n class=special>&lt;</span><span class=keyword>typename</span> <span class=identifier>T</span><span class=special>&gt;</span>
<span class=keyword>struct</span> <span class=identifier>holder</span><span class=special>;</span>

<span class=special>}</span> <span class=comment>// namespace boost::flyweights</span>

<span class=special>}</span> <span class=comment>// namespace boost</span>
</pre></blockquote>

<h3><a name="is_holder">Class template <code>is_holder</code></a></h3>

<p>
Unless specialized by the 