fix CI

Author: kosloot

.github/workflows/foliautils.yml

@@ -36,7 +36,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, macos-latest]
-        compiler: [g++-12, clang++]
+        compiler: [g++-12, clang++ -std=c++17]
 
     steps:
       - uses: actions/checkout@v4.1.1