Equivalent Declaration

// Two parameter declarations that differ only in their default arguments are equivalent.

#include <cstdio>

void func(double i);

void f(int i, int j);
void f(int i, int j = 99); // OK: redeclaration of f(int, int)
void f(int i = 88, int j); // OK: redeclaration of f(int, int)
void f(); // OK: overloaded declaration of f

void prog()
{
    f(1, 2); // OK: call f(int, int)
    f(1); // OK: call f(int, int)
    // f(); // error: f(int, int) or f() ?
}

int main(int argc, char const* argv[])
{
    prog();
    return 0;
}

void f(int i, int j)
{
    printf("i=%d, j=%d\n", i, j);
}