Question

For example:

int WINAPI WinMain ( HINSTANCE instance, HINSTANCE prev_instance, PSTR cmd_line, int cmd_show )

WINAPI is a a define that looks like this:

#define WINAPI      __stdcall

why can’t you just do:

int __stdcall WinMain ( HINSTANCE instance, HINSTANCE prev_instance, PSTR cmd_line, int cmd_show )

actually I think my problem is that I’m sort of confusing defines with typedef’s. Can someone explain this to me? what does the define do and why can’t you just write __stdcall in its place?

Answer 1

Because the WINAPI calling convention is not guaranteed to be __stdcall. Code that uses WINAPI will still be correct even when it isn’t.

You can write the function as in your latter example, and it’d work fine – it’s just not good practice and would not be portable to a platform where the calling convention is something else.