Version 1.16.0

* Replaced fileapi.h include with windows.h, as instructed in https://learn.microsoft.com/en-us/windows/win32/api/fileapi/nf-fileapi-flushfilebuffers
Otherwise this causes compilation error on older sdks.

* Removed the fileapi.h include entirely, since windows.h is already included before

---------

Co-authored-by: MasonAngelio <MasonAngelio>

.github/workflows/coverity_scan.yml

@@ -0,0 +1,52 @@
+name: coverity-linux
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  coverity_scan:
+    runs-on: ubuntu-latest
+    name: Coverity Scan
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install dependencies
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y curl build-essential cmake pkg-config libsystemd-dev
+
+      - name: Download Coverity Tool
+        run: |
+          curl -s -L --output coverity_tool.tgz "https://scan.coverity.com/download/linux64?token=${{ secrets.COVERITY_TOKEN }}&project=gabime%2Fspdlog"
+          mkdir coverity_tool
+          tar -C coverity_tool --strip-components=1 -xf coverity_tool.tgz
+          echo "$PWD/coverity_tool/bin" >> $GITHUB_PATH
+
+      - name: Build with Coverity
+        run: |
+          mkdir build && cd build
+          cmake .. -DCMAKE_BUILD_TYPE=Release -DCMAKE_CXX_STANDARD=17
+          cd ..
+          cov-build --dir cov-int make -C build -j4
+
+      - name: Submit results to Coverity
+        run: |
+          tar czf cov-int.tgz cov-int
+          response=$(curl --silent --show-error --fail \
+            --form email="${{ secrets.EMAIL }}" \
+            --form token="${{ secrets.COVERITY_TOKEN }}" \
+            --form file=@cov-int.tgz \
+            --form version="GitHub PR #${{ github.event.pull_request.number }}" \
+            --form description="CI run for PR" \
+            https://scan.coverity.com/builds?project=gabime%2Fspdlog)
+
+          echo "$response"
+
+          if echo "$response" | grep -qi "Build successfully submitted"; then
+            echo "Coverity upload succeeded"
+          else
+            echo "Coverity upload failed or was rejected"
+            exit 1
+          fi

.github/workflows/linux.yml

@@ -1,9 +1,15 @@
-name: ci
+name: linux
 
 on: [push, pull_request]
 
+permissions:
+  contents: read
+
 jobs:
-  build_linux:
+  # -----------------------------------------------------------------------
+  # Linux build matrix
+  # -----------------------------------------------------------------------
+  build:
     runs-on: ubuntu-latest
     defaults:
       run:
@@ -12,20 +18,20 @@ jobs:
       fail-fast: false
       matrix:
         config:
-          - { compiler: gcc, version: 7, build_type: Release, cppstd: 11 }
+          - { compiler: gcc, version: 9, build_type: Release, cppstd: 11 }
-          - { compiler: gcc, version: 9, build_type: Release, cppstd: 17 }
+          - { compiler: gcc, version: 11, build_type: Debug, cppstd: 17 }
-          - { compiler: gcc, version: 11, build_type: Debug, cppstd: 20 }
           - { compiler: gcc, version: 12, build_type: Release, cppstd: 20 }
-          - { compiler: clang, version: 12, build_type: Debug, cppstd: 17, asan: OFF }
+          - { compiler: gcc, version: 12, build_type: Debug, cppstd: 20, asan: ON }
-          - { compiler: clang, version: 15, build_type: Release, cppstd: 20, asan: OFF }
+          - { compiler: clang, version: 12, build_type: Debug, cppstd: 17 }
+          - { compiler: clang, version: 15, build_type: Release, cppstd: 20, tsan: ON }
     container:
       image: ${{ matrix.config.compiler == 'clang' && 'teeks99/clang-ubuntu' || matrix.config.compiler }}:${{ matrix.config.version }}
-    name: "${{ matrix.config.compiler}} ${{ matrix.config.version }} (C++${{ matrix.config.cppstd }}, ${{ matrix.config.build_type }})"
+    name: "${{ matrix.config.compiler}} ${{ matrix.config.version }} (C++${{ matrix.config.cppstd }} ${{ matrix.config.build_type }} ${{ matrix.config.asan == 'ON' && 'ASAN' || '' }}${{ matrix.config.tsan == 'ON' && 'TSAN' || '' }})"
     steps:
-      - uses: actions/checkout@main
+      - uses: actions/checkout@v4
       - name: Setup
         run: |
-          apt-get update          
+          apt-get update
           apt-get install -y curl git pkg-config libsystemd-dev
           CMAKE_VERSION="3.24.2"
           curl -sSL https://github.com/Kitware/CMake/releases/download/v${CMAKE_VERSION}/cmake-${CMAKE_VERSION}-linux-x86_64.sh -o install-cmake.sh
@@ -34,10 +40,8 @@ jobs:
       - name: Setup Compiler
         if: matrix.config.compiler == 'clang'
         run: |
-          if [[ "${{ matrix.config.version }}" -ge 4 ]]; then
+          scripts/ci_setup_clang.sh "${{ matrix.config.version }}"
-            scripts/ci_setup_clang.sh "${{ matrix.config.version }}"
+          echo "CXXFLAGS=-stdlib=libc++" >> $GITHUB_ENV          
-            echo "CXXFLAGS=-stdlib=libc++" >> $GITHUB_ENV
-          fi
           echo "CC=clang-${{ matrix.config.version }}" >> $GITHUB_ENV
           echo "CXX=clang++-${{ matrix.config.version }}" >> $GITHUB_ENV
       - name: Build
@@ -52,15 +56,19 @@ jobs:
             -DSPDLOG_BUILD_BENCH=OFF \
             -DSPDLOG_BUILD_TESTS=ON \
             -DSPDLOG_BUILD_TESTS_HO=OFF \
-            -DSPDLOG_SANITIZE_ADDRESS=${{ matrix.config.asan || 'ON' }}
+            -DSPDLOG_SANITIZE_ADDRESS=${{ matrix.config.asan || 'OFF' }} \
-          make -j2
+            -DSPDLOG_SANITIZE_THREAD=${{ matrix.config.tsan || 'OFF' }}
-          ctest -j2 --output-on-failure
+          make -j 4
+          ctest -j 4 --output-on-failure
 
+  # -----------------------------------------------------------------------
+  # OS X build matrix
+  # -----------------------------------------------------------------------
   build_osx:
     runs-on: macOS-latest
     name: "OS X Clang (C++11, Release)"
     steps:
-      - uses: actions/checkout@main
+      - uses: actions/checkout@v4
       - name: Build
         run: |
           mkdir -p build && cd build
@@ -74,6 +82,5 @@ jobs:
             -DSPDLOG_BUILD_TESTS=ON \
             -DSPDLOG_BUILD_TESTS_HO=OFF \
             -DSPDLOG_SANITIZE_ADDRESS=OFF
-          make -j2
+          make -j 4
-          ctest -j2 --output-on-failure
+          ctest -j 4 --output-on-failure
-

.github/workflows/macos.yml

@@ -0,0 +1,38 @@
+name: macos
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    runs-on: macOS-latest
+    name: "macOS Clang (C++11, Release)"
+    strategy:
+      fail-fast: true
+      matrix:
+        config:
+            - USE_STD_FORMAT: 'ON'
+              BUILD_EXAMPLE: 'OFF'
+            - USE_STD_FORMAT: 'OFF'
+              BUILD_EXAMPLE: 'ON'
+              
+    steps:
+      - uses: actions/checkout@v4
+      - name: Build
+        run: |
+          mkdir -p build && cd build
+          cmake .. \
+            -DCMAKE_BUILD_TYPE=Release \
+            -DCMAKE_CXX_STANDARD=11 \
+            -DSPDLOG_BUILD_EXAMPLE=${{ matrix.config.BUILD_EXAMPLE }} \
+            -DSPDLOG_BUILD_EXAMPLE_HO=${{ matrix.config.BUILD_EXAMPLE }} \
+            -DSPDLOG_BUILD_WARNINGS=ON \
+            -DSPDLOG_BUILD_BENCH=OFF \
+            -DSPDLOG_BUILD_TESTS=ON \
+            -DSPDLOG_BUILD_TESTS_HO=OFF \
+            -DSPDLOG_USE_STD_FORMAT=${{ matrix.config.USE_STD_FORMAT }} \
+            -DSPDLOG_SANITIZE_ADDRESS=OFF
+          make -j 4
+          ctest -j 4 --output-on-failure

.github/workflows/windows.yml

@@ -0,0 +1,79 @@
+name: windows
+
+on: [push, pull_request]
+
+permissions:
+  contents: read
+
+jobs:
+  build:
+    runs-on: windows-latest
+    strategy:
+      fail-fast: true
+      matrix:
+        config:
+          - GENERATOR: "Visual Studio 17 2022"
+            BUILD_TYPE: Release
+            BUILD_SHARED: 'ON'
+            FATAL_ERRORS: 'ON'
+            WCHAR: 'OFF'
+            WCHAR_FILES: 'OFF'
+            BUILD_EXAMPLE: 'OFF'
+            USE_STD_FORMAT: 'ON'
+            CXX_STANDARD: 20
+          - GENERATOR: "Visual Studio 17 2022"
+            BUILD_TYPE: Release
+            BUILD_SHARED: 'ON'
+            FATAL_ERRORS: 'ON'
+            WCHAR: 'ON'
+            WCHAR_FILES: 'ON'
+            BUILD_EXAMPLE: 'OFF'
+            USE_STD_FORMAT: 'ON'
+            CXX_STANDARD: 20
+          - GENERATOR: "Visual Studio 17 2022"
+            BUILD_TYPE: Release
+            BUILD_SHARED: 'ON'
+            FATAL_ERRORS: 'ON'
+            WCHAR: 'OFF'
+            WCHAR_FILES: 'OFF'
+            BUILD_EXAMPLE: 'ON'
+            USE_STD_FORMAT: 'OFF'
+            CXX_STANDARD: 17
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: CMake ${{ matrix.config.GENERATOR }} CXX=${{matrix.config.CXX_STANDARD}} WCHAR=${{matrix.config.WCHAR_FILES}} STD_FORMAT=${{matrix.config.USE_STD_FORMAT}}
+        shell: pwsh
+        run: |
+          mkdir build
+          cd build
+          cmake -G "${{ matrix.config.GENERATOR }}"  -A x64 `
+            -D CMAKE_BUILD_TYPE=${{ matrix.config.BUILD_TYPE }} `
+            -D BUILD_SHARED_LIBS=${{ matrix.config.BUILD_SHARED }} `
+            -D SPDLOG_WCHAR_SUPPORT=${{ matrix.config.WCHAR }} `
+            -D SPDLOG_WCHAR_FILENAMES=${{ matrix.config.WCHAR_FILES }} `
+            -D SPDLOG_BUILD_EXAMPLE=${{ matrix.config.BUILD_EXAMPLE }} `
+            -D SPDLOG_BUILD_EXAMPLE_HO=${{ matrix.config.BUILD_EXAMPLE }} `
+            -D SPDLOG_BUILD_TESTS=ON `
+            -D SPDLOG_BUILD_TESTS_HO=OFF `
+            -D SPDLOG_BUILD_WARNINGS=${{ matrix.config.FATAL_ERRORS }} `
+            -D SPDLOG_USE_STD_FORMAT=${{ matrix.config.USE_STD_FORMAT }} `
+            -D CMAKE_CXX_STANDARD=${{ matrix.config.CXX_STANDARD }} ..
+
+      - name: Build
+        shell: pwsh
+        run: |
+          cd build
+          cmake --build  . --parallel --config ${{ matrix.config.BUILD_TYPE }}
+
+      - name: Run Tests
+        shell: pwsh
+        env:
+          PATH: ${{ env.PATH }};${{ github.workspace }}\build\_deps\catch2-build\src\${{ matrix.config.BUILD_TYPE }};${{ github.workspace }}\build\${{ matrix.config.BUILD_TYPE }}
+        run: |
+          build\tests\${{ matrix.config.BUILD_TYPE }}\spdlog-utests.exe
+
+
+  

CMakeLists.txt

@@ -33,11 +33,6 @@ elseif(NOT CMAKE_CXX_STANDARD)
     set(CMAKE_CXX_STANDARD_REQUIRED ON)
 endif()
 
-# make sure __cplusplus is defined when using msvc and enable parallel build
-if(MSVC)
-    string(APPEND CMAKE_CXX_FLAGS " /Zc:__cplusplus /MP")
-endif()
-
 set(CMAKE_CXX_EXTENSIONS OFF)
 
 if(CMAKE_SYSTEM_NAME MATCHES "CYGWIN" OR CMAKE_SYSTEM_NAME MATCHES "MSYS" OR CMAKE_SYSTEM_NAME MATCHES "MINGW")
@@ -67,6 +62,9 @@ option(SPDLOG_ENABLE_PCH "Build static or shared library using precompiled heade
 # build position independent code
 option(SPDLOG_BUILD_PIC "Build position independent code (-fPIC)" OFF)
 
+# debug build postfix
+set(SPDLOG_DEBUG_POSTFIX "d" CACHE STRING "Filename postfix for libraries in debug builds")
+
 # example options
 option(SPDLOG_BUILD_EXAMPLE "Build example" ${SPDLOG_MASTER_PROJECT})
 option(SPDLOG_BUILD_EXAMPLE_HO "Build header only example" OFF)
@@ -80,6 +78,10 @@ option(SPDLOG_BUILD_BENCH "Build benchmarks (Requires https://github.com/google/
 
 # sanitizer options
 option(SPDLOG_SANITIZE_ADDRESS "Enable address sanitizer in tests" OFF)
+option(SPDLOG_SANITIZE_THREAD "Enable thread sanitizer in tests" OFF)
+if(SPDLOG_SANITIZE_ADDRESS AND SPDLOG_SANITIZE_THREAD)
+    message(FATAL_ERROR "SPDLOG_SANITIZE_ADDRESS and SPDLOG_SANITIZE_THREAD are mutually exclusive")
+endif()
 
 # warning options
 option(SPDLOG_BUILD_WARNINGS "Enable compiler warnings" OFF)
@@ -108,9 +110,15 @@ endif()
 if(WIN32)
     option(SPDLOG_WCHAR_SUPPORT "Support wchar api" OFF)
     option(SPDLOG_WCHAR_FILENAMES "Support wchar filenames" OFF)
+    option(SPDLOG_WCHAR_CONSOLE "Support wchar output to console" OFF)
 else()
     set(SPDLOG_WCHAR_SUPPORT OFF CACHE BOOL "non supported option" FORCE)
     set(SPDLOG_WCHAR_FILENAMES OFF CACHE BOOL "non supported option" FORCE)
+    set(SPDLOG_WCHAR_CONSOLE OFF CACHE BOOL "non supported option" FORCE)
+endif()
+
+if(MSVC)
+    option(SPDLOG_MSVC_UTF8 "Enable/disable msvc /utf-8 flag required by fmt lib" ON)
 endif()
 
 if(${CMAKE_SYSTEM_NAME} STREQUAL "Linux")
@@ -127,6 +135,7 @@ option(
     "prevent spdlog from using of std::atomic log levels (use only if your code never modifies log levels concurrently"
     OFF)
 option(SPDLOG_DISABLE_DEFAULT_LOGGER "Disable default logger creation" OFF)
+option(SPDLOG_FWRITE_UNLOCKED "Use the unlocked variant of fwrite. Leave this on unless your libc doesn't have it" ON)
 
 # clang-tidy
 option(SPDLOG_TIDY "run clang-tidy" OFF)
@@ -159,7 +168,7 @@ if(SPDLOG_BUILD_SHARED OR BUILD_SHARED_LIBS)
     endif()
     add_library(spdlog SHARED ${SPDLOG_SRCS} ${SPDLOG_ALL_HEADERS})
     target_compile_definitions(spdlog PUBLIC SPDLOG_SHARED_LIB)
-    if(MSVC)
+    if(CMAKE_CXX_COMPILER_ID STREQUAL "MSVC")
         target_compile_options(spdlog PUBLIC $<$<AND:$<CXX_COMPILER_ID:MSVC>,$<NOT:$<COMPILE_LANGUAGE:CUDA>>>:/wd4251
                                              /wd4275>)
     endif()
@@ -185,13 +194,20 @@ spdlog_enable_warnings(spdlog)
 
 set_target_properties(spdlog PROPERTIES VERSION ${SPDLOG_VERSION} SOVERSION
                                                                   ${SPDLOG_VERSION_MAJOR}.${SPDLOG_VERSION_MINOR})
-set_target_properties(spdlog PROPERTIES DEBUG_POSTFIX d)
+set_target_properties(spdlog PROPERTIES DEBUG_POSTFIX ${SPDLOG_DEBUG_POSTFIX})
 
 if(COMMAND target_precompile_headers AND SPDLOG_ENABLE_PCH)
     configure_file(${CMAKE_CURRENT_SOURCE_DIR}/cmake/pch.h.in ${PROJECT_BINARY_DIR}/spdlog_pch.h @ONLY)
     target_precompile_headers(spdlog PRIVATE ${PROJECT_BINARY_DIR}/spdlog_pch.h)
 endif()
 
+# sanitizer support
+if(SPDLOG_SANITIZE_ADDRESS)
+    spdlog_enable_addr_sanitizer(spdlog)
+elseif(SPDLOG_SANITIZE_THREAD)
+    spdlog_enable_thread_sanitizer(spdlog)
+endif()
+
 # ---------------------------------------------------------------------------------------
 # Header only version
 # ---------------------------------------------------------------------------------------
@@ -213,7 +229,7 @@ if(SPDLOG_FMT_EXTERNAL OR SPDLOG_FMT_EXTERNAL_HO)
     target_compile_definitions(spdlog PUBLIC SPDLOG_FMT_EXTERNAL)
     target_compile_definitions(spdlog_header_only INTERFACE SPDLOG_FMT_EXTERNAL)
 
-    # use external fmt-header-nly
+    # use external fmt-header-only
     if(SPDLOG_FMT_EXTERNAL_HO)
         target_link_libraries(spdlog PUBLIC fmt::fmt-header-only)
         target_link_libraries(spdlog_header_only INTERFACE fmt::fmt-header-only)
@@ -225,6 +241,22 @@ if(SPDLOG_FMT_EXTERNAL OR SPDLOG_FMT_EXTERNAL_HO)
     set(PKG_CONFIG_REQUIRES fmt) # add dependency to pkg-config
 endif()
 
+# ---------------------------------------------------------------------------------------
+# Check if fwrite_unlocked/_fwrite_nolock is available
+# ---------------------------------------------------------------------------------------
+if(SPDLOG_FWRITE_UNLOCKED)
+    include(CheckSymbolExists)
+    if(WIN32)
+        check_symbol_exists(_fwrite_nolock "stdio.h" HAVE_FWRITE_UNLOCKED)
+    else()
+        check_symbol_exists(fwrite_unlocked "stdio.h" HAVE_FWRITE_UNLOCKED)
+    endif()
+    if(HAVE_FWRITE_UNLOCKED)
+        target_compile_definitions(spdlog PRIVATE SPDLOG_FWRITE_UNLOCKED)
+        target_compile_definitions(spdlog_header_only INTERFACE SPDLOG_FWRITE_UNLOCKED)
+    endif()
+endif()
+
 # ---------------------------------------------------------------------------------------
 # Add required libraries for Android CMake build
 # ---------------------------------------------------------------------------------------
@@ -237,9 +269,11 @@ endif()
 # Misc definitions according to tweak options
 # ---------------------------------------------------------------------------------------
 set(SPDLOG_WCHAR_TO_UTF8_SUPPORT ${SPDLOG_WCHAR_SUPPORT})
+set(SPDLOG_UTF8_TO_WCHAR_CONSOLE ${SPDLOG_WCHAR_CONSOLE})
 foreach(
     SPDLOG_OPTION
     SPDLOG_WCHAR_TO_UTF8_SUPPORT
+    SPDLOG_UTF8_TO_WCHAR_CONSOLE
     SPDLOG_WCHAR_FILENAMES
     SPDLOG_NO_EXCEPTIONS
     SPDLOG_CLOCK_COARSE
@@ -255,17 +289,31 @@ foreach(
     endif()
 endforeach()
 
+if(MSVC)
+    target_compile_options(spdlog PRIVATE "/Zc:__cplusplus")
+    target_compile_options(spdlog_header_only INTERFACE "/Zc:__cplusplus")
+    if(SPDLOG_MSVC_UTF8)
+        # fmtlib requires the /utf-8 flag when building with msvc. see https://github.com/fmtlib/fmt/pull/4159 on the
+        # purpose of the additional
+        # "$<$<AND:$<COMPILE_LANGUAGE:CXX>,$<CXX_COMPILER_ID:MSVC>>"
+        target_compile_options(spdlog PUBLIC $<$<AND:$<COMPILE_LANGUAGE:CXX>,$<CXX_COMPILER_ID:MSVC>>:/utf-8>)
+        target_compile_options(spdlog_header_only
+                               INTERFACE $<$<AND:$<COMPILE_LANGUAGE:CXX>,$<CXX_COMPILER_ID:MSVC>>:/utf-8>)
+    endif()
+endif()
+
 # ---------------------------------------------------------------------------------------
 # If exceptions are disabled, disable them in the bundled fmt as well
 # ---------------------------------------------------------------------------------------
 if(SPDLOG_NO_EXCEPTIONS)
     if(NOT SPDLOG_FMT_EXTERNAL AND NOT SPDLOG_FMT_EXTERNAL_HO)
-        target_compile_definitions(spdlog PUBLIC FMT_EXCEPTIONS=0)
+        target_compile_definitions(spdlog PUBLIC FMT_USE_EXCEPTIONS=0)
     endif()
     if(NOT MSVC)
         target_compile_options(spdlog PRIVATE -fno-exceptions)
     else()
         target_compile_options(spdlog PRIVATE /EHs-c-)
+        target_compile_definitions(spdlog PRIVATE _HAS_EXCEPTIONS=0)
     endif()
 endif()
 # ---------------------------------------------------------------------------------------

README.md

@@ -1,18 +1,25 @@
 # spdlog
 
-Very fast, header-only/compiled, C++ logging library. [![ci](https://github.com/gabime/spdlog/actions/workflows/ci.yml/badge.svg)](https://github.com/gabime/spdlog/actions/workflows/ci.yml)  [![Build status](https://ci.appveyor.com/api/projects/status/d2jnxclg20vd0o50?svg=true&branch=v1.x)](https://ci.appveyor.com/project/gabime/spdlog) [![Release](https://img.shields.io/github/release/gabime/spdlog.svg)](https://github.com/gabime/spdlog/releases/latest)
+ 
+[![ci](https://github.com/gabime/spdlog/actions/workflows/linux.yml/badge.svg)](https://github.com/gabime/spdlog/actions/workflows/linux.yml) 
+[![ci](https://github.com/gabime/spdlog/actions/workflows/windows.yml/badge.svg)](https://github.com/gabime/spdlog/actions/workflows/windows.yml) 
+[![ci](https://github.com/gabime/spdlog/actions/workflows/macos.yml/badge.svg)](https://github.com/gabime/spdlog/actions/workflows/macos.yml) 
+[![Build status](https://ci.appveyor.com/api/projects/status/d2jnxclg20vd0o50?svg=true&branch=v1.x)](https://ci.appveyor.com/project/gabime/spdlog) [![Release](https://img.shields.io/github/release/gabime/spdlog.svg)](https://github.com/gabime/spdlog/releases/latest)
+
+Fast C++ logging library
+
 
 ## Install
 #### Header-only version
-Copy the include [folder](https://github.com/gabime/spdlog/tree/v1.x/include/spdlog) to your build tree and use a C++11 compiler.
+Copy the include [folder](include/spdlog) to your build tree and use a C++11 compiler.
 
 #### Compiled version (recommended - much faster compile times)
 ```console
 $ git clone https://github.com/gabime/spdlog.git
 $ cd spdlog && mkdir build && cd build
-$ cmake .. && make -j
+$ cmake .. && cmake --build .
 ```
-see example [CMakeLists.txt](https://github.com/gabime/spdlog/blob/v1.x/example/CMakeLists.txt) on how to use.
+see example [CMakeLists.txt](example/CMakeLists.txt) on how to use.
 
 ## Platforms
 * Linux, FreeBSD, OpenBSD, Solaris, AIX
@@ -29,8 +36,9 @@ see example [CMakeLists.txt](https://github.com/gabime/spdlog/blob/v1.x/example/
 * Gentoo: `emerge dev-libs/spdlog`
 * Arch Linux: `pacman -S spdlog`
 * openSUSE: `sudo zypper in spdlog-devel`
+* ALT Linux: `apt-get install libspdlog-devel`
 * vcpkg: `vcpkg install spdlog`
-* conan: `spdlog/[>=1.4.1]`
+* conan: `conan install --requires=spdlog/[*]`
 * conda: `conda install -c conda-forge spdlog`
 * build2: ```depends: spdlog ^1.8.2```
 
@@ -40,7 +48,7 @@ see example [CMakeLists.txt](https://github.com/gabime/spdlog/blob/v1.x/example/
 * Headers only or compiled
 * Feature-rich formatting, using the excellent [fmt](https://github.com/fmtlib/fmt) library.
 * Asynchronous mode (optional)
-* [Custom](https://github.com/gabime/spdlog/wiki/3.-Custom-formatting) formatting.
+* [Custom](https://github.com/gabime/spdlog/wiki/Custom-formatting) formatting.
 * Multi/Single threaded loggers.
 * Various log targets:
   * Rotating log files.
@@ -50,7 +58,7 @@ see example [CMakeLists.txt](https://github.com/gabime/spdlog/blob/v1.x/example/
   * Windows event log.
   * Windows debugger (```OutputDebugString(..)```).
   * Log to Qt widgets ([example](#log-to-qt-with-nice-colors)).
-  * Easily [extendable](https://github.com/gabime/spdlog/wiki/4.-Sinks#implementing-your-own-sink) with custom log targets.
+  * Easily [extendable](https://github.com/gabime/spdlog/wiki/Sinks#implementing-your-own-sink) with custom log targets.
 * Log filtering - log levels can be modified at runtime as well as compile time.
 * Support for loading log levels from argv or environment var.
 * [Backtrace](#backtrace-support) support - store debug messages in a ring buffer and display them later on demand.
@@ -72,7 +80,7 @@ int main()
     spdlog::info("Positional args are {1} {0}..", "too", "supported");
     spdlog::info("{:<30}", "left aligned");
     
-    spdlog::set_level(spdlog::level::debug); // Set global log level to debug
+    spdlog::set_level(spdlog::level::debug); // Set *global* log level to debug
     spdlog::debug("This message should be displayed..");    
     
     // change log pattern
@@ -216,7 +224,7 @@ void binary_example()
 ```c++
 
 // create a logger with 2 targets, with different log levels and formats.
-// The console will show only warnings or errors, while the file will log all.
+// The console will show only warnings or errors, while the file will log all. 
 void multi_sink_example()
 {
     auto console_sink = std::make_shared<spdlog::sinks::stdout_color_sink_mt>();
@@ -233,6 +241,29 @@ void multi_sink_example()
 }
 ```
 
