C++11 vs. volatile

main.cpp

#include <iostream>
#include <chrono>
#include <thread>
#include <atomic>
using namespace std;

// int notify;
// volatile int notify;
atomic<int> notify;

void watcher()
{
	this_thread::sleep_for(chrono::seconds(2));
	notify = 1;
	cout << "Notification sent." << endl;
}

int main()
{
	thread(watcher).detach();

	notify = 0;
	while (!notify)
	{
		cout << "Waiting." << endl;
		this_thread::sleep_for(chrono::seconds(1));
	}

	cout << "Notification received." << endl;

	return 0;
}