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<div class="titlepage"><div><div><h4 class="title">
<a name="asio.reference.read.overload5"></a><a class="link" href="overload5.html" title="read (5 of 16 overloads)">read (5 of 16 overloads)</a>
</h4></div></div></div>
<p>
Attempt to read a certain amount of data from a stream before returning.
</p>
<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span>
<span class="keyword">typename</span> <a class="link" href="../SyncReadStream.html" title="Buffer-oriented synchronous read stream requirements">SyncReadStream</a><span class="special">,</span>
<span class="keyword">typename</span> <a class="link" href="../DynamicBuffer_v1.html" title="Dynamic buffer requirements (version 1)">DynamicBuffer_v1</a><span class="special">></span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">read</span><span class="special">(</span>
<span class="identifier">SyncReadStream</span> <span class="special">&</span> <span class="identifier">s</span><span class="special">,</span>
<span class="identifier">DynamicBuffer_v1</span> <span class="special">&&</span> <span class="identifier">buffers</span><span class="special">,</span>
<span class="keyword">typename</span> <span class="identifier">constraint</span><span class="special"><</span> <span class="identifier">is_dynamic_buffer_v1</span><span class="special"><</span> <span class="keyword">typename</span> <span class="identifier">decay</span><span class="special"><</span> <span class="identifier">DynamicBuffer_v1</span> <span class="special">>::</span><span class="identifier">type</span> <span class="special">>::</span><span class="identifier">value</span> <span class="special">>::</span><span class="identifier">type</span> <span class="special">=</span> <span class="number">0</span><span class="special">,</span>
<span class="keyword">typename</span> <span class="identifier">constraint</span><span class="special"><</span> <span class="special">!</span><span class="identifier">is_dynamic_buffer_v2</span><span class="special"><</span> <span class="keyword">typename</span> <span class="identifier">decay</span><span class="special"><</span> <span class="identifier">DynamicBuffer_v1</span> <span class="special">>::</span><span class="identifier">type</span> <span class="special">>::</span><span class="identifier">value</span> <span class="special">>::</span><span class="identifier">type</span> <span class="special">=</span> <span class="number">0</span><span class="special">);</span>
</pre>
<p>
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:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
The specified dynamic buffer sequence is full (that is, it has reached
maximum size).
</li>
<li class="listitem">
An error occurred.
</li>
</ul></div>
<p>
This operation is implemented in terms of zero or more calls to the stream's
read_some function.
</p>
<h6>
<a name="asio.reference.read.overload5.h0"></a>
<span><a name="asio.reference.read.overload5.parameters"></a></span><a class="link" href="overload5.html#asio.reference.read.overload5.parameters">Parameters</a>
</h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl>
<dt><span class="term">s</span></dt>
<dd><p>
The stream from which the data is to be read. The type must support
the SyncReadStream concept.
</p></dd>
<dt><span class="term">buffers</span></dt>
<dd><p>
The dynamic buffer sequence into which the data will be read.
</p></dd>
</dl>
</div>
<h6>
<a name="asio.reference.read.overload5.h1"></a>
<span><a name="asio.reference.read.overload5.return_value"></a></span><a class="link" href="overload5.html#asio.reference.read.overload5.return_value">Return
Value</a>
</h6>
<p>
The number of bytes transferred.
</p>
<h6>
<a name="asio.reference.read.overload5.h2"></a>
<span><a name="asio.reference.read.overload5.exceptions"></a></span><a class="link" href="overload5.html#asio.reference.read.overload5.exceptions">Exceptions</a>
</h6>
<div class="variablelist">
<p class="title"><b></b></p>
<dl>
<dt><span class="term">asio::system_error</span></dt>
<dd><p>
Thrown on failure.
</p></dd>
</dl>
</div>
<h6>
<a name="asio.reference.read.overload5.h3"></a>
<span><a name="asio.reference.read.overload5.remarks"></a></span><a class="link" href="overload5.html#asio.reference.read.overload5.remarks">Remarks</a>
</h6>
<p>
This overload is equivalent to calling:
</p>
<pre class="programlisting"><span class="identifier">asio</span><span class="special">::</span><span class="identifier">read</span><span class="special">(</span>
<span class="identifier">s</span><span class="special">,</span> <span class="identifier">buffers</span><span class="special">,</span>
<span class="identifier">asio</span><span class="special">::</span><span class="identifier">transfer_all</span><span class="special">());</span>
</pre>
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<div class="copyright-footer">Copyright © 2003-2023 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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