test/other/test_implicit_func.c

#include <stdio.h>
int main() {
    printf("hello %d\n", strnlen("waka", 2)); // Implicit declaration, no header, for strnlen
    int (*my_strnlen)(char*, ...) = strnlen;
    printf("hello %d\n", my_strnlen("shaka", 2));
    return 0;
}