Casting a function pointer to another type

Question

Let\'s say I have a function that accepts a void (*)(void*) function pointer for use as a callback:

void do_stuff(void (*callback_fp)(void*), vo         


        

Answer 1

Void pointers are compatible with other types of pointer. It's the backbone of how malloc and the mem functions (memcpy, memcmp) work. Typically, in C (Rather than C++) NULL is a macro defined as ((void *)0).

Look at 6.3.2.3 (Item 1) in C99:

A pointer to void may be converted to or from a pointer to any incomplete or object type