// read.hpp
// ~~~~~~~~
//
-// Copyright (c) 2003-2018 Christopher M. Kohlhoff (chris at kohlhoff dot com)
+// 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)
/**
* @defgroup read boost::asio::read
*
- * @brief Attempt to read a certain amount of data from a stream before
- * returning.
+ * @brief The @c read function is a composed operation that reads a certain
+ * amount of data from a stream before returning.
*/
/*@{*/
is_mutable_buffer_sequence<MutableBufferSequence>::value
>::type* = 0);
+#if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
+
/// Attempt to read a certain amount of data from a stream before returning.
/**
* This function is used to read a certain number of bytes of data from a
* s, buffers,
* boost::asio::transfer_all()); @endcode
*/
-template <typename SyncReadStream, typename DynamicBuffer>
+template <typename SyncReadStream, typename DynamicBuffer_v1>
std::size_t read(SyncReadStream& s,
- BOOST_ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ BOOST_ASIO_MOVE_ARG(DynamicBuffer_v1) buffers,
typename enable_if<
- is_dynamic_buffer<typename decay<DynamicBuffer>::type>::value
+ is_dynamic_buffer_v1<typename decay<DynamicBuffer_v1>::type>::value
+ && !is_dynamic_buffer_v2<typename decay<DynamicBuffer_v1>::type>::value
>::type* = 0);
/// Attempt to read a certain amount of data from a stream before returning.
* s, buffers,
* boost::asio::transfer_all(), ec); @endcode
*/
-template <typename SyncReadStream, typename DynamicBuffer>
+template <typename SyncReadStream, typename DynamicBuffer_v1>
std::size_t read(SyncReadStream& s,
- BOOST_ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ BOOST_ASIO_MOVE_ARG(DynamicBuffer_v1) buffers,
boost::system::error_code& ec,
typename enable_if<
- is_dynamic_buffer<typename decay<DynamicBuffer>::type>::value
+ is_dynamic_buffer_v1<typename decay<DynamicBuffer_v1>::type>::value
+ && !is_dynamic_buffer_v2<typename decay<DynamicBuffer_v1>::type>::value
>::type* = 0);
/// Attempt to read a certain amount of data from a stream before returning.
*
* @throws boost::system::system_error Thrown on failure.
*/
-template <typename SyncReadStream, typename DynamicBuffer,
+template <typename SyncReadStream, typename DynamicBuffer_v1,
typename CompletionCondition>
std::size_t read(SyncReadStream& s,
- BOOST_ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ BOOST_ASIO_MOVE_ARG(DynamicBuffer_v1) buffers,
CompletionCondition completion_condition,
typename enable_if<
- is_dynamic_buffer<typename decay<DynamicBuffer>::type>::value
+ is_dynamic_buffer_v1<typename decay<DynamicBuffer_v1>::type>::value
+ && !is_dynamic_buffer_v2<typename decay<DynamicBuffer_v1>::type>::value
>::type* = 0);
/// Attempt to read a certain amount of data from a stream before returning.
* @returns The number of bytes read. If an error occurs, returns the total
* number of bytes successfully transferred prior to the error.
*/
-template <typename SyncReadStream, typename DynamicBuffer,
+template <typename SyncReadStream, typename DynamicBuffer_v1,
typename CompletionCondition>
std::size_t read(SyncReadStream& s,
- BOOST_ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ BOOST_ASIO_MOVE_ARG(DynamicBuffer_v1) buffers,
CompletionCondition completion_condition, boost::system::error_code& ec,
typename enable_if<
- is_dynamic_buffer<typename decay<DynamicBuffer>::type>::value
+ is_dynamic_buffer_v1<typename decay<DynamicBuffer_v1>::type>::value
+ && !is_dynamic_buffer_v2<typename decay<DynamicBuffer_v1>::type>::value
>::type* = 0);
#if !defined(BOOST_ASIO_NO_EXTENSIONS)
#endif // !defined(BOOST_ASIO_NO_IOSTREAM)
#endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
+#endif // !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
+
+/// Attempt to read a certain amount of data from a stream before returning.
+/**
+ * This function is used to read a certain number of bytes of data from a
+ * stream. The call will block until one of the following conditions is true:
+ *
+ * @li The specified dynamic buffer sequence is full (that is, it has reached
+ * maximum size).
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ *
+ * @returns The number of bytes transferred.
+ *
+ * @throws boost::system::system_error Thrown on failure.
