// A version with non-member output function. An overloading of operator<<

#include <cmath>
#include <iostream>

using namespace std;

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) const;
};

Point::Point(double x_coord, double y_coord): x(x_coord), y(y_coord){
}

Point::Point(): x(0.0), y(0.0){
}

double Point::getx () const{
  return x;
}

double Point::gety () const{
  return y;
}

void Point::move(double dx, double dy){
    x += dx; y += dy;
}

double Point::distance_to(Point p) const{
    return sqrt((x - p.x) * (x - p.x) + (y - p.y) * (y - p.y));
}

ostream& operator<<(ostream& s, const Point& p){
  return s << "(" << p.getx() << "," << p.gety() << ")" ;
}



int main(){

  Point p, 
        q = Point(3.0, 4.0),
        r(3.0, 4.0);

  p.move(2,3);
  q.move(4,5);

  double d = q.distance_to(r);

  cout << d << endl;

  cout << "Point p: " << p << endl;
  cout << "Point q: " << q << endl;
}