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<title>write_at (2 of 8 overloads)</title>
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<div class="titlepage"><div><div><h4 class="title">
<a name="boost_asio.reference.write_at.overload2"></a><a class="link" href="overload2.html" title="write_at (2 of 8 overloads)">write_at (2
of 8 overloads)</a>
</h4></div></div></div>
<p>
Write all of the supplied data at the specified offset before returning.
</p>
<pre class="programlisting">template<
typename <a class="link" href="../SyncRandomAccessWriteDevice.html" title="Buffer-oriented synchronous random-access write device requirements">SyncRandomAccessWriteDevice</a>,
typename <a class="link" href="../ConstBufferSequence.html" title="Constant buffer sequence requirements">ConstBufferSequence</a>>
std::size_t write_at(
SyncRandomAccessWriteDevice & d,
uint64_t offset,
const ConstBufferSequence & buffers,
boost::system::error_code & ec);
</pre>
<p>
This function is used to write a certain number of bytes of data to a random
access device at a specified offset. The call will block until one of the
following conditions is true:
</p>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
All of the data in the supplied buffers has been written. That is,
the bytes transferred is equal to the sum of the buffer sizes.
</li>
<li class="listitem">
An error occurred.
</li>
</ul></div>
<p>
This operation is implemented in terms of zero or more calls to the device's
write_some_at function.
</p>
<h6>
<a name="boost_asio.reference.write_at.overload2.h0"></a>
<span class="phrase"><a name="boost_asio.reference.write_at.overload2.parameters"></a></span><a class="link" href="overload2.html#boost_asio.reference.write_at.overload2.parameters">Parameters</a>
</h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl class="variablelist">
<dt><span class="term">d</span></dt>
<dd><p>
The device to which the data is to be written. The type must support
the SyncRandomAccessWriteDevice concept.
</p></dd>
<dt><span class="term">offset</span></dt>
<dd><p>
The offset at which the data will be written.
</p></dd>
<dt><span class="term">buffers</span></dt>
<dd><p>
One or more buffers containing the data to be written. The sum of
the buffer sizes indicates the maximum number of bytes to write to
the device.
</p></dd>
<dt><span class="term">ec</span></dt>
<dd><p>
Set to indicate what error occurred, if any.
</p></dd>
</dl>
</div>
<h6>
<a name="boost_asio.reference.write_at.overload2.h1"></a>
<span class="phrase"><a name="boost_asio.reference.write_at.overload2.return_value"></a></span><a class="link" href="overload2.html#boost_asio.reference.write_at.overload2.return_value">Return Value</a>
</h6>
<p>
The number of bytes transferred.
</p>
<h6>
<a name="boost_asio.reference.write_at.overload2.h2"></a>
<span class="phrase"><a name="boost_asio.reference.write_at.overload2.example"></a></span><a class="link" href="overload2.html#boost_asio.reference.write_at.overload2.example">Example</a>
</h6>
<p>
To write a single data buffer use the <a class="link" href="../buffer.html" title="buffer"><code class="computeroutput">buffer</code></a>
function as follows:
</p>
<pre class="programlisting">boost::asio::write_at(d, 42,
boost::asio::buffer(data, size), ec);
</pre>
<p>
See the <a class="link" href="../buffer.html" title="buffer"><code class="computeroutput">buffer</code></a>
documentation for information on writing multiple buffers in one go, and
how to use it with arrays, boost::array or std::vector.
</p>
<h6>
<a name="boost_asio.reference.write_at.overload2.h3"></a>
<span class="phrase"><a name="boost_asio.reference.write_at.overload2.remarks"></a></span><a class="link" href="overload2.html#boost_asio.reference.write_at.overload2.remarks">Remarks</a>
</h6>
<p>
This overload is equivalent to calling:
</p>
<pre class="programlisting">boost::asio::write_at(
d, offset, buffers,
boost::asio::transfer_all(), ec);
</pre>
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<td align="right"><div class="copyright-footer">Copyright © 2003-2017 Christopher M. Kohlhoff<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
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