+ *
+ * @note This overload is equivalent to calling:
+ * @code boost::asio::read(
+ * s, buffers,
+ * boost::asio::transfer_all()); @endcode
+ */
+template <typename SyncReadStream, typename DynamicBuffer_v2>
+std::size_t read(SyncReadStream& s, DynamicBuffer_v2 buffers,
+ typename enable_if<
+ is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+ >::type* = 0);
+
+/// Attempt to read a certain amount of data from a stream before returning.
+/**
+ * This function is used to read a certain number of bytes of data from a
+ * stream. The call will block until one of the following conditions is true:
+ *
+ * @li The supplied buffer is full (that is, it has reached maximum size).
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ *
+ * @param ec Set to indicate what error occurred, if any.
+ *
+ * @returns The number of bytes transferred.
+ *
+ * @note This overload is equivalent to calling:
+ * @code boost::asio::read(
+ * s, buffers,
+ * boost::asio::transfer_all(), ec); @endcode
+ */
+template <typename SyncReadStream, typename DynamicBuffer_v2>
+std::size_t read(SyncReadStream& s, DynamicBuffer_v2 buffers,
+ boost::system::error_code& ec,
+ typename enable_if<
+ is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+ >::type* = 0);
+
+/// Attempt to read a certain amount of data from a stream before returning.
+/**
+ * This function is used to read a certain number of bytes of data from a
+ * stream. The call will block until one of the following conditions is true:
+ *
+ * @li The specified dynamic buffer sequence is full (that is, it has reached
+ * maximum size).
+ *
+ * @li The completion_condition function object returns 0.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ *
+ * @param completion_condition The function object to be called to determine
+ * whether the read operation is complete. The signature of the function object
+ * must be:
+ * @code std::size_t completion_condition(
+ * // Result of latest read_some operation.
+ * const boost::system::error_code& error,
+ *
+ * // Number of bytes transferred so far.
+ * std::size_t bytes_transferred
+ * ); @endcode
+ * A return value of 0 indicates that the read operation is complete. A non-zero
+ * return value indicates the maximum number of bytes to be read on the next
+ * call to the stream's read_some function.
+ *
+ * @returns The number of bytes transferred.
+ *
+ * @throws boost::system::system_error Thrown on failure.
+ */
+template <typename SyncReadStream, typename DynamicBuffer_v2,
+ typename CompletionCondition>
+std::size_t read(SyncReadStream& s, DynamicBuffer_v2 buffers,
+ CompletionCondition completion_condition,
+ typename enable_if<
+ is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+ >::type* = 0);
+
+/// Attempt to read a certain amount of data from a stream before returning.
+/**
+ * This function is used to read a certain number of bytes of data from a
+ * stream. The call will block until one of the following conditions is true:
+ *
+ * @li The specified dynamic buffer sequence is full (that is, it has reached
+ * maximum size).
+ *
+ * @li The completion_condition function object returns 0.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * read_some function.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the SyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ *
+ * @param completion_condition The function object to be called to determine
+ * whether the read operation is complete. The signature of the function object
+ * must be:
+ * @code std::size_t completion_condition(
+ * // Result of latest read_some operation.
+ * const boost::system::error_code& error,
+ *
+ * // Number of bytes transferred so far.
+ * std::size_t bytes_transferred
+ * ); @endcode
+ * A return value of 0 indicates that the read operation is complete. A non-zero
+ * return value indicates the maximum number of bytes to be read on the next
+ * call to the stream's read_some function.
+ *
+ * @param ec Set to indicate what error occurred, if any.
+ *
+ * @returns The number of bytes read. If an error occurs, returns the total
+ * number of bytes successfully transferred prior to the error.
+ */
+template <typename SyncReadStream, typename DynamicBuffer_v2,
+ typename CompletionCondition>
+std::size_t read(SyncReadStream& s, DynamicBuffer_v2 buffers,
+ CompletionCondition completion_condition, boost::system::error_code& ec,
+ typename enable_if<
+ is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+ >::type* = 0);
/*@}*/
/**
* @defgroup async_read boost::asio::async_read
*
- * @brief Start an asynchronous operation to read a certain amount of data from
- * a stream.
+ * @brief The @c async_read function is a composed asynchronous operation that
+ * reads a certain amount of data from a stream before completion.
*/
/*@{*/
* // prior to the error.
* ); @endcode
* Regardless of whether the asynchronous operation completes immediately or
- * not, the handler will not be invoked from within this function. Invocation of
- * the handler will be performed in a manner equivalent to using
- * boost::asio::io_context::post().
+ * not, the handler will not be invoked from within this function. On
+ * immediate completion, invocation of the handler will be performed in a
+ * manner equivalent to using boost::asio::post().
