Default value of a function pointer in C++

Question

What is the default value of a function pointer in C++? (Apparently it can\'t be NULL, so what is it?)

How is this program supposed to behave and why?

Answer 1

A function pointer can be NULL and you may assign NULL to it. Have a look here for instance:

#include 

using namespace std;

struct S { void (*f)(); };

int main()
{
    S s = S();
    s.f = NULL;
    return 0;
}

I believe the way you call the constructor of the structure(with ()), f will be NULL.