em">
<pre class="literallayout"><span class="identifier">implementation_defined</span> <a name="idm31919-bb"></a><span class="keyword">operator</span><span class="special">[</span><span class="special">]</span><span class="special">(</span><span class="identifier">attribute_value_type</span> <span class="keyword">const</span> <span class="special">&amp;</span> key<span class="special">)</span><span class="special">;</span></pre>
<p>Insertion operator</p>
<p>

</p>
<div class="variablelist"><table border="0"