#include <stdio.h>

typedef int (*callback)(int);
typedef int (*cb2)(char *);

void test_ffi(callback cb)
{
    printf("%d\n", cb(3));
}

void test_ffi2(cb2 cb)
{
    printf("%d\n", cb("hello"));
}

void test_ffi3(void (*cb)(void))
{
    printf("Before calling callback\n");
    cb();
    printf("After calling callback\n");
}

int dynamic_fn(int i) {
    printf("I'm dynamic %d\n", i);
    return i*2;
}

callback test_ffi6(void) {
    return &dynamic_fn;
}

void test_mulpar(void (*fn)(int, int)) {
    fn(3,4);
}