r">handler_ptr</span><span class="special">::</span><span class="identifier">release_handler</span></code></a> is called.
          </li>
<li class="listitem">
            The container is destroyed.
          </li>
</ul></div>
<p>
        Objects of this type are used in the implementation of composed operations
        with states that are expensive or impossible to move. This container manages
        that non-trivial state on behalf of the composed operation.
      </p>
<h5>
<a name="beast.ref.boost__be