Insane_DNS/libraries/asio-1.28.1/doc/asio/reference/transfer_at_least.html

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<div class="titlepage"><div><div><h3 class="title">
<a name="asio.reference.transfer_at_least"></a><a class="link" href="transfer_at_least.html" title="transfer_at_least">transfer_at_least</a>
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<p>
<a class="indexterm" name="asio.indexterm.transfer_at_least"></a>
</p>
<p>
Return a completion condition function object that indicates that a read
or write operation should continue until a minimum number of bytes has been
transferred, or until an error occurs.
</p>
<pre class="programlisting"><span class="identifier">unspecified</span> <span class="identifier">transfer_at_least</span><span class="special">(</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">minimum</span><span class="special">);</span>
</pre>
<p>
This function is used to create an object, of unspecified type, that meets
CompletionCondition requirements.
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<h5>
<a name="asio.reference.transfer_at_least.h0"></a>
<span><a name="asio.reference.transfer_at_least.example"></a></span><a class="link" href="transfer_at_least.html#asio.reference.transfer_at_least.example">Example</a>
</h5>
<p>
Reading until a buffer is full or contains at least 64 bytes:
</p>
<pre class="programlisting"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">array</span><span class="special">&lt;</span><span class="keyword">char</span><span class="special">,</span> <span class="number">128</span><span class="special">&gt;</span> <span class="identifier">buf</span><span class="special">;</span>
<span class="identifier">asio</span><span class="special">::</span><span class="identifier">error_code</span> <span class="identifier">ec</span><span class="special">;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">size_t</span> <span class="identifier">n</span> <span class="special">=</span> <span class="identifier">asio</span><span class="special">::</span><span class="identifier">read</span><span class="special">(</span>
<span class="identifier">sock</span><span class="special">,</span> <span class="identifier">asio</span><span class="special">::</span><span class="identifier">buffer</span><span class="special">(</span><span class="identifier">buf</span><span class="special">),</span>
<span class="identifier">asio</span><span class="special">::</span><span class="identifier">transfer_at_least</span><span class="special">(</span><span class="number">64</span><span class="special">),</span> <span class="identifier">ec</span><span class="special">);</span>
<span class="keyword">if</span> <span class="special">(</span><span class="identifier">ec</span><span class="special">)</span>
<span class="special">{</span>
<span class="comment">// An error occurred.</span>
<span class="special">}</span>
<span class="keyword">else</span>
<span class="special">{</span>
<span class="comment">// n &gt;= 64 &amp;&amp; n &lt;= 128</span>
<span class="special">}</span>
</pre>
<h5>
<a name="asio.reference.transfer_at_least.h1"></a>
<span><a name="asio.reference.transfer_at_least.requirements"></a></span><a class="link" href="transfer_at_least.html#asio.reference.transfer_at_least.requirements">Requirements</a>
</h5>
<p>
<span class="emphasis"><em>Header: </em></span><code class="literal">asio/completion_condition.hpp</code>
</p>
<p>
<span class="emphasis"><em>Convenience header: </em></span><code class="literal">asio.hpp</code>
</p>
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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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