+---
+#### Register several loggers - change global level
+```c++
+
+// Creation of loggers. Set levels to all registered loggers. 
+void set_level_example()
+{
+    auto logger1 = spdlog::basic_logger_mt("logger1", "logs/logger1.txt");
+    auto logger2 = spdlog::basic_logger_mt("logger2", "logs/logger2.txt");
+
+    spdlog::set_default_logger(logger2);
+    spdlog::default_logger()->set_level(spdlog::level::trace); // set level for the default logger (logger2) to trace
+
+    spdlog::trace("trace message to the logger2 (specified as default)");
+
+    spdlog::set_level(spdlog::level::off) // (sic!) set level for *all* registered loggers to off (disable)
+  
+    logger1.warn("warn message will not appear because the level set to off");
+    logger2.warn("warn message will not appear because the level set to off");
+    spdlog::warn("warn message will not appear because the level set to off");
+}
+```
+
 ---
 #### User-defined callbacks about log events
 ```c++
@@ -296,7 +327,7 @@ struct fmt::formatter<my_type> : fmt::formatter<std::string>
 {
     auto format(my_type my, format_context &ctx) const -> decltype(ctx.out())
     {
-        return format_to(ctx.out(), "[my_type i={}]", my.i);
+        return fmt::format_to(ctx.out(), "[my_type i={}]", my.i);
     }
 };
 
@@ -380,6 +411,9 @@ void android_example()
 int main (int argc, char *argv[])
 {
     spdlog::cfg::load_env_levels();
+    // or specify the env variable name:
+    // MYAPP_LEVEL=info,mylogger=trace && ./example
+    // spdlog::cfg::load_env_levels("MYAPP_LEVEL");
     // or from the command line:
     // ./example SPDLOG_LEVEL=info,mylogger=trace
     // #include "spdlog/cfg/argv.h" // for loading levels from argv
@@ -456,7 +490,7 @@ void mdc_example()
 ---
 ## Benchmarks
 
-Below are some [benchmarks](https://github.com/gabime/spdlog/blob/v1.x/bench/bench.cpp) done in Ubuntu 64 bit, Intel i7-4770 CPU @ 3.40GHz
+Below are some [benchmarks](bench/bench.cpp) done in Ubuntu 64 bit, Intel i7-4770 CPU @ 3.40GHz
 
 #### Synchronous mode
 ```
@@ -508,10 +542,12 @@ Below are some [benchmarks](https://github.com/gabime/spdlog/blob/v1.x/bench/ben
 ```
 
 ## Documentation
-Documentation can be found in the [wiki](https://github.com/gabime/spdlog/wiki/1.-QuickStart) pages.
+
+Documentation can be found in the [wiki](https://github.com/gabime/spdlog/wiki) pages.
 
 ---
 
-Thanks to [JetBrains](https://www.jetbrains.com/?from=spdlog) for donating product licenses to help develop **spdlog** <a href="https://www.jetbrains.com/?from=spdlog"><img src="logos/jetbrains-variant-4.svg" width="94" align="center" /></a>
+### Powered by
-
+<a href="https://jb.gg/OpenSource">
-
+  <img src="https://resources.jetbrains.com/storage/products/company/brand/logos/jetbrains.svg" alt="JetBrains logo" width="200">
+</a>

bench/async_bench.cpp

@@ -160,7 +160,7 @@ void bench_mt(int howmany, std::shared_ptr<spdlog::logger> logger, int thread_co
 
     for (auto &t : threads) {
         t.join();
-    };
+    }
 
     auto delta = high_resolution_clock::now() - start;
     auto delta_d = duration_cast<duration<double>>(delta).count();

bench/bench.cpp

@@ -181,7 +181,7 @@ void bench_mt(int howmany, std::shared_ptr<spdlog::logger> log, size_t thread_co
 
     for (auto &t : threads) {
         t.join();
-    };
+    }
 
     auto delta = high_resolution_clock::now() - start;
     auto delta_d = duration_cast<duration<double>>(delta).count();
@@ -243,4 +243,4 @@ odio. Maecenas malesuada quam ex, posuere congue nibh turpis duis.";
 delta_d));
 }
 
-*/
+*/

cmake/pch.h.in

@@ -10,7 +10,6 @@
 
 // details/file_helper-inl.h
 // details/os-inl.h
-// fmt/bundled/core.h
 // fmt/bundled/posix.h
 // logger-inl.h
 // sinks/daily_file_sink.h
@@ -23,7 +22,6 @@
 
 // details/os-inl.h
 // details/pattern_formatter-inl.h
-// fmt/bundled/core.h
 // fmt/bundled/format-inl.h
 #include <cstring>
 
@@ -73,7 +71,6 @@
 // details/registry.h
 // details/tcp_client-windows.h
 // details/tcp_client.h
-// fmt/bundled/core.h
 // sinks/android_sink.h
 // sinks/ansicolor_sink.h
 // sinks/basic_file_sink.h
@@ -150,7 +147,6 @@
 
 // common.h
 // details/fmt_helper.h
-// fmt/bundled/core.h
 // fmt/bundled/ranges.h
 #include <type_traits>
 
@@ -255,4 +251,4 @@
 #include <mutex>
 
 // spdlog
-#include <spdlog/common.h>
+#include <spdlog/common.h>

cmake/utils.cmake

@@ -49,7 +49,7 @@ function(spdlog_enable_warnings target_name)
 endfunction()
 
 # Enable address sanitizer (gcc/clang only)
-function(spdlog_enable_sanitizer target_name)
+function(spdlog_enable_addr_sanitizer target_name)
     if(NOT CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
         message(FATAL_ERROR "Sanitizer supported only for gcc/clang")
     endif()
@@ -58,5 +58,16 @@ function(spdlog_enable_sanitizer target_name)
     target_compile_options(${target_name} PRIVATE -fno-sanitize=signed-integer-overflow)
     target_compile_options(${target_name} PRIVATE -fno-sanitize-recover=all)
     target_compile_options(${target_name} PRIVATE -fno-omit-frame-pointer)
-    target_link_libraries(${target_name} PRIVATE -fsanitize=address,undefined -fuse-ld=gold)
+    target_link_libraries(${target_name} PRIVATE -fsanitize=address,undefined)
+endfunction()
+
+# Enable thread sanitizer (gcc/clang only)
+function(spdlog_enable_thread_sanitizer target_name)
+    if(NOT CMAKE_CXX_COMPILER_ID MATCHES "GNU|Clang")
+        message(FATAL_ERROR "Sanitizer supported only for gcc/clang")
+    endif()
+    message(STATUS "Thread sanitizer enabled")
+    target_compile_options(${target_name} PRIVATE -fsanitize=thread)
+    target_compile_options(${target_name} PRIVATE -fno-omit-frame-pointer)
+    target_link_libraries(${target_name} PRIVATE -fsanitize=thread)
 endfunction()

example/example.cpp

@@ -33,41 +33,41 @@ void mdc_example();
 #include "spdlog/fmt/ostr.h"  // support for user defined types
 
 int main(int, char *[]) {
-    // Log levels can be loaded from argv/env using "SPDLOG_LEVEL"
-    load_levels_example();
-
-    spdlog::info("Welcome to spdlog version {}.{}.{}  !", SPDLOG_VER_MAJOR, SPDLOG_VER_MINOR,
-                 SPDLOG_VER_PATCH);
-
-    spdlog::warn("Easy padding in numbers like {:08d}", 12);
-    spdlog::critical("Support for int: {0:d};  hex: {0:x};  oct: {0:o}; bin: {0:b}", 42);
-    spdlog::info("Support for floats {:03.2f}", 1.23456);
-    spdlog::info("Positional args are {1} {0}..", "too", "supported");
-    spdlog::info("{:>8} aligned, {:<8} aligned", "right", "left");
-
-    // Runtime log levels
-    spdlog::set_level(spdlog::level::info);  // Set global log level to info
-    spdlog::debug("This message should not be displayed!");
-    spdlog::set_level(spdlog::level::trace);  // Set specific logger's log level
-    spdlog::debug("This message should be displayed..");
-
-    // Customize msg format for all loggers
-    spdlog::set_pattern("[%H:%M:%S %z] [%^%L%$] [thread %t] %v");
-    spdlog::info("This an info message with custom format");
-    spdlog::set_pattern("%+");  // back to default format
-    spdlog::set_level(spdlog::level::info);
-
-    // Backtrace support
-    // Loggers can store in a ring buffer all messages (including debug/trace) for later inspection.
-    // When needed, call dump_backtrace() to see what happened:
-    spdlog::enable_backtrace(10);  // create ring buffer with capacity of 10  messages
-    for (int i = 0; i < 100; i++) {
-        spdlog::debug("Backtrace message {}", i);  // not logged..
-    }
-    // e.g. if some error happened:
-    spdlog::dump_backtrace();  // log them now!
-
     try {
+        // Log levels can be loaded from argv/env using "SPDLOG_LEVEL"
+        load_levels_example();
+
+        spdlog::info("Welcome to spdlog version {}.{}.{}  !", SPDLOG_VER_MAJOR, SPDLOG_VER_MINOR,
+                     SPDLOG_VER_PATCH);
+
+        spdlog::warn("Easy padding in numbers like {:08d}", 12);
+        spdlog::critical("Support for int: {0:d};  hex: {0:x};  oct: {0:o}; bin: {0:b}", 42);
+        spdlog::info("Support for floats {:03.2f}", 1.23456);
+        spdlog::info("Positional args are {1} {0}..", "too", "supported");
+        spdlog::info("{:>8} aligned, {:<8} aligned", "right", "left");
+
+        // Runtime log levels
+        spdlog::set_level(spdlog::level::info);  // Set global log level to info
+        spdlog::debug("This message should not be displayed!");
+        spdlog::set_level(spdlog::level::trace);  // Set specific logger's log level
+        spdlog::debug("This message should be displayed..");
+
+        // Customize msg format for all loggers
+        spdlog::set_pattern("[%H:%M:%S %z] [%^%L%$] [thread %t] %v");
+        spdlog::info("This an info message with custom format");
+        spdlog::set_pattern("%+");  // back to default format
+        spdlog::set_level(spdlog::level::info);
+
+        // Backtrace support
+        // Loggers can store in a ring buffer all messages (including debug/trace) for later
+        // inspection. When needed, call dump_backtrace() to see what happened:
+        spdlog::enable_backtrace(10);  // create ring buffer with capacity of 10  messages
+        for (int i = 0; i < 100; i++) {
+            spdlog::debug("Backtrace message {}", i);  // not logged..
+        }
+        // e.g. if some error happened:
+        spdlog::dump_backtrace();  // log them now!
+
         stdout_logger_example();
         basic_example();
         rotating_example();
@@ -148,6 +148,9 @@ void load_levels_example() {
     // Set the log level to "info" and mylogger to "trace":
     // SPDLOG_LEVEL=info,mylogger=trace && ./example
     spdlog::cfg::load_env_levels();
+    // or specify the env variable name:
+    // MYAPP_LEVEL=info,mylogger=trace && ./example
+    // spdlog::cfg::load_env_levels("MYAPP_LEVEL");
     // or from command line:
     // ./example SPDLOG_LEVEL=info,mylogger=trace
     // #include "spdlog/cfg/argv.h" // for loading levels from argv
@@ -266,13 +269,13 @@ void multi_sink_example() {
 struct my_type {
     int i = 0;
     explicit my_type(int i)
-        : i(i){};
+        : i(i) {}
 };
 
 #ifndef SPDLOG_USE_STD_FORMAT  // when using fmtlib
 template <>
 struct fmt::formatter<my_type> : fmt::formatter<std::string> {
-    auto format(my_type my, format_context &ctx) -> decltype(ctx.out()) {
+    auto format(my_type my, format_context &ctx) const -> decltype(ctx.out()) {
         return fmt::format_to(ctx.out(), "[my_type i={}]", my.i);
     }
 };
@@ -281,7 +284,7 @@ struct fmt::formatter<my_type> : fmt::formatter<std::string> {
 template <>
 struct std::formatter<my_type> : std::formatter<std::string> {
     auto format(my_type my, format_context &ctx) const -> decltype(ctx.out()) {
-        return format_to(ctx.out(), "[my_type i={}]", my.i);
+        return std::format_to(ctx.out(), "[my_type i={}]", my.i);
     }
 };
 #endif
@@ -368,26 +371,31 @@ void replace_default_logger_example() {
     // store the old logger so we don't break other examples.
     auto old_logger = spdlog::default_logger();
 
-    auto new_logger =
+    auto new_logger = spdlog::basic_logger_mt("new_default_logger", "logs/somelog.txt", true);
-        spdlog::basic_logger_mt("new_default_logger", "logs/new-default-log.txt", true);
+    spdlog::set_default_logger(std::move(new_logger));
-    spdlog::set_default_logger(new_logger);
     spdlog::set_level(spdlog::level::info);
     spdlog::debug("This message should not be displayed!");
     spdlog::set_level(spdlog::level::trace);
     spdlog::debug("This message should be displayed..");
-
+    spdlog::set_default_logger(std::move(old_logger));
-    spdlog::set_default_logger(old_logger);
 }
 
-// Mapped Diagnostic Context (MDC) is a map that stores key-value pairs (string values) in thread local storage.
+// Mapped Diagnostic Context (MDC) is a map that stores key-value pairs (string values) in thread
-// Each thread maintains its own MDC, which loggers use to append diagnostic information to log outputs.
+// local storage. Each thread maintains its own MDC, which loggers use to append diagnostic
-// Note: it is not supported in asynchronous mode due to its reliance on thread-local storage.
+// information to log outputs. Note: it is not supported in asynchronous mode due to its reliance on
-#include "spdlog/mdc.h"
+// thread-local storage.
-void mdc_example()
+
-{
+#ifndef SPDLOG_NO_TLS
+    #include "spdlog/mdc.h"
+void mdc_example() {
     spdlog::mdc::put("key1", "value1");
     spdlog::mdc::put("key2", "value2");
     // if not using the default format, you can use the %& formatter to print mdc data as well
     spdlog::set_pattern("[%H:%M:%S %z] [%^%L%$] [%&] %v");
     spdlog::info("Some log message with context");
 }
+#else
+void mdc_example() {
+    // if TLS feature is disabled
+}
+#endif

include/spdlog/async.h

@@ -89,8 +89,7 @@ inline void init_thread_pool(size_t q_size,
 }
 
 inline void init_thread_pool(size_t q_size, size_t thread_count) {
-    init_thread_pool(
+    init_thread_pool(q_size, thread_count, [] {}, [] {});
-        q_size, thread_count, [] {}, [] {});
 }
 
 // get the global thread pool.

include/spdlog/async_logger-inl.h

@@ -33,7 +33,7 @@ SPDLOG_INLINE spdlog::async_logger::async_logger(std::string logger_name,
 // send the log message to the thread pool
 SPDLOG_INLINE void spdlog::async_logger::sink_it_(const details::log_msg &msg){
     SPDLOG_TRY{if (auto pool_ptr = thread_pool_.lock()){
-        pool_ptr->post_log(shared_from_this(), msg, overflow_policy_);
+        pool_ptr -> post_log(shared_from_this(), msg, overflow_policy_);
 }
 else {
     throw_spdlog_ex("async log: thread pool doesn't exist anymore");
@@ -43,15 +43,13 @@ SPDLOG_LOGGER_CATCH(msg.source)
 }
 
 // send flush request to the thread pool
-SPDLOG_INLINE void spdlog::async_logger::flush_(){SPDLOG_TRY{auto pool_ptr = thread_pool_.lock();
+SPDLOG_INLINE void spdlog::async_logger::flush_(){
-if (!pool_ptr) {
+    SPDLOG_TRY{if (auto pool_ptr = thread_pool_.lock()){
+        pool_ptr -> post_flush(shared_from_this(), overflow_policy_);
+}
+else {
     throw_spdlog_ex("async flush: thread pool doesn't exist anymore");
 }
-
-std::future<void> future = pool_ptr->post_flush(shared_from_this(), overflow_policy_);
-// Wait for the flush operation to complete.
-// This might throw exception if the flush message get dropped because of overflow.
-future.get();
 }
 SPDLOG_LOGGER_CATCH(source_loc())
 }

include/spdlog/cfg/env.h

@@ -25,8 +25,8 @@
 
 namespace spdlog {
 namespace cfg {
-inline void load_env_levels() {
+inline void load_env_levels(const char* var = "SPDLOG_LEVEL") {
-    auto env_val = details::os::getenv("SPDLOG_LEVEL");
+    auto env_val = details::os::getenv(var);
     if (!env_val.empty()) {
         helpers::load_levels(env_val);
     }

include/spdlog/cfg/helpers-inl.h

@@ -9,7 +9,6 @@
 
 #include <spdlog/details/os.h>
 #include <spdlog/details/registry.h>
-#include <spdlog/spdlog.h>
 
 #include <algorithm>
 #include <sstream>
@@ -36,7 +35,7 @@ inline std::string &trim_(std::string &str) {
     return str;
 }
 
-// return (name,value) trimmed pair from given "name=value" string.
+// return (name,value) trimmed pair from the given "name = value" string.
 // return empty string on missing parts
 // "key=val" => ("key", "val")
 // " key  =  val " => ("key", "val")
@@ -55,7 +54,7 @@ inline std::pair<std::string, std::string> extract_kv_(char sep, const std::stri
     return std::make_pair(trim_(k), trim_(v));
 }
 
-// return vector of key/value pairs from sequence of "K1=V1,K2=V2,.."
+// return vector of key/value pairs from a sequence of "K1=V1,K2=V2,.."
 // "a=AAA,b=BBB,c=CCC,.." => {("a","AAA"),("b","BBB"),("c", "CCC"),...}
 inline std::unordered_map<std::string, std::string> extract_key_vals_(const std::string &str) {
     std::string token;
@@ -72,7 +71,7 @@ inline std::unordered_map<std::string, std::string> extract_key_vals_(const std:
 }
 
 SPDLOG_INLINE void load_levels(const std::string &input) {
-    if (input.empty() || input.size() > 512) {
+    if (input.empty() || input.size() >= 32768) {
         return;
     }
 
@@ -82,14 +81,14 @@ SPDLOG_INLINE void load_levels(const std::string &input) {
     bool global_level_found = false;
 
     for (auto &name_level : key_vals) {
-        auto &logger_name = name_level.first;
+        const auto &logger_name = name_level.first;
-        auto level_name = to_lower_(name_level.second);
+        const auto &level_name = to_lower_(name_level.second);
         auto level = level::from_str(level_name);
         // ignore unrecognized level names
         if (level == level::off && level_name != "off") {
             continue;
         }
-        if (logger_name.empty())  // no logger name indicate global level
+        if (logger_name.empty())  // no logger name indicates global level
         {
             global_level_found = true;
             global_level = level;

include/spdlog/common.h

@@ -364,12 +364,7 @@ SPDLOG_CONSTEXPR_FUNC spdlog::wstring_view_t to_string_view(spdlog::wstring_view
 }
 #endif
 
-#ifndef SPDLOG_USE_STD_FORMAT
+#if defined(SPDLOG_USE_STD_FORMAT) && __cpp_lib_format >= 202207L
-template <typename T, typename... Args>
-inline fmt::basic_string_view<T> to_string_view(fmt::basic_format_string<T, Args...> fmt) {
-    return fmt;
-}
-#elif __cpp_lib_format >= 202207L
 template <typename T, typename... Args>
 SPDLOG_CONSTEXPR_FUNC std::basic_string_view<T> to_string_view(
     std::basic_format_string<T, Args...> fmt) SPDLOG_NOEXCEPT {

include/spdlog/details/file_helper-inl.h

@@ -11,10 +11,8 @@
 #include <spdlog/details/os.h>
 
 #include <cerrno>
-#include <chrono>
 #include <cstdio>
 #include <string>
-#include <thread>
 #include <tuple>
 
 namespace spdlog {
@@ -101,7 +99,8 @@ SPDLOG_INLINE void file_helper::write(const memory_buf_t &buf) {
     if (fd_ == nullptr) return;
     size_t msg_size = buf.size();
     auto data = buf.data();
-    if (std::fwrite(data, 1, msg_size, fd_) != msg_size) {
+
+    if (!details::os::fwrite_bytes(data, msg_size, fd_)) {
         throw_spdlog_ex("Failed writing to file " + os::filename_to_str(filename_), errno);
     }
 }

include/spdlog/details/mpmc_blocking_q.h

@@ -148,19 +148,19 @@ public:
 #endif
 
     size_t overrun_counter() {
-        std::unique_lock<std::mutex> lock(queue_mutex_);
+        std::lock_guard<std::mutex> lock(queue_mutex_);
         return q_.overrun_counter();
     }
 
     size_t discard_counter() { return discard_counter_.load(std::memory_order_relaxed); }
 
     size_t size() {
-        std::unique_lock<std::mutex> lock(queue_mutex_);
+        std::lock_guard<std::mutex> lock(queue_mutex_);
         return q_.size();
     }
 
     void reset_overrun_counter() {
-        std::unique_lock<std::mutex> lock(queue_mutex_);
+        std::lock_guard<std::mutex> lock(queue_mutex_);
         q_.reset_overrun_counter();
     }
 

include/spdlog/details/os-inl.h

@@ -23,7 +23,6 @@
 
 #ifdef _WIN32
     #include <spdlog/details/windows_include.h>
-    #include <fileapi.h>  // for FlushFileBuffers
     #include <io.h>       // for _get_osfhandle, _isatty, _fileno
     #include <process.h>  // for _get_pid
 
@@ -265,9 +264,10 @@ SPDLOG_INLINE int utc_minutes_offset(const std::tm &tm) {
     return offset;
 #else
 
-    #if defined(sun) || defined(__sun) || defined(_AIX) || \
+    #if defined(sun) || defined(__sun) || defined(_AIX) ||                        \
-        (defined(__NEWLIB__) && !defined(__TM_GMTOFF)) ||  \
+        (defined(__NEWLIB__) && !defined(__TM_GMTOFF)) ||                         \
-        (!defined(_BSD_SOURCE) && !defined(_GNU_SOURCE))
+        (!defined(__APPLE__) && !defined(_BSD_SOURCE) && !defined(_GNU_SOURCE) && \
+         (!defined(_POSIX_VERSION) || (_POSIX_VERSION < 202405L)))
     // 'tm_gmtoff' field is BSD extension and it's missing on SunOS/Solaris
     struct helper {
         static long int calculate_gmt_offset(const std::tm &localtm = details::os::localtime(),
@@ -482,13 +482,12 @@ SPDLOG_INLINE void utf8_to_wstrbuf(string_view_t str, wmemory_buf_t &target) {
     }
 
     // find the size to allocate for the result buffer
-    int result_size =
+    int result_size = ::MultiByteToWideChar(CP_UTF8, 0, str.data(), str_size, NULL, 0);
-        ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, str.data(), str_size, NULL, 0);
 
     if (result_size > 0) {
         target.resize(result_size);
-        result_size = ::MultiByteToWideChar(CP_UTF8, MB_ERR_INVALID_CHARS, str.data(), str_size,
+        result_size =
-                                            target.data(), result_size);
+            ::MultiByteToWideChar(CP_UTF8, 0, str.data(), str_size, target.data(), result_size);
         if (result_size > 0) {
             assert(result_size == target.size());
             return;
@@ -563,21 +562,21 @@ SPDLOG_INLINE filename_t dir_name(const filename_t &path) {
     return pos != filename_t::npos ? path.substr(0, pos) : filename_t{};
 }
 
+#ifdef _MSC_VER
+    #pragma warning(push)
+    #pragma warning(disable : 4996)
+#endif  // _MSC_VER
 std::string SPDLOG_INLINE getenv(const char *field) {
-#if defined(_MSC_VER)
+#if defined(_MSC_VER) && defined(__cplusplus_winrt)
-    #if defined(__cplusplus_winrt)
     return std::string{};  // not supported under uwp
-    #else
+#else
-    size_t len = 0;
+    char *buf = std::getenv(field);
-    char buf[128];
-    bool ok = ::getenv_s(&len, buf, sizeof(buf), field) == 0;
-    return ok ? buf : std::string{};
-    #endif
-#else  // revert to getenv
-    char *buf = ::getenv(field);
     return buf ? buf : std::string{};
 #endif
 }
+#ifdef _MSC_VER
+    #pragma warning(pop)
+#endif  // _MSC_VER
 
 // Do fsync by FILE handlerpointer
 // Return true on success
@@ -589,6 +588,18 @@ SPDLOG_INLINE bool fsync(FILE *fp) {
 #endif
 }
 
+// Do non-locking fwrite if possible by the os or use the regular locking fwrite
+// Return true on success.
+SPDLOG_INLINE bool fwrite_bytes(const void *ptr, const size_t n_bytes, FILE *fp) {
+#if defined(_WIN32) && defined(SPDLOG_FWRITE_UNLOCKED)
+    return _fwrite_nolock(ptr, 1, n_bytes, fp) == n_bytes;
+#elif defined(SPDLOG_FWRITE_UNLOCKED)
+    return ::fwrite_unlocked(ptr, 1, n_bytes, fp) == n_bytes;
+#else
+    return std::fwrite(ptr, 1, n_bytes, fp) == n_bytes;
+#endif
+}
+
 }  // namespace os
 }  // namespace details
 }  // namespace spdlog

include/spdlog/details/os.h

@@ -114,6 +114,10 @@ SPDLOG_API std::string getenv(const char *field);
 // Return true on success.
 SPDLOG_API bool fsync(FILE *fp);
 
+// Do non-locking fwrite if possible by the os or use the regular locking fwrite
+// Return true on success.
+SPDLOG_API bool fwrite_bytes(const void *ptr, const size_t n_bytes, FILE *fp);
+
 }  // namespace os
 }  // namespace details
 }  // namespace spdlog

include/spdlog/details/registry-inl.h

@@ -54,6 +54,11 @@ SPDLOG_INLINE void registry::register_logger(std::shared_ptr<logger> new_logger)
     register_logger_(std::move(new_logger));
 }
 
+SPDLOG_INLINE void registry::register_or_replace(std::shared_ptr<logger> new_logger) {
+    std::lock_guard<std::mutex> lock(logger_map_mutex_);
+    register_or_replace_(std::move(new_logger));
+}
+
 SPDLOG_INLINE void registry::initialize_logger(std::shared_ptr<logger> new_logger) {
     std::lock_guard<std::mutex> lock(logger_map_mutex_);
     new_logger->set_formatter(formatter_->clone());
@@ -96,7 +101,7 @@ SPDLOG_INLINE std::shared_ptr<logger> registry::default_logger() {
 SPDLOG_INLINE logger *registry::get_default_raw() { return default_logger_.get(); }
 
 // set default logger.
-// default logger is stored in default_logger_ (for faster retrieval) and in the loggers_ map.
+// the default logger is stored in default_logger_ (for faster retrieval) and in the loggers_ map.
 SPDLOG_INLINE void registry::set_default_logger(std::shared_ptr<logger> new_default_logger) {
     std::lock_guard<std::mutex> lock(logger_map_mutex_);
     if (new_default_logger != nullptr) {
@@ -252,10 +257,14 @@ SPDLOG_INLINE void registry::throw_if_exists_(const std::string &logger_name) {
 }
 
 SPDLOG_INLINE void registry::register_logger_(std::shared_ptr<logger> new_logger) {
-    auto logger_name = new_logger->name();
+    auto &logger_name = new_logger->name();
     throw_if_exists_(logger_name);
     loggers_[logger_name] = std::move(new_logger);
 }
 
+SPDLOG_INLINE void registry::register_or_replace_(std::shared_ptr<logger> new_logger) {
+    loggers_[new_logger->name()] = std::move(new_logger);
+}
+
 }  // namespace details
 }  // namespace spdlog

include/spdlog/details/registry.h

@@ -31,6 +31,7 @@ public:
     registry &operator=(const registry &) = delete;
 
     void register_logger(std::shared_ptr<logger> new_logger);
+    void register_or_replace(std::shared_ptr<logger> new_logger);
     void initialize_logger(std::shared_ptr<logger> new_logger);
     std::shared_ptr<logger> get(const std::string &logger_name);
     std::shared_ptr<logger> default_logger();
@@ -105,6 +106,7 @@ private:
 
     void throw_if_exists_(const std::string &logger_name);
     void register_logger_(std::shared_ptr<logger> new_logger);
+    void register_or_replace_(std::shared_ptr<logger> new_logger);
     bool set_level_from_cfg_(logger *logger);
     std::mutex logger_map_mutex_, flusher_mutex_;
     std::recursive_mutex tp_mutex_;

include/spdlog/details/tcp_client-windows.h

@@ -58,8 +58,81 @@ public:
 
     SOCKET fd() const { return socket_; }
 
+    int connect_socket_with_timeout(SOCKET sockfd,
+                                    const struct sockaddr *addr,
+                                    int addrlen,
+                                    const timeval &tv) {
+        // If no timeout requested, do a normal blocking connect.
+        if (tv.tv_sec == 0 && tv.tv_usec == 0) {
+            int rv = ::connect(sockfd, addr, addrlen);
+            if (rv == SOCKET_ERROR && WSAGetLastError() == WSAEISCONN) {
+                return 0;
+            }
+            return rv;
+        }
+
+        // Switch to non‐blocking mode
+        u_long mode = 1UL;
+        if (::ioctlsocket(sockfd, FIONBIO, &mode) == SOCKET_ERROR) {
+            return SOCKET_ERROR;
+        }
+
+        int rv = ::connect(sockfd, addr, addrlen);
+        int last_error = WSAGetLastError();
+        if (rv == 0 || last_error == WSAEISCONN) {
+            mode = 0UL;
+            if (::ioctlsocket(sockfd, FIONBIO, &mode) == SOCKET_ERROR) {
+                return SOCKET_ERROR;
+            }
+            return 0;
+        }
+        if (last_error != WSAEWOULDBLOCK) {
+            // Real error
+            mode = 0UL;
+            if (::ioctlsocket(sockfd, FIONBIO, &mode)) {
+                return SOCKET_ERROR;
+            }
+            return SOCKET_ERROR;
+        }
+
+        // Wait until socket is writable or timeout expires
+        fd_set wfds;
+        FD_ZERO(&wfds);
+        FD_SET(sockfd, &wfds);
+
+        rv = ::select(0, nullptr, &wfds, nullptr, const_cast<timeval *>(&tv));
+
+        // Restore blocking mode regardless of select result
+        mode = 0UL;
+        if (::ioctlsocket(sockfd, FIONBIO, &mode) == SOCKET_ERROR) {
+            return SOCKET_ERROR;
+        }
+
+        if (rv == 0) {
+            WSASetLastError(WSAETIMEDOUT);
+            return SOCKET_ERROR;
+        }
+        if (rv == SOCKET_ERROR) {
+            return SOCKET_ERROR;
+        }
+
+        int so_error = 0;
+        int len = sizeof(so_error);
+        if (::getsockopt(sockfd, SOL_SOCKET, SO_ERROR, reinterpret_cast<char *>(&so_error), &len) ==
+            SOCKET_ERROR) {
+            return SOCKET_ERROR;
+        }
+        if (so_error != 0 && so_error != WSAEISCONN) {
+            // connection failed
+            WSASetLastError(so_error);
+            return SOCKET_ERROR;
+        }
+
+        return 0;  // success
+    }
+
     // try to connect or throw on failure
-    void connect(const std::string &host, int port) {
+    void connect(const std::string &host, int port, int timeout_ms = 0) {
         if (is_connected()) {
             close();
         }
@@ -71,6 +144,10 @@ public:
         hints.ai_flags = AI_NUMERICSERV;  // port passed as as numeric value
         hints.ai_protocol = 0;
 
+        timeval tv;
+        tv.tv_sec = timeout_ms / 1000;
+        tv.tv_usec = (timeout_ms % 1000) * 1000;
+
         auto port_str = std::to_string(port);
         struct addrinfo *addrinfo_result;
         auto rv = ::getaddrinfo(host.c_str(), port_str.c_str(), &hints, &addrinfo_result);
@@ -82,7 +159,6 @@ public:
         }
 
         // Try each address until we successfully connect(2).
-
         for (auto *rp = addrinfo_result; rp != nullptr; rp = rp->ai_next) {
             socket_ = socket(rp->ai_family, rp->ai_socktype, rp->ai_protocol);
             if (socket_ == INVALID_SOCKET) {
@@ -90,18 +166,24 @@ public:
                 WSACleanup();
                 continue;
             }
-            if (::connect(socket_, rp->ai_addr, (int)rp->ai_addrlen) == 0) {
+            if (connect_socket_with_timeout(socket_, rp->ai_addr, (int)rp->ai_addrlen, tv) == 0) {
+                last_error = 0;
                 break;
-            } else {
-                last_error = ::WSAGetLastError();
-                close();
             }
+            last_error = WSAGetLastError();
+            ::closesocket(socket_);
+            socket_ = INVALID_SOCKET;
         }
         ::freeaddrinfo(addrinfo_result);
         if (socket_ == INVALID_SOCKET) {
             WSACleanup();
             throw_winsock_error_("connect failed", last_error);
         }
+        if (timeout_ms > 0) {
+            DWORD tv = static_cast<DWORD>(timeout_ms);
+            ::setsockopt(socket_, SOL_SOCKET, SO_RCVTIMEO, (const char *)&tv, sizeof(tv));
+            ::setsockopt(socket_, SOL_SOCKET, SO_SNDTIMEO, (const char *)&tv, sizeof(tv));
+        }
 
         // set TCP_NODELAY
         int enable_flag = 1;

include/spdlog/details/tcp_client.h

@@ -39,8 +39,72 @@ public:
 
     ~tcp_client() { close(); }
 
+    int connect_socket_with_timeout(int sockfd,
+                                    const struct sockaddr *addr,
+                                    socklen_t addrlen,
+                                    const timeval &tv) {
+        // Blocking connect if timeout is zero
+        if (tv.tv_sec == 0 && tv.tv_usec == 0) {
+            int rv = ::connect(sockfd, addr, addrlen);
+            if (rv < 0 && errno == EISCONN) {
+                // already connected, treat as success
+                return 0;
+            }
+            return rv;
+        }
+
+        // Non-blocking path
+        int orig_flags = ::fcntl(sockfd, F_GETFL, 0);
+        if (orig_flags < 0) {
+            return -1;
+        }
+        if (::fcntl(sockfd, F_SETFL, orig_flags | O_NONBLOCK) < 0) {
+            return -1;
+        }
+
+        int rv = ::connect(sockfd, addr, addrlen);
+        if (rv == 0 || (rv < 0 && errno == EISCONN)) {
+            // immediate connect or already connected
+            ::fcntl(sockfd, F_SETFL, orig_flags);
+            return 0;
+        }
+        if (errno != EINPROGRESS) {
+            ::fcntl(sockfd, F_SETFL, orig_flags);
+            return -1;
+        }
+
+        // wait for writability
+        fd_set wfds;
+        FD_ZERO(&wfds);
+        FD_SET(sockfd, &wfds);
+
+        struct timeval tv_copy = tv;
+        rv = ::select(sockfd + 1, nullptr, &wfds, nullptr, &tv_copy);
+        if (rv <= 0) {
+            // timeout or error
+            ::fcntl(sockfd, F_SETFL, orig_flags);
+            if (rv == 0) errno = ETIMEDOUT;
+            return -1;
+        }
+
+        // check socket error
+        int so_error = 0;
+        socklen_t len = sizeof(so_error);
+        if (::getsockopt(sockfd, SOL_SOCKET, SO_ERROR, &so_error, &len) < 0) {
+            ::fcntl(sockfd, F_SETFL, orig_flags);
+            return -1;
+        }
+        ::fcntl(sockfd, F_SETFL, orig_flags);
+        if (so_error != 0 && so_error != EISCONN) {
+            errno = so_error;
+            return -1;
+        }
+
+        return 0;
+    }
+
     // try to connect or throw on failure
-    void connect(const std::string &host, int port) {
+    void connect(const std::string &host, int port, int timeout_ms = 0) {
         close();
         struct addrinfo hints {};
         memset(&hints, 0, sizeof(struct addrinfo));
@@ -49,6 +113,10 @@ public:
         hints.ai_flags = AI_NUMERICSERV;  // port passed as as numeric value
         hints.ai_protocol = 0;
 
+        struct timeval tv;
+        tv.tv_sec = timeout_ms / 1000;
+        tv.tv_usec = (timeout_ms % 1000) * 1000;
+
         auto port_str = std::to_string(port);
         struct addrinfo *addrinfo_result;
         auto rv = ::getaddrinfo(host.c_str(), port_str.c_str(), &hints, &addrinfo_result);
@@ -69,8 +137,9 @@ public:
                 last_errno = errno;
                 continue;
             }
-            rv = ::connect(socket_, rp->ai_addr, rp->ai_addrlen);
+            ::fcntl(socket_, F_SETFD, FD_CLOEXEC);
-            if (rv == 0) {
+            if (connect_socket_with_timeout(socket_, rp->ai_addr, rp->ai_addrlen, tv) == 0) {
+                last_errno = 0;
                 break;
             }
             last_errno = errno;
@@ -82,6 +151,12 @@ public:
             throw_spdlog_ex("::connect failed", last_errno);
         }
 
+        if (timeout_ms > 0) {
+            // Set timeouts for send and recv
+            ::setsockopt(socket_, SOL_SOCKET, SO_RCVTIMEO, (const char *)&tv, sizeof(tv));
+            ::setsockopt(socket_, SOL_SOCKET, SO_SNDTIMEO, (const char *)&tv, sizeof(tv));
+        }
+
         // set TCP_NODELAY
         int enable_flag = 1;
         ::setsockopt(socket_, IPPROTO_TCP, TCP_NODELAY, reinterpret_cast<char *>(&enable_flag),

include/spdlog/details/thread_pool-inl.h

@@ -35,11 +35,10 @@ SPDLOG_INLINE thread_pool::thread_pool(size_t q_max_items,
 SPDLOG_INLINE thread_pool::thread_pool(size_t q_max_items,
                                        size_t threads_n,
                                        std::function<void()> on_thread_start)
-    : thread_pool(q_max_items, threads_n, on_thread_start, [] {}) {}
+    : thread_pool(q_max_items, threads_n, std::move(on_thread_start), [] {}) {}
 
 SPDLOG_INLINE thread_pool::thread_pool(size_t q_max_items, size_t threads_n)
-    : thread_pool(
+    : thread_pool(q_max_items, threads_n, [] {}, [] {}) {}
-          q_max_items, threads_n, [] {}, [] {}) {}
 
 // message all threads to terminate gracefully join them
 SPDLOG_INLINE thread_pool::~thread_pool() {
@@ -62,13 +61,9 @@ void SPDLOG_INLINE thread_pool::post_log(async_logger_ptr &&worker_ptr,
     post_async_msg_(std::move(async_m), overflow_policy);
 }
 
-std::future<void> SPDLOG_INLINE thread_pool::post_flush(async_logger_ptr &&worker_ptr,
+void SPDLOG_INLINE thread_pool::post_flush(async_logger_ptr &&worker_ptr,
-                                                        async_overflow_policy overflow_policy) {
+                                           async_overflow_policy overflow_policy) {
-    std::promise<void> promise;
+    post_async_msg_(async_msg(std::move(worker_ptr), async_msg_type::flush), overflow_policy);
-    std::future<void> future = promise.get_future();
-    post_async_msg_(async_msg(std::move(worker_ptr), async_msg_type::flush, std::move(promise)),
-                    overflow_policy);
-    return future;
 }
 
 size_t SPDLOG_INLINE thread_pool::overrun_counter() { return q_.overrun_counter(); }
@@ -99,8 +94,7 @@ void SPDLOG_INLINE thread_pool::worker_loop_() {
 }
 
 // process next message in the queue
-// return true if this thread should still be active (while no terminate msg
+// returns true if this thread should still be active (while no terminated msg was received)
-// was received)
 bool SPDLOG_INLINE thread_pool::process_next_msg_() {
     async_msg incoming_async_msg;
     q_.dequeue(incoming_async_msg);
@@ -112,7 +106,6 @@ bool SPDLOG_INLINE thread_pool::process_next_msg_() {
         }
         case async_msg_type::flush: {
             incoming_async_msg.worker_ptr->backend_flush_();
-            incoming_async_msg.flush_promise.set_value();
             return true;
         }
 

include/spdlog/details/thread_pool.h

@@ -9,7 +9,6 @@
 
 #include <chrono>
 #include <functional>
-#include <future>
 #include <memory>
 #include <thread>
 #include <vector>
@@ -28,7 +27,6 @@ enum class async_msg_type { log, flush, terminate };
 struct async_msg : log_msg_buffer {
     async_msg_type msg_type{async_msg_type::log};
     async_logger_ptr worker_ptr;
-    std::promise<void> flush_promise;
 
     async_msg() = default;
     ~async_msg() = default;
@@ -58,20 +56,12 @@ struct async_msg : log_msg_buffer {
     async_msg(async_logger_ptr &&worker, async_msg_type the_type, const details::log_msg &m)
         : log_msg_buffer{m},
           msg_type{the_type},
-          worker_ptr{std::move(worker)},
+          worker_ptr{std::move(worker)} {}
-          flush_promise{} {}
 
     async_msg(async_logger_ptr &&worker, async_msg_type the_type)
         : log_msg_buffer{},
           msg_type{the_type},
-          worker_ptr{std::move(worker)},
+          worker_ptr{std::move(worker)} {}
-          flush_promise{} {}
-
-    async_msg(async_logger_ptr &&worker, async_msg_type the_type, std::promise<void> &&promise)
-        : log_msg_buffer{},
-          msg_type{the_type},
-          worker_ptr{std::move(worker)},
-          flush_promise{std::move(promise)} {}
 
     explicit async_msg(async_msg_type the_type)
         : async_msg{nullptr, the_type} {}
@@ -98,8 +88,7 @@ public:
     void post_log(async_logger_ptr &&worker_ptr,
                   const details::log_msg &msg,
                   async_overflow_policy overflow_policy);
-    std::future<void> post_flush(async_logger_ptr &&worker_ptr,
+    void post_flush(async_logger_ptr &&worker_ptr, async_overflow_policy overflow_policy);
-                                 async_overflow_policy overflow_policy);
     size_t overrun_counter();
     void reset_overrun_counter();
     size_t discard_counter();

include/spdlog/fmt/bin_to_hex.h

@@ -102,7 +102,7 @@ namespace
 
 template <typename T>
 struct formatter<spdlog::details::dump_info<T>, char> {
-    const char delimiter = ' ';
+    char delimiter = ' ';
     bool put_newlines = true;
     bool put_delimiters = true;
     bool use_uppercase = false;
@@ -142,8 +142,8 @@ struct formatter<spdlog::details::dump_info<T>, char> {
 
     // format the given bytes range as hex
     template <typename FormatContext, typename Container>
-    auto format(const spdlog::details::dump_info<Container> &the_range, FormatContext &ctx) const
+    auto format(const spdlog::details::dump_info<Container> &the_range,
-        -> decltype(ctx.out()) {
+                FormatContext &ctx) const -> decltype(ctx.out()) {
         SPDLOG_CONSTEXPR const char *hex_upper = "0123456789ABCDEF";
         SPDLOG_CONSTEXPR const char *hex_lower = "0123456789abcdef";
         const char *hex_chars = use_uppercase ? hex_upper : hex_lower;

include/spdlog/fmt/bundled/args.h

@@ -8,14 +8,15 @@
 #ifndef FMT_ARGS_H_
 #define FMT_ARGS_H_
 
-#include <functional>  // std::reference_wrapper
+#ifndef FMT_MODULE
-#include <memory>      // std::unique_ptr
+#  include <functional>  // std::reference_wrapper
-#include <vector>
+#  include <memory>      // std::unique_ptr
+#  include <vector>
+#endif
 
-#include "core.h"
+#include "format.h"  // std_string_view
 
 FMT_BEGIN_NAMESPACE
-
 namespace detail {
 
 template <typename T> struct is_reference_wrapper : std::false_type {};
@@ -28,15 +29,18 @@ auto unwrap(const std::reference_wrapper<T>& v) -> const T& {
   return static_cast<const T&>(v);
 }
 
-class dynamic_arg_list {
+// node is defined outside dynamic_arg_list to workaround a C2504 bug in MSVC
-  // Workaround for clang's -Wweak-vtables. Unlike for regular classes, for
+// 2022 (v17.10.0).
-  // templates it doesn't complain about inability to deduce single translation
+//
-  // unit for placing vtable. So storage_node_base is made a fake template.
+// Workaround for clang's -Wweak-vtables. Unlike for regular classes, for
-  template <typename = void> struct node {
+// templates it doesn't complain about inability to deduce single translation
-    virtual ~node() = default;
+// unit for placing vtable. So node is made a fake template.
-    std::unique_ptr<node<>> next;
+template <typename = void> struct node {
-  };
+  virtual ~node() = default;
+  std::unique_ptr<node<>> next;
+};
 
+class dynamic_arg_list {
   template <typename T> struct typed_node : node<> {
     T value;
 
@@ -62,28 +66,18 @@ class dynamic_arg_list {
 }  // namespace detail
 
 /**
-  \rst
+ * A dynamic list of formatting arguments with storage.
-  A dynamic version of `fmt::format_arg_store`.
+ *
-  It's equipped with a storage to potentially temporary objects which lifetimes
+ * It can be implicitly converted into `fmt::basic_format_args` for passing
-  could be shorter than the format arguments object.
+ * into type-erased formatting functions such as `fmt::vformat`.
-
-  It can be implicitly converted into `~fmt::basic_format_args` for passing
-  into type-erased formatting functions such as `~fmt::vformat`.
-  \endrst
  */
-template <typename Context>
+FMT_EXPORT template <typename Context> class dynamic_format_arg_store {
-class dynamic_format_arg_store
-#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
-    // Workaround a GCC template argument substitution bug.
-    : public basic_format_args<Context>
-#endif
-{
  private:
   using char_type = typename Context::char_type;
 
   template <typename T> struct need_copy {
     static constexpr detail::type mapped_type =
-        detail::mapped_type_constant<T, Context>::value;
+        detail::mapped_type_constant<T, char_type>::value;
 
     enum {
       value = !(detail::is_reference_wrapper<T>::value ||
@@ -96,7 +90,7 @@ class dynamic_format_arg_store
   };
 
   template <typename T>
-  using stored_type = conditional_t<
+  using stored_t = conditional_t<
       std::is_convertible<T, std::basic_string<char_type>>::value &&
           !detail::is_reference_wrapper<T>::value,
       std::basic_string<char_type>, T>;
@@ -111,80 +105,72 @@ class dynamic_format_arg_store
 
   friend class basic_format_args<Context>;
 
-  auto get_types() const -> unsigned long long {
-    return detail::is_unpacked_bit | data_.size() |
-           (named_info_.empty()
-                ? 0ULL
-                : static_cast<unsigned long long>(detail::has_named_args_bit));
-  }
-
   auto data() const -> const basic_format_arg<Context>* {
     return named_info_.empty() ? data_.data() : data_.data() + 1;
   }
 
   template <typename T> void emplace_arg(const T& arg) {
-    data_.emplace_back(detail::make_arg<Context>(arg));
+    data_.emplace_back(arg);
   }
 
   template <typename T>
   void emplace_arg(const detail::named_arg<char_type, T>& arg) {
-    if (named_info_.empty()) {
+    if (named_info_.empty())
-      constexpr const detail::named_arg_info<char_type>* zero_ptr{nullptr};
+      data_.insert(data_.begin(), basic_format_arg<Context>(nullptr, 0));
-      data_.insert(data_.begin(), {zero_ptr, 0});
+    data_.emplace_back(detail::unwrap(arg.value));
-    }
-    data_.emplace_back(detail::make_arg<Context>(detail::unwrap(arg.value)));
     auto pop_one = [](std::vector<basic_format_arg<Context>>* data) {
       data->pop_back();
     };
     std::unique_ptr<std::vector<basic_format_arg<Context>>, decltype(pop_one)>
         guard{&data_, pop_one};
     named_info_.push_back({arg.name, static_cast<int>(data_.size() - 2u)});
-    data_[0].value_.named_args = {named_info_.data(), named_info_.size()};
+    data_[0] = {named_info_.data(), named_info_.size()};
     guard.release();
   }
 
  public:
   constexpr dynamic_format_arg_store() = default;
 
+  operator basic_format_args<Context>() const {
+    return basic_format_args<Context>(data(), static_cast<int>(data_.size()),
+                                      !named_info_.empty());
+  }
+
   /**
-    \rst
