improve automagic a bit

diff --git a/cmake/checks/check_01_cxx_features.cmake b/cmake/checks/check_01_cxx_features.cmake
index 116c5f023c6b90a95172dac647c8dc8774201955..68aeb2696a58f202a20ad143ddc36e24b78af158 100644 (file)
--- a/cmake/checks/check_01_cxx_features.cmake
+++ b/cmake/checks/check_01_cxx_features.cmake
@@ -255,9 +255,13 @@ MACRO(_test_cxx14_support)
   ENDIF()
 ENDMACRO()
 
+#
+# Try to find out what we support:
+#
+
 _set_up_cmake_required()
+
 _test_cxx14_support()
-_test_cxx17_support()
 
 IF(NOT DEAL_II_HAVE_CXX14)
   MESSAGE(STATUS "C++14 support not available. Try to set -std=c++14 explicitly")
@@ -265,7 +269,6 @@ IF(NOT DEAL_II_HAVE_CXX14)
   ENABLE_IF_SUPPORTED(DEAL_II_CXX_FLAGS "/std:c++14")
   _set_up_cmake_required()
   _test_cxx14_support()
-  _test_cxx17_support()
 ENDIF()
 
 IF(NOT DEAL_II_HAVE_CXX14)
@@ -278,6 +281,8 @@ IF(NOT DEAL_II_HAVE_CXX14)
     )
 ENDIF()
 
+_test_cxx17_support()
+
 
 ########################################################################
 #                                                                      #