Method remove_rear

code/chapter03/deque.rs:48–54

从队尾移除数据

(&mut self)

    // 从队尾移除数据
    fn remove_rear(&mut self) -> Option<T> {
        if self.size() > 0 {
            Some(self.data.remove(0))
        } else {
            None
        }
    }

    fn is_empty(&self) -> bool {
        0 == self.size()