+   * Adds an argument into the dynamic store for later passing to a formatting
-    Adds an argument into the dynamic store for later passing to a formatting
+   * function.
-    function.
+   *
-
+   * Note that custom types and string types (but not string views) are copied
-    Note that custom types and string types (but not string views) are copied
+   * into the store dynamically allocating memory if necessary.
-    into the store dynamically allocating memory if necessary.
+   *
-
+   * **Example**:
-    **Example**::
+   *
-
+   *     fmt::dynamic_format_arg_store<fmt::format_context> store;
-      fmt::dynamic_format_arg_store<fmt::format_context> store;
+   *     store.push_back(42);
-      store.push_back(42);
+   *     store.push_back("abc");
-      store.push_back("abc");
+   *     store.push_back(1.5f);
-      store.push_back(1.5f);
+   *     std::string result = fmt::vformat("{} and {} and {}", store);
-      std::string result = fmt::vformat("{} and {} and {}", store);
+   */
-    \endrst
-  */
   template <typename T> void push_back(const T& arg) {
     if (detail::const_check(need_copy<T>::value))
-      emplace_arg(dynamic_args_.push<stored_type<T>>(arg));
+      emplace_arg(dynamic_args_.push<stored_t<T>>(arg));
     else
       emplace_arg(detail::unwrap(arg));
   }
 
   /**
-    \rst
+   * Adds a reference to the argument into the dynamic store for later passing
-    Adds a reference to the argument into the dynamic store for later passing to
+   * to a formatting function.
-    a formatting function.
+   *
-
+   * **Example**:
-    **Example**::
+   *
-
+   *     fmt::dynamic_format_arg_store<fmt::format_context> store;
-      fmt::dynamic_format_arg_store<fmt::format_context> store;
+   *     char band[] = "Rolling Stones";
-      char band[] = "Rolling Stones";
+   *     store.push_back(std::cref(band));
-      store.push_back(std::cref(band));
+   *     band[9] = 'c'; // Changing str affects the output.
-      band[9] = 'c'; // Changing str affects the output.
+   *     std::string result = fmt::vformat("{}", store);
-      std::string result = fmt::vformat("{}", store);
+   *     // result == "Rolling Scones"
-      // result == "Rolling Scones"
+   */
-    \endrst
-  */
   template <typename T> void push_back(std::reference_wrapper<T> arg) {
     static_assert(
         need_copy<T>::value,
@@ -193,41 +179,40 @@ class dynamic_format_arg_store
   }
 
   /**
-    Adds named argument into the dynamic store for later passing to a formatting
+   * Adds named argument into the dynamic store for later passing to a
-    function. ``std::reference_wrapper`` is supported to avoid copying of the
+   * formatting function. `std::reference_wrapper` is supported to avoid
-    argument. The name is always copied into the store.
+   * copying of the argument. The name is always copied into the store.
-  */
+   */
   template <typename T>
   void push_back(const detail::named_arg<char_type, T>& arg) {
     const char_type* arg_name =
         dynamic_args_.push<std::basic_string<char_type>>(arg.name).c_str();
     if (detail::const_check(need_copy<T>::value)) {
       emplace_arg(
-          fmt::arg(arg_name, dynamic_args_.push<stored_type<T>>(arg.value)));
+          fmt::arg(arg_name, dynamic_args_.push<stored_t<T>>(arg.value)));
     } else {
       emplace_arg(fmt::arg(arg_name, arg.value));
     }
   }
 
-  /** Erase all elements from the store */
+  /// Erase all elements from the store.
   void clear() {
     data_.clear();
     named_info_.clear();
-    dynamic_args_ = detail::dynamic_arg_list();
+    dynamic_args_ = {};
   }
 
-  /**
+  /// Reserves space to store at least `new_cap` arguments including
-    \rst
+  /// `new_cap_named` named arguments.
-    Reserves space to store at least *new_cap* arguments including
-    *new_cap_named* named arguments.
-    \endrst
-  */
   void reserve(size_t new_cap, size_t new_cap_named) {
     FMT_ASSERT(new_cap >= new_cap_named,
-               "Set of arguments includes set of named arguments");
+               "set of arguments includes set of named arguments");
     data_.reserve(new_cap);
     named_info_.reserve(new_cap_named);
   }
+
+  /// Returns the number of elements in the store.
+  auto size() const noexcept -> size_t { return data_.size(); }
 };
 
 FMT_END_NAMESPACE

include/spdlog/fmt/bundled/color.h

@@ -190,11 +190,11 @@ enum class emphasis : uint8_t {
 // rgb is a struct for red, green and blue colors.
 // Using the name "rgb" makes some editors show the color in a tooltip.
 struct rgb {
-  FMT_CONSTEXPR rgb() : r(0), g(0), b(0) {}
+  constexpr rgb() : r(0), g(0), b(0) {}
-  FMT_CONSTEXPR rgb(uint8_t r_, uint8_t g_, uint8_t b_) : r(r_), g(g_), b(b_) {}
+  constexpr rgb(uint8_t r_, uint8_t g_, uint8_t b_) : r(r_), g(g_), b(b_) {}
-  FMT_CONSTEXPR rgb(uint32_t hex)
+  constexpr rgb(uint32_t hex)
       : r((hex >> 16) & 0xFF), g((hex >> 8) & 0xFF), b(hex & 0xFF) {}
-  FMT_CONSTEXPR rgb(color hex)
+  constexpr rgb(color hex)
       : r((uint32_t(hex) >> 16) & 0xFF),
         g((uint32_t(hex) >> 8) & 0xFF),
         b(uint32_t(hex) & 0xFF) {}
@@ -205,97 +205,135 @@ struct rgb {
 
 namespace detail {
 
-// color is a struct of either a rgb color or a terminal color.
+// A bit-packed variant of an RGB color, a terminal color, or unset color.
+// see text_style for the bit-packing scheme.
 struct color_type {
-  FMT_CONSTEXPR color_type() noexcept : is_rgb(), value{} {}
+  constexpr color_type() noexcept = default;
-  FMT_CONSTEXPR color_type(color rgb_color) noexcept : is_rgb(true), value{} {
+  constexpr color_type(color rgb_color) noexcept
-    value.rgb_color = static_cast<uint32_t>(rgb_color);
+      : value_(static_cast<uint32_t>(rgb_color) | (1 << 24)) {}
+  constexpr color_type(rgb rgb_color) noexcept
+      : color_type(static_cast<color>(
+            (static_cast<uint32_t>(rgb_color.r) << 16) |
+            (static_cast<uint32_t>(rgb_color.g) << 8) | rgb_color.b)) {}
+  constexpr color_type(terminal_color term_color) noexcept
+      : value_(static_cast<uint32_t>(term_color) | (3 << 24)) {}
+
+  constexpr auto is_terminal_color() const noexcept -> bool {
+    return (value_ & (1 << 25)) != 0;
   }
-  FMT_CONSTEXPR color_type(rgb rgb_color) noexcept : is_rgb(true), value{} {
+
-    value.rgb_color = (static_cast<uint32_t>(rgb_color.r) << 16) |
+  constexpr auto value() const noexcept -> uint32_t {
-                      (static_cast<uint32_t>(rgb_color.g) << 8) | rgb_color.b;
+    return value_ & 0xFFFFFF;
   }
-  FMT_CONSTEXPR color_type(terminal_color term_color) noexcept
+
-      : is_rgb(), value{} {
+  constexpr color_type(uint32_t value) noexcept : value_(value) {}
-    value.term_color = static_cast<uint8_t>(term_color);
+
-  }
+  uint32_t value_ = 0;
-  bool is_rgb;
-  union color_union {
-    uint8_t term_color;
-    uint32_t rgb_color;
-  } value;
 };
 }  // namespace detail
 
-/** A text style consisting of foreground and background colors and emphasis. */
+/// A text style consisting of foreground and background colors and emphasis.
 class text_style {
+  // The information is packed as follows:
+  // ┌──┐
+  // │ 0│─┐
+  // │..│ ├── foreground color value
+  // │23│─┘
+  // ├──┤
+  // │24│─┬── discriminator for the above value. 00 if unset, 01 if it's
+  // │25│─┘   an RGB color, or 11 if it's a terminal color (10 is unused)
+  // ├──┤
+  // │26│──── overflow bit, always zero (see below)
+  // ├──┤
+  // │27│─┐
+  // │..│ │
+  // │50│ │
+  // ├──┤ │
+  // │51│ ├── background color (same format as the foreground color)
+  // │52│ │
+  // ├──┤ │
+  // │53│─┘
+  // ├──┤
+  // │54│─┐
+  // │..│ ├── emphases
+  // │61│─┘
+  // ├──┤
+  // │62│─┬── unused
+  // │63│─┘
+  // └──┘
+  // The overflow bits are there to make operator|= efficient.
+  // When ORing, we must throw if, for either the foreground or background,
+  // one style specifies a terminal color and the other specifies any color
+  // (terminal or RGB); in other words, if one discriminator is 11 and the
+  // other is 11 or 01.
+  //
+  // We do that check by adding the styles. Consider what adding does to each
+  // possible pair of discriminators:
+  //    00 + 00 = 000
+  //    01 + 00 = 001
+  //    11 + 00 = 011
+  //    01 + 01 = 010
+  //    11 + 01 = 100 (!!)
+  //    11 + 11 = 110 (!!)
+  // In the last two cases, the ones we want to catch, the third bit——the
+  // overflow bit——is set. Bingo.
+  //
+  // We must take into account the possible carry bit from the bits
+  // before the discriminator. The only potentially problematic case is
+  // 11 + 00 = 011 (a carry bit would make it 100, not good!), but a carry
+  // bit is impossible in that case, because 00 (unset color) means the
+  // 24 bits that precede the discriminator are all zero.
+  //
+  // This test can be applied to both colors simultaneously.
+
  public:
   FMT_CONSTEXPR text_style(emphasis em = emphasis()) noexcept
-      : set_foreground_color(), set_background_color(), ems(em) {}
+      : style_(static_cast<uint64_t>(em) << 54) {}
 
-  FMT_CONSTEXPR auto operator|=(const text_style& rhs) -> text_style& {
+  FMT_CONSTEXPR auto operator|=(text_style rhs) -> text_style& {
-    if (!set_foreground_color) {
+    if (((style_ + rhs.style_) & ((1ULL << 26) | (1ULL << 53))) != 0)
-      set_foreground_color = rhs.set_foreground_color;
+      report_error("can't OR a terminal color");
-      foreground_color = rhs.foreground_color;
+    style_ |= rhs.style_;
-    } else if (rhs.set_foreground_color) {
-      if (!foreground_color.is_rgb || !rhs.foreground_color.is_rgb)
-        FMT_THROW(format_error("can't OR a terminal color"));
-      foreground_color.value.rgb_color |= rhs.foreground_color.value.rgb_color;
-    }
-
-    if (!set_background_color) {
-      set_background_color = rhs.set_background_color;
-      background_color = rhs.background_color;
-    } else if (rhs.set_background_color) {
-      if (!background_color.is_rgb || !rhs.background_color.is_rgb)
-        FMT_THROW(format_error("can't OR a terminal color"));
-      background_color.value.rgb_color |= rhs.background_color.value.rgb_color;
-    }
-
-    ems = static_cast<emphasis>(static_cast<uint8_t>(ems) |
-                                static_cast<uint8_t>(rhs.ems));
     return *this;
   }
 
-  friend FMT_CONSTEXPR auto operator|(text_style lhs, const text_style& rhs)
+  friend FMT_CONSTEXPR auto operator|(text_style lhs, text_style rhs)
       -> text_style {
     return lhs |= rhs;
   }
 
+  FMT_CONSTEXPR auto operator==(text_style rhs) const noexcept -> bool {
+    return style_ == rhs.style_;
+  }
+
+  FMT_CONSTEXPR auto operator!=(text_style rhs) const noexcept -> bool {
+    return !(*this == rhs);
+  }
+
   FMT_CONSTEXPR auto has_foreground() const noexcept -> bool {
-    return set_foreground_color;
+    return (style_ & (1 << 24)) != 0;
   }
   FMT_CONSTEXPR auto has_background() const noexcept -> bool {
-    return set_background_color;
+    return (style_ & (1ULL << 51)) != 0;
   }
   FMT_CONSTEXPR auto has_emphasis() const noexcept -> bool {
-    return static_cast<uint8_t>(ems) != 0;
+    return (style_ >> 54) != 0;
   }
   FMT_CONSTEXPR auto get_foreground() const noexcept -> detail::color_type {
     FMT_ASSERT(has_foreground(), "no foreground specified for this style");
-    return foreground_color;
+    return style_ & 0x3FFFFFF;
   }
   FMT_CONSTEXPR auto get_background() const noexcept -> detail::color_type {
     FMT_ASSERT(has_background(), "no background specified for this style");
-    return background_color;
+    return (style_ >> 27) & 0x3FFFFFF;
   }
   FMT_CONSTEXPR auto get_emphasis() const noexcept -> emphasis {
     FMT_ASSERT(has_emphasis(), "no emphasis specified for this style");
-    return ems;
+    return static_cast<emphasis>(style_ >> 54);
   }
 
  private:
-  FMT_CONSTEXPR text_style(bool is_foreground,
+  FMT_CONSTEXPR text_style(uint64_t style) noexcept : style_(style) {}
-                           detail::color_type text_color) noexcept
-      : set_foreground_color(), set_background_color(), ems() {
-    if (is_foreground) {
-      foreground_color = text_color;
-      set_foreground_color = true;
-    } else {
-      background_color = text_color;
-      set_background_color = true;
-    }
-  }
 
   friend FMT_CONSTEXPR auto fg(detail::color_type foreground) noexcept
       -> text_style;
@@ -303,23 +341,19 @@ class text_style {
   friend FMT_CONSTEXPR auto bg(detail::color_type background) noexcept
       -> text_style;
 
-  detail::color_type foreground_color;
+  uint64_t style_ = 0;
-  detail::color_type background_color;
-  bool set_foreground_color;
-  bool set_background_color;
-  emphasis ems;
 };
 
-/** Creates a text style from the foreground (text) color. */
+/// Creates a text style from the foreground (text) color.
 FMT_CONSTEXPR inline auto fg(detail::color_type foreground) noexcept
     -> text_style {
-  return text_style(true, foreground);
+  return foreground.value_;
 }
 
-/** Creates a text style from the background color. */
+/// Creates a text style from the background color.
 FMT_CONSTEXPR inline auto bg(detail::color_type background) noexcept
     -> text_style {
-  return text_style(false, background);
+  return static_cast<uint64_t>(background.value_) << 27;
 }
 
 FMT_CONSTEXPR inline auto operator|(emphasis lhs, emphasis rhs) noexcept
@@ -330,41 +364,39 @@ FMT_CONSTEXPR inline auto operator|(emphasis lhs, emphasis rhs) noexcept
 namespace detail {
 
 template <typename Char> struct ansi_color_escape {
-  FMT_CONSTEXPR ansi_color_escape(detail::color_type text_color,
+  FMT_CONSTEXPR ansi_color_escape(color_type text_color,
                                   const char* esc) noexcept {
     // If we have a terminal color, we need to output another escape code
     // sequence.
-    if (!text_color.is_rgb) {
+    if (text_color.is_terminal_color()) {
       bool is_background = esc == string_view("\x1b[48;2;");
-      uint32_t value = text_color.value.term_color;
+      uint32_t value = text_color.value();
       // Background ASCII codes are the same as the foreground ones but with
       // 10 more.
       if (is_background) value += 10u;
 
-      size_t index = 0;
+      buffer[size++] = static_cast<Char>('\x1b');
-      buffer[index++] = static_cast<Char>('\x1b');
+      buffer[size++] = static_cast<Char>('[');
-      buffer[index++] = static_cast<Char>('[');
 
       if (value >= 100u) {
-        buffer[index++] = static_cast<Char>('1');
+        buffer[size++] = static_cast<Char>('1');
         value %= 100u;
       }
-      buffer[index++] = static_cast<Char>('0' + value / 10u);
+      buffer[size++] = static_cast<Char>('0' + value / 10u);
-      buffer[index++] = static_cast<Char>('0' + value % 10u);
+      buffer[size++] = static_cast<Char>('0' + value % 10u);
 
-      buffer[index++] = static_cast<Char>('m');
+      buffer[size++] = static_cast<Char>('m');
-      buffer[index++] = static_cast<Char>('\0');
       return;
     }
 
     for (int i = 0; i < 7; i++) {
       buffer[i] = static_cast<Char>(esc[i]);
     }
-    rgb color(text_color.value.rgb_color);
+    rgb color(text_color.value());
     to_esc(color.r, buffer + 7, ';');
     to_esc(color.g, buffer + 11, ';');
     to_esc(color.b, buffer + 15, 'm');
-    buffer[19] = static_cast<Char>(0);
+    size = 19;
   }
   FMT_CONSTEXPR ansi_color_escape(emphasis em) noexcept {
     uint8_t em_codes[num_emphases] = {};
@@ -377,26 +409,28 @@ template <typename Char> struct ansi_color_escape {
     if (has_emphasis(em, emphasis::conceal)) em_codes[6] = 8;
     if (has_emphasis(em, emphasis::strikethrough)) em_codes[7] = 9;
 
-    size_t index = 0;
+    buffer[size++] = static_cast<Char>('\x1b');
+    buffer[size++] = static_cast<Char>('[');
+
     for (size_t i = 0; i < num_emphases; ++i) {
       if (!em_codes[i]) continue;
-      buffer[index++] = static_cast<Char>('\x1b');
+      buffer[size++] = static_cast<Char>('0' + em_codes[i]);
-      buffer[index++] = static_cast<Char>('[');
+      buffer[size++] = static_cast<Char>(';');
-      buffer[index++] = static_cast<Char>('0' + em_codes[i]);
-      buffer[index++] = static_cast<Char>('m');
     }
-    buffer[index++] = static_cast<Char>(0);
+
+    buffer[size - 1] = static_cast<Char>('m');
   }
   FMT_CONSTEXPR operator const Char*() const noexcept { return buffer; }
 
   FMT_CONSTEXPR auto begin() const noexcept -> const Char* { return buffer; }
-  FMT_CONSTEXPR_CHAR_TRAITS auto end() const noexcept -> const Char* {
+  FMT_CONSTEXPR auto end() const noexcept -> const Char* {
-    return buffer + std::char_traits<Char>::length(buffer);
+    return buffer + size;
   }
 
  private:
   static constexpr size_t num_emphases = 8;
-  Char buffer[7u + 3u * num_emphases + 1u];
+  Char buffer[7u + 4u * num_emphases];
+  size_t size = 0;
 
   static FMT_CONSTEXPR void to_esc(uint8_t c, Char* out,
                                    char delimiter) noexcept {
@@ -412,13 +446,13 @@ template <typename Char> struct ansi_color_escape {
 };
 
 template <typename Char>
-FMT_CONSTEXPR auto make_foreground_color(detail::color_type foreground) noexcept
+FMT_CONSTEXPR auto make_foreground_color(color_type foreground) noexcept
     -> ansi_color_escape<Char> {
   return ansi_color_escape<Char>(foreground, "\x1b[38;2;");
 }
 
 template <typename Char>
-FMT_CONSTEXPR auto make_background_color(detail::color_type background) noexcept
+FMT_CONSTEXPR auto make_background_color(color_type background) noexcept
     -> ansi_color_escape<Char> {
   return ansi_color_escape<Char>(background, "\x1b[48;2;");
 }
@@ -434,153 +468,116 @@ template <typename Char> inline void reset_color(buffer<Char>& buffer) {
   buffer.append(reset_color.begin(), reset_color.end());
 }
 
-template <typename T> struct styled_arg : detail::view {
+template <typename T> struct styled_arg : view {
   const T& value;
   text_style style;
   styled_arg(const T& v, text_style s) : value(v), style(s) {}
 };
 
 template <typename Char>
-void vformat_to(buffer<Char>& buf, const text_style& ts,
+void vformat_to(buffer<Char>& buf, text_style ts, basic_string_view<Char> fmt,
-                basic_string_view<Char> format_str,
+                basic_format_args<buffered_context<Char>> args) {
-                basic_format_args<buffer_context<type_identity_t<Char>>> args) {
-  bool has_style = false;
   if (ts.has_emphasis()) {
-    has_style = true;
+    auto emphasis = make_emphasis<Char>(ts.get_emphasis());
-    auto emphasis = detail::make_emphasis<Char>(ts.get_emphasis());
     buf.append(emphasis.begin(), emphasis.end());
   }
   if (ts.has_foreground()) {
-    has_style = true;
+    auto foreground = make_foreground_color<Char>(ts.get_foreground());
-    auto foreground = detail::make_foreground_color<Char>(ts.get_foreground());
     buf.append(foreground.begin(), foreground.end());
   }
   if (ts.has_background()) {
-    has_style = true;
+    auto background = make_background_color<Char>(ts.get_background());
-    auto background = detail::make_background_color<Char>(ts.get_background());
     buf.append(background.begin(), background.end());
   }
-  detail::vformat_to(buf, format_str, args, {});
+  vformat_to(buf, fmt, args);
-  if (has_style) detail::reset_color<Char>(buf);
+  if (ts != text_style()) reset_color<Char>(buf);
 }
-
 }  // namespace detail
 
-inline void vprint(std::FILE* f, const text_style& ts, string_view fmt,
+inline void vprint(FILE* f, text_style ts, string_view fmt, format_args args) {
-                   format_args args) {
-  // Legacy wide streams are not supported.
   auto buf = memory_buffer();
   detail::vformat_to(buf, ts, fmt, args);
-  if (detail::is_utf8()) {
+  print(f, FMT_STRING("{}"), string_view(buf.begin(), buf.size()));
-    detail::print(f, string_view(buf.begin(), buf.size()));
-    return;
-  }
-  buf.push_back('\0');
-  int result = std::fputs(buf.data(), f);
-  if (result < 0)
-    FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
 }
 
 /**
-  \rst
+ * Formats a string and prints it to the specified file stream using ANSI
-  Formats a string and prints it to the specified file stream using ANSI
+ * escape sequences to specify text formatting.
-  escape sequences to specify text formatting.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
-    fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
+ *                "Elapsed time: {0:.2f} seconds", 1.23);
-               "Elapsed time: {0:.2f} seconds", 1.23);
-  \endrst
  */
-template <typename S, typename... Args,
+template <typename... T>
-          FMT_ENABLE_IF(detail::is_string<S>::value)>
+void print(FILE* f, text_style ts, format_string<T...> fmt, T&&... args) {
-void print(std::FILE* f, const text_style& ts, const S& format_str,
+  vprint(f, ts, fmt.str, vargs<T...>{{args...}});
-           const Args&... args) {
-  vprint(f, ts, format_str,
-         fmt::make_format_args<buffer_context<char_t<S>>>(args...));
 }
 
 /**
-  \rst
+ * Formats a string and prints it to stdout using ANSI escape sequences to
-  Formats a string and prints it to stdout using ANSI escape sequences to
+ * specify text formatting.
-  specify text formatting.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
-    fmt::print(fmt::emphasis::bold | fg(fmt::color::red),
+ *                "Elapsed time: {0:.2f} seconds", 1.23);
-               "Elapsed time: {0:.2f} seconds", 1.23);
-  \endrst
  */
-template <typename S, typename... Args,
+template <typename... T>
-          FMT_ENABLE_IF(detail::is_string<S>::value)>
+void print(text_style ts, format_string<T...> fmt, T&&... args) {
-void print(const text_style& ts, const S& format_str, const Args&... args) {
+  return print(stdout, ts, fmt, std::forward<T>(args)...);
-  return print(stdout, ts, format_str, args...);
 }
 
-template <typename S, typename Char = char_t<S>>
+inline auto vformat(text_style ts, string_view fmt, format_args args)
-inline auto vformat(
+    -> std::string {
-    const text_style& ts, const S& format_str,
+  auto buf = memory_buffer();
-    basic_format_args<buffer_context<type_identity_t<Char>>> args)
+  detail::vformat_to(buf, ts, fmt, args);
-    -> std::basic_string<Char> {
-  basic_memory_buffer<Char> buf;
-  detail::vformat_to(buf, ts, detail::to_string_view(format_str), args);
   return fmt::to_string(buf);
 }
 
 /**
-  \rst
+ * Formats arguments and returns the result as a string using ANSI escape
-  Formats arguments and returns the result as a string using ANSI
+ * sequences to specify text formatting.
-  escape sequences to specify text formatting.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ * ```
-    #include <fmt/color.h>
+ * #include <fmt/color.h>
-    std::string message = fmt::format(fmt::emphasis::bold | fg(fmt::color::red),
+ * std::string message = fmt::format(fmt::emphasis::bold | fg(fmt::color::red),
-                                      "The answer is {}", 42);
+ *                                   "The answer is {}", 42);
-  \endrst
+ * ```
-*/
+ */
-template <typename S, typename... Args, typename Char = char_t<S>>
+template <typename... T>
-inline auto format(const text_style& ts, const S& format_str,
+inline auto format(text_style ts, format_string<T...> fmt, T&&... args)
-                   const Args&... args) -> std::basic_string<Char> {
+    -> std::string {
-  return fmt::vformat(ts, detail::to_string_view(format_str),
+  return fmt::vformat(ts, fmt.str, vargs<T...>{{args...}});
-                      fmt::make_format_args<buffer_context<Char>>(args...));
 }
 
-/**
+/// Formats a string with the given text_style and writes the output to `out`.
-  Formats a string with the given text_style and writes the output to ``out``.
+template <typename OutputIt,
- */
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, char>::value)>
-template <typename OutputIt, typename Char,
+auto vformat_to(OutputIt out, text_style ts, string_view fmt, format_args args)
-          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value)>
-auto vformat_to(OutputIt out, const text_style& ts,
-                basic_string_view<Char> format_str,
-                basic_format_args<buffer_context<type_identity_t<Char>>> args)
     -> OutputIt {
-  auto&& buf = detail::get_buffer<Char>(out);
+  auto&& buf = detail::get_buffer<char>(out);
-  detail::vformat_to(buf, ts, format_str, args);
+  detail::vformat_to(buf, ts, fmt, args);
   return detail::get_iterator(buf, out);
 }
 
 /**
-  \rst
+ * Formats arguments with the given text style, writes the result to the output
-  Formats arguments with the given text_style, writes the result to the output
+ * iterator `out` and returns the iterator past the end of the output range.
-  iterator ``out`` and returns the iterator past the end of the output range.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     std::vector<char> out;
-    std::vector<char> out;
+ *     fmt::format_to(std::back_inserter(out),
-    fmt::format_to(std::back_inserter(out),
+ *                    fmt::emphasis::bold | fg(fmt::color::red), "{}", 42);
-                   fmt::emphasis::bold | fg(fmt::color::red), "{}", 42);
+ */
-  \endrst
+template <typename OutputIt, typename... T,
-*/
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, char>::value)>
-template <
+inline auto format_to(OutputIt out, text_style ts, format_string<T...> fmt,
-    typename OutputIt, typename S, typename... Args,
+                      T&&... args) -> OutputIt {
-    bool enable = detail::is_output_iterator<OutputIt, char_t<S>>::value &&
+  return vformat_to(out, ts, fmt.str, vargs<T...>{{args...}});
-                  detail::is_string<S>::value>
-inline auto format_to(OutputIt out, const text_style& ts, const S& format_str,
-                      Args&&... args) ->
-    typename std::enable_if<enable, OutputIt>::type {
-  return vformat_to(out, ts, detail::to_string_view(format_str),
-                    fmt::make_format_args<buffer_context<char_t<S>>>(args...));
 }
 
 template <typename T, typename Char>
@@ -589,47 +586,44 @@ struct formatter<detail::styled_arg<T>, Char> : formatter<T, Char> {
   auto format(const detail::styled_arg<T>& arg, FormatContext& ctx) const
       -> decltype(ctx.out()) {
     const auto& ts = arg.style;
-    const auto& value = arg.value;
     auto out = ctx.out();
 
     bool has_style = false;
     if (ts.has_emphasis()) {
       has_style = true;
       auto emphasis = detail::make_emphasis<Char>(ts.get_emphasis());
-      out = std::copy(emphasis.begin(), emphasis.end(), out);
+      out = detail::copy<Char>(emphasis.begin(), emphasis.end(), out);
     }
     if (ts.has_foreground()) {
       has_style = true;
       auto foreground =
           detail::make_foreground_color<Char>(ts.get_foreground());
-      out = std::copy(foreground.begin(), foreground.end(), out);
+      out = detail::copy<Char>(foreground.begin(), foreground.end(), out);
     }
     if (ts.has_background()) {
       has_style = true;
       auto background =
           detail::make_background_color<Char>(ts.get_background());
-      out = std::copy(background.begin(), background.end(), out);
+      out = detail::copy<Char>(background.begin(), background.end(), out);
     }
-    out = formatter<T, Char>::format(value, ctx);
+    out = formatter<T, Char>::format(arg.value, ctx);
     if (has_style) {
       auto reset_color = string_view("\x1b[0m");
-      out = std::copy(reset_color.begin(), reset_color.end(), out);
+      out = detail::copy<Char>(reset_color.begin(), reset_color.end(), out);
     }
     return out;
   }
 };
 
 /**
-  \rst
+ * Returns an argument that will be formatted using ANSI escape sequences,
-  Returns an argument that will be formatted using ANSI escape sequences,
+ * to be used in a formatting function.
-  to be used in a formatting function.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     fmt::print("Elapsed time: {0:.2f} seconds",
-    fmt::print("Elapsed time: {0:.2f} seconds",
+ *                fmt::styled(1.23, fmt::fg(fmt::color::green) |
-               fmt::styled(1.23, fmt::fg(fmt::color::green) |
+ *                                  fmt::bg(fmt::color::blue)));
-                                 fmt::bg(fmt::color::blue)));
-  \endrst
  */
 template <typename T>
 FMT_CONSTEXPR auto styled(const T& value, text_style ts)

include/spdlog/fmt/bundled/compile.h

@@ -8,66 +8,71 @@
 #ifndef FMT_COMPILE_H_
 #define FMT_COMPILE_H_
 
+#ifndef FMT_MODULE
+#  include <iterator>  // std::back_inserter
+#endif
+
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
-namespace detail {
-
-template <typename Char, typename InputIt>
-FMT_CONSTEXPR inline auto copy_str(InputIt begin, InputIt end,
-                                   counting_iterator it) -> counting_iterator {
-  return it + (end - begin);
-}
 
 // A compile-time string which is compiled into fast formatting code.
-class compiled_string {};
+FMT_EXPORT class compiled_string {};
 
 template <typename S>
 struct is_compiled_string : std::is_base_of<compiled_string, S> {};
 
 /**
-  \rst
+ * Converts a string literal `s` into a format string that will be parsed at
-  Converts a string literal *s* into a format string that will be parsed at
+ * compile time and converted into efficient formatting code. Requires C++17
-  compile time and converted into efficient formatting code. Requires C++17
+ * `constexpr if` compiler support.
-  ``constexpr if`` compiler support.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     // Converts 42 into std::string using the most efficient method and no
-    // Converts 42 into std::string using the most efficient method and no
+ *     // runtime format string processing.
-    // runtime format string processing.
+ *     std::string s = fmt::format(FMT_COMPILE("{}"), 42);
-    std::string s = fmt::format(FMT_COMPILE("{}"), 42);
-  \endrst
  */
 #if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
-#  define FMT_COMPILE(s) \
+#  define FMT_COMPILE(s) FMT_STRING_IMPL(s, fmt::compiled_string)
-    FMT_STRING_IMPL(s, fmt::detail::compiled_string, explicit)
 #else
 #  define FMT_COMPILE(s) FMT_STRING(s)
 #endif
 
+/**
+ * Converts a string literal into a format string that will be parsed at
+ * compile time and converted into efficient formatting code. Requires support
+ * for class types in constant template parameters (a C++20 feature).
+ *
+ *  **Example**:
+ *
+ *     // Converts 42 into std::string using the most efficient method and no
+ *     // runtime format string processing.
+ *     using namespace fmt::literals;
+ *     std::string s = fmt::format("{}"_cf, 42);
+ */
 #if FMT_USE_NONTYPE_TEMPLATE_ARGS
-template <typename Char, size_t N,
+inline namespace literals {
-          fmt::detail_exported::fixed_string<Char, N> Str>
+template <detail::fixed_string Str> constexpr auto operator""_cf() {
-struct udl_compiled_string : compiled_string {
+  return FMT_COMPILE(Str.data);
-  using char_type = Char;
+}
-  explicit constexpr operator basic_string_view<char_type>() const {
+}  // namespace literals
-    return {Str.data, N - 1};
-  }
-};
 #endif
 
+namespace detail {
+
 template <typename T, typename... Tail>
-auto first(const T& value, const Tail&...) -> const T& {
+constexpr auto first(const T& value, const Tail&...) -> const T& {
   return value;
 }
 
 #if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
-template <typename... Args> struct type_list {};
+template <typename... T> struct type_list {};
 
 // Returns a reference to the argument at index N from [first, rest...].
 template <int N, typename T, typename... Args>
-constexpr const auto& get([[maybe_unused]] const T& first,
+constexpr auto get([[maybe_unused]] const T& first,
-                          [[maybe_unused]] const Args&... rest) {
+                   [[maybe_unused]] const Args&... rest) -> const auto& {
   static_assert(N < 1 + sizeof...(Args), "index is out of bounds");
   if constexpr (N == 0)
     return first;
@@ -75,9 +80,32 @@ constexpr const auto& get([[maybe_unused]] const T& first,
     return detail::get<N - 1>(rest...);
 }
 
+#  if FMT_USE_NONTYPE_TEMPLATE_ARGS
+template <int N, typename T, typename... Args, typename Char>
+constexpr auto get_arg_index_by_name(basic_string_view<Char> name) -> int {
+  if constexpr (is_static_named_arg<T>()) {
+    if (name == T::name) return N;
+  }
+  if constexpr (sizeof...(Args) > 0)
+    return get_arg_index_by_name<N + 1, Args...>(name);
+  (void)name;  // Workaround an MSVC bug about "unused" parameter.
+  return -1;
+}
+#  endif
+
+template <typename... Args, typename Char>
+FMT_CONSTEXPR auto get_arg_index_by_name(basic_string_view<Char> name) -> int {
+#  if FMT_USE_NONTYPE_TEMPLATE_ARGS
+  if constexpr (sizeof...(Args) > 0)
+    return get_arg_index_by_name<0, Args...>(name);
+#  endif
+  (void)name;
+  return -1;
+}
+
 template <typename Char, typename... Args>
-constexpr int get_arg_index_by_name(basic_string_view<Char> name,
+constexpr auto get_arg_index_by_name(basic_string_view<Char> name,
-                                    type_list<Args...>) {
+                                     type_list<Args...>) -> int {
   return get_arg_index_by_name<Args...>(name);
 }
 
@@ -97,8 +125,8 @@ template <typename Char> struct text {
   basic_string_view<Char> data;
   using char_type = Char;
 
-  template <typename OutputIt, typename... Args>
+  template <typename OutputIt, typename... T>
-  constexpr OutputIt format(OutputIt out, const Args&...) const {
+  constexpr auto format(OutputIt out, const T&...) const -> OutputIt {
     return write<Char>(out, data);
   }
 };
@@ -107,8 +135,8 @@ 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,
+constexpr auto make_text(basic_string_view<Char> s, size_t pos, size_t size)
-                               size_t size) {
+    -> text<Char> {
   return {{&s[pos], size}};
 }
 
@@ -116,8 +144,8 @@ template <typename Char> struct code_unit {
   Char value;
   using char_type = Char;
 
-  template <typename OutputIt, typename... Args>
+  template <typename OutputIt, typename... T>
-  constexpr OutputIt format(OutputIt out, const Args&...) const {
+  constexpr auto format(OutputIt out, const T&...) const -> OutputIt {
     *out++ = value;
     return out;
   }
@@ -125,7 +153,7 @@ template <typename Char> struct code_unit {
 
 // This ensures that the argument type is convertible to `const T&`.
 template <typename T, int N, typename... Args>
-constexpr const T& get_arg_checked(const Args&... args) {
+constexpr auto get_arg_checked(const Args&... args) -> const T& {
   const auto& arg = detail::get<N>(args...);
   if constexpr (detail::is_named_arg<remove_cvref_t<decltype(arg)>>()) {
     return arg.value;
@@ -138,17 +166,18 @@ template <typename Char>
 struct is_compiled_format<code_unit<Char>> : std::true_type {};
 
 // A replacement field that refers to argument N.
-template <typename Char, typename T, int N> struct field {
+template <typename Char, typename V, int N> struct field {
   using char_type = Char;
 
-  template <typename OutputIt, typename... Args>
+  template <typename OutputIt, typename... T>
-  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+  constexpr auto format(OutputIt out, const T&... args) const -> OutputIt {
-    const T& arg = get_arg_checked<T, N>(args...);
+    const V& arg = get_arg_checked<V, N>(args...);
-    if constexpr (std::is_convertible_v<T, basic_string_view<Char>>) {
+    if constexpr (std::is_convertible<V, basic_string_view<Char>>::value) {
       auto s = basic_string_view<Char>(arg);
-      return copy_str<Char>(s.begin(), s.end(), out);
+      return copy<Char>(s.begin(), s.end(), out);
+    } else {
+      return write<Char>(out, arg);
     }
-    return write<Char>(out, arg);
   }
 };
 
@@ -161,10 +190,10 @@ template <typename Char> struct runtime_named_field {
   basic_string_view<Char> name;
 
   template <typename OutputIt, typename T>
-  constexpr static bool try_format_argument(
+  constexpr static auto try_format_argument(
       OutputIt& out,
       // [[maybe_unused]] due to unused-but-set-parameter warning in GCC 7,8,9
-      [[maybe_unused]] basic_string_view<Char> arg_name, const T& arg) {
+      [[maybe_unused]] basic_string_view<Char> arg_name, const T& arg) -> bool {
     if constexpr (is_named_arg<typename std::remove_cv<T>::type>::value) {
       if (arg_name == arg.name) {
         out = write<Char>(out, arg.value);
@@ -174,8 +203,8 @@ template <typename Char> struct runtime_named_field {
     return false;
   }
 
-  template <typename OutputIt, typename... Args>
+  template <typename OutputIt, typename... T>
-  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+  constexpr auto format(OutputIt out, const T&... args) const -> OutputIt {
     bool found = (try_format_argument(out, name, args) || ...);
     if (!found) {
       FMT_THROW(format_error("argument with specified name is not found"));
@@ -188,17 +217,17 @@ template <typename Char>
 struct is_compiled_format<runtime_named_field<Char>> : std::true_type {};
 
 // A replacement field that refers to argument N and has format specifiers.
-template <typename Char, typename T, int N> struct spec_field {
+template <typename Char, typename V, int N> struct spec_field {
   using char_type = Char;
-  formatter<T, Char> fmt;
+  formatter<V, Char> fmt;
 
-  template <typename OutputIt, typename... Args>
+  template <typename OutputIt, typename... T>
-  constexpr FMT_INLINE OutputIt format(OutputIt out,
+  constexpr FMT_INLINE auto format(OutputIt out, const T&... args) const
-                                       const Args&... args) const {
+      -> OutputIt {
     const auto& vargs =
         fmt::make_format_args<basic_format_context<OutputIt, Char>>(args...);
     basic_format_context<OutputIt, Char> ctx(out, vargs);
-    return fmt.format(get_arg_checked<T, N>(args...), ctx);
+    return fmt.format(get_arg_checked<V, N>(args...), ctx);
   }
 };
 
@@ -210,8 +239,8 @@ template <typename L, typename R> struct concat {
   R rhs;
   using char_type = typename L::char_type;
 
-  template <typename OutputIt, typename... Args>
+  template <typename OutputIt, typename... T>
-  constexpr OutputIt format(OutputIt out, const Args&... args) const {
+  constexpr auto format(OutputIt out, const T&... args) const -> OutputIt {
     out = lhs.format(out, args...);
     return rhs.format(out, args...);
   }
@@ -221,14 +250,14 @@ 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) {
+constexpr auto make_concat(L lhs, R rhs) -> concat<L, R> {
   return {lhs, rhs};
 }
 
 struct unknown_format {};
 
 template <typename Char>
-constexpr size_t parse_text(basic_string_view<Char> str, size_t pos) {
+constexpr auto parse_text(basic_string_view<Char> str, size_t pos) -> size_t {
   for (size_t size = str.size(); pos != size; ++pos) {
     if (str[pos] == '{' || str[pos] == '}') break;
   }
@@ -236,13 +265,12 @@ constexpr size_t parse_text(basic_string_view<Char> str, size_t pos) {
 }
 
 template <typename Args, size_t POS, int ID, typename S>
-constexpr auto compile_format_string(S format_str);
+constexpr auto compile_format_string(S fmt);
 
 template <typename Args, size_t POS, int ID, typename T, typename S>
-constexpr auto parse_tail(T head, S format_str) {
+constexpr auto parse_tail(T head, S fmt) {
-  if constexpr (POS !=
+  if constexpr (POS != basic_string_view<typename S::char_type>(fmt).size()) {
-                basic_string_view<typename S::char_type>(format_str).size()) {
+    constexpr auto tail = compile_format_string<Args, POS, ID>(fmt);
-    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;
@@ -262,8 +290,8 @@ template <typename T, typename Char> struct parse_specs_result {
 enum { manual_indexing_id = -1 };
 
 template <typename T, typename Char>
-constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,
+constexpr auto parse_specs(basic_string_view<Char> str, size_t pos,
-                                                  size_t pos, int next_arg_id) {
+                           int next_arg_id) -> parse_specs_result<T, Char> {
   str.remove_prefix(pos);
   auto ctx =
       compile_parse_context<Char>(str, max_value<int>(), nullptr, next_arg_id);
@@ -274,32 +302,36 @@ constexpr parse_specs_result<T, Char> parse_specs(basic_string_view<Char> str,
 }
 
 template <typename Char> struct arg_id_handler {
+  arg_id_kind kind;
   arg_ref<Char> arg_id;
 
-  constexpr int on_auto() {
+  constexpr auto on_auto() -> int {
     FMT_ASSERT(false, "handler cannot be used with automatic indexing");
     return 0;
   }
-  constexpr int on_index(int id) {
+  constexpr auto on_index(int id) -> int {
+    kind = arg_id_kind::index;
     arg_id = arg_ref<Char>(id);
     return 0;
   }
-  constexpr int on_name(basic_string_view<Char> id) {
+  constexpr auto on_name(basic_string_view<Char> id) -> int {
+    kind = arg_id_kind::name;
     arg_id = arg_ref<Char>(id);
     return 0;
   }
 };
 
 template <typename Char> struct parse_arg_id_result {
+  arg_id_kind kind;
   arg_ref<Char> arg_id;
   const Char* arg_id_end;
 };
 
 template <int ID, typename Char>
 constexpr auto parse_arg_id(const Char* begin, const Char* end) {
-  auto handler = arg_id_handler<Char>{arg_ref<Char>{}};
+  auto handler = arg_id_handler<Char>{arg_id_kind::none, arg_ref<Char>{}};
   auto arg_id_end = parse_arg_id(begin, end, handler);
-  return parse_arg_id_result<Char>{handler.arg_id, arg_id_end};
+  return parse_arg_id_result<Char>{handler.kind, handler.arg_id, arg_id_end};
 }
 
 template <typename T, typename Enable = void> struct field_type {
@@ -313,14 +345,13 @@ struct field_type<T, enable_if_t<detail::is_named_arg<T>::value>> {
 
 template <typename T, typename Args, size_t END_POS, int ARG_INDEX, int NEXT_ID,
           typename S>
-constexpr auto parse_replacement_field_then_tail(S format_str) {
+constexpr auto parse_replacement_field_then_tail(S fmt) {
   using char_type = typename S::char_type;
-  constexpr auto str = basic_string_view<char_type>(format_str);
+  constexpr auto str = basic_string_view<char_type>(fmt);
   constexpr char_type c = END_POS != str.size() ? str[END_POS] : char_type();
   if constexpr (c == '}') {
     return parse_tail<Args, END_POS + 1, NEXT_ID>(
-        field<char_type, typename field_type<T>::type, ARG_INDEX>(),
+        field<char_type, typename field_type<T>::type, ARG_INDEX>(), fmt);
-        format_str);
   } else if constexpr (c != ':') {
     FMT_THROW(format_error("expected ':'"));
   } else {
@@ -333,7 +364,7 @@ constexpr auto parse_replacement_field_then_tail(S format_str) {
       return parse_tail<Args, result.end + 1, result.next_arg_id>(
           spec_field<char_type, typename field_type<T>::type, ARG_INDEX>{
               result.fmt},
-          format_str);
+          fmt);
     }
   }
 }
@@ -341,22 +372,21 @@ constexpr auto parse_replacement_field_then_tail(S format_str) {
 // Compiles a non-empty format string and returns the compiled representation
 // or unknown_format() on unrecognized input.
 template <typename Args, size_t POS, int ID, typename S>
-constexpr auto compile_format_string(S format_str) {
+constexpr auto compile_format_string(S fmt) {
   using char_type = typename S::char_type;
-  constexpr auto str = basic_string_view<char_type>(format_str);
+  constexpr auto str = basic_string_view<char_type>(fmt);
   if constexpr (str[POS] == '{') {
     if constexpr (POS + 1 == str.size())
       FMT_THROW(format_error("unmatched '{' in format string"));
     if constexpr (str[POS + 1] == '{') {
-      return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+      return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), fmt);
     } else if constexpr (str[POS + 1] == '}' || str[POS + 1] == ':') {
       static_assert(ID != manual_indexing_id,
                     "cannot switch from manual to automatic argument indexing");
       constexpr auto next_id =
           ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
       return parse_replacement_field_then_tail<get_type<ID, Args>, Args,
-                                               POS + 1, ID, next_id>(
+                                               POS + 1, ID, next_id>(fmt);
-          format_str);
