lass="keyword">static</span> <span class="identifier">node_ptr</span> <a name="idp72478192-bb"></a><span class="identifier">next_node</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">node_ptr</span> <span class="special">&amp;</span> p<span class="special">)</span><span class="special">;</span></pre>
<p><span class="bold"><strong>Requires</strong></span>: p is a node from the tree except the header.</p>
<p><span class="bold"><strong>Effects</strong></span>: Ret