*
* @par Example
* To read into a single data buffer use the @ref buffer function as follows:
* handler); @endcode
*/
template <typename AsyncReadStream, typename MutableBufferSequence,
- typename ReadHandler>
-BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
+ BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
+ std::size_t)) ReadHandler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
+ typename AsyncReadStream::executor_type)>
+BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
void (boost::system::error_code, std::size_t))
async_read(AsyncReadStream& s, const MutableBufferSequence& buffers,
- BOOST_ASIO_MOVE_ARG(ReadHandler) handler,
+ BOOST_ASIO_MOVE_ARG(ReadHandler) handler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(
+ typename AsyncReadStream::executor_type),
typename enable_if<
is_mutable_buffer_sequence<MutableBufferSequence>::value
>::type* = 0);
* // prior to the error.
* ); @endcode
* Regardless of whether the asynchronous operation completes immediately or
- * not, the handler will not be invoked from within this function. Invocation of
- * the handler will be performed in a manner equivalent to using
- * boost::asio::io_context::post().
+ * not, the handler will not be invoked from within this function. On
+ * immediate completion, invocation of the handler will be performed in a
+ * manner equivalent to using boost::asio::post().
*
* @par Example
* To read into a single data buffer use the @ref buffer function as follows:
* buffers in one go, and how to use it with arrays, boost::array or
* std::vector.
*/
-template <typename AsyncReadStream, typename MutableBufferSequence,
- typename CompletionCondition, typename ReadHandler>
-BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
+template <typename AsyncReadStream,
+ typename MutableBufferSequence, typename CompletionCondition,
+ BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
+ std::size_t)) ReadHandler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
+ typename AsyncReadStream::executor_type)>
+BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
void (boost::system::error_code, std::size_t))
async_read(AsyncReadStream& s, const MutableBufferSequence& buffers,
CompletionCondition completion_condition,
- BOOST_ASIO_MOVE_ARG(ReadHandler) handler,
+ BOOST_ASIO_MOVE_ARG(ReadHandler) handler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(
+ typename AsyncReadStream::executor_type),
typename enable_if<
is_mutable_buffer_sequence<MutableBufferSequence>::value
>::type* = 0);
+#if !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
+
/// Start an asynchronous operation to read a certain amount of data from a
/// stream.
/**
* // prior to the error.
* ); @endcode
* Regardless of whether the asynchronous operation completes immediately or
- * not, the handler will not be invoked from within this function. Invocation of
- * the handler will be performed in a manner equivalent to using
- * boost::asio::io_context::post().
+ * not, the handler will not be invoked from within this function. On
+ * immediate completion, invocation of the handler will be performed in a
+ * manner equivalent to using boost::asio::post().
*
* @note This overload is equivalent to calling:
* @code boost::asio::async_read(
* boost::asio::transfer_all(),
* handler); @endcode
*/
-template <typename AsyncReadStream,
- typename DynamicBuffer, typename ReadHandler>
-BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
+template <typename AsyncReadStream, typename DynamicBuffer_v1,
+ BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
+ std::size_t)) ReadHandler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
+ typename AsyncReadStream::executor_type)>
+BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
void (boost::system::error_code, std::size_t))
async_read(AsyncReadStream& s,
- BOOST_ASIO_MOVE_ARG(DynamicBuffer) buffers,
- BOOST_ASIO_MOVE_ARG(ReadHandler) handler,
+ BOOST_ASIO_MOVE_ARG(DynamicBuffer_v1) buffers,
+ BOOST_ASIO_MOVE_ARG(ReadHandler) handler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(
+ typename AsyncReadStream::executor_type),
typename enable_if<
- is_dynamic_buffer<typename decay<DynamicBuffer>::type>::value
+ is_dynamic_buffer_v1<typename decay<DynamicBuffer_v1>::type>::value
+ && !is_dynamic_buffer_v2<typename decay<DynamicBuffer_v1>::type>::value
>::type* = 0);
/// Start an asynchronous operation to read a certain amount of data from a
* // prior to the error.
* ); @endcode
* Regardless of whether the asynchronous operation completes immediately or
- * not, the handler will not be invoked from within this function. Invocation of
- * the handler will be performed in a manner equivalent to using
- * boost::asio::io_context::post().
+ * not, the handler will not be invoked from within this function. On
+ * immediate completion, invocation of the handler will be performed in a
+ * manner equivalent to using boost::asio::post().
