In MSVC it's possible to write: ```` // in Lib.h #if USE_OLD_LIB #pragma comment(lib, "old_lib.lib") #include "old_lib.h" #else #pragma comment(lib, "new_lib.lib") #include "new_lib.h" #endif ```` How can I do this without having the pragma comment support in GCC? Edit: I know it's possible to use a make file, but the USE_OLD_LIB conditional macro is connected to some logic inside another library like the following: ```` // in Lib2.h #if OBJ_SIZE > 20 #define USE_OLD_LIB #endif ```` So, it would be a hassle to use a make file for it.