C++ function pointer as a static member

Question

I cannot figure the syntax to declare a function pointer as a static member.

#include <iostream>
using namespace std;

class A
{
    static void (*cb)(int a, char c);
};

void A::*cb = NULL;

int main()
{
}

g++ outputs the error "cannot declare pointer to `void' member". I assume I need to do something with parentheses but void A::(*cb) = NULL does not work either.

Answer 1

void (*A::cb)(int a, char c) = NULL;

Answer 2

I introduced a typedef, which made it somewhat clearer in my opinion:

class A
{
  typedef void (*FPTR)(int a, char c);

  static FPTR cb;
};

A::FPTR A::cb = NULL;