Add CMake multi-platform workflow for CI

Author: jacnils

.github/workflows/cmake-multi-platform.yml

@@ -0,0 +1,69 @@
+name: CMake on Linux, macOS, and Windows
+
+on:
+  push:
+    branches: [ "master" ]
+  pull_request:
+    branches: [ "master" ]
+
+jobs:
+  build:
+    strategy:
+      fail-fast: false
+      matrix:
+        include:
+          - os: ubuntu-latest
+            c_compiler: gcc
+            cpp_compiler: g++
+            build_type: Release
+          - os: macos-latest
+            c_compiler: clang
+            cpp_compiler: clang++
+            build_type: Release
+          - os: windows-latest
+            c_compiler: cl
+            cpp_compiler: cl
+            build_type: Release
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Install OpenSSL
+        run: |
+          if [[ "${{ matrix.os }}" == "ubuntu-latest" ]]; then
+            sudo apt update
+            sudo apt install -y libssl-dev
+            echo "CMAKE_PREFIX_PATH=/usr" >> $GITHUB_ENV
+          elif [[ "${{ matrix.os }}" == "macos-latest" ]]; then
+            brew update
+            brew install openssl
+            OPENSSL_DIR=$(brew --prefix openssl)
+            echo "CMAKE_PREFIX_PATH=${OPENSSL_DIR}" >> $GITHUB_ENV
+          elif [[ "${{ matrix.os }}" == "windows-latest" ]]; then
+            choco install openssl.light -y
+            echo "CMAKE_PREFIX_PATH=C:/Program Files/OpenSSL-Win64" >> $GITHUB_ENV
+          fi
+        shell: bash
+
+      - name: Set reusable strings
+        id: strings
+        shell: bash
+        run: |
+          echo "build-output-dir=${{ github.workspace }}/build" >> "$GITHUB_OUTPUT"
+
+      - name: Configure CMake
+        run: >
+          cmake -B ${{ steps.strings.outputs.build-output-dir }}
+          -DCMAKE_C_COMPILER=${{ matrix.c_compiler }}
+          -DCMAKE_CXX_COMPILER=${{ matrix.cpp_compiler }}
+          -DCMAKE_BUILD_TYPE=${{ matrix.build_type }}
+          -DCMAKE_PREFIX_PATH=${{ env.CMAKE_PREFIX_PATH }}
+          -S ${{ github.workspace }}
+
+      - name: Build
+        run: cmake --build ${{ steps.strings.outputs.build-output-dir }} --config ${{ matrix.build_type }}
+
+      - name: Test
+        working-directory: ${{ steps.strings.outputs.build-output-dir }}
+        run: ctest --build-config ${{ matrix.build_type }}