std_set_points.cpp

#include <iostream>
#include <set>

using namespace std;

struct Point {
  int x;
  int y;

  Point(int x, int y) 
    : x(x), y(y) {}

  bool operator < (const Point &point) const {
    return this->x < point.x || this->y < point.y;
  }
};


int main(int argc, char *argv[]) {
  Point p1(0,5);
  Point p2(0,5);
  Point p3(11,15);
  set<Point> points;
  points.insert(p1);
  points.insert(p2);
  points.insert(p3);
  cout << points.size() << endl;
}