Function overloading with ellipsis

Question

Can i actually use a function overloading like this:

#include <iostream>

void foo(...)
{
   std::cout << "::foo(...) \n";
}

void foo(int)
{
   std::cout << "::foo(int) \n";
}

int main()
{
   foo(0);
   foo('A');
   foo("str");
   foo(0, 1);
}

What standard says about it? And in what kind of situations i'll get ::foo(...)?

Answer 1

void foo(int)

will accept one argument of type int.

void foo(...)

accepts any number of arguments, of any type. It will be selected when the call doesn't have a single int argument. Not very useful, in general.

Also note that it is undefined behavior to pass objects of class type to ....