/span><span class="special">(</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<p>Returns: Returns: use_count() == 0.</p>
<p>Throws: nothing.</p>
<p>Notes: expired() may be faster than use_count(). </p>
</li>
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<pre class="literallayout"><span class="keyword">void</span> <a name="idp56977648-bb"></a><span class="identifier">reset</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre