Coordinate Sorting with Function Objects

#include "pch.h"
#include <iostream>
#include <ctime>
#include <vector>
#include <algorithm>
using namespace std;

class Coordinate
{
    double x, y;
public:
    Coordinate(double _x=0, double _y=0) :x(_x), y(_y) {}
    double distance(Coordinate& c) { return sqrt(pow(c.x - x, 2) + pow(c.y - y, 2)); }
    void print() { cout << "(" << x << "," << y << ")"; }
};

class CompareCoords
{
    Coordinate ref;
public:
    CompareCoords(Coordinate c) :ref(c) {}
    bool operator () (Coordinate& a, Coordinate& b) { return ref.distance(a) < ref.distance(b); }
};

int main()
{
    vector<Coordinate> coords;
    coords.reserve(20);
    for (int i = 0; i < 20; ++i)
        coords.push_back(Coordinate(rand() % 100, rand() % 100));
    Coordinate me(0, 0);
    sort(coords.begin(), coords.end(), CompareCoords(me));

    for (int i = 0; i < coords.size(); ++i)
        coords[i].print();
}