asio/doc/requirements/SyncRandomAccessWriteDevice.qbk
2019-02-17 19:59:39 -10:00

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[/
/ 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)
/]
[section:SyncRandomAccessWriteDevice Buffer-oriented synchronous random-access
write device requirements]
In the table below, `a` denotes a synchronous random-access write device
object, `o` denotes an offset of type `boost::uint64_t`, `cb` denotes an object
satisfying [link boost_asio.reference.ConstBufferSequence constant buffer sequence]
requirements, and `ec` denotes an object of type `error_code`.
[table Buffer-oriented synchronous random-access write device requirements
[[operation] [type] [semantics, pre/post-conditions]]
[
[`a.write_some_at(o, cb);`]
[`size_t`]
[Equivalent to:
``
error_code ec;
size_t s = a.write_some(o, cb, ec);
if (ec) throw system_error(ec);
return s;
``]
]
[
[`a.write_some_at(o, cb, ec);`]
[`size_t`]
[
Writes one or more bytes of data to the device `a` at offset `o`.\n
\n
The constant buffer sequence `cb` specifies memory where the data to be
written is located. The `write_some_at` operation shall always write a
buffer in the sequence completely before proceeding to the next.\n
\n
If successful, returns the number of bytes written and sets `ec` such
that `!ec` is true. If an error occurred, returns `0` and sets `ec` such
that `!!ec` is true.\n
\n
If the total size of all buffers in the sequence `cb` is `0`, the
function shall return `0` immediately.
]
]
]
[endsect]