;</span></pre>
<p><span class="bold"><strong>Precondition</strong></span>: <code class="computeroutput"><a class="link" href="link_mode.html" title="Struct template link_mode">link_mode</a></code> must be <code class="computeroutput">safe_link</code> or <code class="computeroutput">auto_unlink</code>.</p>
<p><span class="bold"><strong>Returns</strong></span>: true, if the node belongs to a container, false otherwise. This function can be used to test whether <code class="computeroutput">unordered_set::itera