///////////////////////////////////////////////////////////////
// Promise.cpp - getting answers from thread                 //
//                                                           //
// Jim Fawcett, CSE687 - Object Oriented Design, Spring 2013 //
///////////////////////////////////////////////////////////////

#include <future>
#include <thread>
#include <string>
#include <iostream>

void getAnAnswer(std::promise<std::string>* p)
{
  std::cout << "\n  thread is thinking";
  std::this_thread::sleep_for(std::chrono::milliseconds(100));
  p->set_value("The answer is 2");
}

int main()
{
  std::promise<std::string> p;
  std::future<std::string> f = p.get_future();
  std::thread t(getAnAnswer, &p);
  std::cout << "\n  main is waiting for an answer";
  std::cout << "\n  " << f.get();
  t.join();
  std::cout << "\n\n";
}