
+using fmt::internal::bigint;
 using fmt::internal::fp;
+using fmt::internal::max_value;
 
-template <bool is_iec559> void test_construct_from_double() {
+static_assert(!std::is_copy_constructible<bigint>::value, "");
+static_assert(!std::is_copy_assignable<bigint>::value, "");
+
+TEST(BigIntTest, Construct) {
+  EXPECT_EQ("", fmt::format("{}", bigint()));
+  EXPECT_EQ("42", fmt::format("{}", bigint(0x42)));
+  EXPECT_EQ("123456789abcedf0", fmt::format("{}", bigint(0x123456789abcedf0)));
+}
+
+TEST(BigIntTest, 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(BigIntTest, AddCompare) {
+  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(BigIntTest, ShiftLeft) {
+  bigint n(0x42);
+  n <<= 0;
+  EXPECT_EQ("42", fmt::format("{}", n));
+  n <<= 1;
+  EXPECT_EQ("84", fmt::format("{}", n));
+  n <<= 25;
+  EXPECT_EQ("108000000", fmt::format("{}", n));
+}
+
+TEST(BigIntTest, Multiply) {
+  bigint n(0x42);
+  EXPECT_THROW(n *= 0, assertion_failure);
+  n *= 1;
+  EXPECT_EQ("42", fmt::format("{}", n));
+  n *= 2;
+  EXPECT_EQ("84", fmt::format("{}", n));
+  n *= 0x12345678;
+  EXPECT_EQ("962fc95e0", fmt::format("{}", n));
+  bigint bigmax(max_value<uint32_t>());
+  bigmax *= max_value<uint32_t>();
+  EXPECT_EQ("fffffffe00000001", fmt::format("{}", bigmax));
+  bigmax.assign(max_value<uint64_t>());
+  bigmax *= max_value<uint64_t>();
+  EXPECT_EQ("fffffffffffffffe0000000000000001", fmt::format("{}", bigmax));
+}
+
+TEST(BigIntTest, Accumulator) {
+  fmt::internal::accumulator acc;
+  EXPECT_EQ(acc.lower, 0);
+  EXPECT_EQ(acc.upper, 0);
+  acc.upper = 12;
+  acc.lower = 34;
+  EXPECT_EQ(static_cast<uint32_t>(acc), 34);
+  acc += 56;
+  EXPECT_EQ(acc.lower, 90);
+  acc += fmt::internal::max_value<uint64_t>();
+  EXPECT_EQ(acc.upper, 13);
+  EXPECT_EQ(acc.lower, 89);
+  acc >>= 32;
+  EXPECT_EQ(acc.upper, 0);
+  EXPECT_EQ(acc.lower, 13 * 0x100000000);
+}
+
+TEST(BigIntTest, Square) {
+  bigint n0(0);
+  n0.square();
+  EXPECT_EQ("0", fmt::format("{}", n0));
+  bigint n1(0x100);
+  n1.square();
+  EXPECT_EQ("10000", fmt::format("{}", n1));
+  bigint n2(0xfffffffff);
+  n2.square();
+  EXPECT_EQ("ffffffffe000000001", fmt::format("{}", n2));
+  bigint n3(max_value<uint64_t>());
+  n3.square();
+  EXPECT_EQ("fffffffffffffffe0000000000000001", fmt::format("{}", n3));
+  bigint n4;
+  n4.assign_pow10(10);
+  EXPECT_EQ("2540be400", fmt::format("{}", n4));
+}
+
+TEST(BigIntTest, DivModAssignZeroDivisor) {
+  bigint zero(0);
+  EXPECT_THROW(bigint(0).divmod_assign(zero), assertion_failure);
+  EXPECT_THROW(bigint(42).divmod_assign(zero), assertion_failure);
+}
+
+TEST(BigIntTest, DivModAssignSelf) {
+  bigint n(100);
+  EXPECT_THROW(n.divmod_assign(n), assertion_failure);
+}
+
+TEST(BigIntTest, DivModAssignUnaligned) {
+  // (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("10f8353019583bfc29ffc8f564e1b9f9d819dbb4cf783e4507eca1539220p96",
+            fmt::format("{}", n1));
+}
+
+TEST(BigIntTest, DivModAssign) {
+  // 100 / 10:
+  bigint n1(100);
+  int result = n1.divmod_assign(bigint(10));
+  EXPECT_EQ(result, 10);
+  EXPECT_EQ("0", fmt::format("{}", n1));
+  // pow(10, 100) / (42 << 320):
+  n1.assign_pow10(100);
+  result = n1.divmod_assign(bigint(42) <<= 320);
+  EXPECT_EQ(result, 111);
+  EXPECT_EQ("13ad2594c37ceb0b2784c4ce0bf38ace408e211a7caab24308a82e8f10p96",
+            fmt::format("{}", n1));
+  // 42 / 100:
+  bigint n2(42);
+  n1.assign_pow10(2);
+  result = n2.divmod_assign(n1);
+  EXPECT_EQ(result, 0);
+  EXPECT_EQ("2a", fmt::format("{}", n2));
+}
+
+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));
+
+  // Compute boundaries:
+  fp value;
+  // Normalized & not power of 2 - equidistant boundaries:
+  auto b = value.assign_with_boundaries(1.23);
+  EXPECT_EQ(value, fp(0x0013ae147ae147ae, -52));
+  EXPECT_EQ(b.lower, 0x9d70a3d70a3d6c00);
+  EXPECT_EQ(b.upper, 0x9d70a3d70a3d7400);
+  // Normalized power of 2 - lower boundary is closer:
+  b = value.assign_with_boundaries(1.9807040628566084e+28);  // 2**94
+  EXPECT_EQ(value, fp(0x0010000000000000, 42));
+  EXPECT_EQ(b.lower, 0x7ffffffffffffe00);
+  EXPECT_EQ(b.upper, 0x8000000000000400);
+  // Smallest normalized double - equidistant boundaries:
+  b = value.assign_with_boundaries(2.2250738585072014e-308);
+  EXPECT_EQ(value, fp(0x0010000000000000, -1074));
+  EXPECT_EQ(b.lower, 0x7ffffffffffffc00);
+  EXPECT_EQ(b.upper, 0x8000000000000400);
+  // Subnormal - equidistant boundaries:
+  b = value.assign_with_boundaries(4.9406564584124654e-324);
+  EXPECT_EQ(value, fp(0x0000000000000001, -1074));
+  EXPECT_EQ(b.lower, 0x4000000000000000);
+  EXPECT_EQ(b.upper, 0xc000000000000000);
 }
 
-TEST(FPTest, ConstructFromDouble) {
-  test_construct_from_double<std::numeric_limits<double>::is_iec559>();
+TEST(FPTest, DoubleTests) {
+  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);
+  const auto v = fp(0xbeef, 42);
+  auto normalized = normalize(v);
+  EXPECT_EQ(0xbeef000000000000, normalized.f);
+  EXPECT_EQ(-6, normalized.e);
 }
 
-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, ComputeFloatBoundaries) {
+  struct {
+    double x, lower, upper;
+  } tests[] = {
+      // regular
+      {1.5f, 1.4999999403953552, 1.5000000596046448},
+      // boundary
+      {1.0f, 0.9999999701976776, 1.0000000596046448},
+      // min normal
+      {1.1754944e-38f, 1.1754942807573643e-38, 1.1754944208872107e-38},
+      // max subnormal
+      {1.1754942e-38f, 1.1754941406275179e-38, 1.1754942807573643e-38},
+      // min subnormal
+      {1e-45f, 7.006492321624085e-46, 2.1019476964872256e-45},
+  };
+  for (auto test : tests) {
+    fp vlower = normalize(fp(test.lower));
+    fp vupper = normalize(fp(test.upper));
+    vlower.f >>= vupper.e - vlower.e;
+    vlower.e = vupper.e;
+    fp value;
+    auto b = value.assign_float_with_boundaries(test.x);
+    EXPECT_EQ(vlower.f, b.lower);
+    EXPECT_EQ(vupper.f, b.upper);
+  }
 }
 
 TEST(FPTest, Multiply) {
@@ -94,25 +272,26 @@ TEST(FPTest, GetCachedPower) {
 
 TEST(FPTest, GetRoundDirection) {
   using fmt::internal::get_round_direction;
-  EXPECT_EQ(fmt::internal::down, get_round_direction(100, 50, 0));
-  EXPECT_EQ(fmt::internal::up, get_round_direction(100, 51, 0));
-  EXPECT_EQ(fmt::internal::down, get_round_direction(100, 40, 10));
-  EXPECT_EQ(fmt::internal::up, get_round_direction(100, 60, 10));
-  for (int i = 41; i < 60; ++i)
-    EXPECT_EQ(fmt::internal::unknown, get_round_direction(100, i, 10));
-  uint64_t max = std::numeric_limits<uint64_t>::max();
+  using fmt::internal::round_direction;
+  EXPECT_EQ(round_direction::down, get_round_direction(100, 50, 0));
+  EXPECT_EQ(round_direction::up, get_round_direction(100, 51, 0));
+  EXPECT_EQ(round_direction::down, get_round_direction(100, 40, 10));
+  EXPECT_EQ(round_direction::up, get_round_direction(100, 60, 10));
+  for (size_t i = 41; i < 60; ++i)
+    EXPECT_EQ(round_direction::unknown, get_round_direction(100, i, 10));
+  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(fmt::internal::up, get_round_direction(max, max - 1, 2));
+  EXPECT_EQ(round_direction::up, get_round_direction(max, max - 1, 2));
   // Check that 2 * (remainder + error) doesn't overflow.
-  EXPECT_EQ(fmt::internal::unknown,
+  EXPECT_EQ(round_direction::unknown,
             get_round_direction(max, max / 2 + 1, max / 2));
   // Check that remainder - error doesn't overflow.
-  EXPECT_EQ(fmt::internal::unknown, get_round_direction(100, 40, 41));
+  EXPECT_EQ(round_direction::unknown, get_round_direction(100, 40, 41));
   // Check that 2 * (remainder - error) doesn't overflow.
-  EXPECT_EQ(fmt::internal::up, get_round_direction(max, max - 1, 1));
+  EXPECT_EQ(round_direction::up, get_round_direction(max, max - 1, 1));
 }
 
 TEST(FPTest, FixedHandler) {
@@ -132,15 +311,14 @@ TEST(FPTest, FixedHandler) {
   // Check that divisor - error doesn't overflow.
   EXPECT_EQ(handler(1).on_digit('0', 100, 10, 101, exp, false), digits::error);
   // Check that 2 * error doesn't overflow.
-  uint64_t max = std::numeric_limits<uint64_t>::max();
+  uint64_t max = max_value<uint64_t>();
   EXPECT_EQ(handler(1).on_digit('0', max, 10, max - 1, exp, false),
             digits::error);
 }
 
 TEST(FPTest, GrisuFormatCompilesWithNonIEEEDouble) {
   fmt::memory_buffer buf;
-  int exp = 0;
-  grisu_format(4.2f, buf, -1, false, exp);
+  format_float(0.42, -1, fmt::internal::float_specs(), buf);
 }
 
 template <typename T> struct value_extractor {
@@ -149,10 +327,21 @@ template <typename T> struct value_extractor {
   template <typename U> FMT_NORETURN T operator()(U) {
     throw std::runtime_error(fmt::format("invalid type {}", typeid(U).name()));
   }
+
+#if FMT_USE_INT128
+  // Apple Clang does not define typeid for __int128_t and __uint128_t.
+  FMT_NORETURN T operator()(fmt::internal::int128_t) {
+    throw std::runtime_error("invalid type __int128_t");
+  }
+
+  FMT_NORETURN T operator()(fmt::internal::uint128_t) {
+    throw std::runtime_error("invalid type __uint128_t");
+  }
+#endif
 };
 
 TEST(FormatTest, ArgConverter) {
-  long long value = std::numeric_limits<long long>::max();
+  long long value = max_value<long long>();
   auto arg = fmt::internal::make_arg<fmt::format_context>(value);
   fmt::visit_format_arg(
       fmt::internal::arg_converter<long long, fmt::format_context>(arg, 'd'),
@@ -237,14 +426,19 @@ TEST(FormatTest, FormatErrorCode) {
 }
 
 TEST(FormatTest, CountCodePoints) {
-  EXPECT_EQ(4, fmt::internal::count_code_points(fmt::u8string_view("ёжик")));
+#ifndef __cpp_char8_t
+  using fmt::char8_t;
+#endif
+  EXPECT_EQ(
+      4, fmt::internal::count_code_points(
+             fmt::basic_string_view<fmt::internal::char8_type>(
+                 reinterpret_cast<const fmt::internal::char8_type*>("ёжик"))));
 }
 
 // Tests fmt::internal::count_digits for integer type Int.
 template <typename Int> void test_count_digits() {
   for (Int i = 0; i < 10; ++i) EXPECT_EQ(1u, fmt::internal::count_digits(i));
-  for (Int i = 1, n = 1, end = std::numeric_limits<Int>::max() / 10; n <= end;
-       ++i) {
+  for (Int i = 1, n = 1, end = max_value<Int>() / 10; n <= end; ++i) {
     n *= 10;
     EXPECT_EQ(i, fmt::internal::count_digits(n - 1));
     EXPECT_EQ(i + 1, fmt::internal::count_digits(n));
@@ -259,8 +453,8 @@ TEST(UtilTest, CountDigits) {
 TEST(UtilTest, WriteUIntPtr) {
   fmt::memory_buffer buf;
   fmt::internal::writer writer(buf);
-  writer.write_pointer(fmt::internal::bit_cast<fmt::internal::fallback_uintptr>(
-                           reinterpret_cast<void*>(0xface)),
-                       nullptr);
+  writer.write_pointer(
+      fmt::internal::fallback_uintptr(reinterpret_cast<void*>(0xface)),
+      nullptr);
   EXPECT_EQ("0xface", to_string(buf));
 }

test/format-test.cc

@@ -6,6 +6,7 @@
 // For the license information refer to format.h.
 
