[BUILD] Introduce CXX 20 CI pipeline for MSVC/Windows

.github/workflows/ci.yml

@@ -202,6 +202,22 @@ jobs:
     - name: run tests
       run: ./ci/do_ci.ps1 cmake.maintainer.test
 
+  cmake_msvc_maintainer_test_stl_cxx20:
+    name: CMake msvc (maintainer mode) with C++20
+    runs-on: windows-latest
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        submodules: 'recursive'
+    - name: setup
+      run: |
+        ./ci/setup_windows_cmake.ps1
+        ./ci/setup_windows_ci_environment.ps1
+    - name: run tests
+      env:
+        CXX_STANDARD: '20'
+      run: ./ci/do_ci.ps1 cmake.maintainer.cxx20.stl.test
+
   cmake_with_async_export_test:
     name: CMake test (without otlp-exporter and with async export)
     runs-on: ubuntu-latest

CHANGELOG.md

@@ -19,6 +19,8 @@ Increment the:
   [#2435](https://github.com/open-telemetry/opentelemetry-cpp/pull/2435)
 * [BUILD] Fix removing of NOMINMAX on Windows
   [#2449](https://github.com/open-telemetry/opentelemetry-cpp/pull/2449)
+* [BUILD] Introduce CXX 20 CI pipeline for MSVC/Windows
+  [#2450](https://github.com/open-telemetry/opentelemetry-cpp/pull/2450)
 
 Important changes:
 

api/test/nostd/string_view_test.cc

@@ -71,8 +71,8 @@ TEST(StringViewTest, SubstrPortion)
 TEST(StringViewTest, SubstrOutOfRange)
 {
   string_view s = "abc123";
-#if __EXCEPTIONS || ((defined(OPENTELEMETRY_STL_VERSION) && (OPENTELEMETRY_STL_VERSION >= 2020)))
-  EXPECT_THROW(s.substr(10), std::out_of_range);
+#if __EXCEPTIONS || (defined(OPENTELEMETRY_STL_VERSION) && (OPENTELEMETRY_STL_VERSION >= 2017))
+  EXPECT_THROW((void)s.substr(10), std::out_of_range);
 #else
   EXPECT_DEATH({ s.substr(10); }, "");
 #endif

api/test/nostd/variant_test.cc

@@ -48,7 +48,7 @@ TEST(VariantTest, Get)
   EXPECT_EQ(nostd::get<int>(w), 12);
   EXPECT_EQ(*nostd::get_if<int>(&v), 12);
   EXPECT_EQ(nostd::get_if<float>(&v), nullptr);
-#if __EXCEPTIONS
+#if __EXCEPTIONS || (defined(OPENTELEMETRY_STL_VERSION) && (OPENTELEMETRY_STL_VERSION >= 2017))
   EXPECT_THROW(nostd::get<float>(w), nostd::bad_variant_access);
 #else
   EXPECT_DEATH({ nostd::get<float>(w); }, "");

ci/do_ci.ps1

@@ -112,6 +112,30 @@ switch ($action) {
       exit $exit
     }
   }
+  "cmake.maintainer.cxx20.stl.test" {
+    cd "$BUILD_DIR"
+    cmake $SRC_DIR `
+      -DWITH_STL=CXX20 `
+      -DCMAKE_CXX_STANDARD=20 `
+      -DOTELCPP_MAINTAINER_MODE=ON `
+      -DWITH_NO_DEPRECATED_CODE=ON `
+      -DVCPKG_TARGET_TRIPLET=x64-windows `
+      "-DCMAKE_TOOLCHAIN_FILE=$VCPKG_DIR/scripts/buildsystems/vcpkg.cmake"
+    $exit = $LASTEXITCODE
+    if ($exit -ne 0) {
+      exit $exit
+    }
+    cmake --build . -j $nproc
+    $exit = $LASTEXITCODE
+    if ($exit -ne 0) {
+      exit $exit
+    }
+    ctest -C Debug
+    $exit = $LASTEXITCODE
+    if ($exit -ne 0) {
+      exit $exit
+    }
+  }
   "cmake.with_async_export.test" {
     cd "$BUILD_DIR"
     cmake $SRC_DIR `