Improve C++14 test for clang

diff --git a/cmake/checks/check_01_cxx_features.cmake b/cmake/checks/check_01_cxx_features.cmake
index 3e39aed620a84e8141b942f13bbc5bfe4d33e5ae..8ce8edc256def38a106765a80844f352a3c9da6e 100644 (file)
--- a/cmake/checks/check_01_cxx_features.cmake
+++ b/cmake/checks/check_01_cxx_features.cmake
@@ -132,7 +132,10 @@ IF(NOT DEFINED DEAL_II_WITH_CXX14 OR DEAL_II_WITH_CXX14)
       {
         auto func();
       };
-      int main() {}
+      int main()
+      {
+        foo bar;
+      }
       "
       DEAL_II_HAVE_CXX14_CLANGAUTODEBUG_BUG_OK)