boost_1_45_0/libs/asio/doc/requirements/AsyncWriteStream.qbk

[/
 / Copyright (c) 2003-2010 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)
 /]

[section:AsyncWriteStream Buffer-oriented asynchronous write stream requirements]

In the table below, `a` denotes an asynchronous write stream object, `cb`
denotes an object satisfying [link boost_asio.reference.ConstBufferSequence
constant buffer sequence] requirements, and `h` denotes an object satisfying
[link boost_asio.reference.WriteHandler write handler] requirements.

[table Buffer-oriented asynchronous write stream requirements
  [[operation] [type] [semantics, pre/post-conditions]]
  [
    [`a.io_service();`]
    [`io_service&`]
    [Returns the `io_service` object through which the `async_write_some`
    handler `h` will be invoked.]
  ]
  [
    [`a.async_write_some(cb, h);`]
    [`void`]
    [
      Initiates an asynchronous operation to write one or more bytes of data to
      the stream `a`. The operation is performed via the `io_service` object
      `a.io_service()` and behaves according to [link
      boost_asio.reference.asynchronous_operations asynchronous operation]
      requirements.\n
      \n
      The constant buffer sequence `cb` specifies memory where the data to be
      written is located. The `async_write_some` operation shall always write a
      buffer in the sequence completely before proceeding to the next.\n
      \n
      The implementation shall maintain one or more copies of `cb` until such
      time as the write operation no longer requires access to the memory
      specified by the buffers in the sequence. The program must ensure the
      memory is valid until:\n
      \n
      [mdash] the last copy of `cb` is destroyed, or\n
      \n
      [mdash] the handler for the asynchronous write operation is invoked,\n
      \n
      whichever comes first.\n
      \n
      If the total size of all buffers in the sequence `cb` is `0`, the
      asynchronous write operation shall complete immediately and pass `0` as
      the argument to the handler that specifies the number of bytes written.
    ]
  ]
]

[endsect]