#include <iostream>
#include <cstdlib>
 
using namespace std;
 
struct vector {
    double x;
    double y;
 
    friend ostream& operator<< (ostream&, vector);
}    
 
ostream& operator<< (ostream& o, vector a) {
    o << "(" << a.x << "," << a.y << ")" << endl;
    return o;
}    
 
int main(int argc, char *argv[])
{
    vector v1;
    v1.x = 1;
    v1.y = 1;
 
    cout << v1 << endl;
 
    system("PAUSE");	
    return 0;
}

struct vector
{
   double x;
   double y;

   friend ostream& operator<< (ostream&, vector);
};

friend ostream& operator<< (ostream&, ::vector);

 
namespace my_vector
{
    struct vector // might as well class it
    {
        double x, y;
 
        friend ostream& operator<< (ostream& out, const vector& v) // I use references but its not compulsory
        {
            out << "(" << a.x << "," << a.y << ")" << endl;
            return out;
        }
    };
}