summaryrefslogtreecommitdiff
path: root/boost/asio/compose.hpp
diff options
context:
space:
mode:
Diffstat (limited to 'boost/asio/compose.hpp')
-rw-r--r--boost/asio/compose.hpp138
1 files changed, 138 insertions, 0 deletions
diff --git a/boost/asio/compose.hpp b/boost/asio/compose.hpp
new file mode 100644
index 0000000000..b38e4faecb
--- /dev/null
+++ b/boost/asio/compose.hpp
@@ -0,0 +1,138 @@
+//
+// compose.hpp
+// ~~~~~~~~~~~
+//
+// Copyright (c) 2003-2019 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_COMPOSE_HPP
+#define BOOST_ASIO_COMPOSE_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/async_result.hpp>
+
+#include <boost/asio/detail/push_options.hpp>
+
+namespace boost {
+namespace asio {
+
+#if defined(BOOST_ASIO_HAS_VARIADIC_TEMPLATES) \
+ || defined(GENERATING_DOCUMENTATION)
+
+/// Launch an asynchronous operation with a stateful implementation.
+/**
+ * The async_compose function simplifies the implementation of composed
+ * asynchronous operations automatically wrapping a stateful function object
+ * with a conforming intermediate completion handler.
+ *
+ * @param implementation A function object that contains the implementation of
+ * the composed asynchronous operation. The first argument to the function
+ * object is a non-const reference to the enclosing intermediate completion
+ * handler. The remaining arguments are any arguments that originate from the
+ * completion handlers of any asynchronous operations performed by the
+ * implementation.
+
+ * @param token The completion token.
+ *
+ * @param io_objects_or_executors Zero or more I/O objects or I/O executors for
+ * which outstanding work must be maintained.
+ *
+ * @par Example:
+ *
+ * @code struct async_echo_implementation
+ * {
+ * tcp::socket& socket_;
+ * boost::asio::mutable_buffer buffer_;
+ * enum { starting, reading, writing } state_;
+ *
+ * template <typename Self>
+ * void operator()(Self& self,
+ * boost::system::error_code error = {},
+ * std::size_t n = 0)
+ * {
+ * switch (state_)
+ * {
+ * case starting:
+ * state_ = reading;
+ * socket_.async_read_some(
+ * buffer_, std::move(self));
+ * break;
+ * case reading:
+ * if (error)
+ * {
+ * self.complete(error, 0);
+ * }
+ * else
+ * {
+ * state_ = writing;
+ * boost::asio::async_write(socket_, buffer_,
+ * boost::asio::transfer_exactly(n),
+ * std::move(self));
+ * }
+ * break;
+ * case writing:
+ * self.complete(error, n);
+ * break;
+ * }
+ * }
+ * };
+ *
+ * template <typename CompletionToken>
+ * auto async_echo(tcp::socket& socket,
+ * boost::asio::mutable_buffer buffer,
+ * CompletionToken&& token) ->
+ * typename boost::asio::async_result<
+ * typename std::decay<CompletionToken>::type,
+ * void(boost::system::error_code, std::size_t)>::return_type
+ * {
+ * return boost::asio::async_compose<CompletionToken,
+ * void(boost::system::error_code, std::size_t)>(
+ * async_echo_implementation{socket, buffer,
+ * async_echo_implementation::starting},
+ * token, socket);
+ * } @endcode
+ */
+template <typename CompletionToken, typename Signature,
+ typename Implementation, typename... IoObjectsOrExecutors>
+BOOST_ASIO_INITFN_RESULT_TYPE(CompletionToken, Signature)
+async_compose(BOOST_ASIO_MOVE_ARG(Implementation) implementation,
+ BOOST_ASIO_NONDEDUCED_MOVE_ARG(CompletionToken) token,
+ BOOST_ASIO_MOVE_ARG(IoObjectsOrExecutors)... io_objects_or_executors);
+
+#else // defined(BOOST_ASIO_HAS_VARIADIC_TEMPLATES)
+ // || defined(GENERATING_DOCUMENTATION)
+
+template <typename CompletionToken, typename Signature, typename Implementation>
+BOOST_ASIO_INITFN_RESULT_TYPE(CompletionToken, Signature)
+async_compose(BOOST_ASIO_MOVE_ARG(Implementation) implementation,
+ BOOST_ASIO_NONDEDUCED_MOVE_ARG(CompletionToken) token);
+
+#define BOOST_ASIO_PRIVATE_ASYNC_COMPOSE_DEF(n) \
+ template <typename CompletionToken, typename Signature, \
+ typename Implementation, BOOST_ASIO_VARIADIC_TPARAMS(n)> \
+ BOOST_ASIO_INITFN_RESULT_TYPE(CompletionToken, Signature) \
+ async_compose(BOOST_ASIO_MOVE_ARG(Implementation) implementation, \
+ BOOST_ASIO_NONDEDUCED_MOVE_ARG(CompletionToken) token, \
+ BOOST_ASIO_VARIADIC_MOVE_PARAMS(n));
+ /**/
+ BOOST_ASIO_VARIADIC_GENERATE(BOOST_ASIO_PRIVATE_ASYNC_COMPOSE_DEF)
+#undef BOOST_ASIO_PRIVATE_ASYNC_COMPOSE_DEF
+
+#endif // defined(BOOST_ASIO_HAS_VARIADIC_TEMPLATES)
+ // || defined(GENERATING_DOCUMENTATION)
+
+} // namespace asio
+} // namespace boost
+
+#include <boost/asio/detail/pop_options.hpp>
+
+#include <boost/asio/impl/compose.hpp>
+
+#endif // BOOST_ASIO_COMPOSE_HPP