140 lines
4.3 KiB
C++
140 lines
4.3 KiB
C++
//
|
|
// as_tuple.hpp
|
|
// ~~~~~~~~~~~~
|
|
//
|
|
// Copyright (c) 2003-2023 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_AS_TUPLE_HPP
|
|
#define ASIO_AS_TUPLE_HPP
|
|
|
|
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
|
|
# pragma once
|
|
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
|
|
|
|
#include "asio/detail/config.hpp"
|
|
|
|
#if (defined(ASIO_HAS_STD_TUPLE) \
|
|
&& defined(ASIO_HAS_VARIADIC_TEMPLATES)) \
|
|
|| defined(GENERATING_DOCUMENTATION)
|
|
|
|
#include "asio/detail/type_traits.hpp"
|
|
|
|
#include "asio/detail/push_options.hpp"
|
|
|
|
namespace asio {
|
|
|
|
/// A @ref completion_token adapter used to specify that the completion handler
|
|
/// arguments should be combined into a single tuple argument.
|
|
/**
|
|
* The as_tuple_t class is used to indicate that any arguments to the
|
|
* completion handler should be combined and passed as a single tuple argument.
|
|
* The arguments are first moved into a @c std::tuple and that tuple is then
|
|
* passed to the completion handler.
|
|
*/
|
|
template <typename CompletionToken>
|
|
class as_tuple_t
|
|
{
|
|
public:
|
|
/// Tag type used to prevent the "default" constructor from being used for
|
|
/// conversions.
|
|
struct default_constructor_tag {};
|
|
|
|
/// Default constructor.
|
|
/**
|
|
* This constructor is only valid if the underlying completion token is
|
|
* default constructible and move constructible. The underlying completion
|
|
* token is itself defaulted as an argument to allow it to capture a source
|
|
* location.
|
|
*/
|
|
ASIO_CONSTEXPR as_tuple_t(
|
|
default_constructor_tag = default_constructor_tag(),
|
|
CompletionToken token = CompletionToken())
|
|
: token_(ASIO_MOVE_CAST(CompletionToken)(token))
|
|
{
|
|
}
|
|
|
|
/// Constructor.
|
|
template <typename T>
|
|
ASIO_CONSTEXPR explicit as_tuple_t(
|
|
ASIO_MOVE_ARG(T) completion_token)
|
|
: token_(ASIO_MOVE_CAST(T)(completion_token))
|
|
{
|
|
}
|
|
|
|
/// Adapts an executor to add the @c as_tuple_t completion token as the
|
|
/// default.
|
|
template <typename InnerExecutor>
|
|
struct executor_with_default : InnerExecutor
|
|
{
|
|
/// Specify @c as_tuple_t as the default completion token type.
|
|
typedef as_tuple_t default_completion_token_type;
|
|
|
|
/// Construct the adapted executor from the inner executor type.
|
|
template <typename InnerExecutor1>
|
|
executor_with_default(const InnerExecutor1& ex,
|
|
typename constraint<
|
|
conditional<
|
|
!is_same<InnerExecutor1, executor_with_default>::value,
|
|
is_convertible<InnerExecutor1, InnerExecutor>,
|
|
false_type
|
|
>::type::value
|
|
>::type = 0) ASIO_NOEXCEPT
|
|
: InnerExecutor(ex)
|
|
{
|
|
}
|
|
};
|
|
|
|
/// Type alias to adapt an I/O object to use @c as_tuple_t as its
|
|
/// default completion token type.
|
|
#if defined(ASIO_HAS_ALIAS_TEMPLATES) \
|
|
|| defined(GENERATING_DOCUMENTATION)
|
|
template <typename T>
|
|
using as_default_on_t = typename T::template rebind_executor<
|
|
executor_with_default<typename T::executor_type> >::other;
|
|
#endif // defined(ASIO_HAS_ALIAS_TEMPLATES)
|
|
// || defined(GENERATING_DOCUMENTATION)
|
|
|
|
/// Function helper to adapt an I/O object to use @c as_tuple_t as its
|
|
/// default completion token type.
|
|
template <typename T>
|
|
static typename decay<T>::type::template rebind_executor<
|
|
executor_with_default<typename decay<T>::type::executor_type>
|
|
>::other
|
|
as_default_on(ASIO_MOVE_ARG(T) object)
|
|
{
|
|
return typename decay<T>::type::template rebind_executor<
|
|
executor_with_default<typename decay<T>::type::executor_type>
|
|
>::other(ASIO_MOVE_CAST(T)(object));
|
|
}
|
|
|
|
//private:
|
|
CompletionToken token_;
|
|
};
|
|
|
|
/// Adapt a @ref completion_token to specify that the completion handler
|
|
/// arguments should be combined into a single tuple argument.
|
|
template <typename CompletionToken>
|
|
ASIO_NODISCARD inline
|
|
ASIO_CONSTEXPR as_tuple_t<typename decay<CompletionToken>::type>
|
|
as_tuple(ASIO_MOVE_ARG(CompletionToken) completion_token)
|
|
{
|
|
return as_tuple_t<typename decay<CompletionToken>::type>(
|
|
ASIO_MOVE_CAST(CompletionToken)(completion_token));
|
|
}
|
|
|
|
} // namespace asio
|
|
|
|
#include "asio/detail/pop_options.hpp"
|
|
|
|
#include "asio/impl/as_tuple.hpp"
|
|
|
|
#endif // (defined(ASIO_HAS_STD_TUPLE)
|
|
// && defined(ASIO_HAS_VARIADIC_TEMPLATES))
|
|
// || defined(GENERATING_DOCUMENTATION)
|
|
|
|
#endif // ASIO_AS_TUPLE_HPP
|