#include "point_class.h"

//default constructor
point2D::point2D () : x_(0), y_(0) {
  ++count_;
}

// copy constructor
point2D::point2D (const point2D &p) : x_(p.x_), y_(p.y_) {
  ++count_;
}

// assignment operator (chaining, self-assignment)
point2D & point2D::operator= (const point2D &p) {

  // self-assignment check
  if (this != &p) {
    x_ = p.x_;
    y_ = p.y_;
  }

  // allows chaining
  return *this;
}

// destructor
point2D::~point2D () {
  --count_;
}

// static member variable definition (and explicit initialization for readability)
unsigned int point2D::count_ = 0;

// friend operator definition
ostream & operator<< (ostream & os, const point2D &p) {
  os << p.x_ << " " << p.y_;
  return os;
}