eroutput">iterative_size()</code> is different from <code class="computeroutput">size()</code>. </p>
</li>
<li class="listitem">
<pre class="literallayout"><span class="identifier">codomain_type</span> <a name="idp41722944-bb"></a><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">domain_type</span> <span class="special">&amp;</span> key<span class="special">)</span> <span 