Hello everybody. I have a case where I'm using this #define syntax to create function pointers called callback_dragDrop and callback_dragStart, amongst others:

#define defineCallback2(x, arg1, arg2) \
    void (WINAPI *callback_ ## x )( arg1, arg2 );

#define defineCallback3(x, arg1, arg2, arg3) \
    void (WINAPI *callback_ ## x )( arg1, arg2, arg3 );

Note: The pattern above is actually extended up to defineCallback8 for arg1..arg8.

In my code I use it like this:

defineCallback2(dragDrop,  int foo, int noo)
defineCallback3(dragStart, int foo, int noo, int koo)

It works, but I'm thinking there's probably a way to make one function which tests for the presence of argN arguments, and uses only those which are present (like the variable parameters passed to printf). Perhaps something like #define defineCallback(x, y..), where I can use "y" in place of "arg1, arg2" and it conveys everything that's passed regardless of how many parameters there are ??

Any ideas? TYIA! :-)