add STORM_DEVELOPER ALL_WARNINGS GCC case

non exhaustive in this commit, i.e. additional flags might be applicable

CMakeLists.txt

@@ -325,6 +325,11 @@ if (STORM_DEVELOPER)
 			set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-float-equal")
 			set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unused-local-typedef")
 			set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-missing-variable-declarations")
+        elseif (GCC)
+			set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra")
+			set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wunused")
+			set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unknown-pragmas")
+			set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wno-unused-local-typedefs")
 		endif ()
 	else ()
 	    set (CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Wall -Wextra")