C function pointer demo

gistfile1.c

#include <stdio.h>

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

int addtimestwo(int (*fp)(int,int), int a, int b)
{
        return (*fp)(a, b) * 2;
}

int main(void)
{
        int a = 3, b = 5;

        int (*fp)(int, int) = &add;

        printf("add: %d\n", (*fp)(a, b));
        printf("addtimestwo: %d\n", addtimestwo(fp, a, b));

        return 0;
}