// Class Point of which operator<< is declared as a friend

class Point {
private: 
  double x, y;

public:
  friend std::ostream& operator<<(std::ostream&, const Point&);
  Point(double, double);
  Point();
  double getx () const;
  double gety () const;
  void move(double, double);
  double distance_to(Point);
};