#include <iostream>
using namespace std;
class Point {
private:
// fields are accessible only to methods belonging to point
double x;
double y;
public:
// constructor accepting two arguments, called by a
// statement such as: Point p(1, 2);
Point(double a_x, double a_y) : x(a_x), y(a_y) {}
// mark the non-member function overloading << as a friend
friend ostream& operator<<(ostream &os, const Point &p);
};
ostream& operator<<(ostream &os, const Point &p) {
// access private fields since << is a friend of Point
os << '(' << p.x << ',' << p.y << ')';
return os;
}
int main() {
Point p(1,2);
cout << p << endl;
return 0;
}