How to make sure a function is only called once

Question

Suppose I have a function named caller, which will call a function named callee:

void caller()
{
    callee();
}  

Now caller might be called m

Answer 1

Inspired by some people, I think just use a macro to wrap comma expression would also make the intention clear:

#define CALL_ONCE(func) do {static bool dummy = (func, true);} while(0)