C++20 module support

.github/workflows/ci.yml

@@ -763,3 +763,315 @@ jobs:
 
       - name: Run tests
         run: ci/build.sh
+
+
+  posix-cmake-subdir-modules:
+    runs-on: ubuntu-latest
+    container: ubuntu:24.10
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install packages
+        run: |
+          export DEBIAN_FRONTEND=noninteractive
+          apt-get update
+          apt-get install -y --no-install-recommends ninja-build cmake git ca-certificates python3 python-is-python3 \
+            clang-19 llvm-19 libclang-rt-19-dev libc++-19-dev libc++abi-19-dev clang-tools-19
+
+      - name: Setup Boost
+        run: |
+          echo GITHUB_REPOSITORY: $GITHUB_REPOSITORY
+          LIBRARY=${GITHUB_REPOSITORY#*/}
+          echo LIBRARY: $LIBRARY
+          echo "LIBRARY=$LIBRARY" >> $GITHUB_ENV
+          echo GITHUB_BASE_REF: $GITHUB_BASE_REF
+          echo GITHUB_REF: $GITHUB_REF
+          REF=${GITHUB_BASE_REF:-$GITHUB_REF}
+          REF=${REF#refs/heads/}
+          echo REF: $REF
+          BOOST_BRANCH=develop && [ "$REF" == "master" ] && BOOST_BRANCH=master || true
+          echo BOOST_BRANCH: $BOOST_BRANCH
+          cd ..
+          git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          cp -r $GITHUB_WORKSPACE/* libs/$LIBRARY
+          git submodule update --init tools/boostdep
+          python tools/boostdep/depinst/depinst.py $LIBRARY
+          python libs/charconv/tools/setup_boost_with_modules.py # Temporary
+
+      - name: Use library with add_subdirectory
+        run: |
+          cd ../boost-root/libs/$LIBRARY/test/cmake_subdir_test
+          mkdir __build__ && cd __build__
+          cmake -DBOOST_USE_MODULES=1 -DCMAKE_C_COMPILER=clang-19 -DCMAKE_CXX_COMPILER=clang++-19 -DCMAKE_CXX_FLAGS=-stdlib=libc++ -DCMAKE_EXE_LINKER_FLAGS=-stdlib=libc++ -DCMAKE_CXX_STANDARD=23 -DCMAKE_EXPERIMENTAL_CXX_IMPORT_STD=0e5b6991-d74f-4b3d-a41c-cf096e0b2508 -G Ninja ..
+          cmake --build .
+          ctest --output-on-failure --no-tests=error
+
+  posix-cmake-install-modules:
+    env:
+      CMAKE_ARGS: -DCMAKE_CXX_COMPILER=clang++-19 -DCMAKE_CXX_FLAGS=-stdlib=libc++ -DCMAKE_EXE_LINKER_FLAGS=-stdlib=libc++ -DCMAKE_CXX_STANDARD=23 -DCMAKE_EXPERIMENTAL_CXX_IMPORT_STD=0e5b6991-d74f-4b3d-a41c-cf096e0b2508 -G Ninja
+
+    runs-on: ubuntu-latest
+    container: ubuntu:24.10
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install packages
+        run: |
+          export DEBIAN_FRONTEND=noninteractive
+          apt-get update
+          apt-get install -y --no-install-recommends ninja-build cmake git ca-certificates python3 python-is-python3 \
+            clang-19 llvm-19 libclang-rt-19-dev libc++-19-dev libc++abi-19-dev clang-tools-19
+
+      - name: Setup Boost
+        run: |
+          echo GITHUB_REPOSITORY: $GITHUB_REPOSITORY
+          LIBRARY=${GITHUB_REPOSITORY#*/}
+          echo LIBRARY: $LIBRARY
+          echo "LIBRARY=$LIBRARY" >> $GITHUB_ENV
+          echo GITHUB_BASE_REF: $GITHUB_BASE_REF
+          echo GITHUB_REF: $GITHUB_REF
+          REF=${GITHUB_BASE_REF:-$GITHUB_REF}
+          REF=${REF#refs/heads/}
+          echo REF: $REF
+          BOOST_BRANCH=develop && [ "$REF" == "master" ] && BOOST_BRANCH=master || true
+          echo BOOST_BRANCH: $BOOST_BRANCH
+          cd ..
+          git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          cp -r $GITHUB_WORKSPACE/* libs/$LIBRARY
+          git submodule update --init tools/boostdep
+          python tools/boostdep/depinst/depinst.py $LIBRARY
+          python libs/charconv/tools/setup_boost_with_modules.py # Temporary
+
+      - name: Configure
+        run: |
+          cd ../boost-root
+          mkdir __build__ && cd __build__
+          cmake -DBOOST_INCLUDE_LIBRARIES=$LIBRARY -DCMAKE_INSTALL_PREFIX=~/.local -DBOOST_USE_MODULES=1 \
+            -DCMAKE_C_COMPILER=clang-19 $CMAKE_ARGS ..
+
+      - name: Install
+        run: |
+          cd ../boost-root/__build__
+          cmake --build . --target install
+
+      - name: Use the installed library
+        run: |
+          cd ../boost-root/libs/$LIBRARY/test/cmake_install_test && mkdir __build__ && cd __build__
+          cmake -DCMAKE_INSTALL_PREFIX=~/.local $CMAKE_ARGS ..
+          cmake --build .
+          ctest --output-on-failure --no-tests=error
+
