void_receiver.hpp 2.13 KB
//
// execution/detail/void_receiver.hpp
// ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2020 Christopher M. Kohlhoff (chris at kohlhoff dot com)
//
// Distributed under the Boost Software License, Version 1.0. (See accompanying
// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
//

#ifndef ASIO_EXECUTION_DETAIL_VOID_RECEIVER_HPP
#define ASIO_EXECUTION_DETAIL_VOID_RECEIVER_HPP

#if defined(_MSC_VER) && (_MSC_VER >= 1200)
# pragma once
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)

#include "asio/detail/config.hpp"
#include "asio/traits/set_done_member.hpp"
#include "asio/traits/set_error_member.hpp"
#include "asio/traits/set_value_member.hpp"

#include "asio/detail/push_options.hpp"

namespace asio {
namespace execution {
namespace detail {

struct void_receiver
{
  void set_value() ASIO_NOEXCEPT
  {
  }

  template <typename E>
  void set_error(ASIO_MOVE_ARG(E)) ASIO_NOEXCEPT
  {
  }

  void set_done() ASIO_NOEXCEPT
  {
  }
};

} // namespace detail
} // namespace execution
namespace traits {

#if !defined(ASIO_HAS_DEDUCED_SET_VALUE_MEMBER_TRAIT)

template <>
struct set_value_member<asio::execution::detail::void_receiver, void()>
{
  ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
  ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
  typedef void result_type;
};

#endif // !defined(ASIO_HAS_DEDUCED_SET_VALUE_MEMBER_TRAIT)

#if !defined(ASIO_HAS_DEDUCED_SET_ERROR_MEMBER_TRAIT)

template <typename E>
struct set_error_member<asio::execution::detail::void_receiver, E>
{
  ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
  ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
  typedef void result_type;
};

#endif // !defined(ASIO_HAS_DEDUCED_SET_ERROR_MEMBER_TRAIT)

#if !defined(ASIO_HAS_DEDUCED_SET_DONE_MEMBER_TRAIT)

template <>
struct set_done_member<asio::execution::detail::void_receiver>
{
  ASIO_STATIC_CONSTEXPR(bool, is_valid = true);
  ASIO_STATIC_CONSTEXPR(bool, is_noexcept = true);
  typedef void result_type;
};

#endif // !defined(ASIO_HAS_DEDUCED_SET_DONE_MEMBER_TRAIT)

} // namespace traits
} // namespace asio

#include "asio/detail/pop_options.hpp"

#endif // ASIO_EXECUTION_DETAIL_VOID_RECEIVER_HPP