👷 try Clang 8

.github/workflows/windows_clang.yml

@@ -3,6 +3,20 @@ name: Windows
 on: [push, pull_request]
 
 jobs:
+  clang8:
+    runs-on: windows-latest
+
+    steps:
+      - uses: actions/checkout@v1
+      - name: install Clang
+        run: curl -fsSL -o LLVM8.exe https://releases.llvm.org/8.0.0/LLVM-8.0.0-win64.exe ; 7z x LLVM8.exe -y -o"C:/Program Files/LLVM"
+      - name: cmake
+        run: cmake -S . -B build -DCMAKE_CXX_COMPILER="C:/Program Files/LLVM/bin/clang++.exe" -G"MinGW Makefiles" -DCMAKE_BUILD_TYPE=Debug -DJSON_BuildTests=On
+      - name: build
+        run: cmake --build build --parallel 10
+      - name: test
+        run: cd build ; ctest -j 10 -C Debug --exclude-regex "test-unicode" --output-on-failure
+
   clang9:
     runs-on: windows-latest