+  posix-cmake-test-modules:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - cmake-build-type: Debug
+          - cmake-build-type: Release
+
+    runs-on: ubuntu-latest
+    container: ubuntu:24.10
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install packages
+        run: |
+          export DEBIAN_FRONTEND=noninteractive
+          apt-get update
+          apt-get install -y --no-install-recommends ninja-build cmake git ca-certificates python3 python-is-python3 \
+            clang-19 llvm-19 libclang-rt-19-dev libc++-19-dev libc++abi-19-dev clang-tools-19
+
+      - name: Setup Boost
+        run: |
+          echo GITHUB_REPOSITORY: $GITHUB_REPOSITORY
+          LIBRARY=${GITHUB_REPOSITORY#*/}
+          echo LIBRARY: $LIBRARY
+          echo "LIBRARY=$LIBRARY" >> $GITHUB_ENV
+          echo GITHUB_BASE_REF: $GITHUB_BASE_REF
+          echo GITHUB_REF: $GITHUB_REF
+          REF=${GITHUB_BASE_REF:-$GITHUB_REF}
+          REF=${REF#refs/heads/}
+          echo REF: $REF
+          BOOST_BRANCH=develop && [ "$REF" == "master" ] && BOOST_BRANCH=master || true
+          echo BOOST_BRANCH: $BOOST_BRANCH
+          cd ..
+          git clone -b $BOOST_BRANCH --depth 1 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          cp -r $GITHUB_WORKSPACE/* libs/$LIBRARY
+          git submodule update --init tools/boostdep
+          python3 tools/boostdep/depinst/depinst.py $LIBRARY
+          python3 libs/charconv/tools/setup_boost_with_modules.py # Temporary
+
+      - name: Configure
+        run: |
+          cd ../boost-root
+          mkdir __build__ && cd __build__
+          cmake -DBOOST_INCLUDE_LIBRARIES=$LIBRARY -DBUILD_TESTING=ON -DCMAKE_BUILD_TYPE=${{matrix.cmake-build-type}} -DBOOST_USE_MODULES=1 -DCMAKE_C_COMPILER=clang-19 -DCMAKE_CXX_COMPILER=clang++-19 -DCMAKE_CXX_FLAGS=-stdlib=libc++ -DCMAKE_EXE_LINKER_FLAGS=-stdlib=libc++ -DCMAKE_CXX_STANDARD=23 -DCMAKE_EXPERIMENTAL_CXX_IMPORT_STD=0e5b6991-d74f-4b3d-a41c-cf096e0b2508 -G Ninja ..
+
+      - name: Build tests
+        run: |
+          cd ../boost-root/__build__
+          cmake --build . --target tests
+
+      - name: Run tests
+        run: |
+          cd ../boost-root/__build__
+          ctest --output-on-failure --no-tests=error
+
+  windows-cmake-subdir-modules:
+    runs-on: windows-2022
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install packages
+        run: choco install --no-progress ninja
+
+      - name: Setup Boost
+        shell: cmd
+        run: |
+          echo GITHUB_REPOSITORY: %GITHUB_REPOSITORY%
+          for /f %%i in ("%GITHUB_REPOSITORY%") do set LIBRARY=%%~nxi
+          echo LIBRARY: %LIBRARY%
+          echo LIBRARY=%LIBRARY%>>%GITHUB_ENV%
+          echo GITHUB_BASE_REF: %GITHUB_BASE_REF%
+          echo GITHUB_REF: %GITHUB_REF%
+          if "%GITHUB_BASE_REF%" == "" set GITHUB_BASE_REF=%GITHUB_REF%
+          set BOOST_BRANCH=develop
+          for /f %%i in ("%GITHUB_BASE_REF%") do if "%%~nxi" == "master" set BOOST_BRANCH=master
+          echo BOOST_BRANCH: %BOOST_BRANCH%
+          cd ..
+          git clone -b %BOOST_BRANCH% --depth 1 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          xcopy /s /e /q %GITHUB_WORKSPACE% libs\%LIBRARY%\
+          git submodule update --init tools/boostdep
+          python tools/boostdep/depinst/depinst.py --git_args "--jobs 3" %LIBRARY%
+          python libs/charconv/tools/setup_boost_with_modules.py # Temporary
+
+      - name: Use library with add_subdirectory
+        shell: cmd
+        run: |
+          call "C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Auxiliary/Build/vcvarsall.bat" x64
+          cd ../boost-root/libs/%LIBRARY%/test/cmake_subdir_test
+          mkdir __build__ && cd __build__
+          cmake -DBOOST_USE_MODULES=1 -DCMAKE_CXX_STANDARD=23 -DCMAKE_EXPERIMENTAL_CXX_IMPORT_STD=0e5b6991-d74f-4b3d-a41c-cf096e0b2508 -G Ninja ..
+          cmake --build .
+          ctest --output-on-failure --no-tests=error
+
+  windows-cmake-install-modules:
+    runs-on: windows-2022
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install packages
+        run: choco install --no-progress ninja
+
+      - name: Setup Boost
+        shell: cmd
+        run: |
+          echo GITHUB_REPOSITORY: %GITHUB_REPOSITORY%
+          for /f %%i in ("%GITHUB_REPOSITORY%") do set LIBRARY=%%~nxi
+          echo LIBRARY: %LIBRARY%
