Function Pointer to Function wit

#include <cstdio>

void foo(int x = 0, int y = 0) {
    if(x && y);   // To keep the compiler happy
    puts("void foo(int, int)");
}

void (*fp_int_int)(int, int) = foo;

int main() {
    fp_int_int(0, 0);
    fp_int_int();    // This is not allowed
}