set cxx14 cmake variable correctly

The with_cxx14 flag was incorrectly set as a variable instead of settings the
cached variable. This would cause some weirdness (cached and non-cached
variables of the same name coexist). Before this patch, "DEAL_II_WITH_CXX14 =
OFF" would be printed twice in the feature section.

diff --git a/cmake/checks/check_01_cxx_features.cmake b/cmake/checks/check_01_cxx_features.cmake
index 46022e6857dd42377fa3b274f858812365e78d82..2450232e074ec9837b7d43ef7b96acbd61b0f757 100644 (file)
--- a/cmake/checks/check_01_cxx_features.cmake
+++ b/cmake/checks/check_01_cxx_features.cmake
@@ -48,7 +48,7 @@ IF(DEAL_II_WITH_CXX14 AND DEFINED DEAL_II_WITH_CXX11 AND NOT DEAL_II_WITH_CXX11)
 ENDIF()
 
 IF(DEFINED DEAL_II_WITH_CXX11 AND NOT DEAL_II_WITH_CXX11)
-  SET(DEAL_II_WITH_CXX14 OFF)
+  SET(DEAL_II_WITH_CXX14 OFF CACHE STRING "" FORCE)
 ENDIF()