Merge pull request #483 from SCOREC/yus/upgrade_cxx

Enable cxx standard 20 test cases in CI test matrix

Author: cwsmith

.github/workflows/cmake.yml

@@ -16,6 +16,7 @@ jobs:
           - { name: LLVM, CC: clang, CXX: clang++ }
         build_type: [Debug, Release]
         no_mpi: [OFF, ON]
+        cxx_standard: [11, 20]
 
     steps:
     - uses: actions/checkout@v4
@@ -31,7 +32,7 @@ jobs:
       env:
         MPICH_CXX: ${{matrix.compiler.CXX}}
         MPICH_CC: ${{matrix.compiler.CC}}
-      run: cmake -S ${{github.workspace}} -B ${{github.workspace}}/build -DCMAKE_CXX_COMPILER=mpicxx -DCMAKE_C_COMPILER=mpicc -DCMAKE_VERBOSE_MAKEFILE=ON -DMESHES=${{github.workspace}}/pumi-meshes -DIS_TESTING=ON -DSCOREC_CXX_WARNINGS=ON -DCMAKE_BUILD_TYPE=${{matrix.build_type}} -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/build/install -DSCOREC_NO_MPI=${{matrix.no_mpi}}
+      run: cmake -S ${{github.workspace}} -B ${{github.workspace}}/build -DCMAKE_CXX_COMPILER=mpicxx -DCMAKE_C_COMPILER=mpicc -DCMAKE_CXX_STANDARD=${{matrix.cxx_standard}} -DCMAKE_VERBOSE_MAKEFILE=ON -DMESHES=${{github.workspace}}/pumi-meshes -DIS_TESTING=ON -DSCOREC_CXX_WARNINGS=ON -DCMAKE_BUILD_TYPE=${{matrix.build_type}} -DCMAKE_INSTALL_PREFIX=${{github.workspace}}/build/install -DSCOREC_NO_MPI=${{matrix.no_mpi}}
 
     - name: Build
       env: