          unsent data is present.
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
                  <a class="link" href="basic_socket/lowest_layer_type.html" title="basic_socket::lowest_layer_type"><span class="bold"><strong>lowest_layer_type</strong></span></a>
                </p>
              </td>
<td>
                <p>
                  A basic_socket is always the lowest layer.
                </p>
              </td>
</tr>
<tr>
<td>
                <p>
               