#include <stdio.h>

static void blah(int i)
{
    printf("Hello, World! %d\n", i);
}

typedef void (*fn_ptr)(void);
static fn_ptr get_blah(void)
{
    return &blah;
}

int main()
{
    void (*my_fn)(int) = NULL;
    my_fn = get_blah();
    my_fn(10);

    return 0;
}

Hello, World! 10