class Point {
private: 
  double x, y;

public:
  friend Point Move(const Point&, double, double);  

  Point(double, double);
  Point(double);                  // We rely on this constructor in the example:
                                  // Implicit conversion from double to point.
  Point();
  double getx () const;
  double gety () const;
  void move(double, double);
  double distance_to(Point);
};

std::ostream& operator<<(std::ostream&, const Point&);