*/
-template <typename AsyncReadStream, typename DynamicBuffer,
- typename CompletionCondition, typename ReadHandler>
-BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
+template <typename AsyncReadStream,
+ typename DynamicBuffer_v1, typename CompletionCondition,
+ BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
+ std::size_t)) ReadHandler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
+ typename AsyncReadStream::executor_type)>
+BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
void (boost::system::error_code, std::size_t))
async_read(AsyncReadStream& s,
- BOOST_ASIO_MOVE_ARG(DynamicBuffer) buffers,
+ BOOST_ASIO_MOVE_ARG(DynamicBuffer_v1) buffers,
CompletionCondition completion_condition,
- BOOST_ASIO_MOVE_ARG(ReadHandler) handler,
+ BOOST_ASIO_MOVE_ARG(ReadHandler) handler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(
+ typename AsyncReadStream::executor_type),
typename enable_if<
- is_dynamic_buffer<typename decay<DynamicBuffer>::type>::value
+ is_dynamic_buffer_v1<typename decay<DynamicBuffer_v1>::type>::value
+ && !is_dynamic_buffer_v2<typename decay<DynamicBuffer_v1>::type>::value
>::type* = 0);
#if !defined(BOOST_ASIO_NO_EXTENSIONS)
* // prior to the error.
* ); @endcode
* Regardless of whether the asynchronous operation completes immediately or
- * not, the handler will not be invoked from within this function. Invocation of
- * the handler will be performed in a manner equivalent to using
- * boost::asio::io_context::post().
+ * not, the handler will not be invoked from within this function. On
+ * immediate completion, invocation of the handler will be performed in a
+ * manner equivalent to using boost::asio::post().
*
* @note This overload is equivalent to calling:
* @code boost::asio::async_read(
* boost::asio::transfer_all(),
* handler); @endcode
*/
-template <typename AsyncReadStream, typename Allocator, typename ReadHandler>
-BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
+template <typename AsyncReadStream, typename Allocator,
+ BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
+ std::size_t)) ReadHandler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
+ typename AsyncReadStream::executor_type)>
+BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
void (boost::system::error_code, std::size_t))
async_read(AsyncReadStream& s, basic_streambuf<Allocator>& b,
- BOOST_ASIO_MOVE_ARG(ReadHandler) handler);
+ BOOST_ASIO_MOVE_ARG(ReadHandler) handler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(
+ typename AsyncReadStream::executor_type));
/// Start an asynchronous operation to read a certain amount of data from a
/// stream.
* // prior to the error.
* ); @endcode
* Regardless of whether the asynchronous operation completes immediately or
- * not, the handler will not be invoked from within this function. Invocation of
- * the handler will be performed in a manner equivalent to using
- * boost::asio::io_context::post().
+ * not, the handler will not be invoked from within this function. On
+ * immediate completion, invocation of the handler will be performed in a
+ * manner equivalent to using boost::asio::post().
*/
-template <typename AsyncReadStream, typename Allocator,
- typename CompletionCondition, typename ReadHandler>
-BOOST_ASIO_INITFN_RESULT_TYPE(ReadHandler,
+template <typename AsyncReadStream,
+ typename Allocator, typename CompletionCondition,
+ BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
+ std::size_t)) ReadHandler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
+ typename AsyncReadStream::executor_type)>
+BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
void (boost::system::error_code, std::size_t))
async_read(AsyncReadStream& s, basic_streambuf<Allocator>& b,
CompletionCondition completion_condition,
- BOOST_ASIO_MOVE_ARG(ReadHandler) handler);
+ BOOST_ASIO_MOVE_ARG(ReadHandler) handler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(
+ typename AsyncReadStream::executor_type));
#endif // !defined(BOOST_ASIO_NO_IOSTREAM)
#endif // !defined(BOOST_ASIO_NO_EXTENSIONS)
+#endif // !defined(BOOST_ASIO_NO_DYNAMIC_BUFFER_V1)
+
+/// Start an asynchronous operation to read a certain amount of data from a
+/// stream.
+/**
+ * This function is used to asynchronously read a certain number of bytes of
+ * data from a stream. The function call always returns immediately. The
+ * asynchronous operation will continue until one of the following conditions is
+ * true:
+ *
+ * @li The specified dynamic buffer sequence is full (that is, it has reached
+ * maximum size).
+ *
+ * @li An error occurred.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * async_read_some function, and is known as a <em>composed operation</em>. The
+ * program must ensure that the stream performs no other read operations (such
+ * as async_read, the stream's async_read_some function, or any other composed
+ * operations that perform reads) until this operation completes.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the AsyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ * Although the buffers object may be copied as necessary, ownership of the
+ * underlying memory blocks is retained by the caller, which must guarantee
+ * that they remain valid until the handler is called.
+ *
+ * @param handler The handler to be called when the read operation completes.
