/// Pops an item off the tail of the queue or `None` if the queue is empty.
Pops an item off the tail of the queue or `None` if the queue is empty.
Pops an item off the tail of the queue or ` None ` if the queue is empty .
fn pop(&mut self) -> Option<T> {
        let res = pop_queue(&mut self.queue);
        if let Some(msg) = res.as_ref() {
            self.size_bytes -= Self::message_size_bytes(&msg);
            debug_assert_eq!(Self::size_bytes(&self.queue), self.size_bytes);
        }
        res
    }
fn pop ( & mut self ) -> Option < T > { let res = pop_queue ( & mut self . queue ) ; if let Some ( msg ) = res . as_ref ( ) { self . size_bytes -= Self :: message_size_bytes ( & msg ) ; debug_assert_eq ! ( Self size_bytes ( self queue ) self size_bytes ) ; } res }
Pops an item off the tail of the queue or `None` if the queue is empty.
Pops an item off the tail of the queue or ` None ` if the queue is empty .
&mut self