_TOO_SMALL error will be set. </dd>
<dd>
A pointer to <a class="el" href="structmqtt__client.html#a948d816462128ef2216c230644407f21">mqtt_client::publish_response_callback_state</a> is always passed as the <code>state</code> argument to <code>publish_response_callback</code>. Note that the second argument is the <a class="el" href="structmqtt__response__publish.html" title="A publish packet received from the broker.A publish packet is received from the broker when a client ...">mqtt_response_publish</a> tha