 #include <stdint.h>
+
 #include <cctype>
 #include <cfloat>
 #include <climits>
@@ -20,8 +21,14 @@
 #  include <windows.h>
 #endif
 
+// Check if fmt/format.h compiles with the X11 index macro defined.
+#define index(x, y) no nice things
+
 #include "fmt/color.h"
 #include "fmt/format.h"
+
+#undef index
+
 #include "gmock.h"
 #include "gtest-extra.h"
 #include "mock-allocator.h"
@@ -34,12 +41,14 @@
 using std::size_t;
 
 using fmt::basic_memory_buffer;
-using fmt::internal::basic_writer;
 using fmt::format;
 using fmt::format_error;
 using fmt::memory_buffer;
 using fmt::string_view;
 using fmt::wmemory_buffer;
+using fmt::wstring_view;
+using fmt::internal::basic_writer;
+using fmt::internal::max_value;
 
 using testing::Return;
 using testing::StrictMock;
@@ -99,7 +108,7 @@ void std_format(long double value, std::wstring& result) {
 template <typename Char, typename T>
 ::testing::AssertionResult check_write(const T& value, const char* type) {
   fmt::basic_memory_buffer<Char> buffer;
-  using range = fmt::internal::buffer_range<Char>;
+  using range = fmt::buffer_range<Char>;
   basic_writer<range> writer(buffer);
   writer.write(value);
   std::basic_string<Char> actual = to_string(buffer);
@@ -162,8 +171,7 @@ TEST(UtilTest, Increment) {
 }
 
 TEST(UtilTest, ParseNonnegativeInt) {
-  if (std::numeric_limits<int>::max() !=
-      static_cast<int>(static_cast<unsigned>(1) << 31)) {
+  if (max_value<int>() != static_cast<int>(static_cast<unsigned>(1) << 31)) {
     fmt::print("Skipping parse_nonnegative_int test\n");
     return;
   }
@@ -181,7 +189,7 @@ TEST(UtilTest, ParseNonnegativeInt) {
 }
 
 TEST(IteratorTest, CountingIterator) {
-  fmt::internal::counting_iterator<char> it;
+  fmt::internal::counting_iterator it;
   auto prev = it++;
   EXPECT_EQ(prev.count(), 0);
   EXPECT_EQ(it.count(), 1);
@@ -270,7 +278,7 @@ static void check_move_buffer(
   EXPECT_EQ(alloc, buffer2.get_allocator().get());
 }
 
-TEST(MemoryBufferTest, MoveCtor) {
+TEST(MemoryBufferTest, MoveCtorInlineBuffer) {
   std::allocator<char> alloc;
   basic_memory_buffer<char, 5, TestAllocator> buffer((TestAllocator(&alloc)));
   const char test[] = "test";
@@ -280,15 +288,22 @@ TEST(MemoryBufferTest, MoveCtor) {
   // dynamic allocation.
   buffer.push_back('a');
   check_move_buffer("testa", buffer);
+}
+
+TEST(MemoryBufferTest, MoveCtorDynamicBuffer) {
+  std::allocator<char> alloc;
+  basic_memory_buffer<char, 4, TestAllocator> buffer((TestAllocator(&alloc)));
+  const char test[] = "test";
+  buffer.append(test, test + 4);
   const char* inline_buffer_ptr = &buffer[0];
   // Adding one more character causes the content to move from the inline to
   // a dynamically allocated buffer.
-  buffer.push_back('b');
-  basic_memory_buffer<char, 5, TestAllocator> buffer2(std::move(buffer));
+  buffer.push_back('a');
+  basic_memory_buffer<char, 4, TestAllocator> buffer2(std::move(buffer));
   // Move should rip the guts of the first buffer.
   EXPECT_EQ(inline_buffer_ptr, &buffer[0]);
-  EXPECT_EQ("testab", std::string(&buffer2[0], buffer2.size()));
-  EXPECT_GT(buffer2.capacity(), 5u);
+  EXPECT_EQ("testa", std::string(&buffer2[0], buffer2.size()));
+  EXPECT_GT(buffer2.capacity(), 4u);
 }
 
 static void check_move_assign_buffer(const char* str,
@@ -387,26 +402,17 @@ TEST(MemoryBufferTest, ExceptionInDeallocate) {
   EXPECT_CALL(alloc, deallocate(&mem2[0], 2 * size));
 }
 
-#ifdef _WIN32
-TEST(UtilTest, UTF16ToUTF8) {
-  std::string s = "ёжик";
-  fmt::internal::utf16_to_utf8 u(L"\x0451\x0436\x0438\x043A");
-  EXPECT_EQ(s, u.str());
-  EXPECT_EQ(s.size(), u.size());
-}
-
-TEST(UtilTest, UTF16ToUTF8EmptyString) {
-  std::string s = "";
-  fmt::internal::utf16_to_utf8 u(L"");
-  EXPECT_EQ(s, u.str());
-  EXPECT_EQ(s.size(), u.size());
-}
-
 TEST(UtilTest, UTF8ToUTF16) {
-  std::string s = "лошадка";
-  fmt::internal::utf8_to_utf16 u(s.c_str());
+  fmt::internal::utf8_to_utf16 u("лошадка");
   EXPECT_EQ(L"\x043B\x043E\x0448\x0430\x0434\x043A\x0430", u.str());
   EXPECT_EQ(7, u.size());
+  // U+10437 { DESERET SMALL LETTER YEE }
+  EXPECT_EQ(L"\xD801\xDC37", fmt::internal::utf8_to_utf16("𐐷").str());
+  EXPECT_THROW_MSG(fmt::internal::utf8_to_utf16("\xc3\x28"), std::runtime_error,
+                   "invalid utf8");
+  EXPECT_THROW_MSG(fmt::internal::utf8_to_utf16(fmt::string_view("л", 1)),
+                   std::runtime_error, "invalid utf8");
+  EXPECT_EQ(L"123456", fmt::internal::utf8_to_utf16("123456").str());
 }
 
 TEST(UtilTest, UTF8ToUTF16EmptyString) {
@@ -416,59 +422,6 @@ TEST(UtilTest, UTF8ToUTF16EmptyString) {
   EXPECT_EQ(s.size(), u.size());
 }
 
-template <typename Converter, typename Char>
-void check_utf_conversion_error(
-    const char* message,
-    fmt::basic_string_view<Char> str = fmt::basic_string_view<Char>(0, 1)) {
-  fmt::memory_buffer out;
-  fmt::internal::format_windows_error(out, ERROR_INVALID_PARAMETER, message);
-  fmt::system_error error(0, "");
-  try {
-    (Converter)(str);
-  } catch (const fmt::system_error& e) {
-    error = e;
-  }
-  EXPECT_EQ(ERROR_INVALID_PARAMETER, error.error_code());
-  EXPECT_EQ(fmt::to_string(out), error.what());
-}
-
-TEST(UtilTest, UTF16ToUTF8Error) {
-  check_utf_conversion_error<fmt::internal::utf16_to_utf8, wchar_t>(
-      "cannot convert string from UTF-16 to UTF-8");
-}
-
-TEST(UtilTest, UTF8ToUTF16Error) {
-  const char* message = "cannot convert string from UTF-8 to UTF-16";
-  check_utf_conversion_error<fmt::internal::utf8_to_utf16, char>(message);
-  check_utf_conversion_error<fmt::internal::utf8_to_utf16, char>(
-      message, fmt::string_view("foo", INT_MAX + 1u));
-}
-
-TEST(UtilTest, UTF16ToUTF8Convert) {
-  fmt::internal::utf16_to_utf8 u;
-  EXPECT_EQ(ERROR_INVALID_PARAMETER, u.convert(fmt::wstring_view(0, 1)));
-  EXPECT_EQ(ERROR_INVALID_PARAMETER,
-            u.convert(fmt::wstring_view(L"foo", INT_MAX + 1u)));
-}
-#endif  // _WIN32
-
-typedef void (*FormatErrorMessage)(fmt::internal::buffer<char>& out,
-                                   int error_code, string_view message);
-
-template <typename Error>
-void check_throw_error(int error_code, FormatErrorMessage format) {
-  fmt::system_error error(0, "");
-  try {
-    throw Error(error_code, "test {}", "error");
-  } catch (const fmt::system_error& e) {
-    error = e;
-  }
-  fmt::memory_buffer message;
-  format(message, error_code, "test error");
-  EXPECT_EQ(to_string(message), error.what());
-  EXPECT_EQ(error_code, error.error_code());
-}
-
 TEST(UtilTest, FormatSystemError) {
   fmt::memory_buffer message;
   fmt::format_system_error(message, EDOM, "test");
@@ -477,7 +430,7 @@ TEST(UtilTest, FormatSystemError) {
   message = fmt::memory_buffer();
 
   // Check if std::allocator throws on allocating max size_t / 2 chars.
-  size_t max_size = std::numeric_limits<size_t>::max() / 2;
+  size_t max_size = max_value<size_t>() / 2;
   bool throws_on_alloc = false;
   try {
     std::allocator<char> alloc;
@@ -497,7 +450,17 @@ TEST(UtilTest, SystemError) {
   fmt::system_error e(EDOM, "test");
   EXPECT_EQ(fmt::format("test: {}", get_system_error(EDOM)), e.what());
   EXPECT_EQ(EDOM, e.error_code());
-  check_throw_error<fmt::system_error>(EDOM, fmt::format_system_error);
+
+  fmt::system_error error(0, "");
+  try {
+    throw fmt::system_error(EDOM, "test {}", "error");
+  } catch (const fmt::system_error& e) {
+    error = e;
+  }
+  fmt::memory_buffer message;
+  fmt::format_system_error(message, EDOM, "test error");
+  EXPECT_EQ(to_string(message), error.what());
+  EXPECT_EQ(EDOM, error.error_code());
 }
 
 TEST(UtilTest, ReportSystemError) {
@@ -508,70 +471,6 @@ TEST(UtilTest, ReportSystemError) {
                to_string(out));
 }
 
-#ifdef _WIN32
-
-TEST(UtilTest, FormatWindowsError) {
-  LPWSTR message = 0;
-  FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
-                     FORMAT_MESSAGE_IGNORE_INSERTS,
-                 0, ERROR_FILE_EXISTS,
-                 MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-                 reinterpret_cast<LPWSTR>(&message), 0, 0);
-  fmt::internal::utf16_to_utf8 utf8_message(message);
-  LocalFree(message);
-  fmt::memory_buffer actual_message;
-  fmt::internal::format_windows_error(actual_message, ERROR_FILE_EXISTS,
-                                      "test");
-  EXPECT_EQ(fmt::format("test: {}", utf8_message.str()),
-            fmt::to_string(actual_message));
-  actual_message.resize(0);
-  fmt::internal::format_windows_error(
-      actual_message, ERROR_FILE_EXISTS,
-      fmt::string_view(0, std::numeric_limits<size_t>::max()));
-  EXPECT_EQ(fmt::format("error {}", ERROR_FILE_EXISTS),
-            fmt::to_string(actual_message));
-}
-
-TEST(UtilTest, FormatLongWindowsError) {
-  LPWSTR message = 0;
-  // this error code is not available on all Windows platforms and
-  // Windows SDKs, so do not fail the test if the error string cannot
-  // be retrieved.
-  const int provisioning_not_allowed =
-      0x80284013L /*TBS_E_PROVISIONING_NOT_ALLOWED*/;
-  if (FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
-                         FORMAT_MESSAGE_FROM_SYSTEM |
-                         FORMAT_MESSAGE_IGNORE_INSERTS,
-                     0, static_cast<DWORD>(provisioning_not_allowed),
-                     MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
-                     reinterpret_cast<LPWSTR>(&message), 0, 0) == 0) {
-    return;
-  }
-  fmt::internal::utf16_to_utf8 utf8_message(message);
-  LocalFree(message);
-  fmt::memory_buffer actual_message;
-  fmt::internal::format_windows_error(actual_message, provisioning_not_allowed,
-                                      "test");
-  EXPECT_EQ(fmt::format("test: {}", utf8_message.str()),
-            fmt::to_string(actual_message));
-}
-
-TEST(UtilTest, WindowsError) {
-  check_throw_error<fmt::windows_error>(ERROR_FILE_EXISTS,
-                                        fmt::internal::format_windows_error);
-}
-
-TEST(UtilTest, ReportWindowsError) {
-  fmt::memory_buffer out;
-  fmt::internal::format_windows_error(out, ERROR_FILE_EXISTS, "test error");
-  out.push_back('\n');
-  EXPECT_WRITE(stderr,
-               fmt::report_windows_error(ERROR_FILE_EXISTS, "test error"),
-               fmt::to_string(out));
-}
-
-#endif  // _WIN32
-
 TEST(StringViewTest, Ctor) {
   EXPECT_STREQ("abc", string_view("abc").data());
   EXPECT_EQ(3u, string_view("abc").size());
@@ -593,31 +492,31 @@ TEST(WriterTest, WriteInt) {
   CHECK_WRITE(static_cast<short>(12));
   CHECK_WRITE(34u);
   CHECK_WRITE(std::numeric_limits<int>::min());
-  CHECK_WRITE(std::numeric_limits<int>::max());
-  CHECK_WRITE(std::numeric_limits<unsigned>::max());
+  CHECK_WRITE(max_value<int>());
+  CHECK_WRITE(max_value<unsigned>());
 }
 
 TEST(WriterTest, WriteLong) {
   CHECK_WRITE(56l);
   CHECK_WRITE(78ul);
   CHECK_WRITE(std::numeric_limits<long>::min());
-  CHECK_WRITE(std::numeric_limits<long>::max());
-  CHECK_WRITE(std::numeric_limits<unsigned long>::max());
+  CHECK_WRITE(max_value<long>());
+  CHECK_WRITE(max_value<unsigned long>());
 }
 
 TEST(WriterTest, WriteLongLong) {
   CHECK_WRITE(56ll);
   CHECK_WRITE(78ull);
   CHECK_WRITE(std::numeric_limits<long long>::min());
-  CHECK_WRITE(std::numeric_limits<long long>::max());
-  CHECK_WRITE(std::numeric_limits<unsigned long long>::max());
+  CHECK_WRITE(max_value<long long>());
+  CHECK_WRITE(max_value<unsigned long long>());
 }
 
 TEST(WriterTest, WriteDouble) {
   CHECK_WRITE(4.2);
   CHECK_WRITE(-4.2);
   auto min = std::numeric_limits<double>::min();
-  auto max = std::numeric_limits<double>::max();
+  auto max = max_value<double>();
   if (fmt::internal::use_grisu<double>()) {
     EXPECT_EQ("2.2250738585072014e-308", fmt::format("{}", min));
     EXPECT_EQ("1.7976931348623157e+308", fmt::format("{}", max));
@@ -637,7 +536,7 @@ TEST(WriterTest, WriteLongDouble) {
   else
     fmt::print("warning: long double formatting with std::swprintf is broken");
   auto min = std::numeric_limits<long double>::min();
-  auto max = std::numeric_limits<long double>::max();
+  auto max = max_value<long double>();
   if (fmt::internal::use_grisu<long double>()) {
     EXPECT_EQ("2.2250738585072014e-308", fmt::format("{}", min));
     EXPECT_EQ("1.7976931348623157e+308", fmt::format("{}", max));
@@ -673,9 +572,7 @@ TEST(WriterTest, WriteString) {
   CHECK_WRITE_WCHAR("abc");
 }
 
-TEST(WriterTest, WriteWideString) {
-  CHECK_WRITE_WCHAR(L"abc");
-}
+TEST(WriterTest, WriteWideString) { CHECK_WRITE_WCHAR(L"abc"); }
 
 TEST(FormatToTest, FormatWithoutArgs) {
   std::string s;
@@ -697,12 +594,6 @@ TEST(FormatToTest, WideString) {
   EXPECT_STREQ(buf.data(), L"42");
 }
 
-TEST(FormatToTest, FormatToNonbackInsertIteratorWithSignAndNumericAlignment) {
-  char buffer[16] = {};
-  fmt::format_to(fmt::internal::make_checked(buffer, 16), "{: =+}", 42.0);
-  EXPECT_STREQ("+42.0", buffer);
-}
-
 TEST(FormatToTest, FormatToMemoryBuffer) {
   fmt::basic_memory_buffer<char, 100> buffer;
   fmt::format_to(buffer, "{}", "foo");
@@ -856,6 +747,7 @@ TEST(FormatterTest, RightAlign) {
   EXPECT_EQ("  0xface", format("{0:>8}", reinterpret_cast<void*>(0xface)));
 }
 
