co_await vs. future.get()

co_wait will setup a state machine to return, future has to call get() to return

#include "stdafx.h"
#include <experimental\coroutine>
#include <iostream>
#include <string>
#include <future>
#include <thread>

using namespace std;
using namespace std::experimental;

std::future<int> produceAsync()
{
 return std::async(std::launch::async, [] {
  cout << " future thread id:"<< std::this_thread::get_id()<<endl;
  std::this_thread::sleep_for(5s);
  return 42;
 });
}

std::future<void> ConsumeAsync()
{
 auto r = co_await produceAsync(); // set up resume state machine
 cout << r << endl;
}

int main()
{
 cout << "main thread id:" << std::this_thread::get_id() <<endl;
 ConsumeAsync();


 auto r = produceAsync();
 //cout << r.get() << endl; //get causes return, no SM setup

 std::string s;
 getline(cin, s);
    return 0;
}