     } else {
       constexpr auto arg_id_result =
           parse_arg_id<ID>(str.data() + POS + 1, str.data() + str.size());
@@ -364,28 +394,27 @@ constexpr auto compile_format_string(S format_str) {
       constexpr char_type c =
           arg_id_end_pos != str.size() ? str[arg_id_end_pos] : char_type();
       static_assert(c == '}' || c == ':', "missing '}' in format string");
-      if constexpr (arg_id_result.arg_id.kind == arg_id_kind::index) {
+      if constexpr (arg_id_result.kind == arg_id_kind::index) {
         static_assert(
             ID == manual_indexing_id || ID == 0,
             "cannot switch from automatic to manual argument indexing");
-        constexpr auto arg_index = arg_id_result.arg_id.val.index;
+        constexpr auto arg_index = arg_id_result.arg_id.index;
         return parse_replacement_field_then_tail<get_type<arg_index, Args>,
                                                  Args, arg_id_end_pos,
                                                  arg_index, manual_indexing_id>(
-            format_str);
+            fmt);
-      } else if constexpr (arg_id_result.arg_id.kind == arg_id_kind::name) {
+      } else if constexpr (arg_id_result.kind == arg_id_kind::name) {
         constexpr auto arg_index =
-            get_arg_index_by_name(arg_id_result.arg_id.val.name, Args{});
+            get_arg_index_by_name(arg_id_result.arg_id.name, Args{});
         if constexpr (arg_index >= 0) {
           constexpr auto next_id =
               ID != manual_indexing_id ? ID + 1 : manual_indexing_id;
           return parse_replacement_field_then_tail<
               decltype(get_type<arg_index, Args>::value), Args, arg_id_end_pos,
-              arg_index, next_id>(format_str);
+              arg_index, next_id>(fmt);
         } else if constexpr (c == '}') {
           return parse_tail<Args, arg_id_end_pos + 1, ID>(
-              runtime_named_field<char_type>{arg_id_result.arg_id.val.name},
+              runtime_named_field<char_type>{arg_id_result.arg_id.name}, fmt);
-              format_str);
         } else if constexpr (c == ':') {
           return unknown_format();  // no type info for specs parsing
         }
@@ -394,29 +423,26 @@ constexpr auto compile_format_string(S format_str) {
   } else if constexpr (str[POS] == '}') {
     if constexpr (POS + 1 == str.size())
       FMT_THROW(format_error("unmatched '}' in format string"));
-    return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), format_str);
+    return parse_tail<Args, POS + 2, ID>(make_text(str, POS, 1), fmt);
   } else {
     constexpr auto end = parse_text(str, POS + 1);
     if constexpr (end - POS > 1) {
-      return parse_tail<Args, end, ID>(make_text(str, POS, end - POS),
+      return parse_tail<Args, end, ID>(make_text(str, POS, end - POS), fmt);
-                                       format_str);
     } else {
-      return parse_tail<Args, end, ID>(code_unit<char_type>{str[POS]},
+      return parse_tail<Args, end, ID>(code_unit<char_type>{str[POS]}, fmt);
-                                       format_str);
     }
   }
 }
 
 template <typename... Args, typename S,
-          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+          FMT_ENABLE_IF(is_compiled_string<S>::value)>
-constexpr auto compile(S format_str) {
+constexpr auto compile(S fmt) {
-  constexpr auto str = basic_string_view<typename S::char_type>(format_str);
+  constexpr auto str = basic_string_view<typename S::char_type>(fmt);
   if constexpr (str.size() == 0) {
     return detail::make_text(str, 0, 0);
   } else {
     constexpr auto result =
-        detail::compile_format_string<detail::type_list<Args...>, 0, 0>(
+        detail::compile_format_string<detail::type_list<Args...>, 0, 0>(fmt);
-            format_str);
     return result;
   }
 }
@@ -427,27 +453,28 @@ FMT_BEGIN_EXPORT
 
 #if defined(__cpp_if_constexpr) && defined(__cpp_return_type_deduction)
 
-template <typename CompiledFormat, typename... Args,
+template <typename CompiledFormat, typename... T,
           typename Char = typename CompiledFormat::char_type,
           FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
-FMT_INLINE std::basic_string<Char> format(const CompiledFormat& cf,
+FMT_INLINE FMT_CONSTEXPR_STRING auto format(const CompiledFormat& cf,
-                                          const Args&... args) {
+                                            const T&... args)
+    -> std::basic_string<Char> {
   auto s = std::basic_string<Char>();
   cf.format(std::back_inserter(s), args...);
   return s;
 }
 
-template <typename OutputIt, typename CompiledFormat, typename... Args,
+template <typename OutputIt, typename CompiledFormat, typename... T,
           FMT_ENABLE_IF(detail::is_compiled_format<CompiledFormat>::value)>
-constexpr FMT_INLINE OutputIt format_to(OutputIt out, const CompiledFormat& cf,
+constexpr FMT_INLINE auto format_to(OutputIt out, const CompiledFormat& cf,
-                                        const Args&... args) {
+                                    const T&... args) -> OutputIt {
   return cf.format(out, args...);
 }
 
-template <typename S, typename... Args,
+template <typename S, typename... T,
-          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+          FMT_ENABLE_IF(is_compiled_string<S>::value)>
-FMT_INLINE std::basic_string<typename S::char_type> format(const S&,
+FMT_INLINE FMT_CONSTEXPR_STRING auto format(const S&, T&&... args)
-                                                           Args&&... args) {
+    -> std::basic_string<typename S::char_type> {
   if constexpr (std::is_same<typename S::char_type, char>::value) {
     constexpr auto str = basic_string_view<typename S::char_type>(S());
     if constexpr (str.size() == 2 && str[0] == '{' && str[1] == '}') {
@@ -460,74 +487,97 @@ FMT_INLINE std::basic_string<typename S::char_type> format(const S&,
       }
     }
   }
-  constexpr auto compiled = detail::compile<Args...>(S());
+  constexpr auto compiled = detail::compile<T...>(S());
   if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
                              detail::unknown_format>()) {
     return fmt::format(
         static_cast<basic_string_view<typename S::char_type>>(S()),
-        std::forward<Args>(args)...);
+        std::forward<T>(args)...);
   } else {
-    return fmt::format(compiled, std::forward<Args>(args)...);
+    return fmt::format(compiled, std::forward<T>(args)...);
   }
 }
 
-template <typename OutputIt, typename S, typename... Args,
+template <typename OutputIt, typename S, typename... T,
-          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+          FMT_ENABLE_IF(is_compiled_string<S>::value)>
-FMT_CONSTEXPR OutputIt format_to(OutputIt out, const S&, Args&&... args) {
+FMT_CONSTEXPR auto format_to(OutputIt out, const S&, T&&... args) -> OutputIt {
-  constexpr auto compiled = detail::compile<Args...>(S());
+  constexpr auto compiled = detail::compile<T...>(S());
   if constexpr (std::is_same<remove_cvref_t<decltype(compiled)>,
                              detail::unknown_format>()) {
     return fmt::format_to(
         out, static_cast<basic_string_view<typename S::char_type>>(S()),
-        std::forward<Args>(args)...);
+        std::forward<T>(args)...);
   } else {
-    return fmt::format_to(out, compiled, std::forward<Args>(args)...);
+    return fmt::format_to(out, compiled, std::forward<T>(args)...);
   }
 }
 #endif
 
-template <typename OutputIt, typename S, typename... Args,
+template <typename OutputIt, typename S, typename... T,
-          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+          FMT_ENABLE_IF(is_compiled_string<S>::value)>
-auto format_to_n(OutputIt out, size_t n, const S& format_str, Args&&... args)
+auto format_to_n(OutputIt out, size_t n, const S& fmt, T&&... args)
     -> format_to_n_result<OutputIt> {
   using traits = detail::fixed_buffer_traits;
   auto buf = detail::iterator_buffer<OutputIt, char, traits>(out, n);
-  fmt::format_to(std::back_inserter(buf), format_str,
+  fmt::format_to(std::back_inserter(buf), fmt, std::forward<T>(args)...);
-                 std::forward<Args>(args)...);
   return {buf.out(), buf.count()};
 }
 
-template <typename S, typename... Args,
+template <typename S, typename... T,
-          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+          FMT_ENABLE_IF(is_compiled_string<S>::value)>
-FMT_CONSTEXPR20 auto formatted_size(const S& format_str, const Args&... args)
+FMT_CONSTEXPR20 auto formatted_size(const S& fmt, T&&... args) -> size_t {
-    -> size_t {
+  auto buf = detail::counting_buffer<>();
-  return fmt::format_to(detail::counting_iterator(), format_str, args...)
+  fmt::format_to(appender(buf), fmt, std::forward<T>(args)...);
-      .count();
+  return buf.count();
 }
 
-template <typename S, typename... Args,
+template <typename S, typename... T,
-          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+          FMT_ENABLE_IF(is_compiled_string<S>::value)>
-void print(std::FILE* f, const S& format_str, const Args&... args) {
+void print(std::FILE* f, const S& fmt, T&&... args) {
-  memory_buffer buffer;
+  auto buf = memory_buffer();
-  fmt::format_to(std::back_inserter(buffer), format_str, args...);
+  fmt::format_to(appender(buf), fmt, std::forward<T>(args)...);
-  detail::print(f, {buffer.data(), buffer.size()});
+  detail::print(f, {buf.data(), buf.size()});
 }
 
-template <typename S, typename... Args,
+template <typename S, typename... T,
-          FMT_ENABLE_IF(detail::is_compiled_string<S>::value)>
+          FMT_ENABLE_IF(is_compiled_string<S>::value)>
-void print(const S& format_str, const Args&... args) {
+void print(const S& fmt, T&&... args) {
-  print(stdout, format_str, args...);
+  print(stdout, fmt, std::forward<T>(args)...);
 }
 
-#if FMT_USE_NONTYPE_TEMPLATE_ARGS
+template <size_t N> class static_format_result {
-inline namespace literals {
+ private:
-template <detail_exported::fixed_string Str> constexpr auto operator""_cf() {
+  char data[N];
-  using char_t = remove_cvref_t<decltype(Str.data[0])>;
+
-  return detail::udl_compiled_string<char_t, sizeof(Str.data) / sizeof(char_t),
+ public:
-                                     Str>();
+  template <typename S, typename... T,
-}
+            FMT_ENABLE_IF(is_compiled_string<S>::value)>
-}  // namespace literals
+  explicit FMT_CONSTEXPR static_format_result(const S& fmt, T&&... args) {
-#endif
+    *fmt::format_to(data, fmt, std::forward<T>(args)...) = '\0';
+  }
+
+  auto str() const -> fmt::string_view { return {data, N - 1}; }
+  auto c_str() const -> const char* { return data; }
+};
+
+/**
+ * Formats arguments according to the format string `fmt_str` and produces
+ * a string of the exact required size at compile time. Both the format string
+ * and the arguments must be compile-time expressions.
+ *
+ * The resulting string can be accessed as a C string via `c_str()` or as
+ * a `fmt::string_view` via `str()`.
+ *
+ * **Example**:
+ *
+ *     // Produces the static string "42" at compile time.
+ *     static constexpr auto result = FMT_STATIC_FORMAT("{}", 42);
+ *     const char* s = result.c_str();
+ */
+#define FMT_STATIC_FORMAT(fmt_str, ...)                            \
+  fmt::static_format_result<                                       \
+      fmt::formatted_size(FMT_COMPILE(fmt_str), __VA_ARGS__) + 1>( \
+      FMT_COMPILE(fmt_str), __VA_ARGS__)
 
 FMT_END_EXPORT
 FMT_END_NAMESPACE

include/spdlog/fmt/bundled/fmt.license.rst

@@ -1,4 +1,4 @@
-Copyright (c) 2012 - present, Victor Zverovich
+Copyright (c) 2012 - present, Victor Zverovich and {fmt} contributors
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the

include/spdlog/fmt/bundled/format-inl.h

@@ -8,37 +8,72 @@
 #ifndef FMT_FORMAT_INL_H_
 #define FMT_FORMAT_INL_H_
 
-#include <algorithm>
+#ifndef FMT_MODULE
-#include <cerrno>  // errno
+#  include <algorithm>
-#include <climits>
+#  include <cerrno>  // errno
-#include <cmath>
+#  include <climits>
-#include <exception>
+#  include <cmath>
-
+#  include <exception>
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
-#  include <locale>
 #endif
 
-#if defined(_WIN32) && !defined(FMT_WINDOWS_NO_WCHAR)
+#if defined(_WIN32) && !defined(FMT_USE_WRITE_CONSOLE)
 #  include <io.h>  // _isatty
 #endif
 
 #include "format.h"
 
-FMT_BEGIN_NAMESPACE
+#if FMT_USE_LOCALE && !defined(FMT_MODULE)
-namespace detail {
+#  include <locale>
+#endif
 
+#ifndef FMT_FUNC
+#  define FMT_FUNC
+#endif
+
+FMT_BEGIN_NAMESPACE
+
+#ifndef FMT_CUSTOM_ASSERT_FAIL
 FMT_FUNC void assert_fail(const char* file, int line, const char* message) {
   // Use unchecked std::fprintf to avoid triggering another assertion when
-  // writing to stderr fails
+  // writing to stderr fails.
-  std::fprintf(stderr, "%s:%d: assertion failed: %s", file, line, message);
+  fprintf(stderr, "%s:%d: assertion failed: %s", file, line, message);
-  // Chosen instead of std::abort to satisfy Clang in CUDA mode during device
+  abort();
-  // code pass.
+}
-  std::terminate();
+#endif
+
+#if FMT_USE_LOCALE
+namespace detail {
+using std::locale;
+using std::numpunct;
+using std::use_facet;
+}  // namespace detail
+
+template <typename Locale, enable_if_t<(sizeof(Locale::collate) != 0), int>>
+locale_ref::locale_ref(const Locale& loc) : locale_(&loc) {
+  static_assert(std::is_same<Locale, std::locale>::value, "");
+}
+#else
+namespace detail {
+struct locale {};
+template <typename Char> struct numpunct {
+  auto grouping() const -> std::string { return "\03"; }
+  auto thousands_sep() const -> Char { return ','; }
+  auto decimal_point() const -> Char { return '.'; }
+};
+template <typename Facet> Facet use_facet(locale) { return {}; }
+}  // namespace detail
+#endif  // FMT_USE_LOCALE
+
+template <typename Locale> auto locale_ref::get() const -> Locale {
+  using namespace detail;
+  static_assert(std::is_same<Locale, locale>::value, "");
+#if FMT_USE_LOCALE
+  if (locale_) return *static_cast<const locale*>(locale_);
+#endif
+  return locale();
 }
 
-FMT_FUNC void throw_format_error(const char* message) {
+namespace detail {
-  FMT_THROW(format_error(message));
-}
 
 FMT_FUNC void format_error_code(detail::buffer<char>& out, int error_code,
                                 string_view message) noexcept {
@@ -56,89 +91,77 @@ FMT_FUNC void format_error_code(detail::buffer<char>& out, int error_code,
     ++error_code_size;
   }
   error_code_size += detail::to_unsigned(detail::count_digits(abs_value));
-  auto it = buffer_appender<char>(out);
+  auto it = appender(out);
   if (message.size() <= inline_buffer_size - error_code_size)
     fmt::format_to(it, FMT_STRING("{}{}"), message, SEP);
   fmt::format_to(it, FMT_STRING("{}{}"), ERROR_STR, error_code);
   FMT_ASSERT(out.size() <= inline_buffer_size, "");
 }
 
-FMT_FUNC void report_error(format_func func, int error_code,
+FMT_FUNC void do_report_error(format_func func, int error_code,
-                           const char* message) noexcept {
+                              const char* message) noexcept {
   memory_buffer full_message;
   func(full_message, error_code, message);
-  // Don't use fwrite_fully because the latter may throw.
+  // Don't use fwrite_all because the latter may throw.
   if (std::fwrite(full_message.data(), full_message.size(), 1, stderr) > 0)
     std::fputc('\n', stderr);
 }
 
 // A wrapper around fwrite that throws on error.
-inline void fwrite_fully(const void* ptr, size_t count, FILE* stream) {
+inline void fwrite_all(const void* ptr, size_t count, FILE* stream) {
   size_t written = std::fwrite(ptr, 1, count, stream);
   if (written < count)
     FMT_THROW(system_error(errno, FMT_STRING("cannot write to file")));
 }
 
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
-template <typename Locale>
-locale_ref::locale_ref(const Locale& loc) : locale_(&loc) {
-  static_assert(std::is_same<Locale, std::locale>::value, "");
-}
-
-template <typename Locale> auto locale_ref::get() const -> Locale {
-  static_assert(std::is_same<Locale, std::locale>::value, "");
-  return locale_ ? *static_cast<const std::locale*>(locale_) : std::locale();
-}
-
 template <typename Char>
 FMT_FUNC auto thousands_sep_impl(locale_ref loc) -> thousands_sep_result<Char> {
-  auto& facet = std::use_facet<std::numpunct<Char>>(loc.get<std::locale>());
+  auto&& facet = use_facet<numpunct<Char>>(loc.get<locale>());
   auto grouping = facet.grouping();
   auto thousands_sep = grouping.empty() ? Char() : facet.thousands_sep();
   return {std::move(grouping), thousands_sep};
 }
 template <typename Char>
 FMT_FUNC auto decimal_point_impl(locale_ref loc) -> Char {
-  return std::use_facet<std::numpunct<Char>>(loc.get<std::locale>())
+  return use_facet<numpunct<Char>>(loc.get<locale>()).decimal_point();
-      .decimal_point();
 }
-#else
-template <typename Char>
-FMT_FUNC auto thousands_sep_impl(locale_ref) -> thousands_sep_result<Char> {
-  return {"\03", FMT_STATIC_THOUSANDS_SEPARATOR};
-}
-template <typename Char> FMT_FUNC Char decimal_point_impl(locale_ref) {
-  return '.';
-}
-#endif
 
+#if FMT_USE_LOCALE
 FMT_FUNC auto write_loc(appender out, loc_value value,
-                        const format_specs<>& specs, locale_ref loc) -> bool {
+                        const format_specs& specs, locale_ref loc) -> bool {
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
   auto locale = loc.get<std::locale>();
   // We cannot use the num_put<char> facet because it may produce output in
   // a wrong encoding.
   using facet = format_facet<std::locale>;
   if (std::has_facet<facet>(locale))
-    return std::use_facet<facet>(locale).put(out, value, specs);
+    return use_facet<facet>(locale).put(out, value, specs);
   return facet(locale).put(out, value, specs);
-#endif
-  return false;
 }
+#endif
 }  // namespace detail
 
+FMT_FUNC void report_error(const char* message) {
+#if FMT_MSC_VERSION || defined(__NVCC__)
+  // Silence unreachable code warnings in MSVC and NVCC because these
+  // are nearly impossible to fix in a generic code.
+  volatile bool b = true;
+  if (!b) return;
+#endif
+  FMT_THROW(format_error(message));
+}
+
 template <typename Locale> typename Locale::id format_facet<Locale>::id;
 
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
 template <typename Locale> format_facet<Locale>::format_facet(Locale& loc) {
-  auto& numpunct = std::use_facet<std::numpunct<char>>(loc);
+  auto& np = detail::use_facet<detail::numpunct<char>>(loc);
-  grouping_ = numpunct.grouping();
+  grouping_ = np.grouping();
-  if (!grouping_.empty()) separator_ = std::string(1, numpunct.thousands_sep());
+  if (!grouping_.empty()) separator_ = std::string(1, np.thousands_sep());
 }
 
+#if FMT_USE_LOCALE
 template <>
 FMT_API FMT_FUNC auto format_facet<std::locale>::do_put(
-    appender out, loc_value val, const format_specs<>& specs) const -> bool {
+    appender out, loc_value val, const format_specs& specs) const -> bool {
   return val.visit(
       detail::loc_writer<>{out, specs, separator_, grouping_, decimal_point_});
 }
@@ -158,11 +181,11 @@ inline auto operator==(basic_fp<F> x, basic_fp<F> y) -> bool {
 }
 
 // Compilers should be able to optimize this into the ror instruction.
-FMT_CONSTEXPR inline auto rotr(uint32_t n, uint32_t r) noexcept -> uint32_t {
+FMT_INLINE auto rotr(uint32_t n, uint32_t r) noexcept -> uint32_t {
   r &= 31;
   return (n >> r) | (n << (32 - r));
 }
-FMT_CONSTEXPR inline auto rotr(uint64_t n, uint32_t r) noexcept -> uint64_t {
+FMT_INLINE auto rotr(uint64_t n, uint32_t r) noexcept -> uint64_t {
   r &= 63;
   return (n >> r) | (n << (64 - r));
 }
@@ -196,7 +219,7 @@ inline auto floor_log10_pow2_minus_log10_4_over_3(int e) noexcept -> int {
   return (e * 631305 - 261663) >> 21;
 }
 
-FMT_INLINE_VARIABLE constexpr struct {
+FMT_INLINE_VARIABLE constexpr struct div_small_pow10_infos_struct {
   uint32_t divisor;
   int shift_amount;
 } div_small_pow10_infos[] = {{10, 16}, {100, 16}};
@@ -259,7 +282,7 @@ template <> struct cache_accessor<float> {
   static auto get_cached_power(int k) noexcept -> uint64_t {
     FMT_ASSERT(k >= float_info<float>::min_k && k <= float_info<float>::max_k,
                "k is out of range");
-    static constexpr const uint64_t pow10_significands[] = {
+    static constexpr uint64_t pow10_significands[] = {
         0x81ceb32c4b43fcf5, 0xa2425ff75e14fc32, 0xcad2f7f5359a3b3f,
         0xfd87b5f28300ca0e, 0x9e74d1b791e07e49, 0xc612062576589ddb,
         0xf79687aed3eec552, 0x9abe14cd44753b53, 0xc16d9a0095928a28,
@@ -354,7 +377,7 @@ template <> struct cache_accessor<double> {
     FMT_ASSERT(k >= float_info<double>::min_k && k <= float_info<double>::max_k,
                "k is out of range");
 
-    static constexpr const uint128_fallback pow10_significands[] = {
+    static constexpr uint128_fallback pow10_significands[] = {
 #if FMT_USE_FULL_CACHE_DRAGONBOX
       {0xff77b1fcbebcdc4f, 0x25e8e89c13bb0f7b},
       {0x9faacf3df73609b1, 0x77b191618c54e9ad},
@@ -1021,7 +1044,7 @@ template <> struct cache_accessor<double> {
 #if FMT_USE_FULL_CACHE_DRAGONBOX
     return pow10_significands[k - float_info<double>::min_k];
 #else
-    static constexpr const uint64_t powers_of_5_64[] = {
+    static constexpr uint64_t powers_of_5_64[] = {
         0x0000000000000001, 0x0000000000000005, 0x0000000000000019,
         0x000000000000007d, 0x0000000000000271, 0x0000000000000c35,
         0x0000000000003d09, 0x000000000001312d, 0x000000000005f5e1,
@@ -1081,7 +1104,7 @@ template <> struct cache_accessor<double> {
     return {r.high(), r.low() == 0};
   }
 
-  static auto compute_delta(cache_entry_type const& cache, int beta) noexcept
+  static auto compute_delta(const cache_entry_type& cache, int beta) noexcept
       -> uint32_t {
     return static_cast<uint32_t>(cache.high() >> (64 - 1 - beta));
   }
@@ -1133,8 +1156,8 @@ auto is_left_endpoint_integer_shorter_interval(int exponent) noexcept -> bool {
          exponent <= case_shorter_interval_left_endpoint_upper_threshold;
 }
 
-// Remove trailing zeros from n and return the number of zeros removed (float)
+// Remove trailing zeros from n and return the number of zeros removed (float).
-FMT_INLINE int remove_trailing_zeros(uint32_t& n, int s = 0) noexcept {
+FMT_INLINE auto remove_trailing_zeros(uint32_t& n, int s = 0) noexcept -> int {
   FMT_ASSERT(n != 0, "");
   // Modular inverse of 5 (mod 2^32): (mod_inv_5 * 5) mod 2^32 = 1.
   constexpr uint32_t mod_inv_5 = 0xcccccccd;
@@ -1154,22 +1177,19 @@ FMT_INLINE int remove_trailing_zeros(uint32_t& n, int s = 0) noexcept {
   return s;
 }
 
-// Removes trailing zeros and returns the number of zeros removed (double)
+// Removes trailing zeros and returns the number of zeros removed (double).
-FMT_INLINE int remove_trailing_zeros(uint64_t& n) noexcept {
+FMT_INLINE auto remove_trailing_zeros(uint64_t& n) noexcept -> int {
   FMT_ASSERT(n != 0, "");
 
-  // This magic number is ceil(2^90 / 10^8).
-  constexpr uint64_t magic_number = 12379400392853802749ull;
-  auto nm = umul128(n, magic_number);
-
   // Is n is divisible by 10^8?
-  if ((nm.high() & ((1ull << (90 - 64)) - 1)) == 0 && nm.low() < magic_number) {
+  constexpr uint32_t ten_pow_8 = 100000000u;
+  if ((n % ten_pow_8) == 0) {
     // If yes, work with the quotient...
-    auto n32 = static_cast<uint32_t>(nm.high() >> (90 - 64));
+    auto n32 = static_cast<uint32_t>(n / ten_pow_8);
     // ... and use the 32 bit variant of the function
-    int s = remove_trailing_zeros(n32, 8);
+    int num_zeros = remove_trailing_zeros(n32, 8);
     n = n32;
-    return s;
+    return num_zeros;
   }
 
   // If n is not divisible by 10^8, work with n itself.
@@ -1194,7 +1214,7 @@ FMT_INLINE int remove_trailing_zeros(uint64_t& n) noexcept {
 
 // The main algorithm for shorter interval case
 template <typename T>
-FMT_INLINE decimal_fp<T> shorter_interval_case(int exponent) noexcept {
+FMT_INLINE auto shorter_interval_case(int exponent) noexcept -> decimal_fp<T> {
   decimal_fp<T> ret_value;
   // Compute k and beta
   const int minus_k = floor_log10_pow2_minus_log10_4_over_3(exponent);
@@ -1411,7 +1431,7 @@ FMT_FUNC void format_system_error(detail::buffer<char>& out, int error_code,
                                   const char* message) noexcept {
   FMT_TRY {
     auto ec = std::error_code(error_code, std::generic_category());
-    write(std::back_inserter(out), std::system_error(ec, message).what());
+    detail::write(appender(out), std::system_error(ec, message).what());
     return;
   }
   FMT_CATCH(...) {}
@@ -1420,7 +1440,7 @@ FMT_FUNC void format_system_error(detail::buffer<char>& out, int error_code,
 
 FMT_FUNC void report_system_error(int error_code,
                                   const char* message) noexcept {
-  report_error(format_system_error, error_code, message);
+  do_report_error(format_system_error, error_code, message);
 }
 
 FMT_FUNC auto vformat(string_view fmt, format_args args) -> std::string {
@@ -1432,9 +1452,252 @@ FMT_FUNC auto vformat(string_view fmt, format_args args) -> std::string {
 }
 
 namespace detail {
-#if !defined(_WIN32) || defined(FMT_WINDOWS_NO_WCHAR)
+
+FMT_FUNC void vformat_to(buffer<char>& buf, string_view fmt, format_args args,
+                         locale_ref loc) {
+  auto out = appender(buf);
+  if (fmt.size() == 2 && equal2(fmt.data(), "{}"))
+    return args.get(0).visit(default_arg_formatter<char>{out});
+  parse_format_string(fmt,
+                      format_handler<>{parse_context<>(fmt), {out, args, loc}});
+}
+
+template <typename T> struct span {
+  T* data;
+  size_t size;
+};
+
+template <typename F> auto flockfile(F* f) -> decltype(_lock_file(f)) {
+  _lock_file(f);
+}
+template <typename F> auto funlockfile(F* f) -> decltype(_unlock_file(f)) {
+  _unlock_file(f);
+}
+
+#ifndef getc_unlocked
+template <typename F> auto getc_unlocked(F* f) -> decltype(_fgetc_nolock(f)) {
+  return _fgetc_nolock(f);
+}
+#endif
+
+template <typename F = FILE, typename Enable = void>
+struct has_flockfile : std::false_type {};
+
+template <typename F>
+struct has_flockfile<F, void_t<decltype(flockfile(&std::declval<F&>()))>>
+    : std::true_type {};
+
+// A FILE wrapper. F is FILE defined as a template parameter to make system API
+// detection work.
+template <typename F> class file_base {
+ public:
+  F* file_;
+
+ public:
+  file_base(F* file) : file_(file) {}
+  operator F*() const { return file_; }
+
+  // Reads a code unit from the stream.
+  auto get() -> int {
+    int result = getc_unlocked(file_);
+    if (result == EOF && ferror(file_) != 0)
+      FMT_THROW(system_error(errno, FMT_STRING("getc failed")));
+    return result;
+  }
+
+  // Puts the code unit back into the stream buffer.
+  void unget(char c) {
+    if (ungetc(c, file_) == EOF)
+      FMT_THROW(system_error(errno, FMT_STRING("ungetc failed")));
+  }
+
+  void flush() { fflush(this->file_); }
+};
+
+// A FILE wrapper for glibc.
+template <typename F> class glibc_file : public file_base<F> {
+ private:
+  enum {
+    line_buffered = 0x200,  // _IO_LINE_BUF
+    unbuffered = 2          // _IO_UNBUFFERED
+  };
+
+ public:
+  using file_base<F>::file_base;
+
+  auto is_buffered() const -> bool {
+    return (this->file_->_flags & unbuffered) == 0;
+  }
+
+  void init_buffer() {
+    if (this->file_->_IO_write_ptr < this->file_->_IO_write_end) return;
+    // Force buffer initialization by placing and removing a char in a buffer.
+    putc_unlocked(0, this->file_);
+    --this->file_->_IO_write_ptr;
+  }
+
+  // Returns the file's read buffer.
+  auto get_read_buffer() const -> span<const char> {
+    auto ptr = this->file_->_IO_read_ptr;
+    return {ptr, to_unsigned(this->file_->_IO_read_end - ptr)};
+  }
+
+  // Returns the file's write buffer.
+  auto get_write_buffer() const -> span<char> {
+    auto ptr = this->file_->_IO_write_ptr;
+    return {ptr, to_unsigned(this->file_->_IO_buf_end - ptr)};
+  }
+
+  void advance_write_buffer(size_t size) { this->file_->_IO_write_ptr += size; }
+
+  auto needs_flush() const -> bool {
+    if ((this->file_->_flags & line_buffered) == 0) return false;
+    char* end = this->file_->_IO_write_end;
+    auto size = max_of<ptrdiff_t>(this->file_->_IO_write_ptr - end, 0);
+    return memchr(end, '\n', static_cast<size_t>(size));
+  }
+
+  void flush() { fflush_unlocked(this->file_); }
+};
+
+// A FILE wrapper for Apple's libc.
+template <typename F> class apple_file : public file_base<F> {
+ private:
+  enum {
+    line_buffered = 1,  // __SNBF
+    unbuffered = 2      // __SLBF
+  };
+
+ public:
+  using file_base<F>::file_base;
+
+  auto is_buffered() const -> bool {
+    return (this->file_->_flags & unbuffered) == 0;
+  }
+
+  void init_buffer() {
+    if (this->file_->_p) return;
+    // Force buffer initialization by placing and removing a char in a buffer.
+    if (!FMT_CLANG_ANALYZER) putc_unlocked(0, this->file_);
+    --this->file_->_p;
+    ++this->file_->_w;
+  }
+
+  auto get_read_buffer() const -> span<const char> {
+    return {reinterpret_cast<char*>(this->file_->_p),
+            to_unsigned(this->file_->_r)};
+  }
+
+  auto get_write_buffer() const -> span<char> {
+    return {reinterpret_cast<char*>(this->file_->_p),
+            to_unsigned(this->file_->_bf._base + this->file_->_bf._size -
+                        this->file_->_p)};
+  }
+
+  void advance_write_buffer(size_t size) {
+    this->file_->_p += size;
+    this->file_->_w -= size;
+  }
+
+  auto needs_flush() const -> bool {
+    if ((this->file_->_flags & line_buffered) == 0) return false;
+    return memchr(this->file_->_p + this->file_->_w, '\n',
+                  to_unsigned(-this->file_->_w));
+  }
+};
+
+// A fallback FILE wrapper.
+template <typename F> class fallback_file : public file_base<F> {
+ private:
+  char next_;  // The next unconsumed character in the buffer.
+  bool has_next_ = false;
+
+ public:
+  using file_base<F>::file_base;
+
+  auto is_buffered() const -> bool { return false; }
+  auto needs_flush() const -> bool { return false; }
+  void init_buffer() {}
+
+  auto get_read_buffer() const -> span<const char> {
+    return {&next_, has_next_ ? 1u : 0u};
+  }
+
+  auto get_write_buffer() const -> span<char> { return {nullptr, 0}; }
+
+  void advance_write_buffer(size_t) {}
+
+  auto get() -> int {
+    has_next_ = false;
+    return file_base<F>::get();
+  }
+
+  void unget(char c) {
+    file_base<F>::unget(c);
+    next_ = c;
+    has_next_ = true;
+  }
+};
+
+#ifndef FMT_USE_FALLBACK_FILE
+#  define FMT_USE_FALLBACK_FILE 0
+#endif
+
+template <typename F,
+          FMT_ENABLE_IF(sizeof(F::_p) != 0 && !FMT_USE_FALLBACK_FILE)>
+auto get_file(F* f, int) -> apple_file<F> {
+  return f;
+}
+template <typename F,
+          FMT_ENABLE_IF(sizeof(F::_IO_read_ptr) != 0 && !FMT_USE_FALLBACK_FILE)>
+inline auto get_file(F* f, int) -> glibc_file<F> {
+  return f;
+}
+
+inline auto get_file(FILE* f, ...) -> fallback_file<FILE> { return f; }
+
+using file_ref = decltype(get_file(static_cast<FILE*>(nullptr), 0));
+
+template <typename F = FILE, typename Enable = void>
+class file_print_buffer : public buffer<char> {
+ public:
+  explicit file_print_buffer(F*) : buffer(nullptr, size_t()) {}
+};
+
+template <typename F>
+class file_print_buffer<F, enable_if_t<has_flockfile<F>::value>>
+    : public buffer<char> {
+ private:
+  file_ref file_;
+
+  static void grow(buffer<char>& base, size_t) {
+    auto& self = static_cast<file_print_buffer&>(base);
+    self.file_.advance_write_buffer(self.size());
+    if (self.file_.get_write_buffer().size == 0) self.file_.flush();
+    auto buf = self.file_.get_write_buffer();
+    FMT_ASSERT(buf.size > 0, "");
+    self.set(buf.data, buf.size);
+    self.clear();
+  }
+
+ public:
+  explicit file_print_buffer(F* f) : buffer(grow, size_t()), file_(f) {
+    flockfile(f);
+    file_.init_buffer();
+    auto buf = file_.get_write_buffer();
+    set(buf.data, buf.size);
+  }
+  ~file_print_buffer() {
+    file_.advance_write_buffer(size());
+    bool flush = file_.needs_flush();
+    F* f = file_;    // Make funlockfile depend on the template parameter F
+    funlockfile(f);  // for the system API detection to work.
+    if (flush) fflush(file_);
+  }
+};
+
+#if !defined(_WIN32) || defined(FMT_USE_WRITE_CONSOLE)
 FMT_FUNC auto write_console(int, string_view) -> bool { return false; }
-FMT_FUNC auto write_console(std::FILE*, string_view) -> bool { return false; }
 #else
 using dword = conditional_t<sizeof(long) == 4, unsigned long, unsigned>;
 extern "C" __declspec(dllimport) int __stdcall WriteConsoleW(  //
@@ -1445,39 +1708,51 @@ FMT_FUNC bool write_console(int fd, string_view text) {
   return WriteConsoleW(reinterpret_cast<void*>(_get_osfhandle(fd)), u16.c_str(),
                        static_cast<dword>(u16.size()), nullptr, nullptr) != 0;
 }
-
-FMT_FUNC auto write_console(std::FILE* f, string_view text) -> bool {
-  return write_console(_fileno(f), text);
-}
 #endif
 
 #ifdef _WIN32
 // Print assuming legacy (non-Unicode) encoding.
-FMT_FUNC void vprint_mojibake(std::FILE* f, string_view fmt, format_args args) {
+FMT_FUNC void vprint_mojibake(std::FILE* f, string_view fmt, format_args args,
+                              bool newline) {
   auto buffer = memory_buffer();
   detail::vformat_to(buffer, fmt, args);
-  fwrite_fully(buffer.data(), buffer.size(), f);
+  if (newline) buffer.push_back('\n');
+  fwrite_all(buffer.data(), buffer.size(), f);
 }
 #endif
 
 FMT_FUNC void print(std::FILE* f, string_view text) {
-#ifdef _WIN32
+#if defined(_WIN32) && !defined(FMT_USE_WRITE_CONSOLE)
   int fd = _fileno(f);
   if (_isatty(fd)) {
     std::fflush(f);
     if (write_console(fd, text)) return;
   }
 #endif
-  fwrite_fully(text.data(), text.size(), f);
+  fwrite_all(text.data(), text.size(), f);
 }
 }  // namespace detail
 
-FMT_FUNC void vprint(std::FILE* f, string_view fmt, format_args args) {
+FMT_FUNC void vprint_buffered(std::FILE* f, string_view fmt, format_args args) {
   auto buffer = memory_buffer();
   detail::vformat_to(buffer, fmt, args);
   detail::print(f, {buffer.data(), buffer.size()});
 }
 
+FMT_FUNC void vprint(std::FILE* f, string_view fmt, format_args args) {
+  if (!detail::file_ref(f).is_buffered() || !detail::has_flockfile<>())
+    return vprint_buffered(f, fmt, args);
+  auto&& buffer = detail::file_print_buffer<>(f);
+  return detail::vformat_to(buffer, fmt, args);
+}
+
+FMT_FUNC void vprintln(std::FILE* f, string_view fmt, format_args args) {
+  auto buffer = memory_buffer();
+  detail::vformat_to(buffer, fmt, args);
+  buffer.push_back('\n');
+  detail::print(f, {buffer.data(), buffer.size()});
+}
+
 FMT_FUNC void vprint(string_view fmt, format_args args) {
   vprint(stdout, fmt, args);
 }

include/spdlog/fmt/bundled/locale.h

@@ -1,2 +0,0 @@
-#include "xchar.h"
-#warning fmt/locale.h is deprecated, include fmt/format.h or fmt/xchar.h instead

include/spdlog/fmt/bundled/os.h

@@ -8,18 +8,18 @@
 #ifndef FMT_OS_H_
 #define FMT_OS_H_
 
-#include <cerrno>
-#include <cstddef>
-#include <cstdio>
-#include <system_error>  // std::system_error
-
 #include "format.h"
 
-#if defined __APPLE__ || defined(__FreeBSD__)
+#ifndef FMT_MODULE
+#  include <cerrno>
+#  include <cstddef>
+#  include <cstdio>
+#  include <system_error>  // std::system_error
+
 #  if FMT_HAS_INCLUDE(<xlocale.h>)
-#    include <xlocale.h>  // for LC_NUMERIC_MASK on OS X
+#    include <xlocale.h>  // LC_NUMERIC_MASK on macOS
 #  endif
-#endif
+#endif  // FMT_MODULE
 
 #ifndef FMT_USE_FCNTL
 // UWP doesn't provide _pipe.
@@ -29,7 +29,8 @@
 #  if (FMT_HAS_INCLUDE(<fcntl.h>) || defined(__APPLE__) || \
        defined(__linux__)) &&                              \
       (!defined(WINAPI_FAMILY) ||                          \
-       (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP))
+       (WINAPI_FAMILY == WINAPI_FAMILY_DESKTOP_APP)) &&    \
+      !defined(__wasm__)
 #    include <fcntl.h>  // for O_RDONLY
 #    define FMT_USE_FCNTL 1
 #  else
@@ -77,46 +78,33 @@ FMT_BEGIN_NAMESPACE
 FMT_BEGIN_EXPORT
 
 /**
-  \rst
+ * A reference to a null-terminated string. It can be constructed from a C
-  A reference to a null-terminated string. It can be constructed from a C
+ * string or `std::string`.
-  string or ``std::string``.
+ *
-
+ * You can use one of the following type aliases for common character types:
-  You can use one of the following type aliases for common character types:
+ *
-
+ * +---------------+-----------------------------+
-  +---------------+-----------------------------+
+ * | Type          | Definition                  |
-  | Type          | Definition                  |
+ * +===============+=============================+
-  +===============+=============================+
+ * | cstring_view  | basic_cstring_view<char>    |
-  | cstring_view  | basic_cstring_view<char>    |
+ * +---------------+-----------------------------+
-  +---------------+-----------------------------+
+ * | wcstring_view | basic_cstring_view<wchar_t> |
-  | wcstring_view | basic_cstring_view<wchar_t> |
+ * +---------------+-----------------------------+
-  +---------------+-----------------------------+
+ *
-
+ * This class is most useful as a parameter type for functions that wrap C APIs.
-  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. */
+  /// Constructs a string reference object from a C string.
   basic_cstring_view(const Char* s) : data_(s) {}
 
-  /**
+  /// Constructs a string reference from an `std::string` object.
-    \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. */
+  /// Returns the pointer to a C string.
   auto c_str() const -> const Char* { return data_; }
 };
 
@@ -131,41 +119,38 @@ FMT_API void format_windows_error(buffer<char>& out, int error_code,
                                   const char* message) noexcept;
 }
 
-FMT_API std::system_error vwindows_error(int error_code, string_view format_str,
+FMT_API std::system_error vwindows_error(int error_code, string_view fmt,
                                          format_args args);
 
 /**
- \rst
+ * Constructs a `std::system_error` object with the description of the form
- Constructs a :class:`std::system_error` object with the description
+ *
- of the form
+ *     <message>: <system-message>
-
+ *
- .. parsed-literal::
+ * where `<message>` is the formatted message and `<system-message>` is the
-   *<message>*: *<system-message>*
+ * system message corresponding to the error code.
-
+ * `error_code` is a Windows error code as given by `GetLastError`.
- where *<message>* is the formatted message and *<system-message>* is the
+ * If `error_code` is not a valid error code such as -1, the system message
- system message corresponding to the error code.
+ * will look like "error -1".
- *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
+ * **Example**:
- will look like "error -1".
+ *
-
+ *     // This throws a system_error with the description
- **Example**::
+ *     //   cannot open file 'madeup': The system cannot find the file
-
+ * specified.
-   // This throws a system_error with the description
+ *     // or similar (system message may vary).
-   //   cannot open file 'madeup': The system cannot find the file specified.
+ *     const char *filename = "madeup";
-   // or similar (system message may vary).
+ *     LPOFSTRUCT of = LPOFSTRUCT();
-   const char *filename = "madeup";
+ *     HFILE file = OpenFile(filename, &of, OF_READ);
-   LPOFSTRUCT of = LPOFSTRUCT();
+ *     if (file == HFILE_ERROR) {
-   HFILE file = OpenFile(filename, &of, OF_READ);
+ *       throw fmt::windows_error(GetLastError(),
-   if (file == HFILE_ERROR) {
+ *                                "cannot open file '{}'", filename);
-     throw fmt::windows_error(GetLastError(),
+ *     }
-                              "cannot open file '{}'", filename);
+ */
-   }
+template <typename... T>
- \endrst
+auto windows_error(int error_code, string_view message, const T&... args)
-*/
+    -> std::system_error {
-template <typename... Args>
+  return vwindows_error(error_code, message, vargs<T...>{{args...}});
-std::system_error windows_error(int error_code, string_view message,
-                                const Args&... args) {
-  return vwindows_error(error_code, message, fmt::make_format_args(args...));
 }
 
 // Reports a Windows error without throwing an exception.
@@ -180,8 +165,8 @@ inline auto system_category() noexcept -> const std::error_category& {
 // std::system is not available on some platforms such as iOS (#2248).
 #ifdef __OSX__
 template <typename S, typename... Args, typename Char = char_t<S>>
-void say(const S& format_str, Args&&... args) {
+void say(const S& fmt, Args&&... args) {
-  std::system(format("say \"{}\"", format(format_str, args...)).c_str());
+  std::system(format("say \"{}\"", format(fmt, args...)).c_str());
 }
 #endif
 
@@ -192,24 +177,24 @@ class buffered_file {
 
   friend class file;
 
-  explicit buffered_file(FILE* f) : file_(f) {}
+  inline explicit buffered_file(FILE* f) : file_(f) {}
 
  public:
   buffered_file(const buffered_file&) = delete;
   void operator=(const buffered_file&) = delete;
 
   // Constructs a buffered_file object which doesn't represent any file.
-  buffered_file() noexcept : file_(nullptr) {}
+  inline buffered_file() noexcept : file_(nullptr) {}
 
   // Destroys the object closing the file it represents if any.
   FMT_API ~buffered_file() noexcept;
 
  public:
-  buffered_file(buffered_file&& other) noexcept : file_(other.file_) {
+  inline buffered_file(buffered_file&& other) noexcept : file_(other.file_) {
     other.file_ = nullptr;
   }
 
-  auto operator=(buffered_file&& other) -> buffered_file& {
+  inline auto operator=(buffered_file&& other) -> buffered_file& {
     close();
     file_ = other.file_;
     other.file_ = nullptr;
@@ -223,21 +208,20 @@ class buffered_file {
   FMT_API void close();
 
   // Returns the pointer to a FILE object representing this file.
-  auto get() const noexcept -> FILE* { return file_; }
+  inline auto get() const noexcept -> FILE* { return file_; }
 
   FMT_API auto descriptor() const -> int;
 
-  void vprint(string_view format_str, format_args args) {
+  template <typename... T>
-    fmt::vprint(file_, format_str, args);
+  inline void print(string_view fmt, const T&... args) {
-  }
+    fmt::vargs<T...> vargs = {{args...}};
-
+    detail::is_locking<T...>() ? fmt::vprint_buffered(file_, fmt, vargs)
-  template <typename... Args>
+                               : fmt::vprint(file_, fmt, vargs);
-  inline void print(string_view format_str, const Args&... args) {
-    vprint(format_str, fmt::make_format_args(args...));
   }
 };
 
 #if FMT_USE_FCNTL
+
 // A file. Closed file is represented by a file object with descriptor -1.
 // Methods that are not declared with noexcept may throw
 // fmt::system_error in case of failure. Note that some errors such as
@@ -251,6 +235,8 @@ class FMT_API file {
   // Constructs a file object with a given descriptor.
   explicit file(int fd) : fd_(fd) {}
 
+  friend struct pipe;
+
  public:
   // Possible values for the oflag argument to the constructor.
   enum {
@@ -263,7 +249,7 @@ class FMT_API file {
   };
 
   // Constructs a file object which doesn't represent any file.
-  file() noexcept : fd_(-1) {}
+  inline file() noexcept : fd_(-1) {}
 
   // Opens a file and constructs a file object representing this file.
   file(cstring_view path, int oflag);
@@ -272,10 +258,10 @@ class FMT_API file {
   file(const file&) = delete;
   void operator=(const file&) = delete;
 
-  file(file&& other) noexcept : fd_(other.fd_) { other.fd_ = -1; }
+  inline file(file&& other) noexcept : fd_(other.fd_) { other.fd_ = -1; }
 
   // Move assignment is not noexcept because close may throw.
-  auto operator=(file&& other) -> file& {
+  inline auto operator=(file&& other) -> file& {
     close();
     fd_ = other.fd_;
     other.fd_ = -1;
@@ -286,7 +272,7 @@ class FMT_API file {
   ~file() noexcept;
 
   // Returns the file descriptor.
-  auto descriptor() const noexcept -> int { return fd_; }
+  inline auto descriptor() const noexcept -> int { return fd_; }
 