+#if FMT_NUMERIC_ALIGN
 TEST(FormatterTest, NumericAlign) {
   EXPECT_EQ("  42", format("{0:=4}", 42));
   EXPECT_EQ("+ 42", format("{0:=+4}", 42));
@@ -882,6 +774,13 @@ TEST(FormatterTest, NumericAlign) {
   EXPECT_EQ(" 1.0", fmt::format("{:= }", 1.0));
 }
 
+TEST(FormatToTest, FormatToNonbackInsertIteratorWithSignAndNumericAlignment) {
+  char buffer[16] = {};
+  fmt::format_to(fmt::internal::make_checked(buffer, 16), "{: =+}", 42.0);
+  EXPECT_STREQ("+42.0", buffer);
+}
+#endif
+
 TEST(FormatterTest, CenterAlign) {
   EXPECT_EQ(" 42  ", format("{0:^5}", 42));
   EXPECT_EQ(" 42  ", format("{0:^5o}", 042));
@@ -918,6 +817,9 @@ TEST(FormatterTest, Fill) {
   EXPECT_EQ("**0xface", format("{0:*>8}", reinterpret_cast<void*>(0xface)));
   EXPECT_EQ("foo=", format("{:}=", "foo"));
   EXPECT_EQ(std::string("\0\0\0*", 4), format(string_view("{:\0>4}", 6), '*'));
+  EXPECT_EQ("жж42", format("{0:ж>4}", 42));
+  EXPECT_THROW_MSG(format("{:\x80\x80\x80\x80\x80>}", 0), format_error,
+                   "invalid fill");
 }
 
 TEST(FormatterTest, PlusSign) {
@@ -1001,6 +903,7 @@ TEST(FormatterTest, HashFlag) {
   EXPECT_EQ("0x42", format("{0:#x}", 0x42));
   EXPECT_EQ("0X42", format("{0:#X}", 0x42));
   EXPECT_EQ("-0x42", format("{0:#x}", -0x42));
+  EXPECT_EQ("0", format("{0:#o}", 0));
   EXPECT_EQ("042", format("{0:#o}", 042));
   EXPECT_EQ("-042", format("{0:#o}", -042));
   EXPECT_EQ("42", format("{0:#}", 42u));
@@ -1027,6 +930,10 @@ TEST(FormatterTest, HashFlag) {
 
   EXPECT_EQ("-42.0", format("{0:#}", -42.0));
   EXPECT_EQ("-42.0", format("{0:#}", -42.0l));
+  EXPECT_EQ("4.e+01", format("{:#.0e}", 42.0));
+  EXPECT_EQ("0.", format("{:#.0f}", 0.01));
+  auto s = format("{:#.0f}", 0.5);  // MSVC's printf uses wrong rounding mode.
+  EXPECT_TRUE(s == "0." || s == "1.");
   EXPECT_THROW_MSG(format("{0:#", 'c'), format_error,
                    "missing '}' in format string");
   EXPECT_THROW_MSG(format("{0:#}", 'c'), format_error,
@@ -1082,7 +989,9 @@ TEST(FormatterTest, Width) {
   EXPECT_EQ("    0xcafe", format("{0:10}", reinterpret_cast<void*>(0xcafe)));
   EXPECT_EQ("x          ", format("{0:11}", 'x'));
   EXPECT_EQ("str         ", format("{0:12}", "str"));
+  EXPECT_EQ(fmt::format("{:*^5}", "🤡"), "**🤡**");
 }
+
 template <typename T> inline T const_check(T value) { return value; }
 
 TEST(FormatterTest, RuntimeWidth) {
@@ -1185,12 +1094,39 @@ TEST(FormatterTest, Precision) {
                    "precision not allowed for this argument type");
   EXPECT_THROW_MSG(format("{0:.2f}", 42ull), format_error,
                    "precision not allowed for this argument type");
-  EXPECT_THROW_MSG(format("{0:.2%}", 42), format_error,
-                   "precision not allowed for this argument type");
   EXPECT_THROW_MSG(format("{0:3.0}", 'x'), format_error,
                    "precision not allowed for this argument type");
   EXPECT_EQ("1.2", format("{0:.2}", 1.2345));
   EXPECT_EQ("1.2", format("{0:.2}", 1.2345l));
+  EXPECT_EQ("1.2e+56", format("{:.2}", 1.234e56));
+  EXPECT_EQ("1e+00", format("{:.0e}", 1.0L));
+  EXPECT_EQ("  0.0e+00", format("{:9.1e}", 0.0));
+  EXPECT_EQ(
+      "4.9406564584124654417656879286822137236505980261432476442558568250067550"
+      "727020875186529983636163599237979656469544571773092665671035593979639877"
+      "479601078187812630071319031140452784581716784898210368871863605699873072"
+      "305000638740915356498438731247339727316961514003171538539807412623856559"
+      "117102665855668676818703956031062493194527159149245532930545654440112748"
+      "012970999954193198940908041656332452475714786901472678015935523861155013"
+      "480352649347201937902681071074917033322268447533357208324319361e-324",
+      format("{:.494}", 4.9406564584124654E-324));
+  EXPECT_EQ(
+      "-0X1.41FE3FFE71C9E000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000000000000000000000000"
+      "000000000000000000000000000000000000000000000000000P+127",
+      format("{:.838A}", -2.14001164E+38));
+  EXPECT_EQ("123.", format("{:#.0f}", 123.0));
+  EXPECT_EQ("1.23", format("{:.02f}", 1.234));
+  EXPECT_EQ("0.001", format("{:.1g}", 0.001));
 
   EXPECT_THROW_MSG(format("{0:.2}", reinterpret_cast<void*>(0xcafe)),
                    format_error,
@@ -1198,6 +1134,8 @@ TEST(FormatterTest, Precision) {
   EXPECT_THROW_MSG(format("{0:.2f}", reinterpret_cast<void*>(0xcafe)),
                    format_error,
                    "precision not allowed for this argument type");
+  EXPECT_THROW_MSG(format("{:.{}e}", 42.0, fmt::internal::max_value<int>()),
+                   format_error, "number is too big");
 
   EXPECT_EQ("st", format("{0:.2}", "str"));
 }
@@ -1318,7 +1256,7 @@ TEST(FormatterTest, FormatShort) {
 TEST(FormatterTest, FormatInt) {
   EXPECT_THROW_MSG(format("{0:v", 42), format_error,
                    "missing '}' in format string");
-  check_unknown_types(42, "bBdoxXn", "integer");
+  check_unknown_types(42, "bBdoxXnL", "integer");
 }
 
 TEST(FormatterTest, FormatBin) {
@@ -1330,9 +1268,17 @@ TEST(FormatterTest, FormatBin) {
   EXPECT_EQ("10010001101000101011001111000", format("{0:b}", 0x12345678));
   EXPECT_EQ("10010000101010111100110111101111", format("{0:b}", 0x90ABCDEF));
   EXPECT_EQ("11111111111111111111111111111111",
-            format("{0:b}", std::numeric_limits<uint32_t>::max()));
+            format("{0:b}", max_value<uint32_t>()));
 }
 
+#if FMT_USE_INT128
+constexpr auto int128_max = static_cast<__int128_t>(
+    (static_cast<__uint128_t>(1) << ((__SIZEOF_INT128__ * CHAR_BIT) - 1)) - 1);
+constexpr auto int128_min = -int128_max - 1;
+
+constexpr auto uint128_max = ~static_cast<__uint128_t>(0);
+#endif
+
 TEST(FormatterTest, FormatDec) {
   EXPECT_EQ("0", format("{0}", 0));
   EXPECT_EQ("42", format("{0}", 42));
@@ -1341,6 +1287,23 @@ TEST(FormatterTest, FormatDec) {
   EXPECT_EQ("-42", format("{0}", -42));
   EXPECT_EQ("12345", format("{0}", 12345));
   EXPECT_EQ("67890", format("{0}", 67890));
+#if FMT_USE_INT128
+  EXPECT_EQ("0", format("{0}", static_cast<__int128_t>(0)));
+  EXPECT_EQ("0", format("{0}", static_cast<__uint128_t>(0)));
+  EXPECT_EQ("9223372036854775808",
+            format("{0}", static_cast<__int128_t>(INT64_MAX) + 1));
+  EXPECT_EQ("-9223372036854775809",
+            format("{0}", static_cast<__int128_t>(INT64_MIN) - 1));
+  EXPECT_EQ("18446744073709551616",
+            format("{0}", static_cast<__int128_t>(UINT64_MAX) + 1));
+  EXPECT_EQ("170141183460469231731687303715884105727",
+            format("{0}", int128_max));
+  EXPECT_EQ("-170141183460469231731687303715884105728",
+            format("{0}", int128_min));
+  EXPECT_EQ("340282366920938463463374607431768211455",
+            format("{0}", uint128_max));
+#endif
+
   char buffer[BUFFER_SIZE];
   safe_sprintf(buffer, "%d", INT_MIN);
   EXPECT_EQ(buffer, format("{0}", INT_MIN));
@@ -1365,6 +1328,19 @@ TEST(FormatterTest, FormatHex) {
   EXPECT_EQ("90abcdef", format("{0:x}", 0x90abcdef));
   EXPECT_EQ("12345678", format("{0:X}", 0x12345678));
   EXPECT_EQ("90ABCDEF", format("{0:X}", 0x90ABCDEF));
+#if FMT_USE_INT128
+  EXPECT_EQ("0", format("{0:x}", static_cast<__int128_t>(0)));
+  EXPECT_EQ("0", format("{0:x}", static_cast<__uint128_t>(0)));
+  EXPECT_EQ("8000000000000000",
+            format("{0:x}", static_cast<__int128_t>(INT64_MAX) + 1));
+  EXPECT_EQ("-8000000000000001",
+            format("{0:x}", static_cast<__int128_t>(INT64_MIN) - 1));
+  EXPECT_EQ("10000000000000000",
+            format("{0:x}", static_cast<__int128_t>(UINT64_MAX) + 1));
+  EXPECT_EQ("7fffffffffffffffffffffffffffffff", format("{0:x}", int128_max));
+  EXPECT_EQ("-80000000000000000000000000000000", format("{0:x}", int128_min));
+  EXPECT_EQ("ffffffffffffffffffffffffffffffff", format("{0:x}", uint128_max));
+#endif
 
   char buffer[BUFFER_SIZE];
   safe_sprintf(buffer, "-%x", 0 - static_cast<unsigned>(INT_MIN));
@@ -1387,6 +1363,23 @@ TEST(FormatterTest, FormatOct) {
   EXPECT_EQ("42", format("{0:o}", 042u));
   EXPECT_EQ("-42", format("{0:o}", -042));
   EXPECT_EQ("12345670", format("{0:o}", 012345670));
+#if FMT_USE_INT128
+  EXPECT_EQ("0", format("{0:o}", static_cast<__int128_t>(0)));
+  EXPECT_EQ("0", format("{0:o}", static_cast<__uint128_t>(0)));
+  EXPECT_EQ("1000000000000000000000",
+            format("{0:o}", static_cast<__int128_t>(INT64_MAX) + 1));
+  EXPECT_EQ("-1000000000000000000001",
+            format("{0:o}", static_cast<__int128_t>(INT64_MIN) - 1));
+  EXPECT_EQ("2000000000000000000000",
+            format("{0:o}", static_cast<__int128_t>(UINT64_MAX) + 1));
+  EXPECT_EQ("1777777777777777777777777777777777777777777",
+            format("{0:o}", int128_max));
+  EXPECT_EQ("-2000000000000000000000000000000000000000000",
+            format("{0:o}", int128_min));
+  EXPECT_EQ("3777777777777777777777777777777777777777777",
+            format("{0:o}", uint128_max));
+#endif
+
   char buffer[BUFFER_SIZE];
   safe_sprintf(buffer, "-%o", 0 - static_cast<unsigned>(INT_MIN));
   EXPECT_EQ(buffer, format("{0:o}", INT_MIN));
@@ -1403,11 +1396,8 @@ TEST(FormatterTest, FormatOct) {
 }
 
 TEST(FormatterTest, FormatIntLocale) {
-  EXPECT_EQ("123", format("{:n}", 123));
-  EXPECT_EQ("1,234", format("{:n}", 1234));
-  EXPECT_EQ("1,234,567", format("{:n}", 1234567));
-  EXPECT_EQ("4,294,967,295",
-            format("{:n}", std::numeric_limits<uint32_t>::max()));
+  EXPECT_EQ("1234", format("{:n}", 1234));
+  EXPECT_EQ("1234", format("{:L}", 1234));
 }
 
 struct ConvertibleToLongLong {
@@ -1420,7 +1410,6 @@ TEST(FormatterTest, FormatConvertibleToLongLong) {
 
 TEST(FormatterTest, FormatFloat) {
   EXPECT_EQ("392.500000", format("{0:f}", 392.5f));
-  EXPECT_EQ("12.500000%", format("{0:%}", 0.125f));
 }
 
 TEST(FormatterTest, FormatDouble) {
@@ -1433,8 +1422,6 @@ TEST(FormatterTest, FormatDouble) {
   EXPECT_EQ("392.65", format("{:G}", 392.65));
   EXPECT_EQ("392.650000", format("{:f}", 392.65));
   EXPECT_EQ("392.650000", format("{:F}", 392.65));
-  EXPECT_EQ("12.500000%", format("{:%}", 0.125));
-  EXPECT_EQ("12.34%", format("{:.2%}", 0.1234432));
   char buffer[BUFFER_SIZE];
   safe_sprintf(buffer, "%e", 392.65);
   EXPECT_EQ(buffer, format("{0:e}", 392.65));
@@ -1474,7 +1461,6 @@ TEST(FormatterTest, FormatNaN) {
   EXPECT_EQ("nan    ", format("{:<7}", nan));
   EXPECT_EQ("  nan  ", format("{:^7}", nan));
   EXPECT_EQ("    nan", format("{:>7}", nan));
-  EXPECT_EQ("nan%", format("{:%}", nan));
 }
 
 TEST(FormatterTest, FormatInfinity) {
@@ -1487,7 +1473,6 @@ TEST(FormatterTest, FormatInfinity) {
   EXPECT_EQ("inf    ", format("{:<7}", inf));
   EXPECT_EQ("  inf  ", format("{:^7}", inf));
   EXPECT_EQ("    inf", format("{:>7}", inf));
-  EXPECT_EQ("inf%", format("{:%}", inf));
 }
 
 TEST(FormatterTest, FormatLongDouble) {
@@ -1498,8 +1483,6 @@ TEST(FormatterTest, FormatLongDouble) {
   EXPECT_EQ("392.65", format("{0:G}", 392.65l));
   EXPECT_EQ("392.650000", format("{0:f}", 392.65l));
   EXPECT_EQ("392.650000", format("{0:F}", 392.65l));
-  EXPECT_EQ("12.500000%", format("{:%}", 0.125l));
-  EXPECT_EQ("12.34%", format("{:.2%}", 0.1234432l));
   char buffer[BUFFER_SIZE];
   safe_sprintf(buffer, "%Le", 392.65l);
   EXPECT_EQ(buffer, format("{0:e}", 392.65l));
@@ -1509,7 +1492,7 @@ TEST(FormatterTest, FormatLongDouble) {
 }
 
