Add: Test compilation as C++20 on CI

fastgltf uses many features of C++20 conditionally, and this now adds CI tests to verify their usage

.github/workflows/ci_x64.yml

@@ -17,6 +17,9 @@ env:
 
 jobs:
   build_windows:
+    strategy:
+      matrix:
+        cpp20: [NO, YES]
     runs-on: windows-latest
     steps:
       - uses: actions/checkout@v3
@@ -38,13 +41,13 @@ jobs:
         run: git clone https://github.com/KhronosGroup/glTF-Sample-Models ${{ github.workspace }}/${{ env.SAMPLE_MODELS_LOCATION }}
 
       - name: Configure CMake
-        run: cmake -B ${{ github.workspace }}/build -DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }} -DFASTGLTF_ENABLE_TESTS=ON
+        run: cmake -B ${{ github.workspace }}/build -DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }} -DFASTGLTF_ENABLE_TESTS=ON -DFASTGLTF_COMPILE_AS_CPP20=${{ matrix.cpp20 }}
 
       - name: Build (Windows)
         run: cmake --build ${{ github.workspace }}/build --config ${{ env.BUILD_TYPE }} --target tests/fastgltf_tests --verbose
 
       - name: Run tests
-        run: ${{ github.workspace }}\build\tests\Release\fastgltf_tests.exe -d yes --order lex [base64],[gltf-loader],[gltf-tools],[uri-tests],[vector-tests]
+        run: ${{ github.workspace }}\build\tests\Release\fastgltf_tests.exe -d yes --order lex ~[gltf-benchmark]
 
   build_windows_deprecated_extensions:
     runs-on: windows-latest
@@ -74,12 +77,16 @@ jobs:
         run: cmake --build ${{ github.workspace }}/build --config ${{ env.BUILD_TYPE }} --target tests/fastgltf_tests --verbose
 
       - name: Run tests
-        run: ${{ github.workspace }}\build\tests\Release\fastgltf_tests.exe -d yes --order lex [base64],[gltf-loader],[gltf-tools],[uri-tests],[vector-tests]
+        run: ${{ github.workspace }}\build\tests\Release\fastgltf_tests.exe -d yes --order lex ~[gltf-benchmark]
 
   build_linux:
     strategy:
       matrix:
         c_compiler: [gcc-9, gcc-10, clang-13]
+        cpp20: [NO, YES]
+        exclude:
+          - c_compiler: gcc-9
+            cpp20: YES
         include:
           - cxx_compiler: g++-9
             c_compiler: gcc-9
@@ -116,13 +123,13 @@ jobs:
         run: sudo apt-get install -y libxrandr-dev libxinerama-dev libx11-dev libxcursor-dev libxi-dev
 
       - name: Configure CMake
-        run: cmake -B ${{ github.workspace }}/build -DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }} -DFASTGLTF_ENABLE_TESTS=ON
+        run: cmake -B ${{ github.workspace }}/build -DCMAKE_BUILD_TYPE=${{ env.BUILD_TYPE }} -DFASTGLTF_ENABLE_TESTS=ON -DFASTGLTF_COMPILE_AS_CPP20=${{ matrix.cpp20 }}
 
       - name: Build
         run: cmake --build ${{ github.workspace }}/build --config ${{ env.BUILD_TYPE }} --target fastgltf_tests --verbose
 
       - name: Run tests
-        run: ${{ github.workspace }}/build/tests/fastgltf_tests -d yes --order lex [base64],[gltf-loader],[gltf-tools],[uri-tests],[vector-tests]
+        run: ${{ github.workspace }}/build/tests/fastgltf_tests -d yes --order lex ~[gltf-benchmark]
 
   build_linux_deprecated_extensions:
     strategy:
@@ -170,4 +177,4 @@ jobs:
         run: cmake --build ${{ github.workspace }}/build --config ${{ env.BUILD_TYPE }} --target fastgltf_tests --verbose
 
       - name: Run tests
-        run: ${{ github.workspace }}/build/tests/fastgltf_tests -d yes --order lex [base64],[gltf-loader],[gltf-tools],[uri-tests],[vector-tests]
+        run: ${{ github.workspace }}/build/tests/fastgltf_tests -d yes --order lex ~[gltf-benchmark]

