point.h

#ifndef POINT_H
#define POINT_H
#include<ostream>

// Points on 2d grid
class Point {
	// Overloaded operators for convenience.  You must be careful with
	// friend functions if abused you can easily violate encapsulation.  
	// Functions that can be made friends are tightly related to concept
	// of the object. 
	friend std::ostream & operator<<(std::ostream &os, const Point& p);
	friend Point operator+ (const Point &lhs, const Point &rhs);
	friend Point operator- (const Point &lhs, const Point &rhs);
	friend double sqrDist(const Point &p1, const Point &p2);

public:
	Point();

	Point(int x, int y);
	
	// Will make use of implicit copy constructor and assignment operators
	// for shallow copy, which is fine since there is no dynamically
	// allocated memory.

	int x() const;
	int y() const;
	void set(int x, int y);

	// overloaded comparison operator, two points are equal
	// if both their elements are equal
	bool operator==(const Point &other);
	bool operator==(const Point &other) const;
	bool operator!=(const Point &other);
	bool operator!=(const Point &other) const;
private:
	int m_x, m_y;
};

#endif//POINT_H