Function paho_mqtt_sys::MQTTAsync_subscribe

pub unsafe extern "C" fn MQTTAsync_subscribe(
    handle: MQTTAsync, 
    topic: *const c_char, 
    qos: c_int, 
    response: *mut MQTTAsync_responseOptions
) -> c_int

This function attempts to subscribe a client to a single topic, which may contain wildcards (see @ref wildcard). This call also specifies the @ref qos requested for the subscription (see also MQTTAsync_subscribeMany()). @param handle A valid client handle from a successful call to MQTTAsync_create(). @param topic The subscription topic, which may include wildcards. @param qos The requested quality of service for the subscription. @param response A pointer to a response options structure. Used to set callback functions. @return ::MQTTASYNC_SUCCESS if the subscription request is successful. An error code is returned if there was a problem registering the subscription.