 TEST(FormatterTest, FormatChar) {
-  const char types[] = "cbBdoxXn";
+  const char types[] = "cbBdoxXnL";
   check_unknown_types('a', types, "char");
   EXPECT_EQ("a", format("{0}", 'a'));
   EXPECT_EQ("z", format("{0:c}", 'z'));
@@ -1603,6 +1586,26 @@ TEST(FormatterTest, FormatStdStringView) {
   EXPECT_EQ("test", format("{}", std::string_view("test")));
   EXPECT_EQ("foo", format("{}", string_viewable()));
 }
+
+struct explicitly_convertible_to_std_string_view {
+  explicit operator std::string_view() const { return "foo"; }
+};
+
+namespace fmt {
+template <>
+struct formatter<explicitly_convertible_to_std_string_view>
+    : formatter<std::string_view> {
+  auto format(const explicitly_convertible_to_std_string_view& v,
+              format_context& ctx) -> decltype(ctx.out()) {
+    return format_to(ctx.out(), "'{}'", std::string_view(v));
+  }
+};
+}  // namespace fmt
+
+TEST(FormatterTest, FormatExplicitlyConvertibleToStdStringView) {
+  EXPECT_EQ("'foo'",
+            fmt::format("{}", explicitly_convertible_to_std_string_view()));
+}
 #endif
 
 FMT_BEGIN_NAMESPACE
@@ -1745,17 +1748,18 @@ TEST(FormatIntTest, FormatInt) {
   EXPECT_EQ("42", fmt::format_int(42ull).str());
   EXPECT_EQ("-42", fmt::format_int(-42ll).str());
   std::ostringstream os;
-  os << std::numeric_limits<int64_t>::max();
-  EXPECT_EQ(os.str(),
-            fmt::format_int(std::numeric_limits<int64_t>::max()).str());
+  os << max_value<int64_t>();
+  EXPECT_EQ(os.str(), fmt::format_int(max_value<int64_t>()).str());
 }
 
 TEST(FormatTest, Print) {
-#if FMT_USE_FILE_DESCRIPTORS
+#if FMT_USE_FCNTL
   EXPECT_WRITE(stdout, fmt::print("Don't {}!", "panic"), "Don't panic!");
   EXPECT_WRITE(stderr, fmt::print(stderr, "Don't {}!", "panic"),
                "Don't panic!");
 #endif
+  // Check that the wide print overload compiles.
+  if (fmt::internal::const_check(false)) fmt::print(L"test");
 }
 
 TEST(FormatTest, Variadic) {
@@ -1771,12 +1775,18 @@ TEST(FormatTest, Dynamic) {
   args.emplace_back(fmt::internal::make_arg<ctx>(1.5f));
 
   std::string result = fmt::vformat(
-      "{} and {} and {}", fmt::basic_format_args<ctx>(
-                              args.data(), static_cast<unsigned>(args.size())));
+      "{} and {} and {}",
+      fmt::basic_format_args<ctx>(args.data(), static_cast<int>(args.size())));
 
   EXPECT_EQ("42 and abc1 and 1.5", result);
 }
 
+TEST(FormatTest, Bytes) {
+  auto s = fmt::format("{:10}", fmt::bytes("ёжик"));
+  EXPECT_EQ("ёжик  ", s);
+  EXPECT_EQ(10, s.size());
+}
+
 TEST(FormatTest, JoinArg) {
   using fmt::join;
   int v1[3] = {1, 2, 3};
@@ -1848,17 +1858,32 @@ TEST(FormatTest, UnpackedArgs) {
 struct string_like {};
 fmt::string_view to_string_view(string_like) { return "foo"; }
 
+constexpr char with_null[3] = {'{', '}', '\0'};
+constexpr char no_null[2] = {'{', '}'};
+
 TEST(FormatTest, CompileTimeString) {
   EXPECT_EQ("42", fmt::format(FMT_STRING("{}"), 42));
   EXPECT_EQ(L"42", fmt::format(FMT_STRING(L"{}"), 42));
   EXPECT_EQ("foo", fmt::format(FMT_STRING("{}"), string_like()));
+  (void)with_null;
+  (void)no_null;
+#if __cplusplus >= 201703L
+  EXPECT_EQ("42", fmt::format(FMT_STRING(with_null), 42));
+  EXPECT_EQ("42", fmt::format(FMT_STRING(no_null), 42));
+#endif
+#if defined(FMT_USE_STRING_VIEW) && __cplusplus >= 201703L
+  EXPECT_EQ("42", fmt::format(FMT_STRING(std::string_view("{}")), 42));
+  EXPECT_EQ(L"42", fmt::format(FMT_STRING(std::wstring_view(L"{}")), 42));
+#endif
 }
 
 TEST(FormatTest, CustomFormatCompileTimeString) {
   EXPECT_EQ("42", fmt::format(FMT_STRING("{}"), Answer()));
   Answer answer;
   EXPECT_EQ("42", fmt::format(FMT_STRING("{}"), answer));
-  const Answer const_answer;
+  char buf[10] = {};
+  fmt::format_to(buf, FMT_STRING("{}"), answer);
+  const Answer const_answer = Answer();
   EXPECT_EQ("42", fmt::format(FMT_STRING("{}"), const_answer));
 }
 
@@ -1894,6 +1919,11 @@ TEST(FormatTest, UdlTemplate) {
   EXPECT_EQ("foo", "foo"_format());
   EXPECT_EQ("        42", "{0:10}"_format(42));
 }
+
+TEST(FormatTest, UdlPassUserDefinedObjectAsLvalue) {
+  Date date(2015, 10, 21);
+  EXPECT_EQ("2015-10-21", "{}"_format(date));
+}
 #endif  // FMT_USE_USER_DEFINED_LITERALS
 
 enum TestEnum { A };
@@ -1901,22 +1931,29 @@ enum TestEnum { A };
 TEST(FormatTest, Enum) { EXPECT_EQ("0", fmt::format("{}", A)); }
 
 TEST(FormatTest, FormatterNotSpecialized) {
-  EXPECT_FALSE((fmt::internal::has_formatter<fmt::formatter<TestEnum>,
-                                             fmt::format_context>::value));
+  static_assert(
+      !fmt::has_formatter<fmt::formatter<TestEnum>, fmt::format_context>::value,
+      "");
 }
 
 #if FMT_HAS_FEATURE(cxx_strong_enums)
-enum TestFixedEnum : short { B };
+enum big_enum : unsigned long long { big_enum_value = 5000000000ULL };
 
-TEST(FormatTest, FixedEnum) { EXPECT_EQ("0", fmt::format("{}", B)); }
+TEST(FormatTest, StrongEnum) {
+  EXPECT_EQ("5000000000", fmt::format("{}", big_enum_value));
+}
 #endif
 
-using buffer_range = fmt::internal::buffer_range<char>;
+using buffer_range = fmt::buffer_range<char>;
 
 class mock_arg_formatter
     : public fmt::internal::arg_formatter_base<buffer_range> {
  private:
+#if FMT_USE_INT128
+  MOCK_METHOD1(call, void(__int128_t value));
+#else
   MOCK_METHOD1(call, void(long long value));
+#endif
 
  public:
   typedef fmt::internal::arg_formatter_base<buffer_range> base;
@@ -1929,14 +1966,14 @@ class mock_arg_formatter
   }
 
   template <typename T>
-  typename std::enable_if<std::is_integral<T>::value, iterator>::type
+  typename std::enable_if<fmt::internal::is_integral<T>::value, iterator>::type
   operator()(T value) {
     call(value);
     return base::operator()(value);
   }
 
   template <typename T>
-  typename std::enable_if<!std::is_integral<T>::value, iterator>::type
+  typename std::enable_if<!fmt::internal::is_integral<T>::value, iterator>::type
   operator()(T value) {
     return base::operator()(value);
   }
@@ -1988,8 +2025,10 @@ TEST(FormatTest, DynamicFormatter) {
                    "cannot switch from manual to automatic argument indexing");
   EXPECT_THROW_MSG(format("{:{0}}", num), format_error,
                    "cannot switch from automatic to manual argument indexing");
+#if FMT_NUMERIC_ALIGN
   EXPECT_THROW_MSG(format("{:=}", str), format_error,
                    "format specifier requires numeric argument");
+#endif
   EXPECT_THROW_MSG(format("{:+}", str), format_error,
                    "format specifier requires numeric argument");
   EXPECT_THROW_MSG(format("{:-}", str), format_error,
@@ -2068,16 +2107,43 @@ TEST(FormatTest, WideFormatToN) {
   EXPECT_EQ(L"BC x", fmt::wstring_view(buffer, 4));
 }
 
+struct test_output_iterator {
+  char* data;
+
+  using iterator_category = std::output_iterator_tag;
+  using value_type = void;
+  using difference_type = void;
+  using pointer = void;
+  using reference = void;
+
+  test_output_iterator& operator++() {
+    ++data;
+    return *this;
+  }
+  test_output_iterator operator++(int) {
+    auto tmp = *this;
+    ++data;
+    return tmp;
+  }
+  char& operator*() { return *data; }
+};
+
+TEST(FormatTest, FormatToNOutputIterator) {
+  char buf[10] = {};
+  fmt::format_to_n(test_output_iterator{buf}, 10, "{}", 42);
+  EXPECT_STREQ(buf, "42");
+}
+
 #if FMT_USE_CONSTEXPR
 struct test_arg_id_handler {
   enum result { NONE, EMPTY, INDEX, NAME, ERROR };
   result res = NONE;
-  unsigned index = 0;
+  int index = 0;
   string_view name;
 
   FMT_CONSTEXPR void operator()() { res = EMPTY; }
 
-  FMT_CONSTEXPR void operator()(unsigned i) {
+  FMT_CONSTEXPR void operator()(int i) {
     res = INDEX;
     index = i;
   }
@@ -2113,9 +2179,9 @@ struct test_format_specs_handler {
 
   fmt::align_t align = fmt::align::none;
   char fill = 0;
-  unsigned width = 0;
+  int width = 0;
   fmt::internal::arg_ref<char> width_ref;
-  unsigned precision = 0;
+  int precision = 0;
   fmt::internal::arg_ref<char> precision_ref;
   char type = 0;
 
@@ -2134,23 +2200,21 @@ struct test_format_specs_handler {
         type(other.type) {}
 
   FMT_CONSTEXPR void on_align(fmt::align_t a) { align = a; }
-  FMT_CONSTEXPR void on_fill(char f) { fill = f; }
+  FMT_CONSTEXPR void on_fill(fmt::string_view f) { fill = f[0]; }
   FMT_CONSTEXPR void on_plus() { res = PLUS; }
   FMT_CONSTEXPR void on_minus() { res = MINUS; }
   FMT_CONSTEXPR void on_space() { res = SPACE; }
   FMT_CONSTEXPR void on_hash() { res = HASH; }
   FMT_CONSTEXPR void on_zero() { res = ZERO; }
 
-  FMT_CONSTEXPR void on_width(unsigned w) { width = w; }
+  FMT_CONSTEXPR void on_width(int w) { width = w; }
   FMT_CONSTEXPR void on_dynamic_width(fmt::internal::auto_id) {}
-  FMT_CONSTEXPR void on_dynamic_width(unsigned index) { width_ref = index; }
+  FMT_CONSTEXPR void on_dynamic_width(int index) { width_ref = index; }
   FMT_CONSTEXPR void on_dynamic_width(string_view) {}
 
-  FMT_CONSTEXPR void on_precision(unsigned p) { precision = p; }
+  FMT_CONSTEXPR void on_precision(int p) { precision = p; }
   FMT_CONSTEXPR void on_dynamic_precision(fmt::internal::auto_id) {}
-  FMT_CONSTEXPR void on_dynamic_precision(unsigned index) {
-    precision_ref = index;
-  }
+  FMT_CONSTEXPR void on_dynamic_precision(int index) { precision_ref = index; }
   FMT_CONSTEXPR void on_dynamic_precision(string_view) {}
 
   FMT_CONSTEXPR void end_precision() {}
@@ -2185,7 +2249,7 @@ TEST(FormatTest, ConstexprParseFormatSpecs) {
 struct test_parse_context {
   typedef char char_type;
 
-  FMT_CONSTEXPR unsigned next_arg_id() { return 11; }
+  FMT_CONSTEXPR int next_arg_id() { return 11; }
   template <typename Id> FMT_CONSTEXPR void check_arg_id(Id) {}
 
   FMT_CONSTEXPR const char* begin() { return nullptr; }
@@ -2214,9 +2278,9 @@ struct test_context {
 
 template <size_t N>
 FMT_CONSTEXPR fmt::format_specs parse_specs(const char (&s)[N]) {
-  fmt::format_specs specs;
-  test_parse_context parse_ctx;
-  test_context ctx{};
+  auto specs = fmt::format_specs();
+  auto parse_ctx = test_parse_context();
+  auto ctx = test_context();
   fmt::internal::specs_handler<test_parse_context, test_context> h(
       specs, parse_ctx, ctx);
   parse_format_specs(s, s + N, h);
@@ -2270,7 +2334,7 @@ TEST(FormatTest, ConstexprDynamicSpecsHandler) {
 template <size_t N>
 FMT_CONSTEXPR test_format_specs_handler check_specs(const char (&s)[N]) {
   fmt::internal::specs_checker<test_format_specs_handler> checker(
-      test_format_specs_handler(), fmt::internal::double_type);
+      test_format_specs_handler(), fmt::internal::type::double_type);
   parse_format_specs(s, s + N, checker);
   return checker;
 }
@@ -2372,13 +2436,15 @@ TEST(FormatTest, FormatStringErrors) {
   EXPECT_ERROR("{0:s", "unknown format specifier", Date);
 #  if FMT_MSC_VER >= 1916
   // This causes an internal compiler error in MSVC2017.
-  EXPECT_ERROR("{0:=5", "unknown format specifier", int);
   EXPECT_ERROR("{:{<}", "invalid fill character '{'", int);
   EXPECT_ERROR("{:10000000000}", "number is too big", int);
   EXPECT_ERROR("{:.10000000000}", "number is too big", int);
   EXPECT_ERROR_NOARGS("{:x}", "argument index out of range");
+#    if FMT_NUMERIC_ALIGN
+  EXPECT_ERROR("{0:=5", "unknown format specifier", int);
   EXPECT_ERROR("{:=}", "format specifier requires numeric argument",
                const char*);
+#    endif
   EXPECT_ERROR("{:+}", "format specifier requires numeric argument",
                const char*);
   EXPECT_ERROR("{:-}", "format specifier requires numeric argument",
@@ -2457,48 +2523,8 @@ TEST(FormatTest, FmtStringInTemplate) {
 
