ass="computeroutput">at_front</code> indicates that the slot will be
            connected at the front of the list or group of slots and
            <code class="computeroutput">at_back</code> indicates that the slot will be
            connected at the back of the list or group of
            slots.</p></td>
</tr>
<tr>
<td><p><span class="term">Returns:</span></p></td>
<td><p>A
            <code class="computeroutput"><a class="link" href="connection.html" title="Class connection">signals2::connection</a>