   // Closes the file.
   void close();
@@ -313,11 +299,6 @@ class FMT_API file {
   // necessary.
   void dup2(int fd, std::error_code& ec) noexcept;
 
-  // Creates a pipe setting up read_end and write_end file objects for reading
-  // and writing respectively.
-  // DEPRECATED! Taking files as out parameters is deprecated.
-  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.
   auto fdopen(const char* mode) -> buffered_file;
@@ -329,15 +310,24 @@ class FMT_API file {
 #  endif
 };
 
+struct FMT_API pipe {
+  file read_end;
+  file write_end;
+
+  // Creates a pipe setting up read_end and write_end file objects for reading
+  // and writing respectively.
+  pipe();
+};
+
 // Returns the memory page size.
 auto getpagesize() -> long;
 
 namespace detail {
 
 struct buffer_size {
-  buffer_size() = default;
+  constexpr buffer_size() = default;
   size_t value = 0;
-  auto operator=(size_t val) const -> buffer_size {
+  FMT_CONSTEXPR auto operator=(size_t val) const -> buffer_size {
     auto bs = buffer_size();
     bs.value = val;
     return bs;
@@ -348,7 +338,7 @@ struct ostream_params {
   int oflag = file::WRONLY | file::CREATE | file::TRUNC;
   size_t buffer_size = BUFSIZ > 32768 ? BUFSIZ : 32768;
 
-  ostream_params() {}
+  constexpr ostream_params() {}
 
   template <typename... T>
   ostream_params(T... params, int new_oflag) : ostream_params(params...) {
@@ -369,79 +359,62 @@ struct ostream_params {
 #  endif
 };
 
-class file_buffer final : public buffer<char> {
+}  // namespace detail
+
+FMT_INLINE_VARIABLE constexpr auto buffer_size = detail::buffer_size();
+
+/// A fast buffered output stream for writing from a single thread. Writing from
+/// multiple threads without external synchronization may result in a data race.
+class FMT_API ostream : private detail::buffer<char> {
+ private:
   file file_;
 
-  FMT_API void grow(size_t) override;
+  ostream(cstring_view path, const detail::ostream_params& params);
+
+  static void grow(buffer<char>& buf, size_t);
 
  public:
-  FMT_API file_buffer(cstring_view path, const ostream_params& params);
+  ostream(ostream&& other) noexcept;
-  FMT_API file_buffer(file_buffer&& other);
+  ~ostream();
-  FMT_API ~file_buffer();
 
-  void flush() {
+  operator writer() {
+    detail::buffer<char>& buf = *this;
+    return buf;
+  }
+
+  inline void flush() {
     if (size() == 0) return;
     file_.write(data(), size() * sizeof(data()[0]));
     clear();
   }
 
-  void close() {
-    flush();
-    file_.close();
-  }
-};
-
-}  // namespace detail
-
-// Added {} below to work around default constructor error known to
-// occur in Xcode versions 7.2.1 and 8.2.1.
-constexpr detail::buffer_size buffer_size{};
-
-/** A fast output stream which is not thread-safe. */
-class FMT_API ostream {
- private:
-  FMT_MSC_WARNING(suppress : 4251)
-  detail::file_buffer buffer_;
-
-  ostream(cstring_view path, const detail::ostream_params& params)
-      : buffer_(path, params) {}
-
- public:
-  ostream(ostream&& other) : buffer_(std::move(other.buffer_)) {}
-
-  ~ostream();
-
-  void flush() { buffer_.flush(); }
-
   template <typename... T>
   friend auto output_file(cstring_view path, T... params) -> ostream;
 
-  void close() { buffer_.close(); }
+  inline void close() {
+    flush();
+    file_.close();
+  }
 
-  /**
+  /// Formats `args` according to specifications in `fmt` and writes the
-    Formats ``args`` according to specifications in ``fmt`` and writes the
+  /// output to the file.
-    output to the file.
-   */
   template <typename... T> void print(format_string<T...> fmt, T&&... args) {
-    vformat_to(std::back_inserter(buffer_), fmt,
+    vformat_to(appender(*this), fmt.str, vargs<T...>{{args...}});
-               fmt::make_format_args(args...));
   }
 };
 
 /**
-  \rst
+ * Opens a file for writing. Supported parameters passed in `params`:
-  Opens a file for writing. Supported parameters passed in *params*:
+ *
-
+ * - `<integer>`: Flags passed to [open](
-  * ``<integer>``: Flags passed to `open
+ *   https://pubs.opengroup.org/onlinepubs/007904875/functions/open.html)
-    <https://pubs.opengroup.org/onlinepubs/007904875/functions/open.html>`_
+ *   (`file::WRONLY | file::CREATE | file::TRUNC` by default)
-    (``file::WRONLY | file::CREATE | file::TRUNC`` by default)
+ * - `buffer_size=<integer>`: Output buffer size
-  * ``buffer_size=<integer>``: Output buffer size
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     auto out = fmt::output_file("guide.txt");
-    auto out = fmt::output_file("guide.txt");
+ *     out.print("Don't {}", "Panic");
-    out.print("Don't {}", "Panic");
-  \endrst
  */
 template <typename... T>
 inline auto output_file(cstring_view path, T... params) -> ostream {

include/spdlog/fmt/bundled/ostream.h

@@ -8,7 +8,9 @@
 #ifndef FMT_OSTREAM_H_
 #define FMT_OSTREAM_H_
 
-#include <fstream>  // std::filebuf
+#ifndef FMT_MODULE
+#  include <fstream>  // std::filebuf
+#endif
 
 #ifdef _WIN32
 #  ifdef __GLIBCXX__
@@ -18,44 +20,21 @@
 #  include <io.h>
 #endif
 
-#include "format.h"
+#include "chrono.h"  // formatbuf
+
+#ifdef _MSVC_STL_UPDATE
+#  define FMT_MSVC_STL_UPDATE _MSVC_STL_UPDATE
+#elif defined(_MSC_VER) && _MSC_VER < 1912  // VS 15.5
+#  define FMT_MSVC_STL_UPDATE _MSVC_LANG
+#else
+#  define FMT_MSVC_STL_UPDATE 0
+#endif
 
 FMT_BEGIN_NAMESPACE
 namespace detail {
 
-template <typename Streambuf> class formatbuf : public Streambuf {
+// Generate a unique explicit instantiation in every translation unit using a
- private:
+// tag type in an anonymous namespace.
-  using char_type = typename Streambuf::char_type;
-  using streamsize = decltype(std::declval<Streambuf>().sputn(nullptr, 0));
-  using int_type = typename Streambuf::int_type;
-  using traits_type = typename Streambuf::traits_type;
-
-  buffer<char_type>& buffer_;
-
- public:
-  explicit formatbuf(buffer<char_type>& buf) : buffer_(buf) {}
-
- protected:
-  // The put area is always empty. This makes the implementation simpler and has
-  // the advantage that the streambuf and the buffer are always in sync and
-  // sputc never writes into uninitialized memory. A disadvantage is that each
-  // call to sputc always results in a (virtual) call to overflow. There is no
-  // disadvantage here for sputn since this always results in a call to xsputn.
-
-  auto overflow(int_type ch) -> int_type override {
-    if (!traits_type::eq_int_type(ch, traits_type::eof()))
-      buffer_.push_back(static_cast<char_type>(ch));
-    return ch;
-  }
-
-  auto xsputn(const char_type* s, streamsize count) -> streamsize override {
-    buffer_.append(s, s + count);
-    return count;
-  }
-};
-
-// Generate a unique explicit instantion in every translation unit using a tag
-// type in an anonymous namespace.
 namespace {
 struct file_access_tag {};
 }  // namespace
@@ -64,53 +43,18 @@ class file_access {
   friend auto get_file(BufType& obj) -> FILE* { return obj.*FileMemberPtr; }
 };
 
-#if FMT_MSC_VERSION
+#if FMT_MSVC_STL_UPDATE
 template class file_access<file_access_tag, std::filebuf,
                            &std::filebuf::_Myfile>;
 auto get_file(std::filebuf&) -> FILE*;
 #endif
 
-inline auto write_ostream_unicode(std::ostream& os, fmt::string_view data)
-    -> bool {
-  FILE* f = nullptr;
-#if FMT_MSC_VERSION
-  if (auto* buf = dynamic_cast<std::filebuf*>(os.rdbuf()))
-    f = get_file(*buf);
-  else
-    return false;
-#elif defined(_WIN32) && defined(__GLIBCXX__)
-  auto* rdbuf = os.rdbuf();
-  if (auto* sfbuf = dynamic_cast<__gnu_cxx::stdio_sync_filebuf<char>*>(rdbuf))
-    f = sfbuf->file();
-  else if (auto* fbuf = dynamic_cast<__gnu_cxx::stdio_filebuf<char>*>(rdbuf))
-    f = fbuf->file();
-  else
-    return false;
-#else
-  ignore_unused(os, data, f);
-#endif
-#ifdef _WIN32
-  if (f) {
-    int fd = _fileno(f);
-    if (_isatty(fd)) {
-      os.flush();
-      return write_console(fd, data);
-    }
-  }
-#endif
-  return false;
-}
-inline auto write_ostream_unicode(std::wostream&,
-                                  fmt::basic_string_view<wchar_t>) -> bool {
-  return false;
-}
-
 // Write the content of buf to os.
 // It is a separate function rather than a part of vprint to simplify testing.
 template <typename Char>
 void write_buffer(std::basic_ostream<Char>& os, buffer<Char>& buf) {
   const Char* buf_data = buf.data();
-  using unsigned_streamsize = std::make_unsigned<std::streamsize>::type;
+  using unsigned_streamsize = make_unsigned_t<std::streamsize>;
   unsigned_streamsize size = buf.size();
   unsigned_streamsize max_size = to_unsigned(max_value<std::streamsize>());
   do {
@@ -121,21 +65,9 @@ void write_buffer(std::basic_ostream<Char>& os, buffer<Char>& buf) {
   } while (size != 0);
 }
 
-template <typename Char, typename T>
-void format_value(buffer<Char>& buf, const T& value) {
-  auto&& format_buf = formatbuf<std::basic_streambuf<Char>>(buf);
-  auto&& output = std::basic_ostream<Char>(&format_buf);
-#if !defined(FMT_STATIC_THOUSANDS_SEPARATOR)
-  output.imbue(std::locale::classic());  // The default is always unlocalized.
-#endif
-  output << value;
-  output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
-}
-
 template <typename T> struct streamed_view {
   const T& value;
 };
-
 }  // namespace detail
 
 // Formats an object of type T that has an overloaded ostream operator<<.
@@ -143,11 +75,14 @@ template <typename Char>
 struct basic_ostream_formatter : formatter<basic_string_view<Char>, Char> {
   void set_debug_format() = delete;
 
-  template <typename T, typename OutputIt>
+  template <typename T, typename Context>
-  auto format(const T& value, basic_format_context<OutputIt, Char>& ctx) const
+  auto format(const T& value, Context& ctx) const -> decltype(ctx.out()) {
-      -> OutputIt {
     auto buffer = basic_memory_buffer<Char>();
-    detail::format_value(buffer, value);
+    auto&& formatbuf = detail::formatbuf<std::basic_streambuf<Char>>(buffer);
+    auto&& output = std::basic_ostream<Char>(&formatbuf);
+    output.imbue(std::locale::classic());  // The default is always unlocalized.
+    output << value;
+    output.exceptions(std::ios_base::failbit | std::ios_base::badbit);
     return formatter<basic_string_view<Char>, Char>::format(
         {buffer.data(), buffer.size()}, ctx);
   }
@@ -158,86 +93,73 @@ using ostream_formatter = basic_ostream_formatter<char>;
 template <typename T, typename Char>
 struct formatter<detail::streamed_view<T>, Char>
     : basic_ostream_formatter<Char> {
-  template <typename OutputIt>
+  template <typename Context>
-  auto format(detail::streamed_view<T> view,
+  auto format(detail::streamed_view<T> view, Context& ctx) const
-              basic_format_context<OutputIt, Char>& ctx) const -> OutputIt {
+      -> decltype(ctx.out()) {
     return basic_ostream_formatter<Char>::format(view.value, ctx);
   }
 };
 
 /**
-  \rst
+ * Returns a view that formats `value` via an ostream `operator<<`.
-  Returns a view that formats `value` via an ostream ``operator<<``.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     fmt::print("Current thread id: {}\n",
-    fmt::print("Current thread id: {}\n",
+ *                fmt::streamed(std::this_thread::get_id()));
-               fmt::streamed(std::this_thread::get_id()));
-  \endrst
  */
 template <typename T>
 constexpr auto streamed(const T& value) -> detail::streamed_view<T> {
   return {value};
 }
 
-namespace detail {
+inline void vprint(std::ostream& os, string_view fmt, format_args args) {
-
-inline void vprint_directly(std::ostream& os, string_view format_str,
-                            format_args args) {
   auto buffer = memory_buffer();
-  detail::vformat_to(buffer, format_str, args);
+  detail::vformat_to(buffer, fmt, args);
-  detail::write_buffer(os, buffer);
+  FILE* f = nullptr;
-}
+#if FMT_MSVC_STL_UPDATE && FMT_USE_RTTI
-
+  if (auto* buf = dynamic_cast<std::filebuf*>(os.rdbuf()))
-}  // namespace detail
+    f = detail::get_file(*buf);
-
+#elif defined(_WIN32) && defined(__GLIBCXX__) && FMT_USE_RTTI
-FMT_EXPORT template <typename Char>
+  auto* rdbuf = os.rdbuf();
-void vprint(std::basic_ostream<Char>& os,
+  if (auto* sfbuf = dynamic_cast<__gnu_cxx::stdio_sync_filebuf<char>*>(rdbuf))
-            basic_string_view<type_identity_t<Char>> format_str,
+    f = sfbuf->file();
-            basic_format_args<buffer_context<type_identity_t<Char>>> args) {
+  else if (auto* fbuf = dynamic_cast<__gnu_cxx::stdio_filebuf<char>*>(rdbuf))
-  auto buffer = basic_memory_buffer<Char>();
+    f = fbuf->file();
-  detail::vformat_to(buffer, format_str, args);
+#endif
-  if (detail::write_ostream_unicode(os, {buffer.data(), buffer.size()})) return;
+#ifdef _WIN32
+  if (f) {
+    int fd = _fileno(f);
+    if (_isatty(fd)) {
+      os.flush();
+      if (detail::write_console(fd, {buffer.data(), buffer.size()})) return;
+    }
+  }
+#endif
+  detail::ignore_unused(f);
   detail::write_buffer(os, buffer);
 }
 
 /**
-  \rst
+ * Prints formatted data to the stream `os`.
-  Prints formatted data to the stream *os*.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     fmt::print(cerr, "Don't {}!", "panic");
-    fmt::print(cerr, "Don't {}!", "panic");
-  \endrst
  */
 FMT_EXPORT template <typename... T>
 void print(std::ostream& os, format_string<T...> fmt, T&&... args) {
-  const auto& vargs = fmt::make_format_args(args...);
+  fmt::vargs<T...> vargs = {{args...}};
-  if (detail::is_utf8())
+  if (detail::const_check(detail::use_utf8)) return vprint(os, fmt.str, vargs);
-    vprint(os, fmt, vargs);
+  auto buffer = memory_buffer();
-  else
+  detail::vformat_to(buffer, fmt.str, vargs);
-    detail::vprint_directly(os, fmt, vargs);
+  detail::write_buffer(os, buffer);
-}
-
-FMT_EXPORT
-template <typename... Args>
-void print(std::wostream& os,
-           basic_format_string<wchar_t, type_identity_t<Args>...> fmt,
-           Args&&... args) {
-  vprint(os, fmt, fmt::make_format_args<buffer_context<wchar_t>>(args...));
 }
 
 FMT_EXPORT template <typename... T>
 void println(std::ostream& os, format_string<T...> fmt, T&&... args) {
-  fmt::print(os, "{}\n", fmt::format(fmt, std::forward<T>(args)...));
+  fmt::print(os, FMT_STRING("{}\n"),
-}
+             fmt::format(fmt, std::forward<T>(args)...));
-
-FMT_EXPORT
-template <typename... Args>
-void println(std::wostream& os,
-             basic_format_string<wchar_t, type_identity_t<Args>...> fmt,
-             Args&&... args) {
-  print(os, L"{}\n", fmt::format(fmt, std::forward<Args>(args)...));
 }
 
 FMT_END_NAMESPACE

include/spdlog/fmt/bundled/printf.h

@@ -8,21 +8,19 @@
 #ifndef FMT_PRINTF_H_
 #define FMT_PRINTF_H_
 
-#include <algorithm>  // std::max
+#ifndef FMT_MODULE
-#include <limits>     // std::numeric_limits
+#  include <algorithm>  // std::find
+#  include <limits>     // std::numeric_limits
+#endif
 
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
 FMT_BEGIN_EXPORT
 
-template <typename T> struct printf_formatter {
-  printf_formatter() = delete;
-};
-
 template <typename Char> class basic_printf_context {
  private:
-  detail::buffer_appender<Char> out_;
+  basic_appender<Char> out_;
   basic_format_args<basic_printf_context> args_;
 
   static_assert(std::is_same<Char, char>::value ||
@@ -31,43 +29,50 @@ template <typename Char> class basic_printf_context {
 
  public:
   using char_type = Char;
-  using parse_context_type = basic_format_parse_context<Char>;
+  enum { builtin_types = 1 };
-  template <typename T> using formatter_type = printf_formatter<T>;
 
-  /**
+  /// Constructs a `printf_context` object. References to the arguments are
-    \rst
+  /// stored in the context object so make sure they have appropriate lifetimes.
-    Constructs a ``printf_context`` object. References to the arguments are
+  basic_printf_context(basic_appender<Char> out,
-    stored in the context object so make sure they have appropriate lifetimes.
-    \endrst
-   */
-  basic_printf_context(detail::buffer_appender<Char> out,
                        basic_format_args<basic_printf_context> args)
       : out_(out), args_(args) {}
 
-  auto out() -> detail::buffer_appender<Char> { return out_; }
+  auto out() -> basic_appender<Char> { return out_; }
-  void advance_to(detail::buffer_appender<Char>) {}
+  void advance_to(basic_appender<Char>) {}
 
-  auto locale() -> detail::locale_ref { return {}; }
+  auto locale() -> locale_ref { return {}; }
 
   auto arg(int id) const -> basic_format_arg<basic_printf_context> {
     return args_.get(id);
   }
-
-  FMT_CONSTEXPR void on_error(const char* message) {
-    detail::error_handler().on_error(message);
-  }
 };
 
 namespace detail {
 
+// Return the result via the out param to workaround gcc bug 77539.
+template <bool IS_CONSTEXPR, typename T, typename Ptr = const T*>
+FMT_CONSTEXPR auto find(Ptr first, Ptr last, T value, Ptr& out) -> bool {
+  for (out = first; out != last; ++out) {
+    if (*out == value) return true;
+  }
+  return false;
+}
+
+template <>
+inline auto find<false, char>(const char* first, const char* last, char value,
+                              const char*& out) -> bool {
+  out =
+      static_cast<const char*>(memchr(first, value, to_unsigned(last - first)));
+  return out != nullptr;
+}
+
 // Checks if a value fits in int - used to avoid warnings about comparing
 // signed and unsigned integers.
-template <bool IsSigned> struct int_checker {
+template <bool IS_SIGNED> struct int_checker {
   template <typename T> static auto fits_in_int(T value) -> bool {
-    unsigned max = max_value<int>();
+    return value <= to_unsigned(max_value<int>());
-    return value <= max;
   }
-  static auto fits_in_int(bool) -> bool { return true; }
+  inline static auto fits_in_int(bool) -> bool { return true; }
 };
 
 template <> struct int_checker<true> {
@@ -75,20 +80,20 @@ template <> struct int_checker<true> {
     return value >= (std::numeric_limits<int>::min)() &&
            value <= max_value<int>();
   }
-  static auto fits_in_int(int) -> bool { return true; }
+  inline static auto fits_in_int(int) -> bool { return true; }
 };
 
 struct printf_precision_handler {
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
   auto operator()(T value) -> int {
     if (!int_checker<std::numeric_limits<T>::is_signed>::fits_in_int(value))
-      throw_format_error("number is too big");
+      report_error("number is too big");
-    return (std::max)(static_cast<int>(value), 0);
+    return max_of(static_cast<int>(value), 0);
   }
 
   template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
   auto operator()(T) -> int {
-    throw_format_error("precision is not integer");
+    report_error("precision is not integer");
     return 0;
   }
 };
@@ -133,25 +138,19 @@ template <typename T, typename Context> class arg_converter {
     using target_type = conditional_t<std::is_same<T, void>::value, U, T>;
     if (const_check(sizeof(target_type) <= sizeof(int))) {
       // Extra casts are used to silence warnings.
-      if (is_signed) {
+      using unsigned_type = typename make_unsigned_or_bool<target_type>::type;
-        auto n = static_cast<int>(static_cast<target_type>(value));
+      if (is_signed)
-        arg_ = detail::make_arg<Context>(n);
+        arg_ = static_cast<int>(static_cast<target_type>(value));
-      } else {
+      else
-        using unsigned_type = typename make_unsigned_or_bool<target_type>::type;
+        arg_ = static_cast<unsigned>(static_cast<unsigned_type>(value));
-        auto n = static_cast<unsigned>(static_cast<unsigned_type>(value));
-        arg_ = detail::make_arg<Context>(n);
-      }
     } else {
-      if (is_signed) {
+      // glibc's printf doesn't sign extend arguments of smaller types:
-        // glibc's printf doesn't sign extend arguments of smaller types:
+      //   std::printf("%lld", -42);  // prints "4294967254"
-        //   std::printf("%lld", -42);  // prints "4294967254"
+      // but we don't have to do the same because it's a UB.
-        // but we don't have to do the same because it's a UB.
+      if (is_signed)
-        auto n = static_cast<long long>(value);
+        arg_ = static_cast<long long>(value);
-        arg_ = detail::make_arg<Context>(n);
+      else
-      } else {
+        arg_ = static_cast<typename make_unsigned_or_bool<U>::type>(value);
-        auto n = static_cast<typename make_unsigned_or_bool<U>::type>(value);
-        arg_ = detail::make_arg<Context>(n);
-      }
     }
   }
 
@@ -165,7 +164,7 @@ template <typename T, typename Context> class arg_converter {
 // unsigned).
 template <typename T, typename Context, typename Char>
 void convert_arg(basic_format_arg<Context>& arg, Char type) {
-  visit_format_arg(arg_converter<T, Context>(arg, type), arg);
+  arg.visit(arg_converter<T, Context>(arg, type));
 }
 
 // Converts an integer argument to char for printf.
@@ -178,8 +177,7 @@ template <typename Context> class char_converter {
 
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
   void operator()(T value) {
-    auto c = static_cast<typename Context::char_type>(value);
+    arg_ = static_cast<typename Context::char_type>(value);
-    arg_ = detail::make_arg<Context>(c);
   }
 
   template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
@@ -195,28 +193,28 @@ template <typename Char> struct get_cstring {
 
 // Checks if an argument is a valid printf width specifier and sets
 // left alignment if it is negative.
-template <typename Char> class printf_width_handler {
+class printf_width_handler {
  private:
-  format_specs<Char>& specs_;
+  format_specs& specs_;
 
  public:
-  explicit printf_width_handler(format_specs<Char>& specs) : specs_(specs) {}
+  inline explicit printf_width_handler(format_specs& specs) : specs_(specs) {}
 
   template <typename T, FMT_ENABLE_IF(std::is_integral<T>::value)>
   auto operator()(T value) -> unsigned {
     auto width = static_cast<uint32_or_64_or_128_t<T>>(value);
     if (detail::is_negative(value)) {
-      specs_.align = align::left;
+      specs_.set_align(align::left);
       width = 0 - width;
     }
-    unsigned int_max = max_value<int>();
+    unsigned int_max = to_unsigned(max_value<int>());
-    if (width > int_max) throw_format_error("number is too big");
+    if (width > int_max) report_error("number is too big");
     return static_cast<unsigned>(width);
   }
 
   template <typename T, FMT_ENABLE_IF(!std::is_integral<T>::value)>
   auto operator()(T) -> unsigned {
-    throw_format_error("width is not integer");
+    report_error("width is not integer");
     return 0;
   }
 };
@@ -224,12 +222,12 @@ template <typename Char> class printf_width_handler {
 // Workaround for a bug with the XL compiler when initializing
 // printf_arg_formatter's base class.
 template <typename Char>
-auto make_arg_formatter(buffer_appender<Char> iter, format_specs<Char>& s)
+auto make_arg_formatter(basic_appender<Char> iter, format_specs& s)
     -> arg_formatter<Char> {
   return {iter, s, locale_ref()};
 }
 
-// The ``printf`` argument formatter.
+// The `printf` argument formatter.
 template <typename Char>
 class printf_arg_formatter : public arg_formatter<Char> {
  private:
@@ -240,105 +238,96 @@ class printf_arg_formatter : public arg_formatter<Char> {
 
   void write_null_pointer(bool is_string = false) {
     auto s = this->specs;
-    s.type = presentation_type::none;
+    s.set_type(presentation_type::none);
-    write_bytes(this->out, is_string ? "(null)" : "(nil)", s);
+    write_bytes<Char>(this->out, is_string ? "(null)" : "(nil)", s);
+  }
+
+  template <typename T> void write(T value) {
+    detail::write<Char>(this->out, value, this->specs, this->locale);
   }
 
  public:
-  printf_arg_formatter(buffer_appender<Char> iter, format_specs<Char>& s,
+  printf_arg_formatter(basic_appender<Char> iter, format_specs& s,
                        context_type& ctx)
       : base(make_arg_formatter(iter, s)), context_(ctx) {}
 
-  void operator()(monostate value) { base::operator()(value); }
+  void operator()(monostate value) { write(value); }
 
   template <typename T, FMT_ENABLE_IF(detail::is_integral<T>::value)>
   void operator()(T value) {
     // MSVC2013 fails to compile separate overloads for bool and Char so use
     // std::is_same instead.
     if (!std::is_same<T, Char>::value) {
-      base::operator()(value);
+      write(value);
       return;
     }
-    format_specs<Char> fmt_specs = this->specs;
+    format_specs s = this->specs;
-    if (fmt_specs.type != presentation_type::none &&
+    if (s.type() != presentation_type::none &&
-        fmt_specs.type != presentation_type::chr) {
+        s.type() != presentation_type::chr) {
       return (*this)(static_cast<int>(value));
     }
-    fmt_specs.sign = sign::none;
+    s.set_sign(sign::none);
-    fmt_specs.alt = false;
+    s.clear_alt();
-    fmt_specs.fill[0] = ' ';  // Ignore '0' flag for char types.
+    s.set_fill(' ');  // Ignore '0' flag for char types.
     // align::numeric needs to be overwritten here since the '0' flag is
     // ignored for non-numeric types
-    if (fmt_specs.align == align::none || fmt_specs.align == align::numeric)
+    if (s.align() == align::none || s.align() == align::numeric)
-      fmt_specs.align = align::right;
+      s.set_align(align::right);
-    write<Char>(this->out, static_cast<Char>(value), fmt_specs);
+    detail::write<Char>(this->out, static_cast<Char>(value), s);
   }
 
   template <typename T, FMT_ENABLE_IF(std::is_floating_point<T>::value)>
   void operator()(T value) {
-    base::operator()(value);
+    write(value);
   }
 
-  /** Formats a null-terminated C string. */
   void operator()(const char* value) {
     if (value)
-      base::operator()(value);
+      write(value);
     else
-      write_null_pointer(this->specs.type != presentation_type::pointer);
+      write_null_pointer(this->specs.type() != presentation_type::pointer);
   }
 
-  /** Formats a null-terminated wide C string. */
   void operator()(const wchar_t* value) {
     if (value)
-      base::operator()(value);
+      write(value);
     else
-      write_null_pointer(this->specs.type != presentation_type::pointer);
+      write_null_pointer(this->specs.type() != presentation_type::pointer);
   }
 
-  void operator()(basic_string_view<Char> value) { base::operator()(value); }
+  void operator()(basic_string_view<Char> value) { write(value); }
 
-  /** Formats a pointer. */
   void operator()(const void* value) {
     if (value)
-      base::operator()(value);
+      write(value);
     else
       write_null_pointer();
   }
 
-  /** Formats an argument of a custom (user-defined) type. */
   void operator()(typename basic_format_arg<context_type>::handle handle) {
-    auto parse_ctx = basic_format_parse_context<Char>({});
+    auto parse_ctx = parse_context<Char>({});
     handle.format(parse_ctx, context_);
   }
 };
 
 template <typename Char>
-void parse_flags(format_specs<Char>& specs, const Char*& it, const Char* end) {
+void parse_flags(format_specs& specs, const Char*& it, const Char* end) {
   for (; it != end; ++it) {
     switch (*it) {
-    case '-':
+    case '-': specs.set_align(align::left); break;
-      specs.align = align::left;
+    case '+': specs.set_sign(sign::plus); break;
-      break;
+    case '0': specs.set_fill('0'); break;
-    case '+':
-      specs.sign = sign::plus;
-      break;
-    case '0':
-      specs.fill[0] = '0';
-      break;
     case ' ':
-      if (specs.sign != sign::plus) specs.sign = sign::space;
+      if (specs.sign() != sign::plus) specs.set_sign(sign::space);
       break;
-    case '#':
+    case '#': specs.set_alt(); break;
-      specs.alt = true;
+    default:  return;
-      break;
-    default:
-      return;
     }
   }
 }
 
 template <typename Char, typename GetArg>
-auto parse_header(const Char*& it, const Char* end, format_specs<Char>& specs,
+auto parse_header(const Char*& it, const Char* end, format_specs& specs,
                   GetArg get_arg) -> int {
   int arg_index = -1;
   Char c = *it;
@@ -350,11 +339,11 @@ auto parse_header(const Char*& it, const Char* end, format_specs<Char>& specs,
       ++it;
       arg_index = value != -1 ? value : max_value<int>();
     } else {
-      if (c == '0') specs.fill[0] = '0';
+      if (c == '0') specs.set_fill('0');
       if (value != 0) {
         // Nonzero value means that we parsed width and don't need to
         // parse it or flags again, so return now.
-        if (value == -1) throw_format_error("number is too big");
+        if (value == -1) report_error("number is too big");
         specs.width = value;
         return arg_index;
       }
@@ -365,63 +354,47 @@ auto parse_header(const Char*& it, const Char* end, format_specs<Char>& specs,
   if (it != end) {
     if (*it >= '0' && *it <= '9') {
       specs.width = parse_nonnegative_int(it, end, -1);
-      if (specs.width == -1) throw_format_error("number is too big");
+      if (specs.width == -1) report_error("number is too big");
     } else if (*it == '*') {
       ++it;
-      specs.width = static_cast<int>(visit_format_arg(
+      specs.width = static_cast<int>(
-          detail::printf_width_handler<Char>(specs), get_arg(-1)));
+          get_arg(-1).visit(detail::printf_width_handler(specs)));
     }
   }
   return arg_index;
 }
 
-inline auto parse_printf_presentation_type(char c, type t)
+inline auto parse_printf_presentation_type(char c, type t, bool& upper)
     -> presentation_type {
   using pt = presentation_type;
   constexpr auto integral_set = sint_set | uint_set | bool_set | char_set;
   switch (c) {
-  case 'd':
+  case 'd': return in(t, integral_set) ? pt::dec : pt::none;
-    return in(t, integral_set) ? pt::dec : pt::none;
+  case 'o': return in(t, integral_set) ? pt::oct : pt::none;
-  case 'o':
+  case 'X': upper = true; FMT_FALLTHROUGH;
-    return in(t, integral_set) ? pt::oct : pt::none;
+  case 'x': return in(t, integral_set) ? pt::hex : pt::none;
-  case 'x':
+  case 'E': upper = true; FMT_FALLTHROUGH;
-    return in(t, integral_set) ? pt::hex_lower : pt::none;
+  case 'e': return in(t, float_set) ? pt::exp : pt::none;
-  case 'X':
+  case 'F': upper = true; FMT_FALLTHROUGH;
-    return in(t, integral_set) ? pt::hex_upper : pt::none;
+  case 'f': return in(t, float_set) ? pt::fixed : pt::none;
-  case 'a':
+  case 'G': upper = true; FMT_FALLTHROUGH;
-    return in(t, float_set) ? pt::hexfloat_lower : pt::none;
+  case 'g': return in(t, float_set) ? pt::general : pt::none;
-  case 'A':
+  case 'A': upper = true; FMT_FALLTHROUGH;
-    return in(t, float_set) ? pt::hexfloat_upper : pt::none;
+  case 'a': return in(t, float_set) ? pt::hexfloat : pt::none;
-  case 'e':
+  case 'c': return in(t, integral_set) ? pt::chr : pt::none;
-    return in(t, float_set) ? pt::exp_lower : pt::none;
+  case 's': return in(t, string_set | cstring_set) ? pt::string : pt::none;
-  case 'E':
+  case 'p': return in(t, pointer_set | cstring_set) ? pt::pointer : pt::none;
-    return in(t, float_set) ? pt::exp_upper : pt::none;
+  default:  return pt::none;
-  case 'f':
-    return in(t, float_set) ? pt::fixed_lower : pt::none;
-  case 'F':
-    return in(t, float_set) ? pt::fixed_upper : pt::none;
-  case 'g':
-    return in(t, float_set) ? pt::general_lower : pt::none;
-  case 'G':
-    return in(t, float_set) ? pt::general_upper : pt::none;
-  case 'c':
-    return in(t, integral_set) ? pt::chr : pt::none;
-  case 's':
-    return in(t, string_set | cstring_set) ? pt::string : pt::none;
-  case 'p':
-    return in(t, pointer_set | cstring_set) ? pt::pointer : pt::none;
-  default:
-    return pt::none;
   }
 }
 
 template <typename Char, typename Context>
 void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
              basic_format_args<Context> args) {
-  using iterator = buffer_appender<Char>;
+  using iterator = basic_appender<Char>;
   auto out = iterator(buf);
   auto context = basic_printf_context<Char>(out, args);
-  auto parse_ctx = basic_format_parse_context<Char>(format);
+  auto parse_ctx = parse_context<Char>(format);
 
   // Returns the argument with specified index or, if arg_index is -1, the next
   // argument.
@@ -430,7 +403,9 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
       arg_index = parse_ctx.next_arg_id();
     else
       parse_ctx.check_arg_id(--arg_index);
-    return detail::get_arg(context, arg_index);
+    auto arg = context.arg(arg_index);
+    if (!arg) report_error("argument not found");
+    return arg;
   };
 
   const Char* start = parse_ctx.begin();
@@ -449,12 +424,12 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
     }
     write(out, basic_string_view<Char>(start, to_unsigned(it - 1 - start)));
 
-    auto specs = format_specs<Char>();
+    auto specs = format_specs();
-    specs.align = align::right;
+    specs.set_align(align::right);
 
     // Parse argument index, flags and width.
     int arg_index = parse_header(it, end, specs, get_arg);
-    if (arg_index == 0) throw_format_error("argument not found");
+    if (arg_index == 0) report_error("argument not found");
 
     // Parse precision.
     if (it != end && *it == '.') {
@@ -464,8 +439,8 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
         specs.precision = parse_nonnegative_int(it, end, 0);
       } else if (c == '*') {
         ++it;
-        specs.precision = static_cast<int>(
+        specs.precision =
-            visit_format_arg(printf_precision_handler(), get_arg(-1)));
+            static_cast<int>(get_arg(-1).visit(printf_precision_handler()));
       } else {
         specs.precision = 0;
       }
@@ -474,25 +449,26 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
     auto arg = get_arg(arg_index);
     // For d, i, o, u, x, and X conversion specifiers, if a precision is
     // specified, the '0' flag is ignored
-    if (specs.precision >= 0 && arg.is_integral()) {
+    if (specs.precision >= 0 && is_integral_type(arg.type())) {
       // Ignore '0' for non-numeric types or if '-' present.
-      specs.fill[0] = ' ';
+      specs.set_fill(' ');
     }
     if (specs.precision >= 0 && arg.type() == type::cstring_type) {
-      auto str = visit_format_arg(get_cstring<Char>(), arg);
+      auto str = arg.visit(get_cstring<Char>());
       auto str_end = str + specs.precision;
       auto nul = std::find(str, str_end, Char());
       auto sv = basic_string_view<Char>(
           str, to_unsigned(nul != str_end ? nul - str : specs.precision));
-      arg = make_arg<basic_printf_context<Char>>(sv);
+      arg = sv;
     }
-    if (specs.alt && visit_format_arg(is_zero_int(), arg)) specs.alt = false;
+    if (specs.alt() && arg.visit(is_zero_int())) specs.clear_alt();
-    if (specs.fill[0] == '0') {
+    if (specs.fill_unit<Char>() == '0') {
-      if (arg.is_arithmetic() && specs.align != align::left)
+      if (is_arithmetic_type(arg.type()) && specs.align() != align::left) {
-        specs.align = align::numeric;
+        specs.set_align(align::numeric);
-      else
+      } else {
-        specs.fill[0] = ' ';  // Ignore '0' flag for non-numeric types or if '-'
+        // Ignore '0' flag for non-numeric types or if '-' flag is also present.
-                              // flag is also present.
+        specs.set_fill(' ');
+      }
     }
 
     // Parse length and convert the argument to the required type.
@@ -517,47 +493,39 @@ void vprintf(buffer<Char>& buf, basic_string_view<Char> format,
         convert_arg<long>(arg, t);
       }
       break;
-    case 'j':
+    case 'j': convert_arg<intmax_t>(arg, t); break;
-      convert_arg<intmax_t>(arg, t);
+    case 'z': convert_arg<size_t>(arg, t); break;
-      break;
+    case 't': convert_arg<std::ptrdiff_t>(arg, t); break;
-    case 'z':
-      convert_arg<size_t>(arg, t);
-      break;
-    case 't':
-      convert_arg<std::ptrdiff_t>(arg, t);
-      break;
     case 'L':
       // printf produces garbage when 'L' is omitted for long double, no
       // need to do the same.
       break;
-    default:
+    default: --it; convert_arg<void>(arg, c);
-      --it;
-      convert_arg<void>(arg, c);
     }
 
     // Parse type.
-    if (it == end) throw_format_error("invalid format string");
+    if (it == end) report_error("invalid format string");
     char type = static_cast<char>(*it++);
-    if (arg.is_integral()) {
+    if (is_integral_type(arg.type())) {
       // Normalize type.
       switch (type) {
       case 'i':
-      case 'u':
+      case 'u': type = 'd'; break;
-        type = 'd';
-        break;
       case 'c':
-        visit_format_arg(char_converter<basic_printf_context<Char>>(arg), arg);
+        arg.visit(char_converter<basic_printf_context<Char>>(arg));
         break;
       }
     }
-    specs.type = parse_printf_presentation_type(type, arg.type());
+    bool upper = false;
-    if (specs.type == presentation_type::none)
+    specs.set_type(parse_printf_presentation_type(type, arg.type(), upper));
-      throw_format_error("invalid format specifier");
+    if (specs.type() == presentation_type::none)
+      report_error("invalid format specifier");
+    if (upper) specs.set_upper();
 
     start = it;
 
     // Format argument.
-    visit_format_arg(printf_arg_formatter<Char>(out, specs, context), arg);
+    arg.visit(printf_arg_formatter<Char>(out, specs, context));
   }
   write(out, basic_string_view<Char>(start, to_unsigned(it - start)));
 }
@@ -569,56 +537,48 @@ using wprintf_context = basic_printf_context<wchar_t>;
 using printf_args = basic_format_args<printf_context>;
 using wprintf_args = basic_format_args<wprintf_context>;
 
-/**
+/// Constructs an `format_arg_store` object that contains references to
-  \rst
+/// arguments and can be implicitly converted to `printf_args`.
-  Constructs an `~fmt::format_arg_store` object that contains references to
+template <typename Char = char, typename... T>
-  arguments and can be implicitly converted to `~fmt::printf_args`.
+inline auto make_printf_args(T&... args)
-  \endrst
+    -> decltype(fmt::make_format_args<basic_printf_context<Char>>(args...)) {
- */
+  return fmt::make_format_args<basic_printf_context<Char>>(args...);
-template <typename... T>
-inline auto make_printf_args(const T&... args)
-    -> format_arg_store<printf_context, T...> {
-  return {args...};
 }
 
-// DEPRECATED!
+template <typename Char> struct vprintf_args {
-template <typename... T>
+  using type = basic_format_args<basic_printf_context<Char>>;
-inline auto make_wprintf_args(const T&... args)
+};
-    -> format_arg_store<wprintf_context, T...> {
-  return {args...};
-}
 
 template <typename Char>
-inline auto vsprintf(
+inline auto vsprintf(basic_string_view<Char> fmt,
-    basic_string_view<Char> fmt,
+                     typename vprintf_args<Char>::type args)
-    basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
     -> std::basic_string<Char> {
   auto buf = basic_memory_buffer<Char>();
   detail::vprintf(buf, fmt, args);
-  return to_string(buf);
+  return {buf.data(), buf.size()};
 }
 
 /**
-  \rst
+ * Formats `args` according to specifications in `fmt` and returns the result
-  Formats arguments and returns the result as a string.
+ * as as string.
-
+ *
-  **Example**::
+ * **Example**:
-
+ *
-    std::string message = fmt::sprintf("The answer is %d", 42);
+ *     std::string message = fmt::sprintf("The answer is %d", 42);
-  \endrst
+ */
-*/
+template <typename... T>
-template <typename S, typename... T,
+inline auto sprintf(string_view fmt, const T&... args) -> std::string {
-          typename Char = enable_if_t<detail::is_string<S>::value, char_t<S>>>
+  return vsprintf(fmt, make_printf_args(args...));
-inline auto sprintf(const S& fmt, const T&... args) -> std::basic_string<Char> {
+}
-  return vsprintf(detail::to_string_view(fmt),
+template <typename... T>
-                  fmt::make_format_args<basic_printf_context<Char>>(args...));
+FMT_DEPRECATED auto sprintf(basic_string_view<wchar_t> fmt, const T&... args)
+    -> std::wstring {
+  return vsprintf(fmt, make_printf_args<wchar_t>(args...));
 }
 
 template <typename Char>
-inline auto vfprintf(
+auto vfprintf(std::FILE* f, basic_string_view<Char> fmt,
-    std::FILE* f, basic_string_view<Char> fmt,
+              typename vprintf_args<Char>::type args) -> int {
-    basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
-    -> int {
   auto buf = basic_memory_buffer<Char>();
   detail::vprintf(buf, fmt, args);
   size_t size = buf.size();
@@ -628,46 +588,35 @@ inline auto vfprintf(
 }
 
 /**
-  \rst
+ * Formats `args` according to specifications in `fmt` and writes the output
-  Prints formatted data to the file *f*.
+ * to `f`.
-
+ *
-  **Example**::
+ * **Example**:
-
+ *
-    fmt::fprintf(stderr, "Don't %s!", "panic");
+ *     fmt::fprintf(stderr, "Don't %s!", "panic");
-  \endrst
  */
-template <typename S, typename... T, typename Char = char_t<S>>
+template <typename... T>
-inline auto fprintf(std::FILE* f, const S& fmt, const T&... args) -> int {
+inline auto fprintf(std::FILE* f, string_view fmt, const T&... args) -> int {
-  return vfprintf(f, detail::to_string_view(fmt),
+  return vfprintf(f, fmt, make_printf_args(args...));
-                  fmt::make_format_args<basic_printf_context<Char>>(args...));
 }
-
+template <typename... T>
-template <typename Char>
+FMT_DEPRECATED auto fprintf(std::FILE* f, basic_string_view<wchar_t> fmt,
-FMT_DEPRECATED inline auto vprintf(
+                            const T&... args) -> int {
-    basic_string_view<Char> fmt,
+  return vfprintf(f, fmt, make_printf_args<wchar_t>(args...));
-    basic_format_args<basic_printf_context<type_identity_t<Char>>> args)
-    -> int {
-  return vfprintf(stdout, fmt, args);
 }
 
 /**
-  \rst
+ * Formats `args` according to specifications in `fmt` and writes the output
-  Prints formatted data to ``stdout``.
+ * to `stdout`.
-
+ *
-  **Example**::
+ * **Example**:
-
+ *
-    fmt::printf("Elapsed time: %.2f seconds", 1.23);
+ *   fmt::printf("Elapsed time: %.2f seconds", 1.23);
-  \endrst
  */
 template <typename... T>
 inline auto printf(string_view fmt, const T&... args) -> int {
   return vfprintf(stdout, fmt, make_printf_args(args...));
 }
-template <typename... T>
-FMT_DEPRECATED inline auto printf(basic_string_view<wchar_t> fmt,
-                                  const T&... args) -> int {
-  return vfprintf(stdout, fmt, make_wprintf_args(args...));
-}
 
 FMT_END_EXPORT
 FMT_END_NAMESPACE

include/spdlog/fmt/bundled/ranges.h

@@ -8,67 +8,30 @@
 #ifndef FMT_RANGES_H_
 #define FMT_RANGES_H_
 
-#include <initializer_list>
+#ifndef FMT_MODULE
-#include <tuple>
+#  include <initializer_list>
-#include <type_traits>
+#  include <iterator>
+#  include <tuple>
+#  include <type_traits>
+#  include <utility>
+#endif
 
 #include "format.h"
 
 FMT_BEGIN_NAMESPACE
 
+FMT_EXPORT
+enum class range_format { disabled, map, set, sequence, string, debug_string };
+
 namespace detail {
 
-template <typename Range, typename OutputIt>
-auto copy(const Range& range, OutputIt out) -> OutputIt {
-  for (auto it = range.begin(), end = range.end(); it != end; ++it)
-    *out++ = *it;
-  return out;
-}
-
-template <typename OutputIt>
-auto copy(const char* str, OutputIt out) -> OutputIt {
-  while (*str) *out++ = *str++;
-  return out;
-}
-
-template <typename OutputIt> auto copy(char ch, OutputIt out) -> OutputIt {
-  *out++ = ch;
-  return out;
-}
-
-template <typename OutputIt> auto copy(wchar_t ch, OutputIt out) -> OutputIt {
-  *out++ = ch;
-  return out;
-}
-
-// Returns true if T has a std::string-like interface, like std::string_view.
-template <typename T> class is_std_string_like {
-  template <typename U>
-  static auto check(U* p)
-      -> decltype((void)p->find('a'), p->length(), (void)p->data(), int());
-  template <typename> static void check(...);
-
- public:
-  static constexpr const bool value =
-      is_string<T>::value ||
-      std::is_convertible<T, std_string_view<char>>::value ||
-      !std::is_void<decltype(check<T>(nullptr))>::value;
-};
-
-template <typename Char>
-struct is_std_string_like<fmt::basic_string_view<Char>> : std::true_type {};
-
 template <typename T> class is_map {
