Future.cpp

/**
 * \file  Future.cpp
 * \brief
 *
 * \see   http://en.cppreference.com/w/cpp/thread/future
 * \review
 */


//--------------------------------------------------------------------------------------------------
#include <StdStream/StdStream.h>
#include <StdTest/StdTest.h>
#include <Stl.h>
//--------------------------------------------------------------------------------------------------
int main(int, char **)
{
    // future from a packaged_task
    std::packaged_task<int()> task([](){ return 7; }); // wrap the function
    std::future<int> f1 = task.get_future();  // get a future
    std::thread(std::move(task)).detach(); // launch on a thread

    // future from an async()
    std::future<int> f2 = std::async(std::launch::async, [](){ return 8; });

    // future from a promise
    std::promise<int> p;
    std::future<int> f3 = p.get_future();
    std::thread( [](std::promise<int> p){ p.set_value_at_thread_exit(9); }, std::move(p) ).detach();

    std::cout << "Waiting..." << std::flush;
    f1.wait();
    f2.wait();
    f3.wait();
    std::cout << "Done!\nResults are: "
              << f1.get() << ' ' << f2.get() << ' ' << f3.get() << '\n';

    return 0;
}
//--------------------------------------------------------------------------------------------------