add Windows CI

.github/workflows/macos.yml

@@ -22,7 +22,7 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [macos-10.15]
+        os: []
         compiler: [clang++, gcc-8, gcc-9, gcc-10]
 
     steps:

.github/workflows/windows.yml

@@ -0,0 +1,54 @@
+name: Windows CI
+
+on:
+  push:
+    branches:
+    - master
+    - sphinx
+  pull_request:
+    branches:
+    - master
+
+env:
+  # Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)
+  BUILD_TYPE: Release
+
+jobs:
+  build:
+    # The CMake configure and build commands are platform agnostic and should work equally
+    # well on Windows or Mac.  You can convert this to a matrix build if you need
+    # cross-platform coverage.
+    # See: https://docs.github.com/en/free-pro-team@latest/actions/learn-github-actions/managing-complex-workflows#using-a-build-matrix
+    runs-on: windows-2019
+
+    steps:
+    - uses: actions/checkout@v2
+
+    - name: Create Build Environment
+      # Some projects don't allow in-source building, so create a separate build directory
+      # We'll use this as our working directory for all subsequent commands
+      run: cmake -E make_directory ${{github.workspace}}/build
+
+    - name: Configure CMake
+      # Use a bash shell so we can use the same syntax for environment variable
+      # access regardless of the host operating system
+      shell: bash
+      working-directory: ${{github.workspace}}/build
+      # Note the current convention is to use the -S and -B options here to specify source 
+      # and build directories, but this is only available with CMake 3.13 and higher.  
+      # The CMake binaries on the Github Actions machines are (as of this writing) 3.12
+      run: |
+        cmake $GITHUB_WORKSPACE -G "Visual Studio 16 2019" -DCMAKE_BUILD_TYPE=$BUILD_TYPE -DCMAKE_CXX_COMPILER=${{ matrix.compiler }}
+
+    - name: Build
+      working-directory: ${{github.workspace}}/build
+      shell: bash
+      # Execute the build.  You can specify a specific target with "--target <NAME>"
+      run: cmake --build . --config $BUILD_TYPE
+
+    - name: Test
+      working-directory: ${{github.workspace}}/build
+      shell: bash
+      # Execute tests defined by the CMake configuration.  
+      # See https://cmake.org/cmake/help/latest/manual/ctest.1.html for more detail
+      run: ctest -C $BUILD_TYPE