 #endif  // FMT_USE_CONSTEXPR
 
-// C++20 feature test, since r346892 Clang considers char8_t a fundamental
-// type in this mode. If this is the case __cpp_char8_t will be defined.
-#ifndef __cpp_char8_t
-// Locally provide type char8_t defined in format.h
-using fmt::char8_t;
-#endif
-
-TEST(FormatTest, ConstructU8StringViewFromCString) {
-  fmt::u8string_view s("ab");
-  EXPECT_EQ(s.size(), 2u);
-  const char8_t* data = s.data();
-  EXPECT_EQ(data[0], 'a');
-  EXPECT_EQ(data[1], 'b');
-}
-
-TEST(FormatTest, ConstructU8StringViewFromDataAndSize) {
-  fmt::u8string_view s("foobar", 3);
-  EXPECT_EQ(s.size(), 3u);
-  const char8_t* data = s.data();
-  EXPECT_EQ(data[0], 'f');
-  EXPECT_EQ(data[1], 'o');
-  EXPECT_EQ(data[2], 'o');
-}
-
-#if FMT_USE_USER_DEFINED_LITERALS
-TEST(FormatTest, U8StringViewLiteral) {
-  using namespace fmt::literals;
-  fmt::u8string_view s = "ab"_u;
-  EXPECT_EQ(s.size(), 2u);
-  const char8_t* data = s.data();
-  EXPECT_EQ(data[0], 'a');
-  EXPECT_EQ(data[1], 'b');
-  EXPECT_EQ(format("{:*^5}"_u, "🤡"_u), "**🤡**"_u);
-}
-#endif
-
-TEST(FormatTest, FormatU8String) {
-  EXPECT_EQ(format(fmt::u8string_view("{}"), 42), fmt::u8string_view("42"));
-}
-
 TEST(FormatTest, EmphasisNonHeaderOnly) {
-  // ensure this compiles even if FMT_HEADER_ONLY is not defined.
+  // Ensure this compiles even if FMT_HEADER_ONLY is not defined.
   EXPECT_EQ(fmt::format(fmt::emphasis::bold, "bold error"),
             "\x1b[1mbold error\x1b[0m");
 }
@@ -2534,3 +2560,21 @@ TEST(FormatTest, FormatCustomChar) {
   EXPECT_EQ(result.size(), 1);
   EXPECT_EQ(result[0], mychar('x'));
 }
+
+// Convert a char8_t string to std::string. Otherwise GTest will insist on
+// inserting `char8_t` NTBS into a `char` stream which is disabled by P1423.
+template <typename S> std::string from_u8str(const S& str) {
+  return std::string(str.begin(), str.end());
+}
+
+TEST(FormatTest, FormatUTF8Precision) {
+  using str_type = std::basic_string<fmt::internal::char8_type>;
+  str_type format(
+      reinterpret_cast<const fmt::internal::char8_type*>(u8"{:.4}"));
+  str_type str(reinterpret_cast<const fmt::internal::char8_type*>(
+      u8"caf\u00e9s"));  // cafés
+  auto result = fmt::format(format, str);
+  EXPECT_EQ(fmt::internal::count_code_points(result), 4);
+  EXPECT_EQ(result.size(), 5);
+  EXPECT_EQ(from_u8str(result), from_u8str(str.substr(0, 5)));
+}

test/grisu-test.cc

@@ -48,10 +48,28 @@ TEST(GrisuTest, Prettify) {
   EXPECT_EQ("1e-05", fmt::format("{}", 1e-5));
   EXPECT_EQ("9.999e-05", fmt::format("{}", 9.999e-5));
   EXPECT_EQ("10000000000.0", fmt::format("{}", 1e10));
-  EXPECT_EQ("1e+11", fmt::format("{}", 1e11));
+  EXPECT_EQ("100000000000.0", fmt::format("{}", 1e11));
   EXPECT_EQ("12340000000.0", fmt::format("{}", 1234e7));
   EXPECT_EQ("12.34", fmt::format("{}", 1234e-2));
   EXPECT_EQ("0.001234", fmt::format("{}", 1234e-6));
+  EXPECT_EQ("0.1", fmt::format("{}", 0.1f));
+  EXPECT_EQ("0.10000000149011612", fmt::format("{}", double(0.1f)));
 }
 
 TEST(GrisuTest, ZeroPrecision) { EXPECT_EQ("1", fmt::format("{:.0}", 1.0)); }
+
+TEST(GrisuTest, Fallback) {
+  EXPECT_EQ("1e+23", fmt::format("{}", 1e23));
+  EXPECT_EQ("9e-265", fmt::format("{}", 9e-265));
+  EXPECT_EQ("5.423717798060526e+125",
+            fmt::format("{}", 5.423717798060526e+125));
+  EXPECT_EQ("1.372371880954233e-288",
+            fmt::format("{}", 1.372371880954233e-288));
+  EXPECT_EQ("55388492.622190244", fmt::format("{}", 55388492.622190244));
+  EXPECT_EQ("2.2506787569811123e-253",
+            fmt::format("{}", 2.2506787569811123e-253));
+  EXPECT_EQ("1103618912042992.8", fmt::format("{}", 1103618912042992.8));
+  // pow(2, -25) - assymetric boundaries:
+  EXPECT_EQ("2.9802322387695312e-08",
+            fmt::format("{}", 2.9802322387695312e-08));
+}

test/gtest-extra-test.cc

@@ -74,14 +74,6 @@ TEST_F(SingleEvaluationTest, FailedEXPECT_SYSTEM_ERROR) {
   EXPECT_EQ(s_ + 1, p_);
 }
 
-// Tests that when EXPECT_WRITE fails, it evaluates its message argument
-// exactly once.
-TEST_F(SingleEvaluationTest, FailedEXPECT_WRITE) {
-  EXPECT_NONFATAL_FAILURE(EXPECT_WRITE(stdout, std::printf("test"), p_++),
-                          "01234");
-  EXPECT_EQ(s_ + 1, p_);
-}
-
 // Tests that assertion arguments are evaluated exactly once.
 TEST_F(SingleEvaluationTest, ExceptionTests) {
   // successful EXPECT_THROW_MSG
@@ -163,6 +155,15 @@ TEST_F(SingleEvaluationTest, SystemErrorTests) {
   EXPECT_EQ(4, b_);
 }
 
+#if FMT_USE_FCNTL
+// Tests that when EXPECT_WRITE fails, it evaluates its message argument
+// exactly once.
+TEST_F(SingleEvaluationTest, FailedEXPECT_WRITE) {
+  EXPECT_NONFATAL_FAILURE(EXPECT_WRITE(stdout, std::printf("test"), p_++),
+                          "01234");
+  EXPECT_EQ(s_ + 1, p_);
+}
+
 // Tests that assertion arguments are evaluated exactly once.
 TEST_F(SingleEvaluationTest, WriteTests) {
   // successful EXPECT_WRITE
@@ -187,6 +188,24 @@ TEST_F(SingleEvaluationTest, WriteTests) {
   EXPECT_EQ(2, b_);
 }
 
+// Tests EXPECT_WRITE.
+TEST(ExpectTest, EXPECT_WRITE) {
+  EXPECT_WRITE(stdout, do_nothing(), "");
+  EXPECT_WRITE(stdout, std::printf("test"), "test");
+  EXPECT_WRITE(stderr, std::fprintf(stderr, "test"), "test");
+  EXPECT_NONFATAL_FAILURE(EXPECT_WRITE(stdout, std::printf("that"), "this"),
+                          "Expected: this\n"
+                          "  Actual: that");
+}
+
+TEST(StreamingAssertionsTest, EXPECT_WRITE) {
+  EXPECT_WRITE(stdout, std::printf("test"), "test") << "unexpected failure";
+  EXPECT_NONFATAL_FAILURE(EXPECT_WRITE(stdout, std::printf("test"), "other")
+                              << "expected failure",
+                          "expected failure");
+}
+#endif  // FMT_USE_FCNTL
+
 // Tests that the compiler will not complain about unreachable code in the
 // EXPECT_THROW_MSG macro.
 TEST(ExpectThrowTest, DoesNotGenerateUnreachableCodeWarning) {
@@ -280,16 +299,6 @@ TEST(ExpectTest, EXPECT_SYSTEM_ERROR) {
           format_system_error(EDOM, "test")));
 }
 
-// Tests EXPECT_WRITE.
-TEST(ExpectTest, EXPECT_WRITE) {
-  EXPECT_WRITE(stdout, do_nothing(), "");
-  EXPECT_WRITE(stdout, std::printf("test"), "test");
-  EXPECT_WRITE(stderr, std::fprintf(stderr, "test"), "test");
-  EXPECT_NONFATAL_FAILURE(EXPECT_WRITE(stdout, std::printf("that"), "this"),
-                          "Expected: this\n"
-                          "  Actual: that");
-}
-
 TEST(StreamingAssertionsTest, EXPECT_THROW_MSG) {
   EXPECT_THROW_MSG(throw_exception(), std::exception, "test")
       << "unexpected failure";
@@ -308,20 +317,13 @@ TEST(StreamingAssertionsTest, EXPECT_SYSTEM_ERROR) {
       "expected failure");
 }
 
-TEST(StreamingAssertionsTest, EXPECT_WRITE) {
-  EXPECT_WRITE(stdout, std::printf("test"), "test") << "unexpected failure";
-  EXPECT_NONFATAL_FAILURE(EXPECT_WRITE(stdout, std::printf("test"), "other")
-                              << "expected failure",
-                          "expected failure");
-}
-
 TEST(UtilTest, FormatSystemError) {
   fmt::memory_buffer out;
   fmt::format_system_error(out, EDOM, "test message");
   EXPECT_EQ(to_string(out), format_system_error(EDOM, "test message"));
 }
 
-#if FMT_USE_FILE_DESCRIPTORS
+#if FMT_USE_FCNTL
 
 using fmt::buffered_file;
 using fmt::error_code;

test/gtest-extra.cc

@@ -7,7 +7,7 @@
 
 #include "gtest-extra.h"
 
-#if FMT_USE_FILE_DESCRIPTORS
+#if FMT_USE_FCNTL
 
 using fmt::file;
 
@@ -78,7 +78,7 @@ std::string read(file& f, std::size_t count) {
   return buffer;
 }
 
-#endif  // FMT_USE_FILE_DESCRIPTORS
+#endif  // FMT_USE_FCNTL
 
 std::string format_system_error(int error_code, fmt::string_view message) {
   fmt::memory_buffer out;

test/gtest-extra.h

@@ -10,16 +10,7 @@
 
 #include <string>
 #include "gmock.h"
-
-#include "fmt/core.h"
-
-#ifndef FMT_USE_FILE_DESCRIPTORS
-#  define FMT_USE_FILE_DESCRIPTORS 0
-#endif
-
-#if FMT_USE_FILE_DESCRIPTORS
-#  include "fmt/posix.h"
-#endif
+#include "fmt/os.h"
 
 #define FMT_TEST_THROW_(statement, expected_exception, expected_message, fail) \
   GTEST_AMBIGUOUS_ELSE_BLOCKER_                                                \
@@ -65,7 +56,7 @@ std::string format_system_error(int error_code, fmt::string_view message);
   EXPECT_THROW_MSG(statement, fmt::system_error,            \
                    format_system_error(error_code, message))
 
-#if FMT_USE_FILE_DESCRIPTORS
+#if FMT_USE_FCNTL
 
 // Captures file output by redirecting it to a pipe.
 // The output it can handle is limited by the pipe capacity.
@@ -151,7 +142,9 @@ std::string read(fmt::file& f, std::size_t count);
 #  define EXPECT_READ(file, expected_content) \
     EXPECT_EQ(expected_content, read(file, std::strlen(expected_content)))
 
-#endif  // FMT_USE_FILE_DESCRIPTORS
+#else
+#  define EXPECT_WRITE(file, statement, expected_output) SUCCEED()
+#endif  // FMT_USE_FCNTL
 
 template <typename Mock> struct ScopedMock : testing::StrictMock<Mock> {
   ScopedMock() { Mock::instance = this; }

test/locale-test.cc

@@ -8,45 +8,82 @@
 #include "fmt/locale.h"
 #include "gmock.h"
 
+using fmt::internal::max_value;
+
 #ifndef FMT_STATIC_THOUSANDS_SEPARATOR
 template <typename Char> struct numpunct : std::numpunct<Char> {
  protected:
   Char do_decimal_point() const FMT_OVERRIDE { return '?'; }
+  std::string do_grouping() const FMT_OVERRIDE { return "\03"; }
   Char do_thousands_sep() const FMT_OVERRIDE { return '~'; }
 };
 
+template <typename Char> struct no_grouping : std::numpunct<Char> {
+ protected:
+  Char do_decimal_point() const FMT_OVERRIDE { return '.'; }
+  std::string do_grouping() const FMT_OVERRIDE { return ""; }
+  Char do_thousands_sep() const FMT_OVERRIDE { return ','; }
+};
+
+template <typename Char> struct special_grouping : std::numpunct<Char> {
+ protected:
+  Char do_decimal_point() const FMT_OVERRIDE { return '.'; }
+  std::string do_grouping() const FMT_OVERRIDE { return "\03\02"; }
+  Char do_thousands_sep() const FMT_OVERRIDE { return ','; }
+};
+
+template <typename Char> struct small_grouping : std::numpunct<Char> {
+ protected:
+  Char do_decimal_point() const FMT_OVERRIDE { return '.'; }
+  std::string do_grouping() const FMT_OVERRIDE { return "\01"; }
+  Char do_thousands_sep() const FMT_OVERRIDE { return ','; }
+};
+
 TEST(LocaleTest, DoubleDecimalPoint) {
   std::locale loc(std::locale(), new numpunct<char>());
   EXPECT_EQ("1?23", fmt::format(loc, "{:n}", 1.23));
-  // Test with Grisu disabled.
-  fmt::memory_buffer buf;
-  fmt::internal::writer w(buf, fmt::internal::locale_ref(loc));
-  auto specs = fmt::format_specs();
-  specs.type = 'n';
-  w.write_double<double, false>(1.23, specs);
-  EXPECT_EQ(fmt::to_string(buf), "1?23");
 }
 
 TEST(LocaleTest, Format) {
   std::locale loc(std::locale(), new numpunct<char>());
-  EXPECT_EQ("1,234,567", fmt::format(std::locale(), "{:n}", 1234567));
+  EXPECT_EQ("1234567", fmt::format(std::locale(), "{:n}", 1234567));
   EXPECT_EQ("1~234~567", fmt::format(loc, "{:n}", 1234567));
   fmt::format_arg_store<fmt::format_context, int> as{1234567};
   EXPECT_EQ("1~234~567", fmt::vformat(loc, "{:n}", fmt::format_args(as)));
   std::string s;
   fmt::format_to(std::back_inserter(s), loc, "{:n}", 1234567);
   EXPECT_EQ("1~234~567", s);
+
+  std::locale no_grouping_loc(std::locale(), new no_grouping<char>());
+  EXPECT_EQ("1234567", fmt::format(no_grouping_loc, "{:n}", 1234567));
+
+  std::locale special_grouping_loc(std::locale(), new special_grouping<char>());
+  EXPECT_EQ("1,23,45,678", fmt::format(special_grouping_loc, "{:n}", 12345678));
+
+  std::locale small_grouping_loc(std::locale(), new small_grouping<char>());
+  EXPECT_EQ("4,2,9,4,9,6,7,2,9,5",
+            fmt::format(small_grouping_loc, "{:n}", max_value<uint32_t>()));
 }
 
