put">link_mode&lt;&gt;</code> will specify the linking mode of the hook (<code class="computeroutput">normal_link</code>, <code class="computeroutput">auto_unlink</code> or <code class="computeroutput">safe_link</code>).</p>
<p><code class="computeroutput">store_hash&lt;&gt;</code> will tell the hook to store the hash of the value to speed up rehashings.</p>
<p><code class="computeroutput">optimize_multikey&lt;&gt;</code> will tell the hook to store a link to form a group with other value with the same valu