///////////////////////////////////////////////////////////////
// Future.cpp - asynchronous call                            //
//                                                           //
// Jim Fawcett, CSE687 - Object Oriented Design, Spring 2013 //
///////////////////////////////////////////////////////////////

#include <future>
#include <mutex>
#include <iostream>

void say(const std::string& msg, int millisec)
{
  static std::mutex mtx;
  for(int i=0; i<25; ++i)
  {
    mtx.lock();
    std::cout << "\n  " << msg.c_str();
    mtx.unlock();
    std::this_thread::sleep_for(std::chrono::milliseconds(millisec));
  }
}

int main()
{
  auto fut = std::async(say, "hello from async", 2);
  say("hello from main", 0);
  fut.wait();
  // doesn't assert with no wait, but background doesn't complete
  std::cout << "\n\n";
}