/// Register for notification when a message is available
pub unsafe fn mq_notify(mqdes: mqd_t, notification: Option<&sigevent_t>) -> Result<(), Errno> {
let mqdes = mqdes as usize;
let notification_ptr =
notification.map_or(0, |notification| notification as *const sigevent_t as usize);
syscall2(SYS_MQ_NOTIFY, mqdes, notification_ptr).map(drop)
}