e_ptr</span><span class="special">)</span>
        <span class="special">&gt;</span> <span class="identifier">message_handler</span><span class="special">;</span>
<span class="keyword">void</span> <span class="identifier">set_message_handler</span><span class="special">(</span><span class="identifier">message_handler</span> <span class="identifier">h</span><span class="special">);</span>
</pre>
                          </td>
</tr></tbody>
</table></div>
</dd>
<dt><span class="term">6. Extensible Asynchrono