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<div class="titlepage"><div><div><h4 class="title">
<a name="asio.reference.cancellation_slot.emplace"></a><a class="link" href="emplace.html" title="cancellation_slot::emplace">cancellation_slot::emplace</a>
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<p>
<a class="indexterm" name="asio.indexterm.cancellation_slot.emplace"></a>
Installs
a handler into the slot, constructing the new object directly.
</p>
<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span>
<span class="keyword">typename</span> <a class="link" href="../CancellationHandler.html" title="Cancellation handler requirements">CancellationHandler</a><span class="special">,</span>
<span class="keyword">typename</span><span class="special">...</span> <span class="identifier">Args</span><span class="special">></span>
<span class="identifier">CancellationHandler</span> <span class="special">&</span> <span class="identifier">emplace</span><span class="special">(</span>
<span class="identifier">Args</span> <span class="special">&&...</span> <span class="identifier">args</span><span class="special">);</span>
</pre>
<p>
Destroys any existing handler in the slot, then installs the new handler,
constructing it with the supplied <code class="computeroutput"><span class="identifier">args</span></code>.
</p>
<p>
The handler is a function object to be called when the signal is emitted.
The signature of the handler must be
</p>
<pre class="programlisting"><span class="keyword">void</span> <span class="identifier">handler</span><span class="special">(</span><span class="identifier">asio</span><span class="special">::</span><span class="identifier">cancellation_type_t</span><span class="special">);</span>
</pre>
<h6>
<a name="asio.reference.cancellation_slot.emplace.h0"></a>
<span><a name="asio.reference.cancellation_slot.emplace.parameters"></a></span><a class="link" href="emplace.html#asio.reference.cancellation_slot.emplace.parameters">Parameters</a>
</h6>
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<p class="title"><b></b></p>
<dl>
<dt><span class="term">args</span></dt>
<dd><p>
Arguments to be passed to the <code class="computeroutput"><span class="identifier">CancellationHandler</span></code>
object's constructor.
</p></dd>
</dl>
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<h6>
<a name="asio.reference.cancellation_slot.emplace.h1"></a>
<span><a name="asio.reference.cancellation_slot.emplace.return_value"></a></span><a class="link" href="emplace.html#asio.reference.cancellation_slot.emplace.return_value">Return
Value</a>
</h6>
<p>
A reference to the newly installed handler.
</p>
<h6>
<a name="asio.reference.cancellation_slot.emplace.h2"></a>
<span><a name="asio.reference.cancellation_slot.emplace.remarks"></a></span><a class="link" href="emplace.html#asio.reference.cancellation_slot.emplace.remarks">Remarks</a>
</h6>
<p>
Handlers installed into the slot via <code class="computeroutput"><span class="identifier">emplace</span></code>
are not required to be copy constructible or move constructible.
</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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