Re: pointers to functions

Hello all,

    I need some help. I've been learning C++ using the tutorial at
Cplusplus.com (http://www.cplusplus.com/doc/tutorial/pointers.html is
the page in question). Near the bottom of the section on pointers,
there is a code sample which is supposed to be demonstrating using
pointers to point to functions. It didn't seem to make sense, so I
tried compiling it; it wouldn't compile! Since the author of the
tutorial didn't leave any contact information, I'm turning to you
folks. Can anyone correct the following code for me?

#include <iostream>
using namespace std;

int addition (int a, int b)
{ return (a+b); }

int subtraction (int a, int b)
{ return (a-b); }

int minus (int,int) = subtraction;

int operation (int x, int y, int (*functocall)(int,int))
{
   int g;
   g = (*functocall)(x,y);
   return (g);
}

int main ()
{
   int m,n;
   m = operation (7, 5, addition);
   n = operation (20, m, minus);
   cout <<n;
   return 0;
}

Thanks for your help,
Danny

p.s. The compile errors state that "function `int minus(int, int)' is
initialized like a variable" and "`minus' undeclared (first use this
function)".