+          echo LIBRARY=%LIBRARY%>>%GITHUB_ENV%
+          echo GITHUB_BASE_REF: %GITHUB_BASE_REF%
+          echo GITHUB_REF: %GITHUB_REF%
+          if "%GITHUB_BASE_REF%" == "" set GITHUB_BASE_REF=%GITHUB_REF%
+          set BOOST_BRANCH=develop
+          for /f %%i in ("%GITHUB_BASE_REF%") do if "%%~nxi" == "master" set BOOST_BRANCH=master
+          echo BOOST_BRANCH: %BOOST_BRANCH%
+          cd ..
+          git clone -b %BOOST_BRANCH% --depth 1 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          xcopy /s /e /q %GITHUB_WORKSPACE% libs\%LIBRARY%\
+          git submodule update --init tools/boostdep
+          python tools/boostdep/depinst/depinst.py --git_args "--jobs 3" %LIBRARY%
+          python libs/charconv/tools/setup_boost_with_modules.py # Temporary
+
+      - name: Configure
+        shell: cmd
+        run: |
+          call "C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Auxiliary/Build/vcvarsall.bat" x64
+          cd ../boost-root
+          mkdir __build__ && cd __build__
+          cmake -DBOOST_INCLUDE_LIBRARIES=%LIBRARY% -DCMAKE_INSTALL_PREFIX=C:/cmake-prefix -DBOOST_USE_MODULES=1 -DCMAKE_CXX_STANDARD=23 -DCMAKE_EXPERIMENTAL_CXX_IMPORT_STD=0e5b6991-d74f-4b3d-a41c-cf096e0b2508 -G Ninja ..
+
+      - name: Install
+        shell: cmd
+        run: |
+          call "C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Auxiliary/Build/vcvarsall.bat" x64
+          cd ../boost-root/__build__
+          cmake --build . --target install
+
+      - name: Use the installed library
+        shell: cmd
+        run: |
+          call "C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Auxiliary/Build/vcvarsall.bat" x64
+          cd ../boost-root/libs/%LIBRARY%/test/cmake_install_test && mkdir __build__ && cd __build__
+          cmake -DCMAKE_INSTALL_PREFIX=C:/cmake-prefix -DCMAKE_CXX_STANDARD=23 -DCMAKE_EXPERIMENTAL_CXX_IMPORT_STD=0e5b6991-d74f-4b3d-a41c-cf096e0b2508 -G Ninja ..
+          cmake --build .
+          ctest --output-on-failure --no-tests=error
+
+  windows-cmake-test-modules:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - cmake-build-type: Debug
+          - cmake-build-type: Release
+
+    runs-on: windows-2022
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Install packages
+        run: choco install --no-progress ninja
+
+      - name: Setup Boost
+        shell: cmd
+        run: |
+          echo GITHUB_REPOSITORY: %GITHUB_REPOSITORY%
+          for /f %%i in ("%GITHUB_REPOSITORY%") do set LIBRARY=%%~nxi
+          echo LIBRARY: %LIBRARY%
+          echo LIBRARY=%LIBRARY%>>%GITHUB_ENV%
+          echo GITHUB_BASE_REF: %GITHUB_BASE_REF%
+          echo GITHUB_REF: %GITHUB_REF%
+          if "%GITHUB_BASE_REF%" == "" set GITHUB_BASE_REF=%GITHUB_REF%
+          set BOOST_BRANCH=develop
+          for /f %%i in ("%GITHUB_BASE_REF%") do if "%%~nxi" == "master" set BOOST_BRANCH=master
+          echo BOOST_BRANCH: %BOOST_BRANCH%
+          cd ..
+          git clone -b %BOOST_BRANCH% --depth 1 https://github.com/boostorg/boost.git boost-root
+          cd boost-root
+          xcopy /s /e /q %GITHUB_WORKSPACE% libs\%LIBRARY%\
+          git submodule update --init tools/boostdep
+          python tools/boostdep/depinst/depinst.py --git_args "--jobs 3" %LIBRARY%
+          python libs/charconv/tools/setup_boost_with_modules.py # Temporary
+
+      - name: Configure
+        shell: cmd
+        run: |
+          call "C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Auxiliary/Build/vcvarsall.bat" x64
+          cd ../boost-root
+          mkdir __build__ && cd __build__
+          cmake -DBOOST_INCLUDE_LIBRARIES=%LIBRARY% -DBUILD_TESTING=ON -DBOOST_USE_MODULES=1 -DCMAKE_CXX_STANDARD=23 -DCMAKE_EXPERIMENTAL_CXX_IMPORT_STD=0e5b6991-d74f-4b3d-a41c-cf096e0b2508 -DCMAKE_BUILD_TYPE=${{matrix.cmake-build-type}} -G Ninja  ..
+
+      - name: Build tests
+        shell: cmd
+        run: |
+          call "C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Auxiliary/Build/vcvarsall.bat" x64
+          cd ../boost-root/__build__
+          cmake --build . --target tests
+
+      - name: Run tests
+        shell: cmd
+        run: |
+          call "C:/Program Files/Microsoft Visual Studio/2022/Enterprise/VC/Auxiliary/Build/vcvarsall.bat" x64
+          cd ../boost-root/__build__
+          ctest --output-on-failure --no-tests=error

