minor change to work also with swig > 3

CMakeLists.txt

@@ -2,10 +2,16 @@ cmake_minimum_required(VERSION 2.8.7)
 project(macaon2)
 
 
-# for gcc < 5.3
-#add_definitions("-Wall -std=gnu11" )
 add_definitions("-Wall" )
 
+# for gcc < 5.3
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -std=gnu11")
+
+# better, but needs CMake >= 3.0
+#set_property(GLOBAL PROPERTY CXX_STANDARD 11)
+#set_property(GLOBAL PROPERTY C_STANDARD 11)
+
+
 # activate with cmake -DMACA_EXPORT=TRUE 
 # to use macaon in python/java (with swig)
 if(MACA_EXPORT)