+###
+### And we need C11 standard, too
+###
+include(CheckCCompilerFlag)
+CHECK_C_COMPILER_FLAG("-std=gnu11" COMPILER_SUPPORTS_C11)
+if(COMPILER_SUPPORTS_C11)
+ set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu11")
+else()
+ message(FATAL_ERROR
+ "The compiler ${CMAKE_C_COMPILER} has no C11 support. "
+ "Please use a decent C compiler "
+ "(note that c++11 support of ${CMAKE_CXX_COMPILER} seems ok).")
+endif()
+