CMakeLists.txt

@@ -3,7 +3,7 @@
 # Distributed under the Boost Software License, Version 1.0.
 # https://www.boost.org/LICENSE_1_0.txt
 
-cmake_minimum_required(VERSION 3.8...3.20)
+cmake_minimum_required(VERSION 3.8...3.31)
 
 project(boost_charconv VERSION "${BOOST_SUPERPROJECT_VERSION}" LANGUAGES CXX)
 
@@ -14,6 +14,15 @@ add_library(boost_charconv
 
 add_library(Boost::charconv ALIAS boost_charconv)
 
+if (BOOST_USE_MODULES)
+  target_sources(boost_charconv PUBLIC FILE_SET CXX_MODULES BASE_DIRS modules FILES modules/boost_charconv.cppm)
+
+  # Enable and propagate C++23, import std, and the modules macro
+  target_compile_features(boost_charconv PUBLIC cxx_std_23)
+  set_target_properties(boost_charconv PROPERTIES CXX_MODULE_STD 1)
+  target_compile_definitions(boost_charconv PUBLIC BOOST_USE_MODULES)
+endif()
+
 target_include_directories(boost_charconv PUBLIC include)
 
 

include/boost/charconv/config.hpp

@@ -6,8 +6,10 @@
 // Distributed under the Boost Software License, Version 1.0.
 // https://www.boost.org/LICENSE_1_0.txt
 
+#ifndef BOOST_USE_MODULES
 #include <boost/config.hpp>
 #include <climits>
+#endif
 
 // This header implements separate compilation features as described in
 // http://www.boost.org/more/separate_compilation.html

include/boost/charconv/detail/apply_sign.hpp

@@ -5,10 +5,13 @@
 #ifndef BOOST_CHARCONV_DETAIL_APPLY_SIGN_HPP
 #define BOOST_CHARCONV_DETAIL_APPLY_SIGN_HPP
 
-#include <boost/config.hpp>
 #include <boost/charconv/detail/emulated128.hpp>
 #include <boost/charconv/detail/type_traits.hpp>
+#ifndef BOOST_USE_MODULES
+#include <boost/config.hpp>
 #include <type_traits>
+#endif
+
 
 // We are purposefully converting values here
 #ifdef BOOST_MSVC

include/boost/charconv/detail/bit_layouts.hpp

@@ -7,8 +7,11 @@
 
 #include <boost/charconv/detail/config.hpp>
 #include <boost/charconv/detail/emulated128.hpp>
+#ifndef BOOST_USE_MODULES
 #include <cstdint>
 #include <cfloat>
+#endif
+
 
 // Layouts of floating point types as specified by IEEE 754
 // See page 23 of IEEE 754-2008

include/boost/charconv/detail/buffer_sizing.hpp

@@ -7,7 +7,10 @@
 
 #include <boost/charconv/detail/config.hpp>
 #include <boost/charconv/detail/integer_search_trees.hpp>
+#ifndef BOOST_USE_MODULES
 #include <type_traits>
+#endif
+
 
 namespace boost {
 namespace charconv {