#include <iostream>
#include <cstdlib>
#include <chrono>     //for chrono::system_clock
#include <random>     //for default_random_engine
#include <functional> //for bind
#include "derived.h"
using namespace std;

int main()
{
	unsigned seed = chrono::system_clock::now().time_since_epoch().count();
	default_random_engine engine {seed};
	uniform_int_distribution<int> distribution {0, 1};
	auto r {bind(distribution, engine)};

	base b {10};
	derived d {20, 30};

	base *p;
	if (r() == 0) {   //unpredictable 50-50 chance: r() could be 0 or 1
		p = &b;
	} else {
		p = &d;
	}

	//With the keyword virtual we have achieved late binding, a.k.a.,
	//dynamic binding.
	//Calls either base::print or derived::print.
	p->print();
	cout << "\n";
}