text: //===----------------------------------------------------------------------===//
  //
  // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
  // See https://llvm.org/LICENSE.txt for license information.
  // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
  //
  //===----------------------------------------------------------------------===//
  //
  // UNSUPPORTED: libcpp-has-no-threads
  // UNSUPPORTED: c++98, c++03
  
  // <future>
  
  // class shared_future<R>
  
  // template <class Rep, class Period>
  //   future_status
  //   wait_for(const chrono::duration<Rep, Period>& rel_time) const;
  
  #include <future>
  #include <cassert>
  
  #include "test_macros.h"
  
  typedef std::chrono::milliseconds ms;
  
  static const ms sleepTime(500);
  static const ms waitTime(5000);
  
  void func1(std::promise<int> p)
  {
    std::this_thread::sleep_for(sleepTime);
    p.set_value(3);
  }
  
  int j = 0;
  
  void func3(std::promise<int&> p)
  {
    std::this_thread::sleep_for(sleepTime);
    j = 5;
    p.set_value(j);
  }
  
  void func5(std::promise<void> p)
  {
    std::this_thread::sleep_for(sleepTime);
    p.set_value();
  }
  
  int main(int, char**)
  {
    typedef std::chrono::high_resolution_clock Clock;
  
    {
      typedef int T;
      std::promise<T> p;
      std::shared_future<T> f = p.get_future();
      std::thread(func1, std::move(p)).detach();
      assert(f.valid());
      assert(f.wait_for(ms(1)) == std::future_status::timeout);
      assert(f.valid());
      assert(f.wait_for(waitTime) == std::future_status::ready);
      assert(f.valid());
      f.wait();
      assert(f.valid());
    }
    {
      typedef int& T;
      std::promise<T> p;
      std::shared_future<T> f = p.get_future();
      std::thread(func3, std::move(p)).detach();
      assert(f.valid());
      assert(f.wait_for(ms(1)) == std::future_status::timeout);
      assert(f.valid());
      assert(f.wait_for(waitTime) == std::future_status::ready);
      assert(f.valid());
      f.wait();
      assert(f.valid());
    }
    {
      typedef void T;
      std::promise<T> p;
      std::shared_future<T> f = p.get_future();
      std::thread(func5, std::move(p)).detach();
      assert(f.valid());
      assert(f.wait_for(ms(1)) == std::future_status::timeout);
      assert(f.valid());
      assert(f.wait_for(waitTime) == std::future_status::ready);
      assert(f.valid());
      f.wait();
      assert(f.valid());
    }
  
    {
      typedef int T;
      std::promise<T> p;
      std::shared_future<T> f = p.get_future();
      Clock::time_point t0 = Clock::now();
      std::thread(func1, std::move(p)).detach();
      assert(f.valid());
      assert(f.wait_for(ms(1)) == std::future_status::timeout);
      assert(f.valid());
      f.wait();
      Clock::time_point t1 = Clock::now();
      assert(f.valid());
      assert(t1 - t0 >= sleepTime);
      assert(f.wait_for(waitTime) == std::future_status::ready);
      assert(f.valid());
    }
    {
      typedef int& T;
      std::promise<T> p;
      std::shared_future<T> f = p.get_future();
      Clock::time_point t0 = Clock::now();
      std::thread(func3, std::move(p)).detach();
      assert(f.valid());
      assert(f.wait_for(ms(1)) == std::future_status::timeout);
      assert(f.valid());
      f.wait();
      Clock::time_point t1 = Clock::now();
      assert(f.valid());
      assert(t1 - t0 >= sleepTime);
      assert(f.wait_for(waitTime) == std::future_status::ready);
      assert(f.valid());
    }
    {
      typedef void T;
      std::promise<T> p;
      std::shared_future<T> f = p.get_future();
      Clock::time_point t0 = Clock::now();
      std::thread(func5, std::move(p)).detach();
      assert(f.valid());
      assert(f.wait_for(ms(1)) == std::future_status::timeout);
      assert(f.valid());
      f.wait();
      Clock::time_point t1 = Clock::now();
      assert(f.valid());
      assert(t1 - t0 >= sleepTime);
      assert(f.wait_for(waitTime) == std::future_status::ready);
      assert(f.valid());
    }
  
    return 0;
  }
  