an class="identifier">node_base</span><span class="special">*</span></code> object that underlies <code class="computeroutput"><span class="identifier">node_iterator</span></code>
          is itself an iterator, just like all other pointers. If we examine that
          pointer closely from an iterator perspective, we can see that it has much
          in common with the <code class="computeroutput"><span class="identifier">node_iterator</span></code>
          we're building. First, they share most of the