opOverloadExample.cpp

#include <iostream>

using namespace std;

class Point {
public:
  //overloaded constructors!
  Point()
  {
    _x = 0;
    _y = 0;
  }

  Point(double _x, double _y)
  {
    this->_x = _x;
    this->_y = _y;
  }
  
  //overloaded methods for accessing x and y
  double x()
  {
    return _x;
  }

  void x(double val)
  {
    this->_x = val;
  }

  double y()
  {
    return _y;
  }

  void y(double val)
  {
    this->_y = val;
  }
private:
  //private attributes of the class
  double _x;
  double _y;
};


//overload + operator for points
Point operator+(Point & lhs, Point & rhs);

//an insertion operator for points
ostream & operator<<(ostream &os, Point &rhs);

int main()
{
  Point* p1 = new Point(2, 3);
  Point* p2 = new Point(29.2, 17.4);
  Point* p3 = new Point;

  //add the points together
  *p3 = *p1 + *p2;

  cout << *p1 << " + " << *p2 << "=" << *p3 << endl;

  return 0;
}


Point
operator+(Point &lhs, Point &rhs)
{
  //make a new point
  Point result;

  //set the component wise addition
  result.x(lhs.x() + rhs.x());
  result.y(lhs.x() + rhs.y());

  return result;
}


ostream &
operator<<(ostream &os, Point &rhs)
{
  //write to the stream
  os << "(" << rhs.x() << ", " << rhs.y() << ")";

  //return the stream
  return os;
}