an class="special">{};</span>
</pre>
<p>
        <span class="bold"><strong>Inherits:</strong></span> If the expression <code class="computeroutput"><span class="identifier">swap</span><span class="special">(</span><span class="identifier">declval</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&amp;&gt;(),</span>
        <span class="identifier">declval</span><span class="special">&lt;</span><span class="identifier">T</span><span class="special">&amp;&gt;())</s