Add static call operator to C++23 feature check

diff --git a/cmake/checks/check_01_cxx_features.cmake b/cmake/checks/check_01_cxx_features.cmake
index e54e413356bf850be1a023cac56bcf8786ed71fb..462774b39b0277e94027c5b037e6aabbd955f3b4 100644 (file)
--- a/cmake/checks/check_01_cxx_features.cmake
+++ b/cmake/checks/check_01_cxx_features.cmake
@@ -70,6 +70,10 @@ macro(_test_cxx23_support)
     #  error \"insufficient support for C++23\"
     #endif
 
+    struct Dummy {
+      static void operator()() {}
+    };
+
     int main() {}
     "
     DEAL_II_HAVE_CXX23_FEATURES)