   template <typename U> static auto check(U*) -> typename U::mapped_type;
   template <typename> static void check(...);
 
  public:
-#ifdef FMT_FORMAT_MAP_AS_LIST  // DEPRECATED!
+  static constexpr bool value =
-  static constexpr const bool value = false;
-#else
-  static constexpr const bool value =
       !std::is_void<decltype(check<T>(nullptr))>::value;
-#endif
 };
 
 template <typename T> class is_set {
@@ -76,33 +39,16 @@ template <typename T> class is_set {
   template <typename> static void check(...);
 
  public:
-#ifdef FMT_FORMAT_SET_AS_LIST  // DEPRECATED!
+  static constexpr bool value =
-  static constexpr const bool value = false;
-#else
-  static constexpr const bool value =
       !std::is_void<decltype(check<T>(nullptr))>::value && !is_map<T>::value;
-#endif
 };
 
-template <typename... Ts> struct conditional_helper {};
-
-template <typename T, typename _ = void> struct is_range_ : std::false_type {};
-
-#if !FMT_MSC_VERSION || FMT_MSC_VERSION > 1800
-
-#  define FMT_DECLTYPE_RETURN(val)  \
-    ->decltype(val) { return val; } \
-    static_assert(                  \
-        true, "")  // This makes it so that a semicolon is required after the
-                   // macro, which helps clang-format handle the formatting.
-
 // C array overload
-template <typename T, std::size_t N>
+template <typename T, size_t N>
 auto range_begin(const T (&arr)[N]) -> const T* {
   return arr;
 }
-template <typename T, std::size_t N>
+template <typename T, size_t N> auto range_end(const T (&arr)[N]) -> const T* {
-auto range_end(const T (&arr)[N]) -> const T* {
   return arr + N;
 }
 
@@ -110,17 +56,21 @@ template <typename T, typename Enable = void>
 struct has_member_fn_begin_end_t : std::false_type {};
 
 template <typename T>
-struct has_member_fn_begin_end_t<T, void_t<decltype(std::declval<T>().begin()),
+struct has_member_fn_begin_end_t<T, void_t<decltype(*std::declval<T>().begin()),
                                            decltype(std::declval<T>().end())>>
     : std::true_type {};
 
-// Member function overload
+// Member function overloads.
 template <typename T>
-auto range_begin(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).begin());
+auto range_begin(T&& rng) -> decltype(static_cast<T&&>(rng).begin()) {
+  return static_cast<T&&>(rng).begin();
+}
 template <typename T>
-auto range_end(T&& rng) FMT_DECLTYPE_RETURN(static_cast<T&&>(rng).end());
+auto range_end(T&& rng) -> decltype(static_cast<T&&>(rng).end()) {
+  return static_cast<T&&>(rng).end();
+}
 
-// ADL overload. Only participates in overload resolution if member functions
+// ADL overloads. Only participate in overload resolution if member functions
 // are not found.
 template <typename T>
 auto range_begin(T&& rng)
@@ -141,35 +91,34 @@ struct has_mutable_begin_end : std::false_type {};
 
 template <typename T>
 struct has_const_begin_end<
-    T,
+    T, void_t<decltype(*detail::range_begin(
-    void_t<
+                  std::declval<const remove_cvref_t<T>&>())),
-        decltype(detail::range_begin(std::declval<const remove_cvref_t<T>&>())),
+              decltype(detail::range_end(
-        decltype(detail::range_end(std::declval<const remove_cvref_t<T>&>()))>>
+                  std::declval<const remove_cvref_t<T>&>()))>>
     : std::true_type {};
 
 template <typename T>
 struct has_mutable_begin_end<
-    T, void_t<decltype(detail::range_begin(std::declval<T>())),
+    T, void_t<decltype(*detail::range_begin(std::declval<T&>())),
-              decltype(detail::range_end(std::declval<T>())),
+              decltype(detail::range_end(std::declval<T&>())),
               // the extra int here is because older versions of MSVC don't
               // SFINAE properly unless there are distinct types
               int>> : std::true_type {};
 
+template <typename T, typename _ = void> struct is_range_ : std::false_type {};
 template <typename T>
 struct is_range_<T, void>
     : std::integral_constant<bool, (has_const_begin_end<T>::value ||
                                     has_mutable_begin_end<T>::value)> {};
-#  undef FMT_DECLTYPE_RETURN
-#endif
 
 // tuple_size and tuple_element check.
 template <typename T> class is_tuple_like_ {
-  template <typename U>
+  template <typename U, typename V = typename std::remove_cv<U>::type>
-  static auto check(U* p) -> decltype(std::tuple_size<U>::value, int());
+  static auto check(U* p) -> decltype(std::tuple_size<V>::value, 0);
   template <typename> static void check(...);
 
  public:
-  static constexpr const bool value =
+  static constexpr bool value =
       !std::is_void<decltype(check<T>(nullptr))>::value;
 };
 
@@ -203,22 +152,23 @@ using tuple_index_sequence = make_index_sequence<std::tuple_size<T>::value>;
 template <typename T, typename C, bool = is_tuple_like_<T>::value>
 class is_tuple_formattable_ {
  public:
-  static constexpr const bool value = false;
+  static constexpr bool value = false;
 };
 template <typename T, typename C> class is_tuple_formattable_<T, C, true> {
-  template <std::size_t... Is>
+  template <size_t... Is>
-  static auto check2(index_sequence<Is...>,
+  static auto all_true(index_sequence<Is...>,
-                     integer_sequence<bool, (Is == Is)...>) -> std::true_type;
+                       integer_sequence<bool, (Is >= 0)...>) -> std::true_type;
-  static auto check2(...) -> std::false_type;
+  static auto all_true(...) -> std::false_type;
-  template <std::size_t... Is>
+
-  static auto check(index_sequence<Is...>) -> decltype(check2(
+  template <size_t... Is>
+  static auto check(index_sequence<Is...>) -> decltype(all_true(
       index_sequence<Is...>{},
       integer_sequence<bool,
                        (is_formattable<typename std::tuple_element<Is, T>::type,
                                        C>::value)...>{}));
 
  public:
-  static constexpr const bool value =
+  static constexpr bool value =
       decltype(check(tuple_index_sequence<T>{}))::value;
 };
 
@@ -256,7 +206,7 @@ template <typename Char, typename... T>
 using result_t = std::tuple<formatter<remove_cvref_t<T>, Char>...>;
 
 using std::get;
-template <typename Tuple, typename Char, std::size_t... Is>
+template <typename Tuple, typename Char, size_t... Is>
 auto get_formatters(index_sequence<Is...>)
     -> result_t<Char, decltype(get<Is>(std::declval<Tuple>()))...>;
 }  // namespace tuple
@@ -267,7 +217,7 @@ template <typename R> struct range_reference_type_impl {
   using type = decltype(*detail::range_begin(std::declval<R&>()));
 };
 
-template <typename T, std::size_t N> struct range_reference_type_impl<T[N]> {
+template <typename T, size_t N> struct range_reference_type_impl<T[N]> {
   using type = T&;
 };
 
@@ -292,21 +242,32 @@ FMT_CONSTEXPR auto maybe_set_debug_format(Formatter& f, bool set)
 template <typename Formatter>
 FMT_CONSTEXPR void maybe_set_debug_format(Formatter&, ...) {}
 
+template <typename T>
+struct range_format_kind_
+    : std::integral_constant<range_format,
+                             std::is_same<uncvref_type<T>, T>::value
+                                 ? range_format::disabled
+                             : is_map<T>::value ? range_format::map
+                             : is_set<T>::value ? range_format::set
+                                                : range_format::sequence> {};
+
+template <range_format K>
+using range_format_constant = std::integral_constant<range_format, K>;
+
 // These are not generic lambdas for compatibility with C++11.
-template <typename ParseContext> struct parse_empty_specs {
+template <typename Char> struct parse_empty_specs {
   template <typename Formatter> FMT_CONSTEXPR void operator()(Formatter& f) {
     f.parse(ctx);
     detail::maybe_set_debug_format(f, true);
   }
-  ParseContext& ctx;
+  parse_context<Char>& ctx;
 };
 template <typename FormatContext> struct format_tuple_element {
   using char_type = typename FormatContext::char_type;
 
   template <typename T>
   void operator()(const formatter<T, char_type>& f, const T& v) {
-    if (i > 0)
+    if (i > 0) ctx.advance_to(detail::copy<char_type>(separator, ctx.out()));
-      ctx.advance_to(detail::copy_str<char_type>(separator, ctx.out()));
     ctx.advance_to(f.format(v, ctx));
     ++i;
   }
@@ -318,14 +279,15 @@ template <typename FormatContext> struct format_tuple_element {
 
 }  // namespace detail
 
+FMT_EXPORT
 template <typename T> struct is_tuple_like {
-  static constexpr const bool value =
+  static constexpr bool value =
       detail::is_tuple_like_<T>::value && !detail::is_range_<T>::value;
 };
 
+FMT_EXPORT
 template <typename T, typename C> struct is_tuple_formattable {
-  static constexpr const bool value =
+  static constexpr bool value = detail::is_tuple_formattable_<T, C>::value;
-      detail::is_tuple_formattable_<T, C>::value;
 };
 
 template <typename Tuple, typename Char>
@@ -355,66 +317,49 @@ struct formatter<Tuple, Char,
     closing_bracket_ = close;
   }
 
-  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
     auto it = ctx.begin();
-    if (it != ctx.end() && *it != '}')
+    auto end = ctx.end();
-      FMT_THROW(format_error("invalid format specifier"));
+    if (it != end && detail::to_ascii(*it) == 'n') {
-    detail::for_each(formatters_, detail::parse_empty_specs<ParseContext>{ctx});
+      ++it;
+      set_brackets({}, {});
+      set_separator({});
+    }
+    if (it != end && *it != '}') report_error("invalid format specifier");
+    ctx.advance_to(it);
+    detail::for_each(formatters_, detail::parse_empty_specs<Char>{ctx});
     return it;
   }
 
   template <typename FormatContext>
   auto format(const Tuple& value, FormatContext& ctx) const
       -> decltype(ctx.out()) {
-    ctx.advance_to(detail::copy_str<Char>(opening_bracket_, ctx.out()));
+    ctx.advance_to(detail::copy<Char>(opening_bracket_, ctx.out()));
     detail::for_each2(
         formatters_, value,
         detail::format_tuple_element<FormatContext>{0, ctx, separator_});
-    return detail::copy_str<Char>(closing_bracket_, ctx.out());
+    return detail::copy<Char>(closing_bracket_, ctx.out());
   }
 };
 
+FMT_EXPORT
 template <typename T, typename Char> struct is_range {
-  static constexpr const bool value =
+  static constexpr bool value =
-      detail::is_range_<T>::value && !detail::is_std_string_like<T>::value &&
+      detail::is_range_<T>::value && !detail::has_to_string_view<T>::value;
-      !std::is_convertible<T, std::basic_string<Char>>::value &&
-      !std::is_convertible<T, detail::std_string_view<Char>>::value;
 };
 
 namespace detail {
-template <typename Context> struct range_mapper {
-  using mapper = arg_mapper<Context>;
-
-  template <typename T,
-            FMT_ENABLE_IF(has_formatter<remove_cvref_t<T>, Context>::value)>
-  static auto map(T&& value) -> T&& {
-    return static_cast<T&&>(value);
-  }
-  template <typename T,
-            FMT_ENABLE_IF(!has_formatter<remove_cvref_t<T>, Context>::value)>
-  static auto map(T&& value)
-      -> decltype(mapper().map(static_cast<T&&>(value))) {
-    return mapper().map(static_cast<T&&>(value));
-  }
-};
 
 template <typename Char, typename Element>
-using range_formatter_type =
+using range_formatter_type = formatter<remove_cvref_t<Element>, Char>;
-    formatter<remove_cvref_t<decltype(range_mapper<buffer_context<Char>>{}.map(
-                  std::declval<Element>()))>,
-              Char>;
 
 template <typename R>
 using maybe_const_range =
     conditional_t<has_const_begin_end<R>::value, const R, R>;
 
-// Workaround a bug in MSVC 2015 and earlier.
-#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910
 template <typename R, typename Char>
 struct is_formattable_delayed
     : is_formattable<uncvref_type<maybe_const_range<R>>, Char> {};
-#endif
 }  // namespace detail
 
 template <typename...> struct conjunction : std::true_type {};
@@ -423,6 +368,7 @@ template <typename P1, typename... Pn>
 struct conjunction<P1, Pn...>
     : conditional_t<bool(P1::value), conjunction<Pn...>, P1> {};
 
+FMT_EXPORT
 template <typename T, typename Char, typename Enable = void>
 struct range_formatter;
 
@@ -438,6 +384,24 @@ struct range_formatter<
       detail::string_literal<Char, '['>{};
   basic_string_view<Char> closing_bracket_ =
       detail::string_literal<Char, ']'>{};
+  bool is_debug = false;
+
+  template <typename Output, typename It, typename Sentinel, typename U = T,
+            FMT_ENABLE_IF(std::is_same<U, Char>::value)>
+  auto write_debug_string(Output& out, It it, Sentinel end) const -> Output {
+    auto buf = basic_memory_buffer<Char>();
+    for (; it != end; ++it) buf.push_back(*it);
+    auto specs = format_specs();
+    specs.set_type(presentation_type::debug);
+    return detail::write<Char>(
+        out, basic_string_view<Char>(buf.data(), buf.size()), specs);
+  }
+
+  template <typename Output, typename It, typename Sentinel, typename U = T,
+            FMT_ENABLE_IF(!std::is_same<U, Char>::value)>
+  auto write_debug_string(Output& out, It, Sentinel) const -> Output {
+    return out;
+  }
 
  public:
   FMT_CONSTEXPR range_formatter() {}
@@ -456,21 +420,40 @@ struct range_formatter<
     closing_bracket_ = close;
   }
 
-  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
     auto it = ctx.begin();
     auto end = ctx.end();
+    detail::maybe_set_debug_format(underlying_, true);
+    if (it == end) return underlying_.parse(ctx);
 
-    if (it != end && *it == 'n') {
+    switch (detail::to_ascii(*it)) {
+    case 'n':
       set_brackets({}, {});
       ++it;
+      break;
+    case '?':
+      is_debug = true;
+      set_brackets({}, {});
+      ++it;
+      if (it == end || *it != 's') report_error("invalid format specifier");
+      FMT_FALLTHROUGH;
+    case 's':
+      if (!std::is_same<T, Char>::value)
+        report_error("invalid format specifier");
+      if (!is_debug) {
+        set_brackets(detail::string_literal<Char, '"'>{},
+                     detail::string_literal<Char, '"'>{});
+        set_separator({});
+        detail::maybe_set_debug_format(underlying_, false);
+      }
+      ++it;
+      return it;
     }
 
     if (it != end && *it != '}') {
-      if (*it != ':') FMT_THROW(format_error("invalid format specifier"));
+      if (*it != ':') report_error("invalid format specifier");
+      detail::maybe_set_debug_format(underlying_, false);
       ++it;
-    } else {
-      detail::maybe_set_debug_format(underlying_, true);
     }
 
     ctx.advance_to(it);
@@ -479,80 +462,26 @@ struct range_formatter<
 
   template <typename R, typename FormatContext>
   auto format(R&& range, FormatContext& ctx) const -> decltype(ctx.out()) {
-    detail::range_mapper<buffer_context<Char>> mapper;
     auto out = ctx.out();
-    out = detail::copy_str<Char>(opening_bracket_, out);
-    int i = 0;
     auto it = detail::range_begin(range);
     auto end = detail::range_end(range);
+    if (is_debug) return write_debug_string(out, std::move(it), end);
+
+    out = detail::copy<Char>(opening_bracket_, out);
+    int i = 0;
     for (; it != end; ++it) {
-      if (i > 0) out = detail::copy_str<Char>(separator_, out);
+      if (i > 0) out = detail::copy<Char>(separator_, out);
       ctx.advance_to(out);
-      auto&& item = *it;
+      auto&& item = *it;  // Need an lvalue
-      out = underlying_.format(mapper.map(item), ctx);
+      out = underlying_.format(item, ctx);
       ++i;
     }
-    out = detail::copy_str<Char>(closing_bracket_, out);
+    out = detail::copy<Char>(closing_bracket_, out);
     return out;
   }
 };
 
-enum class range_format { disabled, map, set, sequence, string, debug_string };
+FMT_EXPORT
-
-namespace detail {
-template <typename T>
-struct range_format_kind_
-    : std::integral_constant<range_format,
-                             std::is_same<uncvref_type<T>, T>::value
-                                 ? range_format::disabled
-                             : is_map<T>::value ? range_format::map
-                             : is_set<T>::value ? range_format::set
-                                                : range_format::sequence> {};
-
-template <range_format K, typename R, typename Char, typename Enable = void>
-struct range_default_formatter;
-
-template <range_format K>
-using range_format_constant = std::integral_constant<range_format, K>;
-
-template <range_format K, typename R, typename Char>
-struct range_default_formatter<
-    K, R, Char,
-    enable_if_t<(K == range_format::sequence || K == range_format::map ||
-                 K == range_format::set)>> {
-  using range_type = detail::maybe_const_range<R>;
-  range_formatter<detail::uncvref_type<range_type>, Char> underlying_;
-
-  FMT_CONSTEXPR range_default_formatter() { init(range_format_constant<K>()); }
-
-  FMT_CONSTEXPR void init(range_format_constant<range_format::set>) {
-    underlying_.set_brackets(detail::string_literal<Char, '{'>{},
-                             detail::string_literal<Char, '}'>{});
-  }
-
-  FMT_CONSTEXPR void init(range_format_constant<range_format::map>) {
-    underlying_.set_brackets(detail::string_literal<Char, '{'>{},
-                             detail::string_literal<Char, '}'>{});
-    underlying_.underlying().set_brackets({}, {});
-    underlying_.underlying().set_separator(
-        detail::string_literal<Char, ':', ' '>{});
-  }
-
-  FMT_CONSTEXPR void init(range_format_constant<range_format::sequence>) {}
-
-  template <typename ParseContext>
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
-    return underlying_.parse(ctx);
-  }
-
-  template <typename FormatContext>
-  auto format(range_type& range, FormatContext& ctx) const
-      -> decltype(ctx.out()) {
-    return underlying_.format(range, ctx);
-  }
-};
-}  // namespace detail
-
 template <typename T, typename Char, typename Enable = void>
 struct range_format_kind
     : conditional_t<
@@ -562,23 +491,192 @@ struct range_format_kind
 template <typename R, typename Char>
 struct formatter<
     R, Char,
-    enable_if_t<conjunction<bool_constant<range_format_kind<R, Char>::value !=
+    enable_if_t<conjunction<
-                                          range_format::disabled>
+        bool_constant<
-// Workaround a bug in MSVC 2015 and earlier.
+            range_format_kind<R, Char>::value != range_format::disabled &&
-#if !FMT_MSC_VERSION || FMT_MSC_VERSION >= 1910
+            range_format_kind<R, Char>::value != range_format::map &&
-                            ,
+            range_format_kind<R, Char>::value != range_format::string &&
-                            detail::is_formattable_delayed<R, Char>
+            range_format_kind<R, Char>::value != range_format::debug_string>,
-#endif
+        detail::is_formattable_delayed<R, Char>>::value>> {
-                            >::value>>
+ private:
-    : detail::range_default_formatter<range_format_kind<R, Char>::value, R,
+  using range_type = detail::maybe_const_range<R>;
-                                      Char> {
+  range_formatter<detail::uncvref_type<range_type>, Char> range_formatter_;
+
+ public:
+  using nonlocking = void;
+
+  FMT_CONSTEXPR formatter() {
+    if (detail::const_check(range_format_kind<R, Char>::value !=
+                            range_format::set))
+      return;
+    range_formatter_.set_brackets(detail::string_literal<Char, '{'>{},
+                                  detail::string_literal<Char, '}'>{});
+  }
+
+  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
+    return range_formatter_.parse(ctx);
+  }
+
+  template <typename FormatContext>
+  auto format(range_type& range, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    return range_formatter_.format(range, ctx);
+  }
 };
 
-template <typename Char, typename... T> struct tuple_join_view : detail::view {
+// A map formatter.
-  const std::tuple<T...>& tuple;
+template <typename R, typename Char>
+struct formatter<
+    R, Char,
+    enable_if_t<conjunction<
+        bool_constant<range_format_kind<R, Char>::value == range_format::map>,
+        detail::is_formattable_delayed<R, Char>>::value>> {
+ private:
+  using map_type = detail::maybe_const_range<R>;
+  using element_type = detail::uncvref_type<map_type>;
+
+  decltype(detail::tuple::get_formatters<element_type, Char>(
+      detail::tuple_index_sequence<element_type>())) formatters_;
+  bool no_delimiters_ = false;
+
+ public:
+  FMT_CONSTEXPR formatter() {}
+
+  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
+    auto it = ctx.begin();
+    auto end = ctx.end();
+    if (it != end) {
+      if (detail::to_ascii(*it) == 'n') {
+        no_delimiters_ = true;
+        ++it;
+      }
+      if (it != end && *it != '}') {
+        if (*it != ':') report_error("invalid format specifier");
+        ++it;
+      }
+      ctx.advance_to(it);
+    }
+    detail::for_each(formatters_, detail::parse_empty_specs<Char>{ctx});
+    return it;
+  }
+
+  template <typename FormatContext>
+  auto format(map_type& map, FormatContext& ctx) const -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    basic_string_view<Char> open = detail::string_literal<Char, '{'>{};
+    if (!no_delimiters_) out = detail::copy<Char>(open, out);
+    int i = 0;
+    basic_string_view<Char> sep = detail::string_literal<Char, ',', ' '>{};
+    for (auto&& value : map) {
+      if (i > 0) out = detail::copy<Char>(sep, out);
+      ctx.advance_to(out);
+      detail::for_each2(formatters_, value,
+                        detail::format_tuple_element<FormatContext>{
+                            0, ctx, detail::string_literal<Char, ':', ' '>{}});
+      ++i;
+    }
+    basic_string_view<Char> close = detail::string_literal<Char, '}'>{};
+    if (!no_delimiters_) out = detail::copy<Char>(close, out);
+    return out;
+  }
+};
+
+// A (debug_)string formatter.
+template <typename R, typename Char>
+struct formatter<
+    R, Char,
+    enable_if_t<range_format_kind<R, Char>::value == range_format::string ||
+                range_format_kind<R, Char>::value ==
+                    range_format::debug_string>> {
+ private:
+  using range_type = detail::maybe_const_range<R>;
+  using string_type =
+      conditional_t<std::is_constructible<
+                        detail::std_string_view<Char>,
+                        decltype(detail::range_begin(std::declval<R>())),
+                        decltype(detail::range_end(std::declval<R>()))>::value,
+                    detail::std_string_view<Char>, std::basic_string<Char>>;
+
+  formatter<string_type, Char> underlying_;
+
+ public:
+  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
+    return underlying_.parse(ctx);
+  }
+
+  template <typename FormatContext>
+  auto format(range_type& range, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+    if (detail::const_check(range_format_kind<R, Char>::value ==
+                            range_format::debug_string))
+      *out++ = '"';
+    out = underlying_.format(
+        string_type{detail::range_begin(range), detail::range_end(range)}, ctx);
+    if (detail::const_check(range_format_kind<R, Char>::value ==
+                            range_format::debug_string))
+      *out++ = '"';
+    return out;
+  }
+};
+
+template <typename It, typename Sentinel, typename Char = char>
+struct join_view : detail::view {
+  It begin;
+  Sentinel end;
   basic_string_view<Char> sep;
 
-  tuple_join_view(const std::tuple<T...>& t, basic_string_view<Char> s)
+  join_view(It b, Sentinel e, basic_string_view<Char> s)
+      : begin(std::move(b)), end(e), sep(s) {}
+};
+
+template <typename It, typename Sentinel, typename Char>
+struct formatter<join_view<It, Sentinel, Char>, Char> {
+ private:
+  using value_type =
+#ifdef __cpp_lib_ranges
+      std::iter_value_t<It>;
+#else
+      typename std::iterator_traits<It>::value_type;
+#endif
+  formatter<remove_cvref_t<value_type>, Char> value_formatter_;
+
+  using view = conditional_t<std::is_copy_constructible<It>::value,
+                             const join_view<It, Sentinel, Char>,
+                             join_view<It, Sentinel, Char>>;
+
+ public:
+  using nonlocking = void;
+
+  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
+    return value_formatter_.parse(ctx);
+  }
+
+  template <typename FormatContext>
+  auto format(view& value, FormatContext& ctx) const -> decltype(ctx.out()) {
+    using iter =
+        conditional_t<std::is_copy_constructible<view>::value, It, It&>;
+    iter it = value.begin;
+    auto out = ctx.out();
+    if (it == value.end) return out;
+    out = value_formatter_.format(*it, ctx);
+    ++it;
+    while (it != value.end) {
+      out = detail::copy<Char>(value.sep.begin(), value.sep.end(), out);
+      ctx.advance_to(out);
+      out = value_formatter_.format(*it, ctx);
+      ++it;
+    }
+    return out;
+  }
+};
+
+FMT_EXPORT
+template <typename Tuple, typename Char> struct tuple_join_view : detail::view {
+  const Tuple& tuple;
+  basic_string_view<Char> sep;
+
+  tuple_join_view(const Tuple& t, basic_string_view<Char> s)
       : tuple(t), sep{s} {}
 };
 
@@ -589,65 +687,64 @@ template <typename Char, typename... T> struct tuple_join_view : detail::view {
 #  define FMT_TUPLE_JOIN_SPECIFIERS 0
 #endif
 
-template <typename Char, typename... T>
+template <typename Tuple, typename Char>
-struct formatter<tuple_join_view<Char, T...>, Char> {
+struct formatter<tuple_join_view<Tuple, Char>, Char,
-  template <typename ParseContext>
+                 enable_if_t<is_tuple_like<Tuple>::value>> {
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
-    return do_parse(ctx, std::integral_constant<size_t, sizeof...(T)>());
+    return do_parse(ctx, std::tuple_size<Tuple>());
   }
 
   template <typename FormatContext>
-  auto format(const tuple_join_view<Char, T...>& value,
+  auto format(const tuple_join_view<Tuple, Char>& value,
               FormatContext& ctx) const -> typename FormatContext::iterator {
-    return do_format(value, ctx,
+    return do_format(value, ctx, std::tuple_size<Tuple>());
-                     std::integral_constant<size_t, sizeof...(T)>());
   }
 
  private:
-  std::tuple<formatter<typename std::decay<T>::type, Char>...> formatters_;
+  decltype(detail::tuple::get_formatters<Tuple, Char>(
+      detail::tuple_index_sequence<Tuple>())) formatters_;
 
-  template <typename ParseContext>
+  FMT_CONSTEXPR auto do_parse(parse_context<Char>& ctx,
-  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
                               std::integral_constant<size_t, 0>)
-      -> decltype(ctx.begin()) {
+      -> const Char* {
     return ctx.begin();
   }
 
-  template <typename ParseContext, size_t N>
+  template <size_t N>
-  FMT_CONSTEXPR auto do_parse(ParseContext& ctx,
+  FMT_CONSTEXPR auto do_parse(parse_context<Char>& ctx,
                               std::integral_constant<size_t, N>)
-      -> decltype(ctx.begin()) {
+      -> const Char* {
     auto end = ctx.begin();
 #if FMT_TUPLE_JOIN_SPECIFIERS
-    end = std::get<sizeof...(T) - N>(formatters_).parse(ctx);
+    end = std::get<std::tuple_size<Tuple>::value - N>(formatters_).parse(ctx);
     if (N > 1) {
       auto end1 = do_parse(ctx, std::integral_constant<size_t, N - 1>());
       if (end != end1)
-        FMT_THROW(format_error("incompatible format specs for tuple elements"));
+        report_error("incompatible format specs for tuple elements");
     }
 #endif
     return end;
   }
 
   template <typename FormatContext>
-  auto do_format(const tuple_join_view<Char, T...>&, FormatContext& ctx,
+  auto do_format(const tuple_join_view<Tuple, Char>&, FormatContext& ctx,
                  std::integral_constant<size_t, 0>) const ->
       typename FormatContext::iterator {
     return ctx.out();
   }
 
   template <typename FormatContext, size_t N>
-  auto do_format(const tuple_join_view<Char, T...>& value, FormatContext& ctx,
+  auto do_format(const tuple_join_view<Tuple, Char>& value, FormatContext& ctx,
                  std::integral_constant<size_t, N>) const ->
       typename FormatContext::iterator {
-    auto out = std::get<sizeof...(T) - N>(formatters_)
+    using std::get;
-                   .format(std::get<sizeof...(T) - N>(value.tuple), ctx);
+    auto out =
-    if (N > 1) {
+        std::get<std::tuple_size<Tuple>::value - N>(formatters_)
-      out = std::copy(value.sep.begin(), value.sep.end(), out);
+            .format(get<std::tuple_size<Tuple>::value - N>(value.tuple), ctx);
-      ctx.advance_to(out);
+    if (N <= 1) return out;
-      return do_format(value, ctx, std::integral_constant<size_t, N - 1>());
+    out = detail::copy<Char>(value.sep, out);
-    }
+    ctx.advance_to(out);
-    return out;
+    return do_format(value, ctx, std::integral_constant<size_t, N - 1>());
   }
 };
 
@@ -659,7 +756,7 @@ template <typename T> class is_container_adaptor_like {
   template <typename> static void check(...);
 
  public:
-  static constexpr const bool value =
+  static constexpr bool value =
       !std::is_void<decltype(check<T>(nullptr))>::value;
 };
 
@@ -679,52 +776,69 @@ struct formatter<
     : formatter<detail::all<typename T::container_type>, Char> {
   using all = detail::all<typename T::container_type>;
   template <typename FormatContext>
-  auto format(const T& t, FormatContext& ctx) const -> decltype(ctx.out()) {
+  auto format(const T& value, FormatContext& ctx) const -> decltype(ctx.out()) {
     struct getter : T {
-      static auto get(const T& t) -> all {
+      static auto get(const T& v) -> all {
-        return {t.*(&getter::c)};  // Access c through the derived class.
+        return {v.*(&getter::c)};  // Access c through the derived class.
       }
     };
-    return formatter<all>::format(getter::get(t), ctx);
+    return formatter<all>::format(getter::get(value), ctx);
   }
 };
 
 FMT_BEGIN_EXPORT
 
+/// Returns a view that formats the iterator range `[begin, end)` with elements
+/// separated by `sep`.
+template <typename It, typename Sentinel>
+auto join(It begin, Sentinel end, string_view sep) -> join_view<It, Sentinel> {
+  return {std::move(begin), end, sep};
+}
+
 /**
-  \rst
+ * Returns a view that formats `range` with elements separated by `sep`.
-  Returns an object that formats `tuple` with elements separated by `sep`.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     auto v = std::vector<int>{1, 2, 3};
-    std::tuple<int, char> t = {1, 'a'};
+ *     fmt::print("{}", fmt::join(v, ", "));
-    fmt::print("{}", fmt::join(t, ", "));
+ *     // Output: 1, 2, 3
-    // Output: "1, a"
+ *
-  \endrst
+ * `fmt::join` applies passed format specifiers to the range elements:
+ *
+ *     fmt::print("{:02}", fmt::join(v, ", "));
+ *     // Output: 01, 02, 03
  */
-template <typename... T>
+template <typename Range, FMT_ENABLE_IF(!is_tuple_like<Range>::value)>
-FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple, string_view sep)
+auto join(Range&& r, string_view sep)
-    -> tuple_join_view<char, T...> {
+    -> join_view<decltype(detail::range_begin(r)),
-  return {tuple, sep};
+                 decltype(detail::range_end(r))> {
+  return {detail::range_begin(r), detail::range_end(r), sep};
 }
 
-template <typename... T>
+/**
-FMT_CONSTEXPR auto join(const std::tuple<T...>& tuple,
+ * Returns an object that formats `std::tuple` with elements separated by `sep`.
-                        basic_string_view<wchar_t> sep)
+ *
-    -> tuple_join_view<wchar_t, T...> {
+ * **Example**:
+ *
+ *     auto t = std::tuple<int, char>{1, 'a'};
+ *     fmt::print("{}", fmt::join(t, ", "));
+ *     // Output: 1, a
+ */
+template <typename Tuple, FMT_ENABLE_IF(is_tuple_like<Tuple>::value)>
+FMT_CONSTEXPR auto join(const Tuple& tuple, string_view sep)
+    -> tuple_join_view<Tuple, char> {
   return {tuple, sep};
 }
 
 /**
-  \rst
+ * Returns an object that formats `std::initializer_list` with elements
-  Returns an object that formats `initializer_list` with elements separated by
+ * separated by `sep`.
-  `sep`.
+ *
-
+ * **Example**:
-  **Example**::
+ *
-
+ *     fmt::print("{}", fmt::join({1, 2, 3}, ", "));
-    fmt::print("{}", fmt::join({1, 2, 3}, ", "));
+ *     // Output: "1, 2, 3"
-    // Output: "1, 2, 3"
-  \endrst
  */
 template <typename T>
 auto join(std::initializer_list<T> list, string_view sep)

include/spdlog/fmt/bundled/std.h

@@ -8,39 +8,47 @@
 #ifndef FMT_STD_H_
 #define FMT_STD_H_
 
-#include <atomic>
-#include <bitset>
-#include <cstdlib>
-#include <exception>
-#include <memory>
-#include <thread>
-#include <type_traits>
-#include <typeinfo>
-#include <utility>
-#include <vector>
-
 #include "format.h"
 #include "ostream.h"
 
+#ifndef FMT_MODULE
+#  include <atomic>
+#  include <bitset>
+#  include <complex>
+#  include <exception>
+#  include <functional>  // std::reference_wrapper
+#  include <memory>
+#  include <thread>
+#  include <type_traits>
+#  include <typeinfo>  // std::type_info
+#  include <utility>   // std::make_index_sequence
+
+// Check FMT_CPLUSPLUS to suppress a bogus warning in MSVC.
+#  if FMT_CPLUSPLUS >= 201703L
+#    if FMT_HAS_INCLUDE(<filesystem>) && \
+        (!defined(FMT_CPP_LIB_FILESYSTEM) || FMT_CPP_LIB_FILESYSTEM != 0)
+#      include <filesystem>
+#    endif
+#    if FMT_HAS_INCLUDE(<variant>)
+#      include <variant>
+#    endif
+#    if FMT_HAS_INCLUDE(<optional>)
+#      include <optional>
+#    endif
+#  endif
+// Use > instead of >= in the version check because <source_location> may be
+// available after C++17 but before C++20 is marked as implemented.
+#  if FMT_CPLUSPLUS > 201703L && FMT_HAS_INCLUDE(<source_location>)
+#    include <source_location>
+#  endif
+#  if FMT_CPLUSPLUS > 202002L && FMT_HAS_INCLUDE(<expected>)
+#    include <expected>
+#  endif
+#endif  // FMT_MODULE
+
 #if FMT_HAS_INCLUDE(<version>)
 #  include <version>
 #endif
-// Checking FMT_CPLUSPLUS for warning suppression in MSVC.
-#if FMT_CPLUSPLUS >= 201703L
-#  if FMT_HAS_INCLUDE(<filesystem>)
-#    include <filesystem>
-#  endif
-#  if FMT_HAS_INCLUDE(<variant>)
-#    include <variant>
-#  endif
-#  if FMT_HAS_INCLUDE(<optional>)
-#    include <optional>
-#  endif
-#endif
-
-#if FMT_CPLUSPLUS > 201703L && FMT_HAS_INCLUDE(<source_location>)
-#  include <source_location>
-#endif
 
 // GCC 4 does not support FMT_HAS_INCLUDE.
 #if FMT_HAS_INCLUDE(<cxxabi.h>) || defined(__GLIBCXX__)
@@ -52,38 +60,26 @@
 #  endif
 #endif
 
-// Check if typeid is available.
+#ifdef FMT_CPP_LIB_FILESYSTEM
-#ifndef FMT_USE_TYPEID
+// Use the provided definition.
-// __RTTI is for EDG compilers. In MSVC typeid is available without RTTI.
+#elif defined(__cpp_lib_filesystem)
-#  if defined(__GXX_RTTI) || FMT_HAS_FEATURE(cxx_rtti) || FMT_MSC_VERSION || \
+#  define FMT_CPP_LIB_FILESYSTEM __cpp_lib_filesystem
-      defined(__INTEL_RTTI__) || defined(__RTTI)
+#else
-#    define FMT_USE_TYPEID 1
+#  define FMT_CPP_LIB_FILESYSTEM 0
-#  else
-#    define FMT_USE_TYPEID 0
-#  endif
 #endif
 
-// For older Xcode versions, __cpp_lib_xxx flags are inaccurately defined.
+#ifdef FMT_CPP_LIB_VARIANT
-#ifndef FMT_CPP_LIB_FILESYSTEM
+// Use the provided definition.
-#  ifdef __cpp_lib_filesystem
+#elif defined(__cpp_lib_variant)
-#    define FMT_CPP_LIB_FILESYSTEM __cpp_lib_filesystem
+#  define FMT_CPP_LIB_VARIANT __cpp_lib_variant
-#  else
+#else
-#    define FMT_CPP_LIB_FILESYSTEM 0
+#  define FMT_CPP_LIB_VARIANT 0
-#  endif
 #endif
 
-#ifndef FMT_CPP_LIB_VARIANT
+FMT_BEGIN_NAMESPACE
-#  ifdef __cpp_lib_variant
+namespace detail {
-#    define FMT_CPP_LIB_VARIANT __cpp_lib_variant
-#  else
-#    define FMT_CPP_LIB_VARIANT 0
-#  endif
-#endif
 
 #if FMT_CPP_LIB_FILESYSTEM
-FMT_BEGIN_NAMESPACE
-
-namespace detail {
 
 template <typename Char, typename PathChar>
 auto get_path_string(const std::filesystem::path& p,
@@ -112,12 +108,171 @@ void write_escaped_path(basic_memory_buffer<Char>& quoted,
   }
 }
 
+#endif  // FMT_CPP_LIB_FILESYSTEM
+
+#if defined(__cpp_lib_expected) || FMT_CPP_LIB_VARIANT
+template <typename Char, typename OutputIt, typename T>
+auto write_escaped_alternative(OutputIt out, const T& v) -> OutputIt {
+  if constexpr (has_to_string_view<T>::value)
+    return write_escaped_string<Char>(out, detail::to_string_view(v));
+  if constexpr (std::is_same_v<T, Char>) return write_escaped_char(out, v);
+  return write<Char>(out, v);
+}
+#endif
+
+#if FMT_CPP_LIB_VARIANT
+
+template <typename> struct is_variant_like_ : std::false_type {};
+template <typename... Types>
+struct is_variant_like_<std::variant<Types...>> : std::true_type {};
+
+template <typename Variant, typename Char> class is_variant_formattable {
+  template <size_t... Is>
+  static auto check(std::index_sequence<Is...>) -> std::conjunction<
+      is_formattable<std::variant_alternative_t<Is, Variant>, Char>...>;
+
+ public:
+  static constexpr bool value = decltype(check(
+      std::make_index_sequence<std::variant_size<Variant>::value>()))::value;
+};
+
+#endif  // FMT_CPP_LIB_VARIANT
+
+#if FMT_USE_RTTI
+
+template <typename OutputIt>
+auto write_demangled_name(OutputIt out, const std::type_info& ti) -> OutputIt {
+#  ifdef FMT_HAS_ABI_CXA_DEMANGLE
+  int status = 0;
+  size_t size = 0;
+  std::unique_ptr<char, void (*)(void*)> demangled_name_ptr(
+      abi::__cxa_demangle(ti.name(), nullptr, &size, &status), &std::free);
+
+  string_view demangled_name_view;
+  if (demangled_name_ptr) {
+    demangled_name_view = demangled_name_ptr.get();
+
+    // Normalization of stdlib inline namespace names.
+    // libc++ inline namespaces.
+    //  std::__1::*       -> std::*
+    //  std::__1::__fs::* -> std::*
+    // libstdc++ inline namespaces.
+    //  std::__cxx11::*             -> std::*
+    //  std::filesystem::__cxx11::* -> std::filesystem::*
+    if (demangled_name_view.starts_with("std::")) {
+      char* begin = demangled_name_ptr.get();
+      char* to = begin + 5;  // std::
+      for (char *from = to, *end = begin + demangled_name_view.size();
+           from < end;) {
+        // This is safe, because demangled_name is NUL-terminated.
+        if (from[0] == '_' && from[1] == '_') {
+          char* next = from + 1;
+          while (next < end && *next != ':') next++;
+          if (next[0] == ':' && next[1] == ':') {
+            from = next + 2;
+            continue;
+          }
+        }
+        *to++ = *from++;
+      }
+      demangled_name_view = {begin, detail::to_unsigned(to - begin)};
+    }
+  } else {
+    demangled_name_view = string_view(ti.name());
+  }
+  return detail::write_bytes<char>(out, demangled_name_view);
+#  elif FMT_MSC_VERSION
+  const string_view demangled_name(ti.name());
+  for (size_t i = 0; i < demangled_name.size(); ++i) {
+    auto sub = demangled_name;
+    sub.remove_prefix(i);
+    if (sub.starts_with("enum ")) {
+      i += 4;
+      continue;
+    }
+    if (sub.starts_with("class ") || sub.starts_with("union ")) {
+      i += 5;
+      continue;
+    }
+    if (sub.starts_with("struct ")) {
+      i += 6;
+      continue;
+    }
+    if (*sub.begin() != ' ') *out++ = *sub.begin();
+  }
+  return out;
+#  else
+  return detail::write_bytes<char>(out, string_view(ti.name()));
+#  endif
+}
+
+#endif  // FMT_USE_RTTI
+
+template <typename T, typename Enable = void>
+struct has_flip : std::false_type {};
+
+template <typename T>
+struct has_flip<T, void_t<decltype(std::declval<T>().flip())>>
+    : std::true_type {};
+
+template <typename T> struct is_bit_reference_like {
+  static constexpr bool value = std::is_convertible<T, bool>::value &&
+                                std::is_nothrow_assignable<T, bool>::value &&
+                                has_flip<T>::value;
+};
+
+// Workaround for libc++ incompatibility with C++ standard.
+// According to the Standard, `bitset::operator[] const` returns bool.
+#if defined(_LIBCPP_VERSION) && !defined(FMT_IMPORT_STD)
+template <typename C>
+struct is_bit_reference_like<std::__bit_const_reference<C>> {
+  static constexpr bool value = true;
+};
+#endif
+
+template <typename T, typename Enable = void>
+struct has_format_as : std::false_type {};
+template <typename T>
+struct has_format_as<T, void_t<decltype(format_as(std::declval<const T&>()))>>
+    : std::true_type {};
+
+template <typename T, typename Enable = void>
+struct has_format_as_member : std::false_type {};
+template <typename T>
+struct has_format_as_member<
+    T, void_t<decltype(formatter<T>::format_as(std::declval<const T&>()))>>
+    : std::true_type {};
+
 }  // namespace detail
 
-FMT_EXPORT
+template <typename T, typename Deleter>
+auto ptr(const std::unique_ptr<T, Deleter>& p) -> const void* {
+  return p.get();
+}
+template <typename T> auto ptr(const std::shared_ptr<T>& p) -> const void* {
+  return p.get();
+}
+
+#if FMT_CPP_LIB_FILESYSTEM
+
+class path : public std::filesystem::path {
+ public:
+  auto display_string() const -> std::string {
+    const std::filesystem::path& base = *this;
+    return fmt::format(FMT_STRING("{}"), base);
+  }
+  auto system_string() const -> std::string { return string(); }
+
+  auto generic_display_string() const -> std::string {
+    const std::filesystem::path& base = *this;
+    return fmt::format(FMT_STRING("{:g}"), base);
+  }
+  auto generic_system_string() const -> std::string { return generic_string(); }
+};
+
 template <typename Char> struct formatter<std::filesystem::path, Char> {
  private:
-  format_specs<Char> specs_;
+  format_specs specs_;
   detail::arg_ref<Char> width_ref_;
   bool debug_ = false;
   char path_type_ = 0;
@@ -125,33 +280,33 @@ template <typename Char> struct formatter<std::filesystem::path, Char> {
  public:
   FMT_CONSTEXPR void set_debug_format(bool set = true) { debug_ = set; }
 
-  template <typename ParseContext> FMT_CONSTEXPR auto parse(ParseContext& ctx) {
+  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) {
     auto it = ctx.begin(), end = ctx.end();
     if (it == end) return it;
 
     it = detail::parse_align(it, end, specs_);
     if (it == end) return it;
 
-    it = detail::parse_dynamic_spec(it, end, specs_.width, width_ref_, ctx);
+    Char c = *it;
+    if ((c >= '0' && c <= '9') || c == '{')
+      it = detail::parse_width(it, end, specs_, width_ref_, ctx);
     if (it != end && *it == '?') {
       debug_ = true;
       ++it;
     }
-    if (it != end && (*it == 'g')) path_type_ = *it++;
+    if (it != end && (*it == 'g')) path_type_ = detail::to_ascii(*it++);
     return it;
   }
 
   template <typename FormatContext>
   auto format(const std::filesystem::path& p, FormatContext& ctx) const {
     auto specs = specs_;
-#  ifdef _WIN32
+    auto path_string =
-    auto path_string = !path_type_ ? p.native() : p.generic_wstring();
+        !path_type_ ? p.native()
-#  else
+                    : p.generic_string<std::filesystem::path::value_type>();
-    auto path_string = !path_type_ ? p.native() : p.generic_string();
-#  endif
 
-    detail::handle_dynamic_spec<detail::width_checker>(specs.width, width_ref_,
+    detail::handle_dynamic_spec(specs.dynamic_width(), specs.width, width_ref_,
-                                                       ctx);
+                                ctx);
     if (!debug_) {
       auto s = detail::get_path_string<Char>(p, path_string);
       return detail::write(ctx.out(), basic_string_view<Char>(s), specs);
@@ -163,24 +318,21 @@ template <typename Char> struct formatter<std::filesystem::path, Char> {
                          specs);
   }
 };
-FMT_END_NAMESPACE
+
 #endif  // FMT_CPP_LIB_FILESYSTEM
 
-FMT_BEGIN_NAMESPACE
+template <size_t N, typename Char>
-FMT_EXPORT
+struct formatter<std::bitset<N>, Char>
-template <std::size_t N, typename Char>
+    : nested_formatter<basic_string_view<Char>, Char> {
-struct formatter<std::bitset<N>, Char> : nested_formatter<string_view> {
  private:
-  // Functor because C++11 doesn't support generic lambdas.
+  // This is a functor because C++11 doesn't support generic lambdas.
   struct writer {
     const std::bitset<N>& bs;
 
     template <typename OutputIt>
     FMT_CONSTEXPR auto operator()(OutputIt out) -> OutputIt {
-      for (auto pos = N; pos > 0; --pos) {
+      for (auto pos = N; pos > 0; --pos)
