f0805.cpp

it is a usefull thing

//==================================
// f0805.cpp
// overload operator
//==================================
#include<iostream>
using namespace std;
//----------------------------------
class Point{
  int x, y;
public:
  void set(int a, int b){  x=a, y=b;  }
  void print()const{  cout<<"("<<x<<", "<<y<<")\n";  }
  friend Point operator+(const Point& a, const Point& b);
  friend Point add(const Point& a, const Point& b);
};//===============================
Point operator+(const Point& a, const Point& b){
  Point s;
  s.set(a.x+b.x, a.y+b.y);
  return s;
}//--------------------------------
Point add(const Point& a, const Point& b){
  Point s;
  s.set(a.x+b.x, a.y+b.y);
  return s;
}//--------------------------------
int main(){
  Point a, b;
  a.set(3,2);
  b.set(1,5);
  (a+b).print();
  operator+(a,b).print();
  add(a, b).print();
}//================================