CMakeLists.txt

@@ -17,6 +17,13 @@ option(FASTGLTF_ENABLE_ASSIMP "Enables the benchmark usage of assimp" OFF)
 option(FASTGLTF_ENABLE_DEPRECATED_EXT "Enables support for deprecated extensions" OFF)
 option(FASTGLTF_DISABLE_CUSTOM_MEMORY_POOL "Disables the memory allocation algorithm based on polymorphic resources" OFF)
 option(FASTGLTF_USE_64BIT_FLOAT "Default to 64-bit double precision floats for everything" OFF)
+option(FASTGLTF_COMPILE_AS_CPP20 "Have the library compile as C++20" OFF)
+
+if (FASTGLTF_COMPILE_AS_CPP20)
+    set(FASTGLTF_COMPILE_TARGET cxx_std_20)
+else()
+    set(FASTGLTF_COMPILE_TARGET cxx_std_17)
+endif()
 
 include(${CMAKE_CURRENT_SOURCE_DIR}/cmake/add_source_directory.cmake)
 include(${CMAKE_CURRENT_SOURCE_DIR}/cmake/compiler_flags.cmake)
@@ -29,7 +36,7 @@ add_library(fastgltf::fastgltf ALIAS fastgltf)
 
 fastgltf_compiler_flags(fastgltf)
 fastgltf_enable_debug_inlining(fastgltf)
-target_compile_features(fastgltf PUBLIC cxx_std_17)
+target_compile_features(fastgltf PUBLIC ${FASTGLTF_COMPILE_TARGET})
 target_include_directories(fastgltf PUBLIC $<BUILD_INTERFACE:${CMAKE_CURRENT_LIST_DIR}/include> $<INSTALL_INTERFACE:include>)
 
 set_target_properties(fastgltf PROPERTIES WINDOWS_EXPORT_ALL_SYMBOLS YES)

docs/options.rst

@@ -73,6 +73,12 @@ When this ``BOOL`` option is set to ``YES`` fastgltf will use `corrosion`_, whic
 to link against the `gltf-rs`_ Rust library for comparison within the benchmarks.
 Note that this option has no effect when ``FASTGLTF_ENABLE_TESTS`` is set to ``NO``.
 
+``FASTGLTF_COMPILE_AS_CPP20``
+-----------------------------
+
+This ``BOOL`` option controls the C++ standard the library is compiled as. When ``NO`` fastgltf is always compiled as C++17.
+When ``YES`` fastgltf is compiled as C++20, including the tests.
+
 
 Parsing options
 ===============

tests/CMakeLists.txt

@@ -4,7 +4,7 @@ set_directory_properties(PROPERTIES EXCLUDE_FROM_ALL TRUE)
 add_executable(fastgltf_tests EXCLUDE_FROM_ALL
     "base64_tests.cpp" "basic_test.cpp" "benchmarks.cpp" "glb_tests.cpp" "gltf_path.hpp"
     "vector_tests.cpp" "uri_tests.cpp" "extension_tests.cpp" "accessor_tests.cpp" "write_tests.cpp")
-target_compile_features(fastgltf_tests PRIVATE cxx_std_17)
+target_compile_features(fastgltf_tests PRIVATE ${FASTGLTF_COMPILE_TARGET})
 target_link_libraries(fastgltf_tests PRIVATE fastgltf)
 target_link_libraries(fastgltf_tests PRIVATE glm::glm Catch2::Catch2WithMain)
 fastgltf_compiler_flags(fastgltf_tests)

tests/basic_test.cpp

@@ -578,9 +578,9 @@ TEST_CASE("Test unicode characters", "[gltf-loader]") {
 	REQUIRE(fastgltf::validate(asset.get()) == fastgltf::Error::None);
 
 	REQUIRE(!asset->materials.empty());
-	REQUIRE(asset->materials[0].name == u8"Unicode❤♻Material");
+	REQUIRE(asset->materials[0].name == reinterpret_cast<const char*>(u8"Unicode❤♻Material"));
 
 	REQUIRE(!asset->buffers.empty());
 	auto bufferUri = std::get<fastgltf::sources::URI>(asset->buffers[0].data);
-	REQUIRE(bufferUri.uri.path() == u8"Unicode❤♻Binary.bin");
+	REQUIRE(bufferUri.uri.path() == reinterpret_cast<const char*>(u8"Unicode❤♻Binary.bin"));
 }