Function: ... Argument

Hello Friends,
Could you please tell me what is the meaning of this parameter "..." and how to access the ... parameter? The sample code is given below:-

Code:

---

#include <iostream>
using namespace std;
void foo(int x,...);
int main()
{
    foo(5);
    return 0;
}
 
void foo(int x,...)
{
    cout<<x;
}

---

Read about C functions va_start and va_arg

Functions of this type are called Variadic functions. It is a mechanism for specifying a variable number of arguments of unspecified type. Variadic functions are often a bad idea, not type safe for example, and have workable alternatives.

not to be confused with variadic templates in C++11! :)