97 lines
2.7 KiB
C++
97 lines
2.7 KiB
C++
//
|
|
// async_result.hpp
|
|
// ~~~~~~~~~~~~~~~~
|
|
//
|
|
// Copyright (c) 2003-2016 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 BOOST_ASIO_ASYNC_RESULT_HPP
|
|
#define BOOST_ASIO_ASYNC_RESULT_HPP
|
|
|
|
#if defined(_MSC_VER) && (_MSC_VER >= 1200)
|
|
# pragma once
|
|
#endif // defined(_MSC_VER) && (_MSC_VER >= 1200)
|
|
|
|
#include <boost/asio/detail/config.hpp>
|
|
#include <boost/asio/handler_type.hpp>
|
|
|
|
#include <boost/asio/detail/push_options.hpp>
|
|
|
|
namespace boost {
|
|
namespace asio {
|
|
|
|
/// An interface for customising the behaviour of an initiating function.
|
|
/**
|
|
* This template may be specialised for user-defined handler types.
|
|
*/
|
|
template <typename Handler>
|
|
class async_result
|
|
{
|
|
public:
|
|
/// The return type of the initiating function.
|
|
typedef void type;
|
|
|
|
/// Construct an async result from a given handler.
|
|
/**
|
|
* When using a specalised async_result, the constructor has an opportunity
|
|
* to initialise some state associated with the handler, which is then
|
|
* returned from the initiating function.
|
|
*/
|
|
explicit async_result(Handler&)
|
|
{
|
|
}
|
|
|
|
/// Obtain the value to be returned from the initiating function.
|
|
type get()
|
|
{
|
|
}
|
|
};
|
|
|
|
namespace detail {
|
|
|
|
// Helper template to deduce the true type of a handler, capture a local copy
|
|
// of the handler, and then create an async_result for the handler.
|
|
template <typename Handler, typename Signature>
|
|
struct async_result_init
|
|
{
|
|
explicit async_result_init(BOOST_ASIO_MOVE_ARG(Handler) orig_handler)
|
|
: handler(BOOST_ASIO_MOVE_CAST(Handler)(orig_handler)),
|
|
result(handler)
|
|
{
|
|
}
|
|
|
|
typename handler_type<Handler, Signature>::type handler;
|
|
async_result<typename handler_type<Handler, Signature>::type> result;
|
|
};
|
|
|
|
template <typename Handler, typename Signature>
|
|
struct async_result_type_helper
|
|
{
|
|
typedef typename async_result<
|
|
typename handler_type<Handler, Signature>::type
|
|
>::type type;
|
|
};
|
|
|
|
} // namespace detail
|
|
} // namespace asio
|
|
} // namespace boost
|
|
|
|
#include <boost/asio/detail/pop_options.hpp>
|
|
|
|
#if defined(GENERATING_DOCUMENTATION)
|
|
# define BOOST_ASIO_INITFN_RESULT_TYPE(h, sig) \
|
|
void_or_deduced
|
|
#elif defined(_MSC_VER) && (_MSC_VER < 1500)
|
|
# define BOOST_ASIO_INITFN_RESULT_TYPE(h, sig) \
|
|
typename ::boost::asio::detail::async_result_type_helper<h, sig>::type
|
|
#else
|
|
# define BOOST_ASIO_INITFN_RESULT_TYPE(h, sig) \
|
|
typename ::boost::asio::async_result< \
|
|
typename ::boost::asio::handler_type<h, sig>::type>::type
|
|
#endif
|
|
|
|
#endif // BOOST_ASIO_ASYNC_RESULT_HPP
|