How do you pass a function as a parameter in C?

Question

I want to create a function that performs a function passed by parameter on a set of data. How do you pass a function as a parameter in C?

Answer 1

Functions can be "passed" as function pointers, as per ISO C11 6.7.6.3p8: "A declaration of a parameter as ‘‘function returning type’’ shall be adjusted to ‘‘pointer to function returning type’’, as in 6.3.2.1. ". For example, this:

void foo(int bar(int, int));

is equivalent to this:

void foo(int (*bar)(int, int));