         out = detail::write<Char>(out, bs[pos - 1] ? Char('1') : Char('0'));
-      }
-
       return out;
     }
   };
@@ -189,18 +341,14 @@ struct formatter<std::bitset<N>, Char> : nested_formatter<string_view> {
   template <typename FormatContext>
   auto format(const std::bitset<N>& bs, FormatContext& ctx) const
       -> decltype(ctx.out()) {
-    return write_padded(ctx, writer{bs});
+    return this->write_padded(ctx, writer{bs});
   }
 };
 
-FMT_EXPORT
 template <typename Char>
 struct formatter<std::thread::id, Char> : basic_ostream_formatter<Char> {};
-FMT_END_NAMESPACE
 
 #ifdef __cpp_lib_optional
-FMT_BEGIN_NAMESPACE
-FMT_EXPORT
 template <typename T, typename Char>
 struct formatter<std::optional<T>, Char,
                  std::enable_if_t<is_formattable<T, Char>::value>> {
@@ -222,7 +370,7 @@ struct formatter<std::optional<T>, Char,
   FMT_CONSTEXPR static void maybe_set_debug_format(U&, ...) {}
 
  public:
-  template <typename ParseContext> FMT_CONSTEXPR auto parse(ParseContext& ctx) {
+  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) {
     maybe_set_debug_format(underlying_, true);
     return underlying_.parse(ctx);
   }
@@ -239,17 +387,41 @@ struct formatter<std::optional<T>, Char,
     return detail::write(out, ')');
   }
 };
-FMT_END_NAMESPACE
 #endif  // __cpp_lib_optional
 
-#ifdef __cpp_lib_source_location
+#ifdef __cpp_lib_expected
-FMT_BEGIN_NAMESPACE
+template <typename T, typename E, typename Char>
-FMT_EXPORT
+struct formatter<std::expected<T, E>, Char,
-template <> struct formatter<std::source_location> {
+                 std::enable_if_t<(std::is_void<T>::value ||
-  template <typename ParseContext> FMT_CONSTEXPR auto parse(ParseContext& ctx) {
+                                   is_formattable<T, Char>::value) &&
+                                  is_formattable<E, Char>::value>> {
+  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
     return ctx.begin();
   }
 
+  template <typename FormatContext>
+  auto format(const std::expected<T, E>& value, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto out = ctx.out();
+
+    if (value.has_value()) {
+      out = detail::write<Char>(out, "expected(");
+      if constexpr (!std::is_void<T>::value)
+        out = detail::write_escaped_alternative<Char>(out, *value);
+    } else {
+      out = detail::write<Char>(out, "unexpected(");
+      out = detail::write_escaped_alternative<Char>(out, value.error());
+    }
+    *out++ = ')';
+    return out;
+  }
+};
+#endif  // __cpp_lib_expected
+
+#ifdef __cpp_lib_source_location
+template <> struct formatter<std::source_location> {
+  FMT_CONSTEXPR auto parse(parse_context<>& ctx) { return ctx.begin(); }
+
   template <typename FormatContext>
   auto format(const std::source_location& loc, FormatContext& ctx) const
       -> decltype(ctx.out()) {
@@ -264,58 +436,16 @@ template <> struct formatter<std::source_location> {
     return out;
   }
 };
-FMT_END_NAMESPACE
 #endif
 
 #if FMT_CPP_LIB_VARIANT
-FMT_BEGIN_NAMESPACE
-namespace detail {
-
-template <typename T>
-using variant_index_sequence =
-    std::make_index_sequence<std::variant_size<T>::value>;
-
-template <typename> struct is_variant_like_ : std::false_type {};
-template <typename... Types>
-struct is_variant_like_<std::variant<Types...>> : std::true_type {};
-
-// formattable element check.
-template <typename T, typename C> class is_variant_formattable_ {
-  template <std::size_t... Is>
-  static std::conjunction<
-      is_formattable<std::variant_alternative_t<Is, T>, C>...>
-      check(std::index_sequence<Is...>);
-
- public:
-  static constexpr const bool value =
-      decltype(check(variant_index_sequence<T>{}))::value;
-};
-
-template <typename Char, typename OutputIt, typename T>
-auto write_variant_alternative(OutputIt out, const T& v) -> OutputIt {
-  if constexpr (is_string<T>::value)
-    return write_escaped_string<Char>(out, detail::to_string_view(v));
-  else if constexpr (std::is_same_v<T, Char>)
-    return write_escaped_char(out, v);
-  else
-    return write<Char>(out, v);
-}
-
-}  // namespace detail
 
 template <typename T> struct is_variant_like {
-  static constexpr const bool value = detail::is_variant_like_<T>::value;
+  static constexpr bool value = detail::is_variant_like_<T>::value;
 };
 
-template <typename T, typename C> struct is_variant_formattable {
-  static constexpr const bool value =
-      detail::is_variant_formattable_<T, C>::value;
-};
-
-FMT_EXPORT
 template <typename Char> struct formatter<std::monostate, Char> {
-  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
 
@@ -326,14 +456,12 @@ template <typename Char> struct formatter<std::monostate, Char> {
   }
 };
 
-FMT_EXPORT
 template <typename Variant, typename Char>
-struct formatter<
+struct formatter<Variant, Char,
-    Variant, Char,
+                 std::enable_if_t<std::conjunction_v<
-    std::enable_if_t<std::conjunction_v<
+                     is_variant_like<Variant>,
-        is_variant_like<Variant>, is_variant_formattable<Variant, Char>>>> {
+                     detail::is_variant_formattable<Variant, Char>>>> {
-  template <typename ParseContext>
+  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
     return ctx.begin();
   }
 
@@ -346,7 +474,7 @@ struct formatter<
     FMT_TRY {
       std::visit(
           [&](const auto& v) {
-            out = detail::write_variant_alternative<Char>(out, v);
+            out = detail::write_escaped_alternative<Char>(out, v);
           },
           value);
     }
@@ -357,147 +485,113 @@ struct formatter<
     return out;
   }
 };
-FMT_END_NAMESPACE
+
 #endif  // FMT_CPP_LIB_VARIANT
 
-FMT_BEGIN_NAMESPACE
+template <> struct formatter<std::error_code> {
-FMT_EXPORT
+ private:
-template <typename Char> struct formatter<std::error_code, Char> {
+  format_specs specs_;
-  template <typename ParseContext>
+  detail::arg_ref<char> width_ref_;
-  FMT_CONSTEXPR auto parse(ParseContext& ctx) -> decltype(ctx.begin()) {
+  bool debug_ = false;
-    return ctx.begin();
+
+ public:
+  FMT_CONSTEXPR auto parse(parse_context<>& ctx) -> const char* {
+    auto it = ctx.begin(), end = ctx.end();
+    if (it == end) return it;
+
+    it = detail::parse_align(it, end, specs_);
+
+    char c = *it;
+    if (it != end && ((c >= '0' && c <= '9') || c == '{'))
+      it = detail::parse_width(it, end, specs_, width_ref_, ctx);
+
+    if (it != end && *it == '?') {
+      debug_ = true;
+      ++it;
+    }
+    if (it != end && *it == 's') {
+      specs_.set_type(presentation_type::string);
+      ++it;
+    }
+    return it;
   }
 
   template <typename FormatContext>
-  FMT_CONSTEXPR auto format(const std::error_code& ec, FormatContext& ctx) const
+  FMT_CONSTEXPR20 auto format(const std::error_code& ec,
-      -> decltype(ctx.out()) {
+                              FormatContext& ctx) const -> decltype(ctx.out()) {
-    auto out = ctx.out();
+    auto specs = specs_;
-    out = detail::write_bytes(out, ec.category().name(), format_specs<Char>());
+    detail::handle_dynamic_spec(specs.dynamic_width(), specs.width, width_ref_,
-    out = detail::write<Char>(out, Char(':'));
+                                ctx);
-    out = detail::write<Char>(out, ec.value());
+    auto buf = memory_buffer();
-    return out;
+    if (specs_.type() == presentation_type::string) {
+      buf.append(ec.message());
+    } else {
+      buf.append(string_view(ec.category().name()));
+      buf.push_back(':');
+      detail::write<char>(appender(buf), ec.value());
+    }
+    auto quoted = memory_buffer();
+    auto str = string_view(buf.data(), buf.size());
+    if (debug_) {
+      detail::write_escaped_string<char>(std::back_inserter(quoted), str);
+      str = string_view(quoted.data(), quoted.size());
+    }
+    return detail::write<char>(ctx.out(), str, specs);
   }
 };
 
-FMT_EXPORT
+#if FMT_USE_RTTI
-template <typename T, typename Char>
+template <> struct formatter<std::type_info> {
+ public:
+  FMT_CONSTEXPR auto parse(parse_context<>& ctx) -> const char* {
+    return ctx.begin();
+  }
+
+  template <typename Context>
+  auto format(const std::type_info& ti, Context& ctx) const
+      -> decltype(ctx.out()) {
+    return detail::write_demangled_name(ctx.out(), ti);
+  }
+};
+#endif  // FMT_USE_RTTI
+
+template <typename T>
 struct formatter<
-    T, Char,  // DEPRECATED! Mixing code unit types.
+    T, char,
     typename std::enable_if<std::is_base_of<std::exception, T>::value>::type> {
  private:
   bool with_typename_ = false;
 
  public:
-  FMT_CONSTEXPR auto parse(basic_format_parse_context<Char>& ctx)
+  FMT_CONSTEXPR auto parse(parse_context<>& ctx) -> const char* {
-      -> decltype(ctx.begin()) {
     auto it = ctx.begin();
     auto end = ctx.end();
     if (it == end || *it == '}') return it;
     if (*it == 't') {
       ++it;
-      with_typename_ = FMT_USE_TYPEID != 0;
+      with_typename_ = FMT_USE_RTTI != 0;
     }
     return it;
   }
 
-  template <typename OutputIt>
+  template <typename Context>
-  auto format(const std::exception& ex,
+  auto format(const std::exception& ex, Context& ctx) const
-              basic_format_context<OutputIt, Char>& ctx) const -> OutputIt {
+      -> decltype(ctx.out()) {
-    format_specs<Char> spec;
     auto out = ctx.out();
-    if (!with_typename_)
+#if FMT_USE_RTTI
-      return detail::write_bytes(out, string_view(ex.what()), spec);
+    if (with_typename_) {
-
+      out = detail::write_demangled_name(out, typeid(ex));
-#if FMT_USE_TYPEID
+      *out++ = ':';
-    const std::type_info& ti = typeid(ex);
+      *out++ = ' ';
-#  ifdef FMT_HAS_ABI_CXA_DEMANGLE
-    int status = 0;
-    std::size_t size = 0;
-    std::unique_ptr<char, void (*)(void*)> demangled_name_ptr(
-        abi::__cxa_demangle(ti.name(), nullptr, &size, &status), &std::free);
-
-    string_view demangled_name_view;
-    if (demangled_name_ptr) {
-      demangled_name_view = demangled_name_ptr.get();
-
-      // Normalization of stdlib inline namespace names.
-      // libc++ inline namespaces.
-      //  std::__1::*       -> std::*
-      //  std::__1::__fs::* -> std::*
-      // libstdc++ inline namespaces.
-      //  std::__cxx11::*             -> std::*
-      //  std::filesystem::__cxx11::* -> std::filesystem::*
-      if (demangled_name_view.starts_with("std::")) {
-        char* begin = demangled_name_ptr.get();
-        char* to = begin + 5;  // std::
-        for (char *from = to, *end = begin + demangled_name_view.size();
-             from < end;) {
-          // This is safe, because demangled_name is NUL-terminated.
-          if (from[0] == '_' && from[1] == '_') {
-            char* next = from + 1;
-            while (next < end && *next != ':') next++;
-            if (next[0] == ':' && next[1] == ':') {
-              from = next + 2;
-              continue;
-            }
-          }
-          *to++ = *from++;
-        }
-        demangled_name_view = {begin, detail::to_unsigned(to - begin)};
-      }
-    } else {
-      demangled_name_view = string_view(ti.name());
     }
-    out = detail::write_bytes(out, demangled_name_view, spec);
-#  elif FMT_MSC_VERSION
-    string_view demangled_name_view(ti.name());
-    if (demangled_name_view.starts_with("class "))
-      demangled_name_view.remove_prefix(6);
-    else if (demangled_name_view.starts_with("struct "))
-      demangled_name_view.remove_prefix(7);
-    out = detail::write_bytes(out, demangled_name_view, spec);
-#  else
-    out = detail::write_bytes(out, string_view(ti.name()), spec);
-#  endif
-    *out++ = ':';
-    *out++ = ' ';
-    return detail::write_bytes(out, string_view(ex.what()), spec);
 #endif
+    return detail::write_bytes<char>(out, string_view(ex.what()));
   }
 };
 
-namespace detail {
-
-template <typename T, typename Enable = void>
-struct has_flip : std::false_type {};
-
-template <typename T>
-struct has_flip<T, void_t<decltype(std::declval<T>().flip())>>
-    : std::true_type {};
-
-template <typename T> struct is_bit_reference_like {
-  static constexpr const bool value =
-      std::is_convertible<T, bool>::value &&
-      std::is_nothrow_assignable<T, bool>::value && has_flip<T>::value;
-};
-
-#ifdef _LIBCPP_VERSION
-
-// Workaround for libc++ incompatibility with C++ standard.
-// According to the Standard, `bitset::operator[] const` returns bool.
-template <typename C>
-struct is_bit_reference_like<std::__bit_const_reference<C>> {
-  static constexpr const bool value = true;
-};
-
-#endif
-
-}  // namespace detail
-
 // We can't use std::vector<bool, Allocator>::reference and
 // std::bitset<N>::reference because the compiler can't deduce Allocator and N
 // in partial specialization.
-FMT_EXPORT
 template <typename BitRef, typename Char>
 struct formatter<BitRef, Char,
                  enable_if_t<detail::is_bit_reference_like<BitRef>::value>>
@@ -509,7 +603,6 @@ struct formatter<BitRef, Char,
   }
 };
 
-FMT_EXPORT
 template <typename T, typename Char>
 struct formatter<std::atomic<T>, Char,
                  enable_if_t<is_formattable<T, Char>::value>>
@@ -522,7 +615,6 @@ struct formatter<std::atomic<T>, Char,
 };
 
 #ifdef __cpp_lib_atomic_flag_test
-FMT_EXPORT
 template <typename Char>
 struct formatter<std::atomic_flag, Char> : formatter<bool, Char> {
   template <typename FormatContext>
@@ -533,5 +625,83 @@ struct formatter<std::atomic_flag, Char> : formatter<bool, Char> {
 };
 #endif  // __cpp_lib_atomic_flag_test
 
+template <typename T, typename Char> struct formatter<std::complex<T>, Char> {
+ private:
+  detail::dynamic_format_specs<Char> specs_;
+
+  template <typename FormatContext, typename OutputIt>
+  FMT_CONSTEXPR auto do_format(const std::complex<T>& c,
+                               detail::dynamic_format_specs<Char>& specs,
+                               FormatContext& ctx, OutputIt out) const
+      -> OutputIt {
+    if (c.real() != 0) {
+      *out++ = Char('(');
+      out = detail::write<Char>(out, c.real(), specs, ctx.locale());
+      specs.set_sign(sign::plus);
+      out = detail::write<Char>(out, c.imag(), specs, ctx.locale());
+      if (!detail::isfinite(c.imag())) *out++ = Char(' ');
+      *out++ = Char('i');
+      *out++ = Char(')');
+      return out;
+    }
+    out = detail::write<Char>(out, c.imag(), specs, ctx.locale());
+    if (!detail::isfinite(c.imag())) *out++ = Char(' ');
+    *out++ = Char('i');
+    return out;
+  }
+
+ public:
+  FMT_CONSTEXPR auto parse(parse_context<Char>& ctx) -> const Char* {
+    if (ctx.begin() == ctx.end() || *ctx.begin() == '}') return ctx.begin();
+    return parse_format_specs(ctx.begin(), ctx.end(), specs_, ctx,
+                              detail::type_constant<T, Char>::value);
+  }
+
+  template <typename FormatContext>
+  auto format(const std::complex<T>& c, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    auto specs = specs_;
+    if (specs.dynamic()) {
+      detail::handle_dynamic_spec(specs.dynamic_width(), specs.width,
+                                  specs.width_ref, ctx);
+      detail::handle_dynamic_spec(specs.dynamic_precision(), specs.precision,
+                                  specs.precision_ref, ctx);
+    }
+
+    if (specs.width == 0) return do_format(c, specs, ctx, ctx.out());
+    auto buf = basic_memory_buffer<Char>();
+
+    auto outer_specs = format_specs();
+    outer_specs.width = specs.width;
+    outer_specs.copy_fill_from(specs);
+    outer_specs.set_align(specs.align());
+
+    specs.width = 0;
+    specs.set_fill({});
+    specs.set_align(align::none);
+
+    do_format(c, specs, ctx, basic_appender<Char>(buf));
+    return detail::write<Char>(ctx.out(),
+                               basic_string_view<Char>(buf.data(), buf.size()),
+                               outer_specs);
+  }
+};
+
+template <typename T, typename Char>
+struct formatter<std::reference_wrapper<T>, Char,
+                 // Guard against format_as because reference_wrapper is
+                 // implicitly convertible to T&.
+                 enable_if_t<is_formattable<remove_cvref_t<T>, Char>::value &&
+                             !detail::has_format_as<T>::value &&
+                             !detail::has_format_as_member<T>::value>>
+    : formatter<remove_cvref_t<T>, Char> {
+  template <typename FormatContext>
+  auto format(std::reference_wrapper<T> ref, FormatContext& ctx) const
+      -> decltype(ctx.out()) {
+    return formatter<remove_cvref_t<T>, Char>::format(ref.get(), ctx);
+  }
+};
+
 FMT_END_NAMESPACE
+
 #endif  // FMT_STD_H_

include/spdlog/fmt/bundled/xchar.h

@@ -8,12 +8,16 @@
 #ifndef FMT_XCHAR_H_
 #define FMT_XCHAR_H_
 
-#include <cwchar>
+#include "color.h"
-
 #include "format.h"
+#include "ostream.h"
+#include "ranges.h"
 
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+#ifndef FMT_MODULE
-#  include <locale>
+#  include <cwchar>
+#  if FMT_USE_LOCALE
+#    include <locale>
+#  endif
 #endif
 
 FMT_BEGIN_NAMESPACE
@@ -22,10 +26,26 @@ namespace detail {
 template <typename T>
 using is_exotic_char = bool_constant<!std::is_same<T, char>::value>;
 
-inline auto write_loc(std::back_insert_iterator<detail::buffer<wchar_t>> out,
+template <typename S, typename = void> struct format_string_char {};
-                      loc_value value, const format_specs<wchar_t>& specs,
+
-                      locale_ref loc) -> bool {
+template <typename S>
-#ifndef FMT_STATIC_THOUSANDS_SEPARATOR
+struct format_string_char<
+    S, void_t<decltype(sizeof(detail::to_string_view(std::declval<S>())))>> {
+  using type = char_t<S>;
+};
+
+template <typename S>
+struct format_string_char<
+    S, enable_if_t<std::is_base_of<detail::compile_string, S>::value>> {
+  using type = typename S::char_type;
+};
+
+template <typename S>
+using format_string_char_t = typename format_string_char<S>::type;
+
+inline auto write_loc(basic_appender<wchar_t> out, loc_value value,
+                      const format_specs& specs, locale_ref loc) -> bool {
+#if FMT_USE_LOCALE
   auto& numpunct =
       std::use_facet<std::numpunct<wchar_t>>(loc.get<std::locale>());
   auto separator = std::wstring();
@@ -35,47 +55,86 @@ inline auto write_loc(std::back_insert_iterator<detail::buffer<wchar_t>> out,
 #endif
   return false;
 }
+
+template <typename Char>
+void vformat_to(buffer<Char>& buf, basic_string_view<Char> fmt,
+                basic_format_args<buffered_context<Char>> args,
+                locale_ref loc = {}) {
+  static_assert(!std::is_same<Char, char>::value, "");
+  auto out = basic_appender<Char>(buf);
+  parse_format_string(
+      fmt, format_handler<Char>{parse_context<Char>(fmt), {out, args, loc}});
+}
 }  // namespace detail
 
 FMT_BEGIN_EXPORT
 
 using wstring_view = basic_string_view<wchar_t>;
-using wformat_parse_context = basic_format_parse_context<wchar_t>;
+using wformat_parse_context = parse_context<wchar_t>;
-using wformat_context = buffer_context<wchar_t>;
+using wformat_context = buffered_context<wchar_t>;
 using wformat_args = basic_format_args<wformat_context>;
 using wmemory_buffer = basic_memory_buffer<wchar_t>;
 
-#if FMT_GCC_VERSION && FMT_GCC_VERSION < 409
+template <typename Char, typename... T> struct basic_fstring {
-// Workaround broken conversion on older gcc.
+ private:
-template <typename... Args> using wformat_string = wstring_view;
+  basic_string_view<Char> str_;
-inline auto runtime(wstring_view s) -> wstring_view { return s; }
+
-#else
+  static constexpr int num_static_named_args =
-template <typename... Args>
+      detail::count_static_named_args<T...>();
-using wformat_string = basic_format_string<wchar_t, type_identity_t<Args>...>;
+
+  using checker = detail::format_string_checker<
+      Char, static_cast<int>(sizeof...(T)), num_static_named_args,
+      num_static_named_args != detail::count_named_args<T...>()>;
+
+  using arg_pack = detail::arg_pack<T...>;
+
+ public:
+  using t = basic_fstring;
+
+  template <typename S,
+            FMT_ENABLE_IF(
+                std::is_convertible<const S&, basic_string_view<Char>>::value)>
+  FMT_CONSTEVAL FMT_ALWAYS_INLINE basic_fstring(const S& s) : str_(s) {
+    if (FMT_USE_CONSTEVAL)
+      detail::parse_format_string<Char>(s, checker(s, arg_pack()));
+  }
+  template <typename S,
+            FMT_ENABLE_IF(std::is_base_of<detail::compile_string, S>::value&&
+                              std::is_same<typename S::char_type, Char>::value)>
+  FMT_ALWAYS_INLINE basic_fstring(const S&) : str_(S()) {
+    FMT_CONSTEXPR auto sv = basic_string_view<Char>(S());
+    FMT_CONSTEXPR int ignore =
+        (parse_format_string(sv, checker(sv, arg_pack())), 0);
+    detail::ignore_unused(ignore);
+  }
+  basic_fstring(runtime_format_string<Char> fmt) : str_(fmt.str) {}
+
+  operator basic_string_view<Char>() const { return str_; }
+  auto get() const -> basic_string_view<Char> { return str_; }
+};
+
+template <typename Char, typename... T>
+using basic_format_string = basic_fstring<Char, T...>;
+
+template <typename... T>
+using wformat_string = typename basic_format_string<wchar_t, T...>::t;
 inline auto runtime(wstring_view s) -> runtime_format_string<wchar_t> {
   return {{s}};
 }
-#endif
-
-template <> struct is_char<wchar_t> : std::true_type {};
-template <> struct is_char<detail::char8_type> : std::true_type {};
-template <> struct is_char<char16_t> : std::true_type {};
-template <> struct is_char<char32_t> : std::true_type {};
 
 template <typename... T>
-constexpr auto make_wformat_args(const T&... args)
+constexpr auto make_wformat_args(T&... args)
-    -> format_arg_store<wformat_context, T...> {
+    -> decltype(fmt::make_format_args<wformat_context>(args...)) {
-  return {args...};
+  return fmt::make_format_args<wformat_context>(args...);
 }
 
+#if !FMT_USE_NONTYPE_TEMPLATE_ARGS
 inline namespace literals {
-#if FMT_USE_USER_DEFINED_LITERALS && !FMT_USE_NONTYPE_TEMPLATE_ARGS
+inline auto operator""_a(const wchar_t* s, size_t) -> detail::udl_arg<wchar_t> {
-constexpr auto operator""_a(const wchar_t* s, size_t)
-    -> detail::udl_arg<wchar_t> {
   return {s};
 }
-#endif
 }  // namespace literals
+#endif
 
 template <typename It, typename Sentinel>
 auto join(It begin, Sentinel end, wstring_view sep)
@@ -83,9 +142,9 @@ auto join(It begin, Sentinel end, wstring_view sep)
   return {begin, end, sep};
 }
 
-template <typename Range>
+template <typename Range, FMT_ENABLE_IF(!is_tuple_like<Range>::value)>
 auto join(Range&& range, wstring_view sep)
-    -> join_view<detail::iterator_t<Range>, detail::sentinel_t<Range>,
+    -> join_view<decltype(std::begin(range)), decltype(std::end(range)),
                  wchar_t> {
   return join(std::begin(range), std::end(range), sep);
 }
@@ -96,13 +155,19 @@ auto join(std::initializer_list<T> list, wstring_view sep)
   return join(std::begin(list), std::end(list), sep);
 }
 
+template <typename Tuple, FMT_ENABLE_IF(is_tuple_like<Tuple>::value)>
+auto join(const Tuple& tuple, basic_string_view<wchar_t> sep)
+    -> tuple_join_view<Tuple, wchar_t> {
+  return {tuple, sep};
+}
+
 template <typename Char, FMT_ENABLE_IF(!std::is_same<Char, char>::value)>
-auto vformat(basic_string_view<Char> format_str,
+auto vformat(basic_string_view<Char> fmt,
-             basic_format_args<buffer_context<type_identity_t<Char>>> args)
+             basic_format_args<buffered_context<Char>> args)
     -> std::basic_string<Char> {
   auto buf = basic_memory_buffer<Char>();
-  detail::vformat_to(buf, format_str, args);
+  detail::vformat_to(buf, fmt, args);
-  return to_string(buf);
+  return {buf.data(), buf.size()};
 }
 
 template <typename... T>
@@ -110,110 +175,115 @@ auto format(wformat_string<T...> fmt, T&&... args) -> std::wstring {
   return vformat(fmt::wstring_view(fmt), fmt::make_wformat_args(args...));
 }
 
+template <typename OutputIt, typename... T>
+auto format_to(OutputIt out, wformat_string<T...> fmt, T&&... args)
+    -> OutputIt {
+  return vformat_to(out, fmt::wstring_view(fmt),
+                    fmt::make_wformat_args(args...));
+}
+
 // Pass char_t as a default template parameter instead of using
 // std::basic_string<char_t<S>> to reduce the symbol size.
-template <typename S, typename... T, typename Char = char_t<S>,
+template <typename S, typename... T,
+          typename Char = detail::format_string_char_t<S>,
           FMT_ENABLE_IF(!std::is_same<Char, char>::value &&
                         !std::is_same<Char, wchar_t>::value)>
-auto format(const S& format_str, T&&... args) -> std::basic_string<Char> {
+auto format(const S& fmt, T&&... args) -> std::basic_string<Char> {
-  return vformat(detail::to_string_view(format_str),
+  return vformat(detail::to_string_view(fmt),
-                 fmt::make_format_args<buffer_context<Char>>(args...));
+                 fmt::make_format_args<buffered_context<Char>>(args...));
 }
 
-template <typename Locale, typename S, typename Char = char_t<S>,
+template <typename S, typename Char = detail::format_string_char_t<S>,
-          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+          FMT_ENABLE_IF(detail::is_exotic_char<Char>::value)>
-                            detail::is_exotic_char<Char>::value)>
+inline auto vformat(locale_ref loc, const S& fmt,
-inline auto vformat(
+                    basic_format_args<buffered_context<Char>> args)
-    const Locale& loc, const S& format_str,
-    basic_format_args<buffer_context<type_identity_t<Char>>> args)
     -> std::basic_string<Char> {
-  return detail::vformat(loc, detail::to_string_view(format_str), args);
+  auto buf = basic_memory_buffer<Char>();
+  detail::vformat_to(buf, detail::to_string_view(fmt), args, loc);
+  return {buf.data(), buf.size()};
 }
 
-template <typename Locale, typename S, typename... T, typename Char = char_t<S>,
+template <typename S, typename... T,
-          FMT_ENABLE_IF(detail::is_locale<Locale>::value&&
+          typename Char = detail::format_string_char_t<S>,
-                            detail::is_exotic_char<Char>::value)>
+          FMT_ENABLE_IF(detail::is_exotic_char<Char>::value)>
-inline auto format(const Locale& loc, const S& format_str, T&&... args)
+inline auto format(locale_ref loc, const S& fmt, T&&... args)
     -> std::basic_string<Char> {
-  return detail::vformat(loc, detail::to_string_view(format_str),
+  return vformat(loc, detail::to_string_view(fmt),
-                         fmt::make_format_args<buffer_context<Char>>(args...));
+                 fmt::make_format_args<buffered_context<Char>>(args...));
 }
 
-template <typename OutputIt, typename S, typename Char = char_t<S>,
+template <typename OutputIt, typename S,
+          typename Char = detail::format_string_char_t<S>,
           FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
                             detail::is_exotic_char<Char>::value)>
-auto vformat_to(OutputIt out, const S& format_str,
+auto vformat_to(OutputIt out, const S& fmt,
-                basic_format_args<buffer_context<type_identity_t<Char>>> args)
+                basic_format_args<buffered_context<Char>> args) -> OutputIt {
-    -> OutputIt {
   auto&& buf = detail::get_buffer<Char>(out);
-  detail::vformat_to(buf, detail::to_string_view(format_str), args);
+  detail::vformat_to(buf, detail::to_string_view(fmt), args);
   return detail::get_iterator(buf, out);
 }
 
 template <typename OutputIt, typename S, typename... T,
-          typename Char = char_t<S>,
+          typename Char = detail::format_string_char_t<S>,
-          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
+          FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value &&
-                            detail::is_exotic_char<Char>::value)>
+                        !std::is_same<Char, char>::value &&
+                        !std::is_same<Char, wchar_t>::value)>
 inline auto format_to(OutputIt out, const S& fmt, T&&... args) -> OutputIt {
   return vformat_to(out, detail::to_string_view(fmt),
-                    fmt::make_format_args<buffer_context<Char>>(args...));
+                    fmt::make_format_args<buffered_context<Char>>(args...));
 }
 
-template <typename Locale, typename S, typename OutputIt, typename... Args,
+template <typename S, typename OutputIt, typename... Args,
-          typename Char = char_t<S>,
+          typename Char = detail::format_string_char_t<S>,
           FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
-                            detail::is_locale<Locale>::value&&
+                            detail::is_exotic_char<Char>::value)>
-                                detail::is_exotic_char<Char>::value)>
+inline auto vformat_to(OutputIt out, locale_ref loc, const S& fmt,
-inline auto vformat_to(
+                       basic_format_args<buffered_context<Char>> args)
-    OutputIt out, const Locale& loc, const S& format_str,
+    -> OutputIt {
-    basic_format_args<buffer_context<type_identity_t<Char>>> args) -> OutputIt {
   auto&& buf = detail::get_buffer<Char>(out);
-  vformat_to(buf, detail::to_string_view(format_str), args,
+  vformat_to(buf, detail::to_string_view(fmt), args, loc);
-             detail::locale_ref(loc));
   return detail::get_iterator(buf, out);
 }
 
-template <typename OutputIt, typename Locale, typename S, typename... T,
+template <typename OutputIt, typename S, typename... T,
-          typename Char = char_t<S>,
+          typename Char = detail::format_string_char_t<S>,
           bool enable = detail::is_output_iterator<OutputIt, Char>::value &&
-                        detail::is_locale<Locale>::value &&
                         detail::is_exotic_char<Char>::value>
-inline auto format_to(OutputIt out, const Locale& loc, const S& format_str,
+inline auto format_to(OutputIt out, locale_ref loc, const S& fmt, T&&... args)
-                      T&&... args) ->
+    -> typename std::enable_if<enable, OutputIt>::type {
-    typename std::enable_if<enable, OutputIt>::type {
+  return vformat_to(out, loc, detail::to_string_view(fmt),
-  return vformat_to(out, loc, detail::to_string_view(format_str),
+                    fmt::make_format_args<buffered_context<Char>>(args...));
-                    fmt::make_format_args<buffer_context<Char>>(args...));
 }
 
 template <typename OutputIt, typename Char, typename... Args,
           FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
                             detail::is_exotic_char<Char>::value)>
-inline auto vformat_to_n(
+inline auto vformat_to_n(OutputIt out, size_t n, basic_string_view<Char> fmt,
-    OutputIt out, size_t n, basic_string_view<Char> format_str,
+                         basic_format_args<buffered_context<Char>> args)
-    basic_format_args<buffer_context<type_identity_t<Char>>> args)
     -> format_to_n_result<OutputIt> {
   using traits = detail::fixed_buffer_traits;
   auto buf = detail::iterator_buffer<OutputIt, Char, traits>(out, n);
-  detail::vformat_to(buf, format_str, args);
+  detail::vformat_to(buf, fmt, args);
   return {buf.out(), buf.count()};
 }
 
 template <typename OutputIt, typename S, typename... T,
-          typename Char = char_t<S>,
+          typename Char = detail::format_string_char_t<S>,
           FMT_ENABLE_IF(detail::is_output_iterator<OutputIt, Char>::value&&
                             detail::is_exotic_char<Char>::value)>
 inline auto format_to_n(OutputIt out, size_t n, const S& fmt, T&&... args)
     -> format_to_n_result<OutputIt> {
-  return vformat_to_n(out, n, detail::to_string_view(fmt),
+  return vformat_to_n(out, n, fmt::basic_string_view<Char>(fmt),
-                      fmt::make_format_args<buffer_context<Char>>(args...));
+                      fmt::make_format_args<buffered_context<Char>>(args...));
 }
 
-template <typename S, typename... T, typename Char = char_t<S>,
+template <typename S, typename... T,
+          typename Char = detail::format_string_char_t<S>,
           FMT_ENABLE_IF(detail::is_exotic_char<Char>::value)>
 inline auto formatted_size(const S& fmt, T&&... args) -> size_t {
   auto buf = detail::counting_buffer<Char>();
   detail::vformat_to(buf, detail::to_string_view(fmt),
-                     fmt::make_format_args<buffer_context<Char>>(args...));
+                     fmt::make_format_args<buffered_context<Char>>(args...));
   return buf.count();
 }
 
@@ -247,9 +317,36 @@ template <typename... T> void println(wformat_string<T...> fmt, T&&... args) {
   return print(L"{}\n", fmt::format(fmt, std::forward<T>(args)...));
 }
 
-/**
+inline auto vformat(text_style ts, wstring_view fmt, wformat_args args)
-  Converts *value* to ``std::wstring`` using the default format for type *T*.
+    -> std::wstring {
- */
+  auto buf = wmemory_buffer();
+  detail::vformat_to(buf, ts, fmt, args);
+  return {buf.data(), buf.size()};
+}
+
+template <typename... T>
+inline auto format(text_style ts, wformat_string<T...> fmt, T&&... args)
+    -> std::wstring {
+  return fmt::vformat(ts, fmt, fmt::make_wformat_args(args...));
+}
+
+inline void vprint(std::wostream& os, wstring_view fmt, wformat_args args) {
+  auto buffer = basic_memory_buffer<wchar_t>();
+  detail::vformat_to(buffer, fmt, args);
+  detail::write_buffer(os, buffer);
+}
+
+template <typename... T>
+void print(std::wostream& os, wformat_string<T...> fmt, T&&... args) {
+  vprint(os, fmt, fmt::make_format_args<buffered_context<wchar_t>>(args...));
+}
+
+template <typename... T>
+void println(std::wostream& os, wformat_string<T...> fmt, T&&... args) {
+  print(os, L"{}\n", fmt::format(fmt, std::forward<T>(args)...));
+}
+
+/// Converts `value` to `std::wstring` using the default format for type `T`.
 template <typename T> inline auto to_wstring(const T& value) -> std::wstring {
   return format(FMT_STRING(L"{}"), value);
 }

include/spdlog/fmt/fmt.h

@@ -20,11 +20,7 @@
     #ifndef FMT_USE_WINDOWS_H
         #define FMT_USE_WINDOWS_H 0
     #endif
-
-    #include <spdlog/fmt/bundled/core.h>
     #include <spdlog/fmt/bundled/format.h>
-
 #else  // SPDLOG_FMT_EXTERNAL is defined - use external fmtlib
-    #include <fmt/core.h>
     #include <fmt/format.h>
 #endif

include/spdlog/logger-inl.h

@@ -57,7 +57,7 @@ SPDLOG_INLINE void logger::swap(spdlog::logger &other) SPDLOG_NOEXCEPT {
     std::swap(tracer_, other.tracer_);
 }
 
-SPDLOG_INLINE void swap(logger &a, logger &b) { a.swap(b); }
+SPDLOG_INLINE void swap(logger &a, logger &b) noexcept { a.swap(b); }
 
 SPDLOG_INLINE void logger::set_level(level::level_enum log_level) { level_.store(log_level); }
 
@@ -163,12 +163,12 @@ SPDLOG_INLINE void logger::dump_backtrace_() {
     }
 }
 
-SPDLOG_INLINE bool logger::should_flush_(const details::log_msg &msg) {
+SPDLOG_INLINE bool logger::should_flush_(const details::log_msg &msg) const {
     auto flush_level = flush_level_.load(std::memory_order_relaxed);
     return (msg.level >= flush_level) && (msg.level != level::off);
 }
 
-SPDLOG_INLINE void logger::err_handler_(const std::string &msg) {
+SPDLOG_INLINE void logger::err_handler_(const std::string &msg) const {
     if (custom_err_handler_) {
         custom_err_handler_(msg);
     } else {

include/spdlog/logger.h

@@ -363,14 +363,14 @@ protected:
     virtual void sink_it_(const details::log_msg &msg);
     virtual void flush_();
     void dump_backtrace_();
-    bool should_flush_(const details::log_msg &msg);
+    bool should_flush_(const details::log_msg &msg) const;
 
     // handle errors during logging.
     // default handler prints the error to stderr at max rate of 1 message/sec.
-    void err_handler_(const std::string &msg);
+    void err_handler_(const std::string &msg) const;
 };
 
-void swap(logger &a, logger &b);
+void swap(logger &a, logger &b) noexcept;
 
 }  // namespace spdlog
 

include/spdlog/mdc.h

@@ -3,17 +3,23 @@
 
 #pragma once
 
+#if defined(SPDLOG_NO_TLS)
+    #error "This header requires thread local storage support, but SPDLOG_NO_TLS is defined."
+#endif
+
 #include <map>
 #include <string>
 
 #include <spdlog/common.h>
 
-// MDC is a simple map of key->string values stored in thread local storage whose content will be printed by the loggers.
+// MDC is a simple map of key->string values stored in thread local storage whose content will be
-// Note: Not supported in async mode (thread local storage - so the async thread pool have different copy).
+// printed by the loggers. Note: Not supported in async mode (thread local storage - so the async
+// thread pool have different copy).
 //
 // Usage example:
 // spdlog::mdc::put("mdc_key_1", "mdc_value_1");
-// spdlog::info("Hello, {}", "World!");  // => [2024-04-26 02:08:05.040] [info] [mdc_key_1:mdc_value_1] Hello, World!
+// spdlog::info("Hello, {}", "World!");  // => [2024-04-26 02:08:05.040] [info]
+// [mdc_key_1:mdc_value_1] Hello, World!
 
 namespace spdlog {
 class SPDLOG_API mdc {

include/spdlog/pattern_formatter-inl.h

@@ -10,7 +10,11 @@
 #include <spdlog/details/fmt_helper.h>
 #include <spdlog/details/log_msg.h>
 #include <spdlog/details/os.h>
-#include <spdlog/mdc.h>
+
+#ifndef SPDLOG_NO_TLS
+    #include <spdlog/mdc.h>
+#endif
+
 #include <spdlog/fmt/fmt.h>
 #include <spdlog/formatter.h>
 
@@ -66,6 +70,9 @@ public:
             pad_it(remaining_pad_);
         } else if (padinfo_.truncate_) {
             long new_size = static_cast<long>(dest_.size()) + remaining_pad_;
+            if (new_size < 0) {
+                new_size = 0;
+            }
             dest_.resize(static_cast<size_t>(new_size));
         }
     }
@@ -176,7 +183,7 @@ public:
 
 // Abbreviated month
 static const std::array<const char *, 12> months{
-    {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sept", "Oct", "Nov", "Dec"}};
+    {"Jan", "Feb", "Mar", "Apr", "May", "Jun", "Jul", "Aug", "Sep", "Oct", "Nov", "Dec"}};
 
 template <typename ScopedPadder>
 class b_formatter final : public flag_formatter {
@@ -260,7 +267,7 @@ public:
         : flag_formatter(padinfo) {}
 
     void format(const details::log_msg &, const std::tm &tm_time, memory_buf_t &dest) override {
-        const size_t field_size = 10;
+        const size_t field_size = 8;
         ScopedPadder p(field_size, padinfo_, dest);
 
         fmt_helper::pad2(tm_time.tm_mon + 1, dest);
@@ -786,6 +793,7 @@ private:
 
 // Class for formatting Mapped Diagnostic Context (MDC) in log messages.
 // Example: [logger-name] [info] [mdc_key_1:mdc_value_1 mdc_key_2:mdc_value_2] some message
+#ifndef SPDLOG_NO_TLS
 template <typename ScopedPadder>
 class mdc_formatter : public flag_formatter {
 public:
@@ -824,6 +832,7 @@ public:
         }
     }
 };
+#endif
 
 // Full info formatter
 // pattern: [%Y-%m-%d %H:%M:%S.%e] [%n] [%l] [%s:%#] %v
@@ -901,6 +910,7 @@ public:
             dest.push_back(' ');
         }
 
+#ifndef SPDLOG_NO_TLS
         // add mdc if present
         auto &mdc_map = mdc::get_context();
         if (!mdc_map.empty()) {
@@ -909,6 +919,7 @@ public:
             dest.push_back(']');
             dest.push_back(' ');
         }
+#endif
         // fmt_helper::append_string_view(msg.msg(), dest);
         fmt_helper::append_string_view(msg.payload, dest);
     }
@@ -916,7 +927,10 @@ public:
 private:
     std::chrono::seconds cache_timestamp_{0};
     memory_buf_t cached_datetime_;
-    mdc_formatter<null_scoped_padder> mdc_formatter_{padding_info{}};
+
+#ifndef SPDLOG_NO_TLS
+    mdc_formatter<null_scoped_padder> mdc_formatter_{padding_info {}};
+#endif
 };
 
 }  // namespace details
@@ -1211,9 +1225,11 @@ SPDLOG_INLINE void pattern_formatter::handle_flag_(char flag, details::padding_i
                     padding));
             break;
 
+#ifndef SPDLOG_NO_TLS  // mdc formatter requires TLS support
         case ('&'):
             formatters_.push_back(details::make_unique<details::mdc_formatter<Padder>>(padding));
             break;
+#endif
 
         default:  // Unknown flag appears as is
             auto unknown_flag = details::make_unique<details::aggregate_formatter>();

include/spdlog/sinks/ansicolor_sink-inl.h

@@ -20,7 +20,7 @@ SPDLOG_INLINE ansicolor_sink<ConsoleMutex>::ansicolor_sink(FILE *target_file, co
       formatter_(details::make_unique<spdlog::pattern_formatter>())
 
 {
-    set_color_mode(mode);
+    set_color_mode_(mode);
     colors_.at(level::trace) = to_string_(white);
     colors_.at(level::debug) = to_string_(cyan);
     colors_.at(level::info) = to_string_(green);
@@ -82,12 +82,18 @@ SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::set_formatter(
 }
 
 template <typename ConsoleMutex>
-SPDLOG_INLINE bool ansicolor_sink<ConsoleMutex>::should_color() {
+SPDLOG_INLINE bool ansicolor_sink<ConsoleMutex>::should_color() const {
     return should_do_colors_;
 }
 
 template <typename ConsoleMutex>
 SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::set_color_mode(color_mode mode) {
+    std::lock_guard<mutex_t> lock(mutex_);
+    set_color_mode_(mode);
+}
+
+template <typename ConsoleMutex>
+SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::set_color_mode_(color_mode mode) {
     switch (mode) {
         case color_mode::always:
             should_do_colors_ = true;
@@ -105,15 +111,16 @@ SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::set_color_mode(color_mode mode)
 }
 
 template <typename ConsoleMutex>
-SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::print_ccode_(const string_view_t &color_code) {
+SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::print_ccode_(
-    fwrite(color_code.data(), sizeof(char), color_code.size(), target_file_);
+    const string_view_t &color_code) const {
+    details::os::fwrite_bytes(color_code.data(), color_code.size(), target_file_);
 }
 
 template <typename ConsoleMutex>
 SPDLOG_INLINE void ansicolor_sink<ConsoleMutex>::print_range_(const memory_buf_t &formatted,
                                                               size_t start,
-                                                              size_t end) {
+                                                              size_t end) const {
-    fwrite(formatted.data() + start, sizeof(char), end - start, target_file_);
+    details::os::fwrite_bytes(formatted.data() + start, end - start, target_file_);
 }
 
 template <typename ConsoleMutex>

include/spdlog/sinks/ansicolor_sink.h

@@ -36,11 +36,11 @@ public:
 
     void set_color(level::level_enum color_level, string_view_t color);
     void set_color_mode(color_mode mode);
-    bool should_color();
+    bool should_color() const;
 
     void log(const details::log_msg &msg) override;
     void flush() override;
-    void set_pattern(const std::string &pattern) final;
+    void set_pattern(const std::string &pattern) override;
     void set_formatter(std::unique_ptr<spdlog::formatter> sink_formatter) override;
 
     // Formatting codes
@@ -84,8 +84,9 @@ private:
     bool should_do_colors_;
     std::unique_ptr<spdlog::formatter> formatter_;
     std::array<std::string, level::n_levels> colors_;
-    void print_ccode_(const string_view_t &color_code);
+    void set_color_mode_(color_mode mode);
-    void print_range_(const memory_buf_t &formatted, size_t start, size_t end);
+    void print_ccode_(const string_view_t &color_code) const;
+    void print_range_(const memory_buf_t &formatted, size_t start, size_t end) const;
     static std::string to_string_(const string_view_t &sv);
 };
 

include/spdlog/sinks/base_sink.h

@@ -28,10 +28,10 @@ public:
     base_sink &operator=(const base_sink &) = delete;
     base_sink &operator=(base_sink &&) = delete;
 
-    void log(const details::log_msg &msg) final;
+    void log(const details::log_msg &msg) final override;
-    void flush() final;
+    void flush() final override;
-    void set_pattern(const std::string &pattern) final;
+    void set_pattern(const std::string &pattern) final override;
-    void set_formatter(std::unique_ptr<spdlog::formatter> sink_formatter) final;
+    void set_formatter(std::unique_ptr<spdlog::formatter> sink_formatter) final override;
 
 protected:
     // sink formatter

include/spdlog/sinks/basic_file_sink-inl.h

@@ -26,6 +26,12 @@ SPDLOG_INLINE const filename_t &basic_file_sink<Mutex>::filename() const {
     return file_helper_.filename();
 }
 
+template <typename Mutex>
