1//
2// packaged_task.hpp
3// ~~~~~~~~~~~~~~~~~
4//
5// Copyright (c) 2003-2024 Christopher M. Kohlhoff (chris at kohlhoff dot com)
6//
7// Distributed under the Boost Software License, Version 1.0. (See accompanying
8// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
9//
10
11#ifndef BOOST_ASIO_PACKAGED_TASK_HPP
12#define BOOST_ASIO_PACKAGED_TASK_HPP
13
14#if defined(_MSC_VER) && (_MSC_VER >= 1200)
15# pragma once
16#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
17
18#include <boost/asio/detail/config.hpp>
19#include <boost/asio/detail/future.hpp>
20
21#if defined(BOOST_ASIO_HAS_STD_FUTURE_CLASS) \
22 || defined(GENERATING_DOCUMENTATION)
23
24#include <boost/asio/async_result.hpp>
25#include <boost/asio/detail/type_traits.hpp>
26
27#include <boost/asio/detail/push_options.hpp>
28
29namespace boost {
30namespace asio {
31
32/// Partial specialisation of @c async_result for @c std::packaged_task.
33template <typename Result, typename... Args, typename Signature>
34class async_result<std::packaged_task<Result(Args...)>, Signature>
35{
36public:
37 /// The packaged task is the concrete completion handler type.
38 typedef std::packaged_task<Result(Args...)> completion_handler_type;
39
40 /// The return type of the initiating function is the future obtained from
41 /// the packaged task.
42 typedef std::future<Result> return_type;
43
44 /// The constructor extracts the future from the packaged task.
45 explicit async_result(completion_handler_type& h)
46 : future_(h.get_future())
47 {
48 }
49
50 /// Returns the packaged task's future.
51 return_type get()
52 {
53 return std::move(future_);
54 }
55
56private:
57 return_type future_;
58};
59
60} // namespace asio
61} // namespace boost
62
63#include <boost/asio/detail/pop_options.hpp>
64
65#endif // defined(BOOST_ASIO_HAS_STD_FUTURE_CLASS)
66 // || defined(GENERATING_DOCUMENTATION)
67
68#endif // BOOST_ASIO_PACKAGED_TASK_HPP
69

source code of boost/libs/asio/include/boost/asio/packaged_task.hpp