agged versions.
        Remember that when the bimap has user defined tags you can still use the
        untagged version structures.
      </p>
<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">Left</span>  <span class="special">{};</span>
<span class="keyword">struct</span> <span class="identifier">Right</span> <span class="special">{};</span>
<span class="keyword">typedef</span> <span class="identifier">bimap</span><span class="special">&lt;</span>
         <span cl