condition_variable/example5.cpp

// condition_variable::wait_for example
#include <iostream>           // std::cout
#include <thread>             // std::thread
#include <chrono>             // std::chrono::seconds
#include <mutex>              // std::mutex, std::unique_lock
#include <condition_variable> // std::condition_variable, std::cv_status

std::condition_variable cv;

int value;

void read_value() {
 std::cin >> value;
 cv.notify_one();
}

int main ()
{
 std::cout << "Please, enter an integer (I'll be printing dots): \n";
 std::thread th (read_value);

 std::mutex mtx;
 std::unique_lock<std::mutex> lck(mtx);
 while (cv.wait_for(lck,std::chrono::seconds(1))==std::cv_status::timeout) {
   std::cout << '.' << std::endl;
 }
 std::cout << "You entered: " << value << '\n';

 th.join();

 return 0;
}