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

int main()
{
	cout << "I am thinking of a number in the range 1 to 100 inclusive.\n"
		<< "Keep trying until you guess it.\n\n";

	//The value of the expression r() will be a random int in the range
	//1 to 100 inclusive.
	unsigned seed = chrono::system_clock::now().time_since_epoch().count();
        default_random_engine engine {seed};
        uniform_int_distribution<int> distribution {1, 100};
        auto r {bind(distribution, engine)};

	int correct {r()};

	for (;;) {                  //Looks like an infinite loop, but it isn't.
		cout << "Go ahead: ";
		int guess {0};
		cin >> guess;

		if (!cin) {
			cerr << "Sorry, that wasn't a number.\n";
			return EXIT_FAILURE;
		}

		if (guess == correct) {
			break;   //out of the for loop
		}

		//Give the user a hint.
		if (guess < correct) {
			cout << "Too low.";
		} else { 
			cout << "Too high.";
		}

		cout << "  Try again.\n\n";
	}

	//Arrive here after the break.
	cout << "That's right, the number was " << correct << ".\n";
	return EXIT_SUCCESS;
}