ci: Add clang builds & C++17

.github/workflows/ci.yml

@@ -60,22 +60,90 @@ jobs:
     - name: Prepare env
       run: python -m pip install -r tests/requirements.txt
 
-    - name: Configure
+    - name: Configure C++11
       shell: bash
       run: >
+        cmake --version &&
         cmake -S . -B build
         -DPYBIND11_WERROR=ON
         -DDOWNLOAD_CATCH=ON
+        -DCMAKE_CXX_STANDARD=11
         -DPYTHON_EXECUTABLE=$(python -c "import sys; print(sys.executable)")
 
+    - name: Build C++11
+      run: cmake --build build -j 2
+
+    - name: Python tests C++11
+      run: cmake --build build --target pytest -j 2 -v
+
+    - name: C++11 tests
+      run: cmake --build build --target cpptest -j 2 -v
+
+    - name: Interface test C++11
+      run: cmake --build build --target test_cmake_build
+
+    - name: Configure C++17
+      shell: bash
+      run: >
+        cmake -S . -B build17
+        -DPYBIND17_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DCMAKE_CXX_STANDARD=17
+        -DPYTHON_EXECUTABLE=$(python -c "import sys; print(sys.executable)")
+
+    - name: Build C++17
+      run: cmake --build build17 -j 2
+
+    - name: Python tests C++17
+      run: cmake --build build17 --target pytest
+
+    - name: C++17 tests
+      run: cmake --build build17 --target cpptest
+
+    - name: Interface test C++17
+      run: cmake --build build17 --target test_cmake_build
+
+  clang:
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        clang:
+          - 3.6
+          - 3.7
+          - 3.8
+          - 3.9
+          - 5
+          - 7
+          - 9
+          - dev
+
+    name: Clang ${{ matrix.clang }}
+    container: "silkeh/clang:${{ matrix.clang }}"
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Add wget and python3
+      run: apt-get update && apt-get install -y python3-dev python3-numpy python3-pytest
+
+    - name: Configure
+      shell: bash
+      run: >
+        cmake --version &&
+        cmake -S . -B build
+        -DPYBIND11_WERROR=ON
+        -DDOWNLOAD_CATCH=ON
+        -DPYTHON_EXECUTABLE=$(python3 -c "import sys; print(sys.executable)")
+
     - name: Build
       run: cmake --build build -j 2
 
     - name: Python tests
-      run: cmake --build build --target pytest -j 2 -v
+      run: cmake --build build --target pytest
 
     - name: C++ tests
-      run: cmake --build build --target cpptest -j 2 -v
+      run: cmake --build build --target cpptest
 
     - name: Interface test
       run: cmake --build build --target test_cmake_build