 TEST(LocaleTest, WFormat) {
   std::locale loc(std::locale(), new numpunct<wchar_t>());
-  EXPECT_EQ(L"1,234,567", fmt::format(std::locale(), L"{:n}", 1234567));
+  EXPECT_EQ(L"1234567", fmt::format(std::locale(), L"{:n}", 1234567));
   EXPECT_EQ(L"1~234~567", fmt::format(loc, L"{:n}", 1234567));
   fmt::format_arg_store<fmt::wformat_context, int> as{1234567};
   EXPECT_EQ(L"1~234~567", fmt::vformat(loc, L"{:n}", fmt::wformat_args(as)));
-  auto sep =
-      std::use_facet<std::numpunct<wchar_t>>(std::locale("C")).thousands_sep();
-  auto result = sep == ',' ? L"1,234,567" : L"1234567";
-  EXPECT_EQ(result, fmt::format(std::locale("C"), L"{:n}", 1234567));
+  EXPECT_EQ(L"1234567", fmt::format(std::locale("C"), L"{:n}", 1234567));
+
+  std::locale no_grouping_loc(std::locale(), new no_grouping<wchar_t>());
+  EXPECT_EQ(L"1234567", fmt::format(no_grouping_loc, L"{:n}", 1234567));
+
+  std::locale special_grouping_loc(std::locale(),
+                                   new special_grouping<wchar_t>());
+  EXPECT_EQ(L"1,23,45,678",
+            fmt::format(special_grouping_loc, L"{:n}", 12345678));
+
+  std::locale small_grouping_loc(std::locale(), new small_grouping<wchar_t>());
+  EXPECT_EQ(L"4,2,9,4,9,6,7,2,9,5",
+            fmt::format(small_grouping_loc, L"{:n}", max_value<uint32_t>()));
 }
+
 #endif  // FMT_STATIC_THOUSANDS_SEPARATOR

test/os-test.cc

@@ -1,4 +1,4 @@
-// Formatting library for C++ - tests of the C++ interface to POSIX functions
+// Formatting library for C++ - tests of the OS-specific functionality
 //
 // Copyright (c) 2012 - present, Victor Zverovich
 // All rights reserved.
@@ -9,7 +9,7 @@
 #include <cstring>
 #include <memory>
 
-#include "fmt/posix.h"
+#include "fmt/os.h"
 #include "gtest-extra.h"
 #include "util.h"
 
@@ -19,6 +19,125 @@
 
 using fmt::buffered_file;
 using fmt::error_code;
+
+#ifdef _WIN32
+
+#  include <windows.h>
+
+TEST(UtilTest, UTF16ToUTF8) {
+  std::string s = "ёжик";
+  fmt::internal::utf16_to_utf8 u(L"\x0451\x0436\x0438\x043A");
+  EXPECT_EQ(s, u.str());
+  EXPECT_EQ(s.size(), u.size());
+}
+
+TEST(UtilTest, UTF16ToUTF8EmptyString) {
+  std::string s = "";
+  fmt::internal::utf16_to_utf8 u(L"");
+  EXPECT_EQ(s, u.str());
+  EXPECT_EQ(s.size(), u.size());
+}
+
+template <typename Converter, typename Char>
+void check_utf_conversion_error(
+    const char* message,
+    fmt::basic_string_view<Char> str = fmt::basic_string_view<Char>(0, 1)) {
+  fmt::memory_buffer out;
+  fmt::internal::format_windows_error(out, ERROR_INVALID_PARAMETER, message);
+  fmt::system_error error(0, "");
+  try {
+    (Converter)(str);
+  } catch (const fmt::system_error& e) {
+    error = e;
+  }
+  EXPECT_EQ(ERROR_INVALID_PARAMETER, error.error_code());
+  EXPECT_EQ(fmt::to_string(out), error.what());
+}
+
+TEST(UtilTest, UTF16ToUTF8Error) {
+  check_utf_conversion_error<fmt::internal::utf16_to_utf8, wchar_t>(
+      "cannot convert string from UTF-16 to UTF-8");
+}
+
+TEST(UtilTest, UTF16ToUTF8Convert) {
+  fmt::internal::utf16_to_utf8 u;
+  EXPECT_EQ(ERROR_INVALID_PARAMETER, u.convert(fmt::wstring_view(0, 1)));
+  EXPECT_EQ(ERROR_INVALID_PARAMETER,
+            u.convert(fmt::wstring_view(L"foo", INT_MAX + 1u)));
+}
+
+TEST(UtilTest, FormatWindowsError) {
+  LPWSTR message = 0;
+  FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |
+                     FORMAT_MESSAGE_IGNORE_INSERTS,
+                 0, ERROR_FILE_EXISTS,
+                 MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                 reinterpret_cast<LPWSTR>(&message), 0, 0);
+  fmt::internal::utf16_to_utf8 utf8_message(message);
+  LocalFree(message);
+  fmt::memory_buffer actual_message;
+  fmt::internal::format_windows_error(actual_message, ERROR_FILE_EXISTS,
+                                      "test");
+  EXPECT_EQ(fmt::format("test: {}", utf8_message.str()),
+            fmt::to_string(actual_message));
+  actual_message.resize(0);
+  auto max_size = fmt::internal::max_value<size_t>();
+  fmt::internal::format_windows_error(actual_message, ERROR_FILE_EXISTS,
+                                      fmt::string_view(0, max_size));
+  EXPECT_EQ(fmt::format("error {}", ERROR_FILE_EXISTS),
+            fmt::to_string(actual_message));
+}
+
+TEST(UtilTest, FormatLongWindowsError) {
+  LPWSTR message = 0;
+  // this error code is not available on all Windows platforms and
+  // Windows SDKs, so do not fail the test if the error string cannot
+  // be retrieved.
+  const int provisioning_not_allowed =
+      0x80284013L /*TBS_E_PROVISIONING_NOT_ALLOWED*/;
+  if (FormatMessageW(FORMAT_MESSAGE_ALLOCATE_BUFFER |
+                         FORMAT_MESSAGE_FROM_SYSTEM |
+                         FORMAT_MESSAGE_IGNORE_INSERTS,
+                     0, static_cast<DWORD>(provisioning_not_allowed),
+                     MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT),
+                     reinterpret_cast<LPWSTR>(&message), 0, 0) == 0) {
+    return;
+  }
+  fmt::internal::utf16_to_utf8 utf8_message(message);
+  LocalFree(message);
+  fmt::memory_buffer actual_message;
+  fmt::internal::format_windows_error(actual_message, provisioning_not_allowed,
+                                      "test");
+  EXPECT_EQ(fmt::format("test: {}", utf8_message.str()),
+            fmt::to_string(actual_message));
+}
+
+TEST(UtilTest, WindowsError) {
+  fmt::system_error error(0, "");
+  try {
+    throw fmt::windows_error(ERROR_FILE_EXISTS, "test {}", "error");
+  } catch (const fmt::system_error& e) {
+    error = e;
+  }
+  fmt::memory_buffer message;
+  fmt::internal::format_windows_error(message, ERROR_FILE_EXISTS, "test error");
+  EXPECT_EQ(to_string(message), error.what());
+  EXPECT_EQ(ERROR_FILE_EXISTS, error.error_code());
+}
+
+TEST(UtilTest, ReportWindowsError) {
+  fmt::memory_buffer out;
+  fmt::internal::format_windows_error(out, ERROR_FILE_EXISTS, "test error");
+  out.push_back('\n');
+  EXPECT_WRITE(stderr,
+               fmt::report_windows_error(ERROR_FILE_EXISTS, "test error"),
+               fmt::to_string(out));
+}
+
+#endif  // _WIN32
+
+#if FMT_USE_FCNTL
+
 using fmt::file;
 
 // Checks if the file is open by reading one character from it.
@@ -148,7 +267,7 @@ TEST(BufferedFileTest, CloseError) {
 
 TEST(BufferedFileTest, Fileno) {
   buffered_file f;
-#ifndef __COVERITY__
+#  ifndef __COVERITY__
   // fileno on a null FILE pointer either crashes or returns an error.
   // Disable Coverity because this is intentional.
   EXPECT_DEATH_IF_SUPPORTED(
@@ -160,7 +279,7 @@ TEST(BufferedFileTest, Fileno) {
         }
       },
       "");
-#endif
+#  endif
   f = open_buffered_file();
   EXPECT_TRUE(f.fileno() != -1);
   file copy = file::dup(f.fileno());
@@ -312,13 +431,13 @@ TEST(FileTest, Dup) {
   EXPECT_EQ(FILE_CONTENT, read(copy, std::strlen(FILE_CONTENT)));
 }
 
-#ifndef __COVERITY__
+#  ifndef __COVERITY__
 TEST(FileTest, DupError) {
   int value = -1;
   EXPECT_SYSTEM_ERROR_NOASSERT(file::dup(value), EBADF,
                                "cannot duplicate file descriptor -1");
 }
-#endif
+#  endif
 
 TEST(FileTest, Dup2) {
   file f = open_file();
@@ -368,17 +487,12 @@ TEST(FileTest, Fdopen) {
   EXPECT_EQ(read_fd, FMT_POSIX(fileno(read_end.fdopen("r").get())));
 }
 
-TEST(FileTest, FdopenError) {
-  file f;
-  EXPECT_SYSTEM_ERROR_NOASSERT(f.fdopen("r"), EBADF,
-                               "cannot associate stream with file descriptor");
-}
-
-#ifdef FMT_LOCALE
+#  ifdef FMT_LOCALE
 TEST(LocaleTest, Strtod) {
-  fmt::Locale locale;
+  fmt::locale loc;
   const char *start = "4.2", *ptr = start;
-  EXPECT_EQ(4.2, locale.strtod(ptr));
+  EXPECT_EQ(4.2, loc.strtod(ptr));
   EXPECT_EQ(start + 3, ptr);
 }
-#endif
+#  endif
+#endif  // FMT_USE_FCNTL

test/ostream-test.cc

@@ -64,7 +64,7 @@ TEST(OStreamTest, Enum) {
   EXPECT_EQ(L"0", fmt::format(L"{}", unstreamable_enum()));
 }
 
-using range = fmt::internal::buffer_range<char>;
+using range = fmt::buffer_range<char>;
 
 struct test_arg_formatter : fmt::arg_formatter<range> {
   fmt::format_parse_context parse_ctx;
@@ -95,8 +95,10 @@ TEST(OStreamTest, Format) {
 TEST(OStreamTest, FormatSpecs) {
   EXPECT_EQ("def  ", format("{0:<5}", TestString("def")));
   EXPECT_EQ("  def", format("{0:>5}", TestString("def")));
+#if FMT_NUMERIC_ALIGN
   EXPECT_THROW_MSG(format("{0:=5}", TestString("def")), format_error,
                    "format specifier requires numeric argument");
+#endif
   EXPECT_EQ(" def ", format("{0:^5}", TestString("def")));
   EXPECT_EQ("def**", format("{0:*<5}", TestString("def")));
   EXPECT_THROW_MSG(format("{0:+}", TestString()), format_error,
@@ -143,8 +145,8 @@ TEST(OStreamTest, WriteToOStream) {
 }
 
 TEST(OStreamTest, WriteToOStreamMaxSize) {
-  std::size_t max_size = std::numeric_limits<std::size_t>::max();
-  std::streamsize max_streamsize = std::numeric_limits<std::streamsize>::max();
+  std::size_t max_size = fmt::internal::max_value<std::size_t>();
+  std::streamsize max_streamsize = fmt::internal::max_value<std::streamsize>();
   if (max_size <= fmt::internal::to_unsigned(max_streamsize)) return;
 
   struct test_buffer : fmt::internal::buffer<char> {
@@ -185,8 +187,8 @@ TEST(OStreamTest, Join) {
 
 #if FMT_USE_CONSTEXPR
 TEST(OStreamTest, ConstexprString) {
-  EXPECT_EQ("42", format(fmt("{}"), std::string("42")));
-  EXPECT_EQ("a string", format(fmt("{0}"), TestString("a string")));
+  EXPECT_EQ("42", format(FMT_STRING("{}"), std::string("42")));
+  EXPECT_EQ("a string", format(FMT_STRING("{0}"), TestString("a string")));
 }
 #endif
 
@@ -240,3 +242,51 @@ TEST(FormatTest, UDL) {
   EXPECT_EQ("{}"_format("test"), "test");
 }
 #endif
+
+template <typename T> struct convertible {
+  T value;
+  explicit convertible(const T& val) : value(val) {}
+  operator T() const { return value; }
+};
+
+TEST(OStreamTest, DisableBuiltinOStreamOperators) {
+  EXPECT_EQ("42", fmt::format("{:d}", convertible<unsigned short>(42)));
+  EXPECT_EQ(L"42", fmt::format(L"{:d}", convertible<unsigned short>(42)));
+  EXPECT_EQ("foo", fmt::format("{}", convertible<const char*>("foo")));
+}
+
+struct explicitly_convertible_to_string_like {
+  template <typename String,
+            typename = typename std::enable_if<std::is_constructible<
+                String, const char*, std::size_t>::value>::type>
+  explicit operator String() const {
+    return String("foo", 3u);
+  }
+};
+
+std::ostream& operator<<(std::ostream& os,
+                         explicitly_convertible_to_string_like) {
+  return os << "bar";
+}
+
+TEST(FormatterTest, FormatExplicitlyConvertibleToStringLike) {
+  EXPECT_EQ("bar", fmt::format("{}", explicitly_convertible_to_string_like()));
+}
+
+#ifdef FMT_USE_STRING_VIEW
+struct explicitly_convertible_to_std_string_view {
+  explicit operator fmt::internal::std_string_view<char>() const {
+    return {"foo", 3u};
+  }
+};
+
+std::ostream& operator<<(std::ostream& os,
+                         explicitly_convertible_to_std_string_view) {
+  return os << "bar";
+}
+
+TEST(FormatterTest, FormatExplicitlyConvertibleToStdStringView) {
+  EXPECT_EQ("bar", fmt::format("{}", explicitly_convertible_to_string_like()));
+}
+
+#endif  // FMT_USE_STRING_VIEW

test/posix-mock-test.cc

@@ -11,13 +11,15 @@
 #endif
 
 #include "posix-mock.h"
-#include "../src/posix.cc"
 
 #include <errno.h>
 #include <fcntl.h>
+
 #include <climits>
 #include <memory>
 
+#include "../src/os.cc"
+
 #ifdef _WIN32
 #  include <io.h>
 #  undef max
@@ -30,7 +32,6 @@
 
 using fmt::buffered_file;
 using fmt::error_code;
-using fmt::file;
 
 using testing::_;
 using testing::Return;
@@ -52,7 +53,7 @@ std::size_t read_nbyte;
 std::size_t write_nbyte;
 bool sysconf_error;
 
-enum FStatSimulation { NONE, MAX_SIZE, ERROR } fstat_sim;
+enum { NONE, MAX_SIZE, ERROR } fstat_sim;
 }  // namespace
 
 #define EMULATE_EINTR(func, error_result) \
@@ -198,29 +199,32 @@ static void write_file(fmt::cstring_view filename, fmt::string_view content) {
   f.print("{}", content);
 }
 
+#if FMT_USE_FCNTL
+using fmt::file;
+
 TEST(UtilTest, GetPageSize) {
-#ifdef _WIN32
+#  ifdef _WIN32
   SYSTEM_INFO si = {};
   GetSystemInfo(&si);
   EXPECT_EQ(si.dwPageSize, fmt::getpagesize());
-#else
+#  else
   EXPECT_EQ(sysconf(_SC_PAGESIZE), fmt::getpagesize());
   sysconf_error = true;
   EXPECT_SYSTEM_ERROR(fmt::getpagesize(), EINVAL,
                       "cannot get memory page size");
   sysconf_error = false;
-#endif
+#  endif
 }
 
 TEST(FileTest, OpenRetry) {
-  write_file("test", "there must be something here");
+  write_file("temp", "there must be something here");
   std::unique_ptr<file> f{nullptr};
-  EXPECT_RETRY(f.reset(new file("test", file::RDONLY)), open,
-               "cannot open file test");
-#ifndef _WIN32
+  EXPECT_RETRY(f.reset(new file("temp", file::RDONLY)), open,
+               "cannot open file temp");
+#  ifndef _WIN32
   char c = 0;
   f->read(&c, 1);
-#endif
+#  endif
 }
 
 TEST(FileTest, CloseNoRetryInDtor) {
@@ -228,14 +232,15 @@ TEST(FileTest, CloseNoRetryInDtor) {
   file::pipe(read_end, write_end);
   std::unique_ptr<file> f(new file(std::move(read_end)));
   int saved_close_count = 0;
-  EXPECT_WRITE(stderr,
-               {
-                 close_count = 1;
-                 f.reset(nullptr);
-                 saved_close_count = close_count;
-                 close_count = 0;
-               },
-               format_system_error(EINTR, "cannot close file") + "\n");
+  EXPECT_WRITE(
+      stderr,
+      {
+        close_count = 1;
+        f.reset(nullptr);
+        saved_close_count = close_count;
+        close_count = 0;
+      },
+      format_system_error(EINTR, "cannot close file") + "\n");
   EXPECT_EQ(2, saved_close_count);
 }
 
@@ -250,26 +255,26 @@ TEST(FileTest, CloseNoRetry) {
 
 TEST(FileTest, Size) {
   std::string content = "top secret, destroy before reading";
-  write_file("test", content);
-  file f("test", file::RDONLY);
+  write_file("temp", content);
+  file f("temp", file::RDONLY);
   EXPECT_GE(f.size(), 0);
   EXPECT_EQ(content.size(), static_cast<unsigned long long>(f.size()));
-#ifdef _WIN32
+#  ifdef _WIN32
   fmt::memory_buffer message;
   fmt::internal::format_windows_error(message, ERROR_ACCESS_DENIED,
                                       "cannot get file size");
   fstat_sim = ERROR;
   EXPECT_THROW_MSG(f.size(), fmt::windows_error, fmt::to_string(message));
   fstat_sim = NONE;
-#else
+#  else
   f.close();
   EXPECT_SYSTEM_ERROR(f.size(), EBADF, "cannot get file attributes");
-#endif
+#  endif
 }
 
 TEST(FileTest, MaxSize) {
-  write_file("test", "");
-  file f("test", file::RDONLY);
+  write_file("temp", "");
+  file f("temp", file::RDONLY);
   fstat_sim = MAX_SIZE;
   EXPECT_GE(f.size(), 0);
   EXPECT_EQ(max_file_size(), f.size());
@@ -297,16 +302,16 @@ TEST(FileTest, WriteRetry) {
   EXPECT_RETRY(count = write_end.write("test", SIZE), write,
                "cannot write to file");
   write_end.close();
-#ifndef _WIN32
+#  ifndef _WIN32
   EXPECT_EQ(static_cast<std::streamsize>(SIZE), count);
   char buffer[SIZE + 1];
   read_end.read(buffer, SIZE);
   buffer[SIZE] = '\0';
   EXPECT_STREQ("test", buffer);
-#endif
+#  endif
 }
 
-#ifdef _WIN32
+#  ifdef _WIN32
 TEST(FileTest, ConvertReadCount) {
   file read_end, write_end;
   file::pipe(read_end, write_end);
@@ -332,7 +337,7 @@ TEST(FileTest, ConvertWriteCount) {
   write_count = 0;
   EXPECT_EQ(UINT_MAX, write_nbyte);
 }
-#endif
+#  endif
 
 TEST(FileTest, DupNoRetry) {
   int stdout_fd = FMT_POSIX(fileno(stdout));
@@ -357,11 +362,11 @@ TEST(FileTest, Dup2NoExceptRetry) {
   error_code ec;
   dup2_count = 1;
   f1.dup2(f2.descriptor(), ec);
-#ifndef _WIN32
+#  ifndef _WIN32
   EXPECT_EQ(4, dup2_count);
-#else
+#  else
   EXPECT_EQ(EINTR, ec.get());
-#endif
+#  endif
   dup2_count = 0;
 }
 
@@ -383,15 +388,15 @@ TEST(FileTest, FdopenNoRetry) {
 }
 
 TEST(BufferedFileTest, OpenRetry) {
-  write_file("test", "there must be something here");
+  write_file("temp", "there must be something here");
   std::unique_ptr<buffered_file> f{nullptr};
-  EXPECT_RETRY(f.reset(new buffered_file("test", "r")), fopen,
-               "cannot open file test");
-#ifndef _WIN32
+  EXPECT_RETRY(f.reset(new buffered_file("temp", "r")), fopen,
+               "cannot open file temp");
+#  ifndef _WIN32
   char c = 0;
   if (fread(&c, 1, 1, f->get()) < 1)
     throw fmt::system_error(errno, "fread failed");
-#endif
+#  endif
 }
 
 TEST(BufferedFileTest, CloseNoRetryInDtor) {
@@ -399,14 +404,15 @@ TEST(BufferedFileTest, CloseNoRetryInDtor) {
   file::pipe(read_end, write_end);
   std::unique_ptr<buffered_file> f(new buffered_file(read_end.fdopen("r")));
   int saved_fclose_count = 0;
-  EXPECT_WRITE(stderr,
-               {
-                 fclose_count = 1;
-                 f.reset(nullptr);
-                 saved_fclose_count = fclose_count;
-                 fclose_count = 0;
-               },
-               format_system_error(EINTR, "cannot close file") + "\n");
+  EXPECT_WRITE(
+      stderr,
+      {
+        fclose_count = 1;
+        f.reset(nullptr);
+        saved_fclose_count = fclose_count;
+        fclose_count = 0;
+      },
+      format_system_error(EINTR, "cannot close file") + "\n");
   EXPECT_EQ(2, saved_fclose_count);
 }
 
@@ -429,34 +435,35 @@ TEST(BufferedFileTest, FilenoNoRetry) {
   EXPECT_EQ(2, fileno_count);
   fileno_count = 0;
 }
+#endif  // FMT_USE_FCNTL
 
-struct TestMock {
-  static TestMock* instance;
-} * TestMock::instance;
+struct test_mock {
+  static test_mock* instance;
+} * test_mock::instance;
 
 TEST(ScopedMock, Scope) {
   {
-    ScopedMock<TestMock> mock;
-    EXPECT_EQ(&mock, TestMock::instance);
-    TestMock& copy = mock;
+    ScopedMock<test_mock> mock;
+    EXPECT_EQ(&mock, test_mock::instance);
+    test_mock& copy = mock;
     static_cast<void>(copy);
   }
-  EXPECT_EQ(nullptr, TestMock::instance);
+  EXPECT_EQ(nullptr, test_mock::instance);
 }
 
 #ifdef FMT_LOCALE
 
-typedef fmt::Locale::type LocaleType;
+typedef fmt::locale::type locale_type;
 
-struct LocaleMock {
-  static LocaleMock* instance;
-  MOCK_METHOD3(newlocale, LocaleType(int category_mask, const char* locale,
-                                     LocaleType base));
-  MOCK_METHOD1(freelocale, void(LocaleType locale));
+struct locale_mock {
+  static locale_mock* instance;
+  MOCK_METHOD3(newlocale, locale_type(int category_mask, const char* locale,
+                                      locale_type base));
+  MOCK_METHOD1(freelocale, void(locale_type locale));
 
   MOCK_METHOD3(strtod_l,
-               double(const char* nptr, char** endptr, LocaleType locale));
-} * LocaleMock::instance;
+               double(const char* nptr, char** endptr, locale_type locale));
+} * locale_mock::instance;
 
 #  ifdef _MSC_VER
 #    pragma warning(push)
@@ -467,15 +474,15 @@ struct LocaleMock {
 #    endif
 
 _locale_t _create_locale(int category, const char* locale) {
-  return LocaleMock::instance->newlocale(category, locale, 0);
+  return locale_mock::instance->newlocale(category, locale, 0);
 }
 
 void _free_locale(_locale_t locale) {
-  LocaleMock::instance->freelocale(locale);
+  locale_mock::instance->freelocale(locale);
 }
 
 double _strtod_l(const char* nptr, char** endptr, _locale_t locale) {
-  return LocaleMock::instance->strtod_l(nptr, endptr, locale);
+  return locale_mock::instance->strtod_l(nptr, endptr, locale);
 }
 #    ifdef __clang__
 #      pragma clang diagnostic pop
@@ -489,11 +496,6 @@ double _strtod_l(const char* nptr, char** endptr, _locale_t locale) {
 #    define FMT_LOCALE_THROW
 #  endif
 
-LocaleType newlocale(int category_mask, const char* locale,
-                     LocaleType base) FMT_LOCALE_THROW {
-  return LocaleMock::instance->newlocale(category_mask, locale, base);
-}
-
 #  if defined(__APPLE__) || \
       (defined(__FreeBSD__) && __FreeBSD_version < 1200002)
 typedef int FreeLocaleResult;
@@ -501,49 +503,55 @@ typedef int FreeLocaleResult;
 typedef void FreeLocaleResult;
 #  endif
 
-FreeLocaleResult freelocale(LocaleType locale) FMT_LOCALE_THROW {
-  LocaleMock::instance->freelocale(locale);
+FreeLocaleResult freelocale(locale_type locale) FMT_LOCALE_THROW {
+  locale_mock::instance->freelocale(locale);
   return FreeLocaleResult();
 }
 
 double strtod_l(const char* nptr, char** endptr,
-                LocaleType locale) FMT_LOCALE_THROW {
-  return LocaleMock::instance->strtod_l(nptr, endptr, locale);
+                locale_type locale) FMT_LOCALE_THROW {
+  return locale_mock::instance->strtod_l(nptr, endptr, locale);
 }
 
 #  undef FMT_LOCALE_THROW
 
-TEST(LocaleTest, LocaleMock) {
-  ScopedMock<LocaleMock> mock;
-  LocaleType locale = reinterpret_cast<LocaleType>(11);
-  EXPECT_CALL(mock, newlocale(222, StrEq("foo"), locale));
-  newlocale(222, "foo", locale);
+#  ifndef _WIN32
+locale_t test::newlocale(int category_mask, const char* locale, locale_t base) {
+  return locale_mock::instance->newlocale(category_mask, locale, base);
 }
 
+TEST(LocaleTest, LocaleMock) {
+  ScopedMock<locale_mock> mock;
+  locale_type locale = reinterpret_cast<locale_type>(11);
+  EXPECT_CALL(mock, newlocale(222, StrEq("foo"), locale));
+  FMT_SYSTEM(newlocale(222, "foo", locale));
+}
+#  endif
+
 TEST(LocaleTest, Locale) {
 #  ifndef LC_NUMERIC_MASK
   enum { LC_NUMERIC_MASK = LC_NUMERIC };
 #  endif
-  ScopedMock<LocaleMock> mock;
-  LocaleType impl = reinterpret_cast<LocaleType>(42);
+  ScopedMock<locale_mock> mock;
+  locale_type impl = reinterpret_cast<locale_type>(42);
   EXPECT_CALL(mock, newlocale(LC_NUMERIC_MASK, StrEq("C"), nullptr))
       .WillOnce(Return(impl));
   EXPECT_CALL(mock, freelocale(impl));
-  fmt::Locale locale;
-  EXPECT_EQ(impl, locale.get());
+  fmt::locale loc;
+  EXPECT_EQ(impl, loc.get());
 }
 
 TEST(LocaleTest, Strtod) {
-  ScopedMock<LocaleMock> mock;
+  ScopedMock<locale_mock> mock;
   EXPECT_CALL(mock, newlocale(_, _, _))
-      .WillOnce(Return(reinterpret_cast<LocaleType>(42)));
+      .WillOnce(Return(reinterpret_cast<locale_type>(42)));
   EXPECT_CALL(mock, freelocale(_));
-  fmt::Locale locale;
+  fmt::locale loc;
   const char* str = "4.2";
   char end = 'x';
-  EXPECT_CALL(mock, strtod_l(str, _, locale.get()))
+  EXPECT_CALL(mock, strtod_l(str, _, loc.get()))
       .WillOnce(testing::DoAll(testing::SetArgPointee<1>(&end), Return(777)));
-  EXPECT_EQ(777, locale.strtod(str));
+  EXPECT_EQ(777, loc.strtod(str));
   EXPECT_EQ(&end, str);
 }
 

test/posix-mock.h

@@ -9,7 +9,11 @@
 #define FMT_POSIX_TEST_H
 
 #include <errno.h>
+#include <locale.h>
 #include <stdio.h>
+#ifdef __APPLE__
+#  include <xlocale.h>
+#endif
 
 #ifdef _WIN32
 #  include <windows.h>
@@ -62,6 +66,10 @@ int pipe(int* pfds, unsigned psize, int textmode);
 FILE* fopen(const char* filename, const char* mode);
 int fclose(FILE* stream);
 int(fileno)(FILE* stream);
+
+#if defined(FMT_LOCALE) && !defined(_WIN32)
+locale_t newlocale(int category_mask, const char* locale, locale_t base);
+#endif
 }  // namespace test
 
 #define FMT_SYSTEM(call) test::call

test/printf-test.cc

@@ -5,17 +5,19 @@
 //
 // For the license information refer to format.h.
 
+#include "fmt/printf.h"
+
 #include <cctype>
 #include <climits>
 #include <cstring>
 
 #include "fmt/core.h"
-#include "fmt/printf.h"
 #include "gtest-extra.h"
 #include "util.h"
 
 using fmt::format;
 using fmt::format_error;
+using fmt::internal::max_value;
 
 const unsigned BIG_NUM = INT_MAX + 1u;
 
@@ -295,20 +297,19 @@ void TestLength(const char* length_spec, U value) {
   long long signed_value = 0;
   unsigned long long unsigned_value = 0;
   // Apply integer promotion to the argument.
-  using std::numeric_limits;
-  unsigned long long max = numeric_limits<U>::max();
+  unsigned long long max = max_value<U>();
   using fmt::internal::const_check;
-  if (const_check(max <= static_cast<unsigned>(numeric_limits<int>::max()))) {
+  if (const_check(max <= static_cast<unsigned>(max_value<int>()))) {
     signed_value = static_cast<int>(value);
-    unsigned_value = static_cast<unsigned>(value);
-  } else if (const_check(max <= numeric_limits<unsigned>::max())) {
+    unsigned_value = static_cast<unsigned long long>(value);
+  } else if (const_check(max <= max_value<unsigned>())) {
     signed_value = static_cast<unsigned>(value);
-    unsigned_value = static_cast<unsigned>(value);
+    unsigned_value = static_cast<unsigned long long>(value);
   }
   if (sizeof(U) <= sizeof(int) && sizeof(int) < sizeof(T)) {
     signed_value = static_cast<long long>(value);
-    unsigned_value =
-        static_cast<typename std::make_unsigned<unsigned>::type>(value);
+    unsigned_value = static_cast<unsigned long long>(
+        static_cast<typename std::make_unsigned<unsigned>::type>(value));
   } else {
     signed_value = static_cast<typename make_signed<T>::type>(value);
     unsigned_value = static_cast<typename std::make_unsigned<T>::type>(value);
@@ -332,25 +333,27 @@ void TestLength(const char* length_spec, U value) {
 }
 
 template <typename T> void TestLength(const char* length_spec) {
-  T min = std::numeric_limits<T>::min(), max = std::numeric_limits<T>::max();
+  T min = std::numeric_limits<T>::min(), max = max_value<T>();
   TestLength<T>(length_spec, 42);
   TestLength<T>(length_spec, -42);
   TestLength<T>(length_spec, min);
   TestLength<T>(length_spec, max);
-  TestLength<T>(length_spec, static_cast<long long>(min) - 1);
-  unsigned long long long_long_max = std::numeric_limits<long long>::max();
+  long long long_long_min = std::numeric_limits<long long>::min();
+  if (static_cast<long long>(min) > long_long_min)
+    TestLength<T>(length_spec, static_cast<long long>(min) - 1);
+  unsigned long long long_long_max = max_value<long long>();
   if (static_cast<unsigned long long>(max) < long_long_max)
     TestLength<T>(length_spec, static_cast<long long>(max) + 1);
   TestLength<T>(length_spec, std::numeric_limits<short>::min());
-  TestLength<T>(length_spec, std::numeric_limits<unsigned short>::max());
+  TestLength<T>(length_spec, max_value<unsigned short>());
   TestLength<T>(length_spec, std::numeric_limits<int>::min());
-  TestLength<T>(length_spec, std::numeric_limits<int>::max());
+  TestLength<T>(length_spec, max_value<int>());
   TestLength<T>(length_spec, std::numeric_limits<unsigned>::min());
-  TestLength<T>(length_spec, std::numeric_limits<unsigned>::max());
+  TestLength<T>(length_spec, max_value<unsigned>());
   TestLength<T>(length_spec, std::numeric_limits<long long>::min());
-  TestLength<T>(length_spec, std::numeric_limits<long long>::max());
+  TestLength<T>(length_spec, max_value<long long>());
   TestLength<T>(length_spec, std::numeric_limits<unsigned long long>::min());
-  TestLength<T>(length_spec, std::numeric_limits<unsigned long long>::max());
+  TestLength<T>(length_spec, max_value<unsigned long long>());
 }
 
 TEST(PrintfTest, Length) {
@@ -366,7 +369,7 @@ TEST(PrintfTest, Length) {
   TestLength<intmax_t>("j");
   TestLength<std::size_t>("z");
   TestLength<std::ptrdiff_t>("t");
-  long double max = std::numeric_limits<long double>::max();
+  long double max = max_value<long double>();
   EXPECT_PRINTF(fmt::format("{:.6}", max), "%g", max);
   EXPECT_PRINTF(fmt::format("{:.6}", max), "%Lg", max);
 }
@@ -389,7 +392,7 @@ TEST(PrintfTest, Int) {
 TEST(PrintfTest, long_long) {
   // fmt::printf allows passing long long arguments to %d without length
   // specifiers.
-  long long max = std::numeric_limits<long long>::max();
+  long long max = max_value<long long>();
   EXPECT_PRINTF(fmt::format("{}", max), "%d", max);
 }
 
@@ -408,6 +411,7 @@ TEST(PrintfTest, Float) {
   EXPECT_PRINTF("392.65", "%G", 392.65);
   EXPECT_PRINTF("392", "%g", 392.0);
   EXPECT_PRINTF("392", "%G", 392.0);
+  EXPECT_PRINTF("4.56e-07", "%g", 0.000000456);
   safe_sprintf(buffer, "%a", -392.65);
   EXPECT_EQ(buffer, format("{:a}", -392.65));
   safe_sprintf(buffer, "%A", -392.65);
@@ -425,7 +429,7 @@ TEST(PrintfTest, Inf) {
 
 TEST(PrintfTest, Char) {
   EXPECT_PRINTF("x", "%c", 'x');
-  int max = std::numeric_limits<int>::max();
+  int max = max_value<int>();
   EXPECT_PRINTF(fmt::format("{}", static_cast<char>(max)), "%c", max);
   // EXPECT_PRINTF("x", "%lc", L'x');
   EXPECT_PRINTF(L"x", L"%c", L'x');
@@ -470,11 +474,15 @@ TEST(PrintfTest, Location) {
   // TODO: test %n
 }
 
-enum E { A = 42 };
+enum test_enum { answer = 42 };
 
-TEST(PrintfTest, Enum) { EXPECT_PRINTF("42", "%d", A); }
+TEST(PrintfTest, Enum) {
+  EXPECT_PRINTF("42", "%d", answer);
+  volatile test_enum volatile_enum = answer;
+  EXPECT_PRINTF("42", "%d", volatile_enum);
+}
 
-#if FMT_USE_FILE_DESCRIPTORS
+#if FMT_USE_FCNTL
 TEST(PrintfTest, Examples) {
   const char* weekday = "Thursday";
   const char* month = "August";
@@ -494,7 +502,9 @@ TEST(PrintfTest, PrintfError) {
 TEST(PrintfTest, WideString) { EXPECT_EQ(L"abc", fmt::sprintf(L"%s", L"abc")); }
 
 TEST(PrintfTest, PrintfCustom) {
-  EXPECT_EQ("abc", test_sprintf("%s", TestString("abc")));
+  // The test is disabled for now because it requires decoupling
+  // fallback_formatter::format from format_context.
+  //EXPECT_EQ("abc", test_sprintf("%s", TestString("abc")));
 }
 
 TEST(PrintfTest, OStream) {
@@ -561,8 +571,7 @@ TEST(PrintfTest, VSPrintfMakeWArgsExample) {
 #endif
 }
 
-typedef fmt::printf_arg_formatter<fmt::internal::buffer_range<char>>
-    formatter_t;
+typedef fmt::printf_arg_formatter<fmt::buffer_range<char>> formatter_t;
 typedef fmt::basic_printf_context<formatter_t::iterator, char> context_t;
 
 // A custom printf argument formatter that doesn't print `-` for floating-point

test/ranges-test.cc

@@ -9,13 +9,14 @@
 // All Rights Reserved
 // {fmt} support for ranges, containers and types tuple interface.
 
-/// Check if  'if constexpr' is supported.
+#include "fmt/ranges.h"
+
+#include "gtest.h"
+
+// Check if  'if constexpr' is supported.
 #if (__cplusplus > 201402L) || \
     (defined(_MSVC_LANG) && _MSVC_LANG > 201402L && _MSC_VER >= 1910)
 
-#  include "fmt/ranges.h"
-#  include "gtest.h"
-
 #  include <array>
 #  include <map>
 #  include <string>
@@ -44,9 +45,35 @@ TEST(RangesTest, FormatPair) {
 }
 
 TEST(RangesTest, FormatTuple) {
-  std::tuple<int64_t, float, std::string, char> tu1{42, 1.5f, "this is tuple",
-                                                    'i'};
-  EXPECT_EQ("(42, 1.5, \"this is tuple\", 'i')", fmt::format("{}", tu1));
+  std::tuple<int64_t, float, std::string, char> t{42, 1.5f, "this is tuple",
+                                                  'i'};
+  EXPECT_EQ("(42, 1.5, \"this is tuple\", 'i')", fmt::format("{}", t));
+  EXPECT_EQ("()", fmt::format("{}", std::tuple<>()));
+}
+
+TEST(RangesTest, JoinTuple) {
+  // Value tuple args
+  std::tuple<char, int, float> t1 = std::make_tuple('a', 1, 2.0f);
+  EXPECT_EQ("(a, 1, 2.0)", fmt::format("({})", fmt::join(t1, ", ")));
+
+  // Testing lvalue tuple args
+  int x = 4;
+  std::tuple<char, int&> t2{'b', x};
+  EXPECT_EQ("b + 4", fmt::format("{}", fmt::join(t2, " + ")));
+
+  // Empty tuple
+  std::tuple<> t3;
+  EXPECT_EQ("", fmt::format("{}", fmt::join(t3, "|")));
+
+  // Single element tuple
+  std::tuple<float> t4{4.0f};
+  EXPECT_EQ("4.0", fmt::format("{}", fmt::join(t4, "/")));
+}
+
+TEST(RangesTest, JoinInitializerList) {
+  EXPECT_EQ("1, 2, 3", fmt::format("{}", fmt::join({1, 2, 3}, ", ")));
+  EXPECT_EQ("fmt rocks !",
+            fmt::format("{}", fmt::join({"fmt", "rocks", "!"}, " ")));
 }
 
 struct my_struct {
@@ -100,3 +127,16 @@ TEST(RangesTest, PathLike) {
 
 #endif  // (__cplusplus > 201402L) || (defined(_MSVC_LANG) && _MSVC_LANG >
         // 201402L && _MSC_VER >= 1910)
+
+#ifdef FMT_USE_STRING_VIEW
+struct string_like {
+  const char* begin();
+  const char* end();
+  explicit operator fmt::string_view() const { return "foo"; }
+  explicit operator std::string_view() const { return "foo"; }
+};
+
+TEST(RangesTest, FormatStringLike) {
+  EXPECT_EQ("foo", fmt::format("{}", string_like()));
+}
+#endif  // FMT_USE_STRING_VIEW

test/scan.h

@@ -6,6 +6,8 @@
 // For the license information refer to format.h.
 
 #include <array>
+#include <cassert>
+#include <climits>
 
 #include "fmt/format.h"
 
@@ -135,21 +137,20 @@ struct scan_handler : error_handler {
       char c = *it++;
       if (c < '0' || c > '9') on_error("invalid input");
       // TODO: check overflow
-      value = value * 10 + (c - '0');
+      value = value * 10 + static_cast<unsigned>(c - '0');
     }
     scan_ctx_.advance_to(it);
     return value;
   }
 
   template <typename T = int> T read_int() {
-    T value = 0;
     auto it = scan_ctx_.begin(), end = scan_ctx_.end();
     bool negative = it != end && *it == '-';
     if (negative) ++it;
     scan_ctx_.advance_to(it);
-    value = read_uint<typename std::make_unsigned<T>::type>();
-    if (negative) value = -value;
-    return value;
+    const auto value = read_uint<typename std::make_unsigned<T>::type>();
+    if (negative) return -static_cast<T>(value);
+    return static_cast<T>(value);
   }
 
  public:
@@ -159,7 +160,7 @@ struct scan_handler : error_handler {
   const char* pos() const { return scan_ctx_.begin(); }
 
   void on_text(const char* begin, const char* end) {
-    auto size = end - begin;
+    auto size = to_unsigned(end - begin);
     auto it = scan_ctx_.begin();
     if (it + size > scan_ctx_.end() ||
         !std::equal(begin, end, make_checked(it, size))) {
@@ -197,11 +198,12 @@ struct scan_handler : error_handler {
     case scan_type::string_view_type: {
       auto s = it;
       while (it != end && *it != ' ') ++it;
-      *arg_.string_view = fmt::string_view(s, it - s);
+      *arg_.string_view = fmt::string_view(s, to_unsigned(it - s));
       scan_ctx_.advance_to(it);
       break;
     }
-    default:
+    case scan_type::none_type:
+    case scan_type::custom_type:
       assert(false);
     }
   }

test/std-format-test.cc

@@ -29,19 +29,15 @@ TEST(StdFormatTest, Alignment) {
   string s4 = format("{:*^6}", 'x');  // s4 == "**x***"
   // Error: '=' with charT and no integer presentation type
   EXPECT_THROW(string s5 = format("{:=6}", 'x'), std::format_error);
-  string s6 = format("{:6d}", c);       // s6 == "   120"
-  string s7 = format("{:=+06d}", c);    // s7 == "+00120"
-  string s8 = format("{:0=#6x}", 0xa);  // s8 == "0x000a"
-  string s9 = format("{:6}", true);     // s9 == "true  "
+  string s6 = format("{:6d}", c);    // s6 == "   120"
+  string s7 = format("{:6}", true);  // s9 == "true  "
   EXPECT_EQ(s0, "    42");
   EXPECT_EQ(s1, "x     ");
   EXPECT_EQ(s2, "x*****");
   EXPECT_EQ(s3, "*****x");
   EXPECT_EQ(s4, "**x***");
   EXPECT_EQ(s6, "   120");
-  EXPECT_EQ(s7, "+00120");
-  EXPECT_EQ(s8, "0x000a");
-  EXPECT_EQ(s9, "true  ");
+  EXPECT_EQ(s7, "true  ");
 }
 
 TEST(StdFormatTest, Float) {
@@ -65,11 +61,11 @@ TEST(StdFormatTest, Int) {
   string s0 = format("{}", 42);                       // s0 == "42"
   string s1 = format("{0:b} {0:d} {0:o} {0:x}", 42);  // s1 == "101010 42 52 2a"
   string s2 = format("{0:#x} {0:#X}", 42);            // s2 == "0x2a 0X2A"
-  string s3 = format("{:n}", 1234);  // s3 == "1,234" (depends on the locale)
+  string s3 = format("{:n}", 1234);  // s3 == "1234" (depends on the locale)
   EXPECT_EQ(s0, "42");
   EXPECT_EQ(s1, "101010 42 52 2a");
   EXPECT_EQ(s2, "0x2a 0X2A");
-  EXPECT_EQ(s3, "1,234");
+  EXPECT_EQ(s3, "1234");
 }
 
 #include <format>

test/test-assert.h

@@ -14,8 +14,13 @@
 class assertion_failure : public std::logic_error {
  public:
   explicit assertion_failure(const char* message) : std::logic_error(message) {}
+
+ private:
+  virtual void avoid_weak_vtable();
 };
 
+void assertion_failure::avoid_weak_vtable() {}
+
 #define FMT_ASSERT(condition, message) \
   if (!(condition)) throw assertion_failure(message);
 

test/util.cc

@@ -33,11 +33,17 @@ std::string get_system_error(int error_code) {
 const char* const FILE_CONTENT = "Don't panic!";
 
 fmt::buffered_file open_buffered_file(FILE** fp) {
+#if FMT_USE_FCNTL
   fmt::file read_end, write_end;
   fmt::file::pipe(read_end, write_end);
   write_end.write(FILE_CONTENT, std::strlen(FILE_CONTENT));
   write_end.close();
   fmt::buffered_file f = read_end.fdopen("r");
   if (fp) *fp = f.get();
+#else
+  fmt::buffered_file f("test-file", "w");
+  fputs(FILE_CONTENT, f.get());
+  if (fp) *fp = f.get();
+#endif
   return f;
 }

test/util.h

@@ -9,7 +9,7 @@
 #include <cstdio>
 #include <string>
 
-#include "fmt/posix.h"
+#include "fmt/os.h"
 
 enum { BUFFER_SIZE = 256 };