// Samples of overloading operators in four different ways

// **************************  METHOD 1 ***********************************
// OVERLOADING AS NON-MEMBER FUNCTIONS, IF ONLY DATA ACCESSORS ARE PROVIDED
// Note: this would require the protoypes to be in the header file, after the
//       end of the class declaration.
bool operator==(const Point& p1, const Point& p2) {
    return p1.x() == p2.x() && p1.y() == p2.y();
}
istream& operator>>(istream& in, Point& p) {
   double x,y;
   in >> x >> y;
   if (in) p = Point(x,y);
   return in;
}
ostream& operator << (ostream& out, const Point& p) {
    out << p.x() << ' ' << p.y();
    return out;
}

// **************************  METHOD 2 ***********************************
// OVERLOADING AS NON-MEMBERS USING MEMBER FUNCTIONS; EG sameAs, read and print
// Note: this would require the protoypes to be in the header file, after the
//       end of the class declaration.
bool operator==(const Point& p1, const Point& p2) {
   return p1.sameAs(p2);
}
istream& operator>>(istream& in, Point& p) {
   p.read(in);
   return in;
}
ostream& operator<<(ostream& out, const Point& p) {
   p.print(out);
   return out;
}


// **************************  METHOD 3 ***********************************
// OVERLOADING AS A MEMBER FUNCTION
// Note: this would require the protoype to be inside the class declaration
bool Point::operator==(const Point& p) const {
    return xValue == p.xValue && yValue == p.yValue;
}

// Note: we cannot overload the insertion and extraction operators as member
// functions since the left hand operand is not a Point object, but a stream


// **************************  METHOD 4 ***********************************
// OVERLOADING AS NON-MEMBER FRIEND FUNCTIONS
// Note: this requires that the class declare these to be friends.
//       i.e. inside the class declaration, you would include the following
//            friend prototypes:
       friend bool operator==(const Point& p1, const Point& p2);
       friend istream& operator>>(istream& in, Point& p);
       friend ostream& operator<<(ostream& out, const Point& p);


bool operator==(const Point& p1, const Point& p2) {
    return p1.xValue == p2.xValue && p1.yValue == p2.yValue;
}
istream& operator>>(istream& in, Point& p) {
   double x,y;
   in >> x >> y;
   if (in) {
      p.xValue = x;
      p.yValue = y;
   }
   return in;
}
ostream& operator<<(ostream& out, const Point& p) {
    out << p.xValue << ' ' << p.yValue;
    return out;
}