// Class Point becomes a function object, because it can be called as a function.
// Class Point with two overloads of the function call operator, operator().

class Point {
private: 
  double x, y;

public:
  Point(double, double);
  Point();
  double getx () const;
  double gety () const;
  void move(double, double);
  double distance_to(Point);

  double operator()(int) const;
  double operator()(Point) const;
};

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