+SPDLOG_INLINE void basic_file_sink<Mutex>::truncate() {
+    std::lock_guard<Mutex> lock(base_sink<Mutex>::mutex_);
+    file_helper_.reopen(true);
+}
+
 template <typename Mutex>
 SPDLOG_INLINE void basic_file_sink<Mutex>::sink_it_(const details::log_msg &msg) {
     memory_buf_t formatted;

include/spdlog/sinks/basic_file_sink.h

@@ -23,6 +23,7 @@ public:
                              bool truncate = false,
                              const file_event_handlers &event_handlers = {});
     const filename_t &filename() const;
+    void truncate();
 
 protected:
     void sink_it_(const details::log_msg &msg) override;

include/spdlog/sinks/callback_sink.h

@@ -27,7 +27,7 @@ public:
 
 protected:
     void sink_it_(const details::log_msg &msg) override { callback_(msg); }
-    void flush_() override{};
+    void flush_() override {}
 
 private:
     custom_log_callback callback_;

include/spdlog/sinks/daily_file_sink.h

@@ -62,6 +62,8 @@ struct daily_filename_format_calculator {
  * Rotating file sink based on date.
  * If truncate != false , the created file will be truncated.
  * If max_files > 0, retain only the last max_files and delete previous.
+ * Note that old log files from previous executions will not be deleted by this class,
+ * rotation and deletion is only applied while the program is running.
  */
 template <typename Mutex, typename FileNameCalc = daily_filename_calculator>
 class daily_file_sink final : public base_sink<Mutex> {

include/spdlog/sinks/dup_filter_sink.h

@@ -40,22 +40,21 @@ template <typename Mutex>
 class dup_filter_sink : public dist_sink<Mutex> {
 public:
     template <class Rep, class Period>
-    explicit dup_filter_sink(std::chrono::duration<Rep, Period> max_skip_duration,
+    explicit dup_filter_sink(std::chrono::duration<Rep, Period> max_skip_duration)
-                             level::level_enum notification_level = level::info)
+        : max_skip_duration_{max_skip_duration} {}
-        : max_skip_duration_{max_skip_duration},
-          log_level_{notification_level} {}
 
 protected:
     std::chrono::microseconds max_skip_duration_;
     log_clock::time_point last_msg_time_;
     std::string last_msg_payload_;
     size_t skip_counter_ = 0;
-    level::level_enum log_level_;
+    level::level_enum skipped_msg_log_level_ = spdlog::level::level_enum::off;
 
     void sink_it_(const details::log_msg &msg) override {
         bool filtered = filter_(msg);
         if (!filtered) {
             skip_counter_ += 1;
+            skipped_msg_log_level_ = msg.level;
             return;
         }
 
@@ -65,7 +64,7 @@ protected:
             auto msg_size = ::snprintf(buf, sizeof(buf), "Skipped %u duplicate messages..",
                                        static_cast<unsigned>(skip_counter_));
             if (msg_size > 0 && static_cast<size_t>(msg_size) < sizeof(buf)) {
-                details::log_msg skipped_msg{msg.source, msg.logger_name, log_level_,
+                details::log_msg skipped_msg{msg.source, msg.logger_name, skipped_msg_log_level_,
                                              string_view_t{buf, static_cast<size_t>(msg_size)}};
                 dist_sink<Mutex>::sink_it_(skipped_msg);
             }

include/spdlog/sinks/hourly_file_sink.h

@@ -39,6 +39,8 @@ struct hourly_filename_calculator {
  * Rotating file sink based on time.
  * If truncate != false , the created file will be truncated.
  * If max_files > 0, retain only the last max_files and delete previous.
+ * Note that old log files from previous executions will not be deleted by this class,
+ * rotation and deletion is only applied while the program is running.
  */
 template <typename Mutex, typename FileNameCalc = hourly_filename_calculator>
 class hourly_file_sink final : public base_sink<Mutex> {

include/spdlog/sinks/msvc_sink.h

@@ -32,7 +32,7 @@ class msvc_sink : public base_sink<Mutex> {
 public:
     msvc_sink() = default;
     msvc_sink(bool check_debugger_present)
-        : check_debugger_present_{check_debugger_present} {};
+        : check_debugger_present_{check_debugger_present} {}
 
 protected:
     void sink_it_(const details::log_msg &msg) override {

include/spdlog/sinks/null_sink.h

@@ -13,7 +13,7 @@ namespace spdlog {
 namespace sinks {
 
 template <typename Mutex>
-class null_sink : public base_sink<Mutex> {
+class null_sink final : public base_sink<Mutex> {
 protected:
     void sink_it_(const details::log_msg &) override {}
     void flush_() override {}

include/spdlog/sinks/ringbuffer_sink.h

@@ -21,7 +21,11 @@ template <typename Mutex>
 class ringbuffer_sink final : public base_sink<Mutex> {
 public:
     explicit ringbuffer_sink(size_t n_items)
-        : q_{n_items} {}
+        : q_{n_items} {
+        if (n_items == 0) {
+            throw_spdlog_ex("ringbuffer_sink: n_items cannot be zero");
+        }
+    }
 
     std::vector<details::log_msg_buffer> last_raw(size_t lim = 0) {
         std::lock_guard<Mutex> lock(base_sink<Mutex>::mutex_);

include/spdlog/sinks/rotating_file_sink-inl.h

@@ -14,7 +14,6 @@
 #include <spdlog/fmt/fmt.h>
 
 #include <cerrno>
-#include <chrono>
 #include <ctime>
 #include <mutex>
 #include <string>
@@ -38,8 +37,8 @@ SPDLOG_INLINE rotating_file_sink<Mutex>::rotating_file_sink(
         throw_spdlog_ex("rotating sink constructor: max_size arg cannot be zero");
     }
 
-    if (max_files > 200000) {
+    if (max_files > MaxFiles) {
-        throw_spdlog_ex("rotating sink constructor: max_files arg cannot exceed 200000");
+        throw_spdlog_ex("rotating sink constructor: max_files arg cannot exceed MaxFiles");
     }
     file_helper_.open(calc_filename(base_filename_, 0));
     current_size_ = file_helper_.size();  // expensive. called only once
@@ -54,13 +53,14 @@ SPDLOG_INLINE rotating_file_sink<Mutex>::rotating_file_sink(
 template <typename Mutex>
 SPDLOG_INLINE filename_t rotating_file_sink<Mutex>::calc_filename(const filename_t &filename,
                                                                   std::size_t index) {
-    if (index == 0u) {
+    if (index == 0U) {
         return filename;
     }
 
-    filename_t basename, ext;
+    filename_t basename;
+    filename_t ext;
     std::tie(basename, ext) = details::file_helper::split_by_extension(filename);
-    return fmt_lib::format(SPDLOG_FILENAME_T("{}.{}{}"), basename, index, ext);
+    return fmt_lib::format(SPDLOG_FMT_STRING(SPDLOG_FILENAME_T("{}.{}{}")), basename, index, ext);
 }
 
 template <typename Mutex>
@@ -69,6 +69,41 @@ SPDLOG_INLINE filename_t rotating_file_sink<Mutex>::filename() {
     return file_helper_.filename();
 }
 
+template <typename Mutex>
+SPDLOG_INLINE void rotating_file_sink<Mutex>::rotate_now() {
+    std::lock_guard<Mutex> lock(base_sink<Mutex>::mutex_);
+    rotate_();
+}
+template <typename Mutex>
+SPDLOG_INLINE void rotating_file_sink<Mutex>::set_max_size(std::size_t max_size) {
+    std::lock_guard<Mutex> lock(base_sink<Mutex>::mutex_);
+    if (max_size == 0) {
+        throw_spdlog_ex("rotating sink set_max_size: max_size arg cannot be zero");
+    }
+    max_size_ = max_size;
+}
+
+template <typename Mutex>
+SPDLOG_INLINE std::size_t rotating_file_sink<Mutex>::get_max_size() {
+    std::lock_guard<Mutex> lock(base_sink<Mutex>::mutex_);
+    return max_size_;
+}
+
+template <typename Mutex>
+SPDLOG_INLINE void rotating_file_sink<Mutex>::set_max_files(std::size_t max_files) {
+    std::lock_guard<Mutex> lock(base_sink<Mutex>::mutex_);
+    if (max_files > MaxFiles) {
+        throw_spdlog_ex("rotating sink set_max_files: max_files arg cannot exceed 200000");
+    }
+    max_files_ = max_files;
+}
+
+template <typename Mutex>
+std::size_t rotating_file_sink<Mutex>::get_max_files() {
+    std::lock_guard<Mutex> lock(base_sink<Mutex>::mutex_);
+    return max_files_;
+}
+
 template <typename Mutex>
 SPDLOG_INLINE void rotating_file_sink<Mutex>::sink_it_(const details::log_msg &msg) {
     memory_buf_t formatted;

include/spdlog/sinks/rotating_file_sink.h

@@ -8,7 +8,6 @@
 #include <spdlog/details/synchronous_factory.h>
 #include <spdlog/sinks/base_sink.h>
 
-#include <chrono>
 #include <mutex>
 #include <string>
 
@@ -21,6 +20,7 @@ namespace sinks {
 template <typename Mutex>
 class rotating_file_sink final : public base_sink<Mutex> {
 public:
+    static constexpr size_t MaxFiles = 200000;
     rotating_file_sink(filename_t base_filename,
                        std::size_t max_size,
                        std::size_t max_files,
@@ -28,6 +28,11 @@ public:
                        const file_event_handlers &event_handlers = {});
     static filename_t calc_filename(const filename_t &filename, std::size_t index);
     filename_t filename();
+    void rotate_now();
+    void set_max_size(std::size_t max_size);
+    std::size_t get_max_size();
+    void set_max_files(std::size_t max_files);
+    std::size_t get_max_files();
 
 protected:
     void sink_it_(const details::log_msg &msg) override;
@@ -41,7 +46,7 @@ private:
     // log.3.txt -> delete
     void rotate_();
 
-    // delete the target if exists, and rename the src file  to target
+    // delete the target if exists, and rename the src file to target
     // return true on success, false otherwise.
     bool rename_file_(const filename_t &src_filename, const filename_t &target_filename);
 
@@ -60,25 +65,24 @@ using rotating_file_sink_st = rotating_file_sink<details::null_mutex>;
 //
 // factory functions
 //
-
 template <typename Factory = spdlog::synchronous_factory>
-inline std::shared_ptr<logger> rotating_logger_mt(const std::string &logger_name,
+std::shared_ptr<logger> rotating_logger_mt(const std::string &logger_name,
-                                                  const filename_t &filename,
+                                           const filename_t &filename,
-                                                  size_t max_file_size,
+                                           size_t max_file_size,
-                                                  size_t max_files,
+                                           size_t max_files,
-                                                  bool rotate_on_open = false,
+                                           bool rotate_on_open = false,
-                                                  const file_event_handlers &event_handlers = {}) {
+                                           const file_event_handlers &event_handlers = {}) {
     return Factory::template create<sinks::rotating_file_sink_mt>(
         logger_name, filename, max_file_size, max_files, rotate_on_open, event_handlers);
 }
 
 template <typename Factory = spdlog::synchronous_factory>
-inline std::shared_ptr<logger> rotating_logger_st(const std::string &logger_name,
+std::shared_ptr<logger> rotating_logger_st(const std::string &logger_name,
-                                                  const filename_t &filename,
+                                           const filename_t &filename,
-                                                  size_t max_file_size,
+                                           size_t max_file_size,
-                                                  size_t max_files,
+                                           size_t max_files,
-                                                  bool rotate_on_open = false,
+                                           bool rotate_on_open = false,
-                                                  const file_event_handlers &event_handlers = {}) {
+                                           const file_event_handlers &event_handlers = {}) {
     return Factory::template create<sinks::rotating_file_sink_st>(
         logger_name, filename, max_file_size, max_files, rotate_on_open, event_handlers);
 }

include/spdlog/sinks/stdout_sinks-inl.h

@@ -10,6 +10,7 @@
 #include <memory>
 #include <spdlog/details/console_globals.h>
 #include <spdlog/pattern_formatter.h>
+#include <spdlog/details/os.h>
 
 #ifdef _WIN32
     // under windows using fwrite to non-binary stream results in \r\r\n (see issue #1675)
@@ -22,7 +23,7 @@
 
     #include <io.h>     // _get_osfhandle(..)
     #include <stdio.h>  // _fileno(..)
-#endif                  // WIN32
+#endif                  // _WIN32
 
 namespace spdlog {
 
@@ -44,7 +45,7 @@ SPDLOG_INLINE stdout_sink_base<ConsoleMutex>::stdout_sink_base(FILE *file)
     if (handle_ == INVALID_HANDLE_VALUE && file != stdout && file != stderr) {
         throw_spdlog_ex("spdlog::stdout_sink_base: _get_osfhandle() failed", errno);
     }
-#endif  // WIN32
+#endif  // _WIN32
 }
 
 template <typename ConsoleMutex>
@@ -67,8 +68,8 @@ SPDLOG_INLINE void stdout_sink_base<ConsoleMutex>::log(const details::log_msg &m
     std::lock_guard<mutex_t> lock(mutex_);
     memory_buf_t formatted;
     formatter_->format(msg, formatted);
-    ::fwrite(formatted.data(), sizeof(char), formatted.size(), file_);
+    details::os::fwrite_bytes(formatted.data(), formatted.size(), file_);
-#endif                // WIN32
+#endif                // _WIN32
     ::fflush(file_);  // flush every line to terminal
 }
 

include/spdlog/sinks/syslog_sink.h

@@ -64,13 +64,14 @@ protected:
     //
     // Simply maps spdlog's log level to syslog priority level.
     //
-    int syslog_prio_from_level(const details::log_msg &msg) const {
+    virtual int syslog_prio_from_level(const details::log_msg &msg) const {
         return syslog_levels_.at(static_cast<levels_array::size_type>(msg.level));
     }
 
-private:
     using levels_array = std::array<int, 7>;
     levels_array syslog_levels_;
+
+private:
     // must store the ident because the man says openlog might use the pointer as
     // is and not a string copy
     const std::string ident_;

include/spdlog/sinks/tcp_sink.h

@@ -31,6 +31,8 @@ namespace sinks {
 struct tcp_sink_config {
     std::string server_host;
     int server_port;
+    int timeout_ms =
+        0;  // The timeout for all 3 major socket operations that is connect, send, and recv
     bool lazy_connect = false;  // if true connect on first log call instead of on construction
 
     tcp_sink_config(std::string host, int port)
@@ -44,10 +46,22 @@ public:
     // connect to tcp host/port or throw if failed
     // host can be hostname or ip address
 
+    explicit tcp_sink(const std::string &host,
+                      int port,
+                      int timeout_ms = 0,
+                      bool lazy_connect = false)
+        : config_{host, port} {
+        config_.timeout_ms = timeout_ms;
+        config_.lazy_connect = lazy_connect;
+        if (!config_.lazy_connect) {
+            client_.connect(config_.server_host, config_.server_port, config_.timeout_ms);
+        }
+    }
+
     explicit tcp_sink(tcp_sink_config sink_config)
         : config_{std::move(sink_config)} {
         if (!config_.lazy_connect) {
-            this->client_.connect(config_.server_host, config_.server_port);
+            client_.connect(config_.server_host, config_.server_port, config_.timeout_ms);
         }
     }
 
@@ -58,7 +72,7 @@ protected:
         spdlog::memory_buf_t formatted;
         spdlog::sinks::base_sink<Mutex>::formatter_->format(msg, formatted);
         if (!client_.is_connected()) {
-            client_.connect(config_.server_host, config_.server_port);
+            client_.connect(config_.server_host, config_.server_port, config_.timeout_ms);
         }
         client_.send(formatted.data(), formatted.size());
     }

include/spdlog/sinks/wincolor_sink-inl.h

@@ -134,9 +134,18 @@ void SPDLOG_INLINE wincolor_sink<ConsoleMutex>::print_range_(const memory_buf_t
                                                              size_t start,
                                                              size_t end) {
     if (end > start) {
+#if defined(SPDLOG_UTF8_TO_WCHAR_CONSOLE)
+        wmemory_buf_t wformatted;
+        details::os::utf8_to_wstrbuf(string_view_t(formatted.data() + start, end - start),
+                                     wformatted);
+        auto size = static_cast<DWORD>(wformatted.size());
+        auto ignored = ::WriteConsoleW(static_cast<HANDLE>(out_handle_), wformatted.data(), size,
+                                       nullptr, nullptr);
+#else
         auto size = static_cast<DWORD>(end - start);
         auto ignored = ::WriteConsoleA(static_cast<HANDLE>(out_handle_), formatted.data() + start,
                                        size, nullptr, nullptr);
+#endif
         (void)(ignored);
     }
 }

include/spdlog/sinks/wincolor_sink.h

@@ -31,10 +31,10 @@ public:
 
     // change the color for the given level
     void set_color(level::level_enum level, std::uint16_t color);
-    void log(const details::log_msg &msg) final override;
+    void log(const details::log_msg &msg) override;
-    void flush() final override;
+    void flush() override;
-    void set_pattern(const std::string &pattern) override final;
+    void set_pattern(const std::string &pattern) override;
-    void set_formatter(std::unique_ptr<spdlog::formatter> sink_formatter) override final;
+    void set_formatter(std::unique_ptr<spdlog::formatter> sink_formatter) override;
     void set_color_mode(color_mode mode);
 
 protected:

include/spdlog/spdlog-inl.h

@@ -59,6 +59,10 @@ SPDLOG_INLINE void register_logger(std::shared_ptr<logger> logger) {
     details::registry::instance().register_logger(std::move(logger));
 }
 
+SPDLOG_INLINE void register_or_replace(std::shared_ptr<logger> logger) {
+    details::registry::instance().register_or_replace(std::move(logger));
+}
+
 SPDLOG_INLINE void apply_all(const std::function<void(std::shared_ptr<logger>)> &fun) {
     details::registry::instance().apply_all(fun);
 }

include/spdlog/spdlog.h

@@ -25,7 +25,7 @@ namespace spdlog {
 using default_factory = synchronous_factory;
 
 // Create and register a logger with a templated sink type
-// The logger's level, formatter and flush level will be set according the
+// The logger's level, formatter and flush level will be set according to the
 // global settings.
 //
 // Example:
@@ -46,7 +46,7 @@ inline std::shared_ptr<spdlog::logger> create(std::string logger_name, SinkArgs
 //   spdlog::initialize_logger(mylogger);
 SPDLOG_API void initialize_logger(std::shared_ptr<logger> logger);
 
-// Return an existing logger or nullptr if a logger with such name doesn't
+// Return an existing logger or nullptr if a logger with such a name doesn't
 // exist.
 // example: spdlog::get("my_logger")->info("hello {}", "world");
 SPDLOG_API std::shared_ptr<logger> get(const std::string &name);
@@ -71,13 +71,13 @@ SPDLOG_API void dump_backtrace();
 // Get global logging level
 SPDLOG_API level::level_enum get_level();
 
-// Set global logging level
+// Set the global logging level
 SPDLOG_API void set_level(level::level_enum log_level);
 
 // Determine whether the default logger should log messages with a certain level
 SPDLOG_API bool should_log(level::level_enum lvl);
 
-// Set global flush level
+// Set a global flush level
 SPDLOG_API void flush_on(level::level_enum log_level);
 
 // Start/Restart a periodic flusher thread
@@ -91,9 +91,14 @@ inline void flush_every(std::chrono::duration<Rep, Period> interval) {
 SPDLOG_API void set_error_handler(void (*handler)(const std::string &msg));
 
 // Register the given logger with the given name
+// Will throw if a logger with the same name already exists.
 SPDLOG_API void register_logger(std::shared_ptr<logger> logger);
 
-// Apply a user defined function on all registered loggers
+// Register the given logger with the given name
+// Will replace any existing logger with the same name.
+SPDLOG_API void register_or_replace(std::shared_ptr<logger> logger);
+
+// Apply a user-defined function on all registered loggers
 // Example:
 // spdlog::apply_all([&](std::shared_ptr<spdlog::logger> l) {l->flush();});
 SPDLOG_API void apply_all(const std::function<void(std::shared_ptr<logger>)> &fun);
@@ -111,19 +116,19 @@ SPDLOG_API void shutdown();
 SPDLOG_API void set_automatic_registration(bool automatic_registration);
 
 // API for using default logger (stdout_color_mt),
-// e.g: spdlog::info("Message {}", 1);
+// e.g.: spdlog::info("Message {}", 1);
 //
 // The default logger object can be accessed using the spdlog::default_logger():
 // For example, to add another sink to it:
 // spdlog::default_logger()->sinks().push_back(some_sink);
 //
-// The default logger can replaced using spdlog::set_default_logger(new_logger).
+// The default logger can be replaced using spdlog::set_default_logger(new_logger).
 // For example, to replace it with a file logger.
 //
 // IMPORTANT:
 // The default API is thread safe (for _mt loggers), but:
 // set_default_logger() *should not* be used concurrently with the default API.
-// e.g do not call set_default_logger() from one thread while calling spdlog::info() from another.
+// e.g., do not call set_default_logger() from one thread while calling spdlog::info() from another.
 
 SPDLOG_API std::shared_ptr<spdlog::logger> default_logger();
 

include/spdlog/tweakme.h

@@ -104,6 +104,13 @@
 //
 // #define SPDLOG_LEVEL_NAMES { "MY TRACE", "MY DEBUG", "MY INFO", "MY WARNING", "MY ERROR", "MY
 // CRITICAL", "OFF" }
+//
+// For C++17 use string_view_literals:
+//
+// #include <string_view>
+// using namespace std::string_view_literals;
+// #define SPDLOG_LEVEL_NAMES { "MY TRACE"sv, "MY DEBUG"sv, "MY INFO"sv, "MY WARNING"sv, "MY
+// ERROR"sv, "MY CRITICAL"sv, "OFF"sv }
 ///////////////////////////////////////////////////////////////////////////////
 
 ///////////////////////////////////////////////////////////////////////////////

include/spdlog/version.h

@@ -4,8 +4,8 @@
 #pragma once
 
 #define SPDLOG_VER_MAJOR 1
-#define SPDLOG_VER_MINOR 14
+#define SPDLOG_VER_MINOR 16
-#define SPDLOG_VER_PATCH 1
+#define SPDLOG_VER_PATCH 0
 
 #define SPDLOG_TO_VERSION(major, minor, patch) (major * 10000 + minor * 100 + patch)
 #define SPDLOG_VERSION SPDLOG_TO_VERSION(SPDLOG_VER_MAJOR, SPDLOG_VER_MINOR, SPDLOG_VER_PATCH)

src/bundled_fmtlib_format.cpp

@@ -11,33 +11,35 @@
     #include <spdlog/fmt/bundled/format-inl.h>
 
 FMT_BEGIN_NAMESPACE
-namespace detail {
 
-template FMT_API auto dragonbox::to_decimal(float x) noexcept -> dragonbox::decimal_fp<float>;
+#if FMT_USE_LOCALE
-template FMT_API auto dragonbox::to_decimal(double x) noexcept -> dragonbox::decimal_fp<double>;
-
-    #ifndef FMT_STATIC_THOUSANDS_SEPARATOR
 template FMT_API locale_ref::locale_ref(const std::locale& loc);
 template FMT_API auto locale_ref::get<std::locale>() const -> std::locale;
-    #endif
+#endif
+
+namespace detail {
+
+template FMT_API auto dragonbox::to_decimal(float x) noexcept
+    -> dragonbox::decimal_fp<float>;
+template FMT_API auto dragonbox::to_decimal(double x) noexcept
+    -> dragonbox::decimal_fp<double>;
 
 // Explicit instantiations for char.
 
-template FMT_API auto thousands_sep_impl(locale_ref) -> thousands_sep_result<char>;
+template FMT_API auto thousands_sep_impl(locale_ref)
+    -> thousands_sep_result<char>;
 template FMT_API auto decimal_point_impl(locale_ref) -> char;
 
+// DEPRECATED!
 template FMT_API void buffer<char>::append(const char*, const char*);
 
-template FMT_API void vformat_to(buffer<char>&,
-                                 string_view,
-                                 typename vformat_args<>::type,
-                                 locale_ref);
-
 // Explicit instantiations for wchar_t.
 
-template FMT_API auto thousands_sep_impl(locale_ref) -> thousands_sep_result<wchar_t>;
+template FMT_API auto thousands_sep_impl(locale_ref)
+    -> thousands_sep_result<wchar_t>;
 template FMT_API auto decimal_point_impl(locale_ref) -> wchar_t;
 
+// DEPRECATED!
 template FMT_API void buffer<wchar_t>::append(const wchar_t*, const wchar_t*);
 
 }  // namespace detail

tests/CMakeLists.txt

@@ -19,9 +19,9 @@ if(Catch2_FOUND)
 else()
     message(STATUS "Bundled version of Catch will be downloaded and used.")
     include(FetchContent)
-    FetchContent_Declare(Catch2
+    FetchContent_Declare(
-            GIT_REPOSITORY https://github.com/catchorg/Catch2.git
+        Catch2 GIT_REPOSITORY https://github.com/catchorg/Catch2.git
-            GIT_TAG 53d0d913a422d356b23dd927547febdf69ee9081 # v3.5.0
+        GIT_TAG 53d0d913a422d356b23dd927547febdf69ee9081 # v3.5.0
     )
     FetchContent_MakeAvailable(Catch2)
 endif()
@@ -48,7 +48,9 @@ set(SPDLOG_UTESTS_SOURCES
     test_cfg.cpp
     test_time_point.cpp
     test_stopwatch.cpp
-    test_circular_q.cpp)
+    test_circular_q.cpp
+    test_bin_to_hex.cpp
+    test_ringbuffer.cpp)
 
 if(NOT SPDLOG_NO_EXCEPTIONS)
     list(APPEND SPDLOG_UTESTS_SOURCES test_errors.cpp)
@@ -58,10 +60,6 @@ if(systemd_FOUND)
     list(APPEND SPDLOG_UTESTS_SOURCES test_systemd.cpp)
 endif()
 
-if(NOT SPDLOG_USE_STD_FORMAT)
-    list(APPEND SPDLOG_UTESTS_SOURCES test_bin_to_hex.cpp)
-endif()
-
 enable_testing()
 
 function(spdlog_prepare_test test_target spdlog_lib)
@@ -73,9 +71,11 @@ function(spdlog_prepare_test test_target spdlog_lib)
     endif()
     target_link_libraries(${test_target} PRIVATE Catch2::Catch2WithMain)
     if(SPDLOG_SANITIZE_ADDRESS)
-        spdlog_enable_sanitizer(${test_target})
+        spdlog_enable_addr_sanitizer(${test_target})
+    elseif(SPDLOG_SANITIZE_THREAD)
+        spdlog_enable_thread_sanitizer(${test_target})
     endif()
-    add_test(NAME ${test_target} COMMAND ${test_target})
+    add_test(NAME ${test_target} COMMAND ${test_target} --order decl)
     set_tests_properties(${test_target} PROPERTIES RUN_SERIAL ON)
 endfunction()
 

tests/includes.h

@@ -26,7 +26,12 @@
 #include "spdlog/spdlog.h"
 #include "spdlog/async.h"
 #include "spdlog/details/fmt_helper.h"
-#include "spdlog/mdc.h"
+#include "spdlog/details/os.h"
+
+#ifndef SPDLOG_NO_TLS
+    #include "spdlog/mdc.h"
+#endif
+
 #include "spdlog/sinks/basic_file_sink.h"
 #include "spdlog/sinks/daily_file_sink.h"
 #include "spdlog/sinks/null_sink.h"

tests/test_async.cpp

@@ -93,50 +93,6 @@ TEST_CASE("flush", "[async]") {
     REQUIRE(test_sink->flush_counter() == 1);
 }
 
-TEST_CASE("multithread flush", "[async]") {
-    auto test_sink = std::make_shared<spdlog::sinks::test_sink_mt>();
-    size_t queue_size = 2;
-    size_t messages = 10;
-    size_t n_threads = 10;
-    size_t flush_count = 1024;
-    std::mutex mtx;
-    std::vector<std::string> errmsgs;
-    {
-        auto tp = std::make_shared<spdlog::details::thread_pool>(queue_size, 1);
-        auto logger = std::make_shared<spdlog::async_logger>(
-            "as", test_sink, tp, spdlog::async_overflow_policy::discard_new);
-
-        logger->set_error_handler([&](const std::string &) {
-            std::unique_lock<std::mutex> lock(mtx);
-            errmsgs.push_back("Broken promise");
-        });
-
-        for (size_t i = 0; i < messages; i++) {
-            logger->info("Hello message #{}", i);
-        }
-
-        std::vector<std::thread> threads;
-        for (size_t i = 0; i < n_threads; i++) {
-            threads.emplace_back([logger, flush_count] {
-                for (size_t j = 0; j < flush_count; j++) {
-                    // flush does not throw exception even if failed.
-                    // Instead, the error handler is invoked.
-                    logger->flush();
-                }
-            });
-        }
-
-        for (auto &t : threads) {
-            t.join();
-        }
-    }
-    REQUIRE(test_sink->flush_counter() >= 1);
-    REQUIRE(test_sink->flush_counter() + errmsgs.size() == n_threads * flush_count);
-    if (errmsgs.size() > 0) {
-        REQUIRE(errmsgs[0] == "Broken promise");
-    }
-}
-
 TEST_CASE("async periodic flush", "[async]") {
     auto logger = spdlog::create_async<spdlog::sinks::test_sink_mt>("as");
     auto test_sink = std::static_pointer_cast<spdlog::sinks::test_sink_mt>(logger->sinks()[0]);

tests/test_cfg.cpp

@@ -19,6 +19,15 @@ TEST_CASE("env", "[cfg]") {
 #endif
     load_env_levels();
     REQUIRE(l1->level() == spdlog::level::warn);
+
+#ifdef CATCH_PLATFORM_WINDOWS
+    _putenv_s("MYAPP_LEVEL", "l1=trace");
+#else
+    setenv("MYAPP_LEVEL", "l1=trace", 1);
+#endif
+    load_env_levels("MYAPP_LEVEL");
+    REQUIRE(l1->level() == spdlog::level::trace);
+
     spdlog::set_default_logger(spdlog::create<test_sink_st>("cfg-default"));
     REQUIRE(spdlog::default_logger()->level() == spdlog::level::info);
 }

tests/test_custom_callbacks.cpp

@@ -16,7 +16,9 @@ TEST_CASE("custom_callback_logger", "[custom_callback_logger]") {
             spdlog::memory_buf_t formatted;
             formatter.format(msg, formatted);
             auto eol_len = strlen(spdlog::details::os::default_eol);
-            lines.emplace_back(formatted.begin(), formatted.end() - eol_len);
+            using diff_t =
+                typename std::iterator_traits<decltype(formatted.end())>::difference_type;
+            lines.emplace_back(formatted.begin(), formatted.end() - static_cast<diff_t>(eol_len));
         });
     std::shared_ptr<spdlog::sinks::test_sink_st> test_sink(new spdlog::sinks::test_sink_st);
 

tests/test_daily_logger.cpp

@@ -46,12 +46,8 @@ TEST_CASE("daily_logger with dateonly calculator", "[daily_logger]") {
 
 struct custom_daily_file_name_calculator {
     static spdlog::filename_t calc_filename(const spdlog::filename_t &basename, const tm &now_tm) {
-        filename_memory_buf_t w;
+        return spdlog::fmt_lib::format(SPDLOG_FILENAME_T("{}{:04d}{:02d}{:02d}"), basename,
-        spdlog::fmt_lib::format_to(std::back_inserter(w), SPDLOG_FILENAME_T("{}{:04d}{:02d}{:02d}"),
+                                       now_tm.tm_year + 1900, now_tm.tm_mon + 1, now_tm.tm_mday);
-                                   basename, now_tm.tm_year + 1900, now_tm.tm_mon + 1,
-                                   now_tm.tm_mday);
-
-        return SPDLOG_BUF_TO_STRING(w);
     }
 };
 

tests/test_file_logging.cpp

@@ -45,6 +45,26 @@ TEST_CASE("flush_on", "[flush_on]") {
                                     default_eol, default_eol, default_eol));
 }
 
+TEST_CASE("simple_file_logger", "[truncate]") {
+    prepare_logdir();
+    const spdlog::filename_t filename = SPDLOG_FILENAME_T(SIMPLE_LOG);
+    const bool truncate = true;
+    const auto sink = std::make_shared<spdlog::sinks::basic_file_sink_mt>(filename, truncate);
+    const auto logger = std::make_shared<spdlog::logger>("simple_file_logger", sink);
+
+    logger->info("Test message {}", 3.14);
+    logger->info("Test message {}", 2.71);
+    logger->flush();
+    REQUIRE(count_lines(SIMPLE_LOG) == 2);
+
+    sink->truncate();
+    REQUIRE(count_lines(SIMPLE_LOG) == 0);
+
+    logger->info("Test message {}", 6.28);
+    logger->flush();
+    REQUIRE(count_lines(SIMPLE_LOG) == 1);
+}
+
 TEST_CASE("rotating_file_logger1", "[rotating_logger]") {
     prepare_logdir();
     size_t max_size = 1024 * 10;
@@ -74,14 +94,11 @@ TEST_CASE("rotating_file_logger2", "[rotating_logger]") {
         // next logger can rename the first output file.
         spdlog::drop(logger->name());
     }
-
     auto logger = spdlog::rotating_logger_mt("logger", basename, max_size, 2, true);
     for (int i = 0; i < 10; ++i) {
         logger->info("Test message {}", i);
     }
-
     logger->flush();
-
     require_message_count(ROTATING_LOG, 10);
 
     for (int i = 0; i < 1000; i++) {
@@ -101,3 +118,70 @@ TEST_CASE("rotating_file_logger3", "[rotating_logger]") {
     REQUIRE_THROWS_AS(spdlog::rotating_logger_mt("logger", basename, max_size, 0),
                       spdlog::spdlog_ex);
 }
+
+// test on-demand rotation of logs
+TEST_CASE("rotating_file_logger4", "[rotating_logger]") {
+    prepare_logdir();
+    size_t max_size = 1024 * 10;
+    spdlog::filename_t basename = SPDLOG_FILENAME_T(ROTATING_LOG);
+    auto sink = std::make_shared<spdlog::sinks::rotating_file_sink_st>(basename, max_size, 2);
+    auto logger = std::make_shared<spdlog::logger>("rotating_sink_logger", sink);
+
+    logger->info("Test message - pre-rotation");
+    logger->flush();
+
+    sink->rotate_now();
+
+    logger->info("Test message - post-rotation");
+    logger->flush();
+
+    REQUIRE(get_filesize(ROTATING_LOG) > 0);
+    REQUIRE(get_filesize(ROTATING_LOG ".1") > 0);
+}
+
+// test changing the max size of the rotating file sink
+TEST_CASE("rotating_file_logger5", "[rotating_logger]") {
+    prepare_logdir();
+    size_t max_size = 5 * 1024;
+    size_t max_files = 2;
+    spdlog::filename_t basename = SPDLOG_FILENAME_T(ROTATING_LOG);
+    auto sink =
+        std::make_shared<spdlog::sinks::rotating_file_sink_st>(basename, max_size, max_files);
+    auto logger = std::make_shared<spdlog::logger>("rotating_sink_logger", sink);
+    logger->set_pattern("%v");
+
+    REQUIRE(sink->get_max_size() == max_size);
+    REQUIRE(sink->get_max_files() == max_files);
+    max_size = 7 * 1024;
+    max_files = 3;
+
+    sink->set_max_size(max_size);
+    sink->set_max_files(max_files);
+    REQUIRE(sink->get_max_size() == max_size);
+    REQUIRE(sink->get_max_files() == max_files);
+
+    const auto message = std::string(200, 'x');
+    assert(message.size() < max_size);
+    const auto n_messages = max_files * max_size / message.size();
+    for (size_t i = 0; i < n_messages; ++i) {
+        logger->info(message);
+    }
+    logger.reset();  // force flush and close the file
+
+    // validate that the files were rotated correctly with the new max size and max files
+    for (size_t i = 0; i <= max_files; i++) {
+        // calc filenames
+        // e.g. rotating_log, rotating_log.0 rotating_log.1, rotating_log.2, etc.
+        std::ostringstream oss;
+        oss << ROTATING_LOG;
+        if (i > 0) {
+            oss << '.' << i;
+        }
+        const auto filename = oss.str();
+        const auto filesize = get_filesize(filename);
+        REQUIRE(filesize <= max_size);
+        if (i > 0) {
+            REQUIRE(filesize >= max_size - message.size() - 2);
+        }
+    }
+}

tests/test_misc.cpp

@@ -1,8 +1,12 @@
+#ifdef _WIN32  // to prevent fopen warning on windows
+    #define _CRT_SECURE_NO_WARNINGS
+#endif
+
 #include "includes.h"
 #include "test_sink.h"
 
 template <class T>
-std::string log_info(const T &what, spdlog::level::level_enum logger_level = spdlog::level::info) {
+std::string log_info(const T& what, spdlog::level::level_enum logger_level = spdlog::level::info) {
     std::ostringstream oss;
     auto oss_sink = std::make_shared<spdlog::sinks::ostream_sink_mt>(oss);
 
@@ -105,9 +109,9 @@ TEST_CASE("clone-logger", "[clone]") {
 }
 
 TEST_CASE("clone async", "[clone]") {
-    using spdlog::sinks::test_sink_st;
+    using spdlog::sinks::test_sink_mt;
     spdlog::init_thread_pool(4, 1);
-    auto test_sink = std::make_shared<test_sink_st>();
+    auto test_sink = std::make_shared<test_sink_mt>();
     auto logger = std::make_shared<spdlog::async_logger>("orig", test_sink, spdlog::thread_pool());
     logger->set_pattern("%v");
     auto cloned = logger->clone("clone");
@@ -167,3 +171,54 @@ TEST_CASE("default logger API", "[default logger]") {
     spdlog::drop_all();
     spdlog::set_pattern("%v");
 }
+
+#if (defined(SPDLOG_WCHAR_TO_UTF8_SUPPORT) || defined(SPDLOG_WCHAR_FILENAMES)) && defined(_WIN32)
+TEST_CASE("utf8 to utf16 conversion using windows api", "[windows utf]") {
+    spdlog::wmemory_buf_t buffer;
+
+    spdlog::details::os::utf8_to_wstrbuf("", buffer);
+    REQUIRE(std::wstring(buffer.data(), buffer.size()) == std::wstring(L""));
+
+    spdlog::details::os::utf8_to_wstrbuf("abc", buffer);
+    REQUIRE(std::wstring(buffer.data(), buffer.size()) == std::wstring(L"abc"));
+
+    spdlog::details::os::utf8_to_wstrbuf("\xc3\x28", buffer);  // Invalid UTF-8 sequence.
+    REQUIRE(std::wstring(buffer.data(), buffer.size()) == std::wstring(L"\xfffd("));
+
+    spdlog::details::os::utf8_to_wstrbuf("\xe3\x81\xad\xe3\x81\x93",
+                                         buffer);  // "Neko" in hiragana.
+    REQUIRE(std::wstring(buffer.data(), buffer.size()) == std::wstring(L"\x306d\x3053"));
+}
+#endif
+
+struct auto_closer {
+    FILE* fp = nullptr;
+    explicit auto_closer(FILE* f)
+        : fp(f) {}
+    auto_closer(const auto_closer&) = delete;
+    auto_closer& operator=(const auto_closer&) = delete;
+    ~auto_closer() {
+        if (fp != nullptr) (void)std::fclose(fp);
+    }
+};
+
+TEST_CASE("os::fwrite_bytes", "[os]") {
+    using spdlog::details::os::create_dir;
+    using spdlog::details::os::fwrite_bytes;
+    const char* filename = "log_tests/test_fwrite_bytes.txt";
+    const char* msg = "hello";
+    prepare_logdir();
+    REQUIRE(create_dir(SPDLOG_FILENAME_T("log_tests")) == true);
+    {
+        auto_closer closer(std::fopen(filename, "wb"));
+        REQUIRE(closer.fp != nullptr);
+        REQUIRE(fwrite_bytes(msg, std::strlen(msg), closer.fp) == true);
+        REQUIRE(fwrite_bytes(msg, 0, closer.fp) == true);
+        std::fflush(closer.fp);
+        REQUIRE(spdlog::details::os::filesize(closer.fp) == 5);
+    }
+    // fwrite_bytes should return false on write failure
+    auto_closer closer(std::fopen(filename, "r"));
+    REQUIRE(closer.fp != nullptr);
+    REQUIRE_FALSE(fwrite_bytes("Hello", 5, closer.fp));
+}

tests/test_pattern_formatter.cpp

@@ -1,6 +1,8 @@
 #include "includes.h"
 #include "test_sink.h"
 
+#include <chrono>
+
 using spdlog::memory_buf_t;
 using spdlog::details::to_string_view;
 
@@ -19,6 +21,23 @@ static std::string log_to_str(const std::string &msg, const Args &...args) {
     return oss.str();
 }
 
+// log to str and return it with time
+template <typename... Args>
+static std::string log_to_str_with_time(spdlog::log_clock::time_point log_time,
+                                        const std::string &msg,
+                                        const Args &...args) {
+    std::ostringstream oss;
+    auto oss_sink = std::make_shared<spdlog::sinks::ostream_sink_mt>(oss);
+    spdlog::logger oss_logger("pattern_tester", oss_sink);
+    oss_logger.set_level(spdlog::level::info);
+
+    oss_logger.set_formatter(
+        std::unique_ptr<spdlog::formatter>(new spdlog::pattern_formatter(args...)));
+
+    oss_logger.log(log_time, {}, spdlog::level::info, msg);
+    return oss.str();
+}
+
 TEST_CASE("custom eol", "[pattern_formatter]") {
     std::string msg = "Hello custom eol test";
     std::string eol = ";)";
@@ -58,6 +77,15 @@ TEST_CASE("date MM/DD/YY ", "[pattern_formatter]") {
             oss.str());
 }
 
+TEST_CASE("GMT offset ", "[pattern_formatter]") {
+    using namespace std::chrono_literals;
+    const auto now = std::chrono::system_clock::now();
+    const auto yesterday = now - 24h;
+
+    REQUIRE(log_to_str_with_time(yesterday, "Some message", "%z", spdlog::pattern_time_type::utc,
+                                 "\n") == "+00:00\n");
+}
+
 TEST_CASE("color range test1", "[pattern_formatter]") {
     auto formatter = std::make_shared<spdlog::pattern_formatter>(
         "%^%v%$", spdlog::pattern_time_type::local, "\n");
@@ -501,6 +529,7 @@ TEST_CASE("override need_localtime", "[pattern_formatter]") {
     }
 }
 
+#ifndef SPDLOG_NO_TLS
 TEST_CASE("mdc formatter test-1", "[pattern_formatter]") {
     spdlog::mdc::put("mdc_key_1", "mdc_value_1");
     spdlog::mdc::put("mdc_key_2", "mdc_value_2");
@@ -628,3 +657,4 @@ TEST_CASE("mdc empty", "[pattern_formatter]") {
 
     SECTION("Tear down") { spdlog::mdc::clear(); }
 }
+#endif

tests/test_registry.cpp

@@ -25,6 +25,19 @@ TEST_CASE("explicit register", "[registry]") {
 }
 #endif
 
+TEST_CASE("register_or_replace", "[registry]") {
+    spdlog::drop_all();
+    auto logger1 = std::make_shared<spdlog::logger>(
+        tested_logger_name, std::make_shared<spdlog::sinks::null_sink_st>());
+    spdlog::register_logger(logger1);
+    REQUIRE(spdlog::get(tested_logger_name) == logger1);
+
+    auto logger2 = std::make_shared<spdlog::logger>(
+        tested_logger_name, std::make_shared<spdlog::sinks::null_sink_st>());
+    spdlog::register_or_replace(logger2);
+    REQUIRE(spdlog::get(tested_logger_name) == logger2);
+}
+
 TEST_CASE("apply_all", "[registry]") {
     spdlog::drop_all();
     auto logger = std::make_shared<spdlog::logger>(tested_logger_name,

tests/test_ringbuffer.cpp

@@ -0,0 +1,52 @@
+#include "includes.h"
+#include "spdlog/sinks/ringbuffer_sink.h"
+
+TEST_CASE("ringbuffer invalid size", "[ringbuffer]") {
+    REQUIRE_THROWS_AS(spdlog::sinks::ringbuffer_sink_mt(0), spdlog::spdlog_ex);
+}
+
+TEST_CASE("ringbuffer stores formatted messages", "[ringbuffer]") {
+    spdlog::sinks::ringbuffer_sink_st sink(3);
+    sink.set_pattern("%v");
+
+    sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "msg1"});
+    sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "msg2"});
+    sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "msg3"});
+
+    auto formatted = sink.last_formatted();
+    REQUIRE(formatted.size() == 3);
+    using spdlog::details::os::default_eol;
+    REQUIRE(formatted[0] == spdlog::fmt_lib::format("msg1{}", default_eol));
+    REQUIRE(formatted[1] == spdlog::fmt_lib::format("msg2{}", default_eol));
+    REQUIRE(formatted[2] == spdlog::fmt_lib::format("msg3{}", default_eol));
+}
+
+TEST_CASE("ringbuffer overrun keeps last items", "[ringbuffer]") {
+    spdlog::sinks::ringbuffer_sink_st sink(2);
+    sink.set_pattern("%v");
+
+    sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "first"});
+    sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "second"});
+    sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "third"});
+
+    auto formatted = sink.last_formatted();
+    REQUIRE(formatted.size() == 2);
+    using spdlog::details::os::default_eol;
+    REQUIRE(formatted[0] == spdlog::fmt_lib::format("second{}", default_eol));
+    REQUIRE(formatted[1] == spdlog::fmt_lib::format("third{}", default_eol));
+}
+
+TEST_CASE("ringbuffer retrieval limit", "[ringbuffer]") {
+    spdlog::sinks::ringbuffer_sink_st sink(3);
+    sink.set_pattern("%v");
+
+    sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "A"});
+    sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "B"});
+    sink.log(spdlog::details::log_msg{"test", spdlog::level::info, "C"});
+
+    auto formatted = sink.last_formatted(2);
+    REQUIRE(formatted.size() == 2);
+    using spdlog::details::os::default_eol;
+    REQUIRE(formatted[0] == spdlog::fmt_lib::format("B{}", default_eol));
+    REQUIRE(formatted[1] == spdlog::fmt_lib::format("C{}", default_eol));
+}

tests/test_sink.h

@@ -47,8 +47,9 @@ protected:
         base_sink<Mutex>::formatter_->format(msg, formatted);
         // save the line without the eol
         auto eol_len = strlen(details::os::default_eol);
+        using diff_t = typename std::iterator_traits<decltype(formatted.end())>::difference_type;
         if (lines_.size() < lines_to_save) {
-            lines_.emplace_back(formatted.begin(), formatted.end() - eol_len);
+            lines_.emplace_back(formatted.begin(), formatted.end() - static_cast<diff_t>(eol_len));
         }
         msg_counter_++;
         std::this_thread::sleep_for(delay_);

tests/test_stopwatch.cpp

@@ -5,7 +5,7 @@
 TEST_CASE("stopwatch1", "[stopwatch]") {
     using std::chrono::milliseconds;
     using clock = std::chrono::steady_clock;
-    milliseconds wait_ms(200);
+    milliseconds wait_ms(500);
     milliseconds tolerance_ms(250);
     auto start = clock::now();
     spdlog::stopwatch sw;
@@ -22,7 +22,7 @@ TEST_CASE("stopwatch2", "[stopwatch]") {
     using std::chrono::milliseconds;
     using clock = std::chrono::steady_clock;
 
-    clock::duration wait_duration(milliseconds(200));
+    clock::duration wait_duration(milliseconds(500));
     clock::duration tolerance_duration(milliseconds(250));
 
     auto test_sink = std::make_shared<test_sink_st>();

tests/utils.cpp

@@ -50,9 +50,8 @@ void require_message_count(const std::string &filename, const std::size_t messag
 std::size_t get_filesize(const std::string &filename) {
     std::ifstream ifs(filename, std::ifstream::ate | std::ifstream::binary);
     if (!ifs) {
-        throw std::runtime_error("Failed open file ");
+        throw std::runtime_error("Failed open file " + filename);
     }
-
     return static_cast<std::size_t>(ifs.tellg());
 }