+ * Copies will be made of the handler as required. The function signature of the
+ * handler must be:
+ * @code void handler(
+ * const boost::system::error_code& error, // Result of operation.
+ *
+ * std::size_t bytes_transferred // Number of bytes copied into the
+ * // buffers. If an error occurred,
+ * // this will be the number of
+ * // bytes successfully transferred
+ * // prior to the error.
+ * ); @endcode
+ * Regardless of whether the asynchronous operation completes immediately or
+ * not, the handler will not be invoked from within this function. On
+ * immediate completion, invocation of the handler will be performed in a
+ * manner equivalent to using boost::asio::post().
+ *
+ * @note This overload is equivalent to calling:
+ * @code boost::asio::async_read(
+ * s, buffers,
+ * boost::asio::transfer_all(),
+ * handler); @endcode
+ */
+template <typename AsyncReadStream, typename DynamicBuffer_v2,
+ BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
+ std::size_t)) ReadHandler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
+ typename AsyncReadStream::executor_type)>
+BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
+ void (boost::system::error_code, std::size_t))
+async_read(AsyncReadStream& s, DynamicBuffer_v2 buffers,
+ BOOST_ASIO_MOVE_ARG(ReadHandler) handler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(
+ typename AsyncReadStream::executor_type),
+ typename enable_if<
+ is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+ >::type* = 0);
+
+/// Start an asynchronous operation to read a certain amount of data from a
+/// stream.
+/**
+ * This function is used to asynchronously read a certain number of bytes of
+ * data from a stream. The function call always returns immediately. The
+ * asynchronous operation will continue until one of the following conditions is
+ * true:
+ *
+ * @li The specified dynamic buffer sequence is full (that is, it has reached
+ * maximum size).
+ *
+ * @li The completion_condition function object returns 0.
+ *
+ * This operation is implemented in terms of zero or more calls to the stream's
+ * async_read_some function, and is known as a <em>composed operation</em>. The
+ * program must ensure that the stream performs no other read operations (such
+ * as async_read, the stream's async_read_some function, or any other composed
+ * operations that perform reads) until this operation completes.
+ *
+ * @param s The stream from which the data is to be read. The type must support
+ * the AsyncReadStream concept.
+ *
+ * @param buffers The dynamic buffer sequence into which the data will be read.
+ * Although the buffers object may be copied as necessary, ownership of the
+ * underlying memory blocks is retained by the caller, which must guarantee
+ * that they remain valid until the handler is called.
+ *
+ * @param completion_condition The function object to be called to determine
+ * whether the read operation is complete. The signature of the function object
+ * must be:
+ * @code std::size_t completion_condition(
+ * // Result of latest async_read_some operation.
+ * const boost::system::error_code& error,
+ *
+ * // Number of bytes transferred so far.
+ * std::size_t bytes_transferred
+ * ); @endcode
+ * A return value of 0 indicates that the read operation is complete. A non-zero
+ * return value indicates the maximum number of bytes to be read on the next
+ * call to the stream's async_read_some function.
+ *
+ * @param handler The handler to be called when the read operation completes.
+ * Copies will be made of the handler as required. The function signature of the
+ * handler must be:
+ * @code void handler(
+ * const boost::system::error_code& error, // Result of operation.
+ *
+ * std::size_t bytes_transferred // Number of bytes copied into the
+ * // buffers. If an error occurred,
+ * // this will be the number of
+ * // bytes successfully transferred
+ * // prior to the error.
+ * ); @endcode
+ * Regardless of whether the asynchronous operation completes immediately or
+ * not, the handler will not be invoked from within this function. On
+ * immediate completion, invocation of the handler will be performed in a
+ * manner equivalent to using boost::asio::post().
+ */
+template <typename AsyncReadStream,
+ typename DynamicBuffer_v2, typename CompletionCondition,
+ BOOST_ASIO_COMPLETION_TOKEN_FOR(void (boost::system::error_code,
+ std::size_t)) ReadHandler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN_TYPE(
+ typename AsyncReadStream::executor_type)>
+BOOST_ASIO_INITFN_AUTO_RESULT_TYPE(ReadHandler,
+ void (boost::system::error_code, std::size_t))
+async_read(AsyncReadStream& s, DynamicBuffer_v2 buffers,
+ CompletionCondition completion_condition,
+ BOOST_ASIO_MOVE_ARG(ReadHandler) handler
+ BOOST_ASIO_DEFAULT_COMPLETION_TOKEN(
+ typename AsyncReadStream::executor_type),
+ typename enable_if<
+ is_dynamic_buffer_v2<DynamicBuffer_v2>::value
+ >::type* = 0);
/*@}*/
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