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53d4f4b166
In essence, yield_t et al. become very like use_future_t et al. The only real difference is the async_result return type and get() method. Factor out common functionality into promise_completion_token and promise_handler. Remove the boost::fibers::asio::spawn() function and its basic_yield_context infrastructure. Fix up all existing references in example source code.
78 lines
2.4 KiB
C++
78 lines
2.4 KiB
C++
//
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// use_future.hpp
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// ~~~~~~~~~~~~~~
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//
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// Copyright (c) 2003-2013 Christopher M. Kohlhoff (chris at kohlhoff dot com)
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//
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// Distributed under the Boost Software License, Version 1.0. (See accompanying
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// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
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//
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// modified by Oliver Kowalke and Nat Goodspeed
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//
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#ifndef BOOST_FIBERS_ASIO_USE_FUTURE_HPP
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#define BOOST_FIBERS_ASIO_USE_FUTURE_HPP
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#include <memory> // std::allocator
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#include <boost/config.hpp>
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#include "promise_completion_token.hpp"
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#ifdef BOOST_HAS_ABI_HEADERS
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# include BOOST_ABI_PREFIX
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#endif
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namespace boost {
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namespace fibers {
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namespace asio {
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/// Class used to specify that a Boost.Asio asynchronous operation should
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/// return a future.
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/**
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* The use_future_t class is used to indicate that a Boost.Asio asynchronous
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* operation should return a boost::fibers::future object. A use_future_t
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* object may be passed as a handler to an asynchronous operation, typically
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* using the special value @c boost::fibers::asio::use_future. For example:
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*
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* @code boost::fibers::future<std::size_t> my_future
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* = my_socket.async_read_some(my_buffer, boost::fibers::asio::use_future); @endcode
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*
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* The initiating function (async_read_some in the above example) returns a
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* future that will receive the result of the operation. If the operation
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* completes with an error_code indicating failure, it is converted into a
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* system_error and passed back to the caller via the future.
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*/
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template< typename Allocator = std::allocator< void > >
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class use_future_t: public promise_completion_token<Allocator>
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{
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public:
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/// Construct using default-constructed allocator.
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BOOST_CONSTEXPR use_future_t()
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{}
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/// Construct using specified allocator.
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explicit use_future_t( Allocator const& allocator) :
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promise_completion_token<Allocator>( allocator)
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{}
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/// Specify an alternate allocator.
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template< typename OtherAllocator >
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use_future_t< OtherAllocator >
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operator[]( OtherAllocator const& allocator) const
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{ return use_future_t< OtherAllocator >( allocator); }
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};
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/// A special value, similar to std::nothrow.
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BOOST_CONSTEXPR_OR_CONST use_future_t<> use_future;
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} // namespace asio
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} // namespace fibers
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} // namespace boost
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#ifdef BOOST_HAS_ABI_HEADERS
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# include BOOST_ABI_SUFFIX
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#endif
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#include "detail/use_future.hpp"
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#endif // BOOST_FIBERS_ASIO_USE_FUTURE_HPP
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