pan><span class="special">(</span><span class="keyword">const</span> <span class="identifier">const_node_ptr</span> <span class="special">&amp;</span> node<span class="special">)</span><span class="special">;</span></pre>
<p><span class="bold"><strong>Requires</strong></span>: 'node' is a node of the tree or a node initialized by init(...) or init_node.</p>
<p><span class="bold"><strong>Effects</strong></span>: Returns true if the node is initialized by init() or init_node().</p>
<p><span class="bold"><stro