Method node

publication/code/chapter08/avl.rs:173–178

获取子节点

(&mut self)

    // 获取子节点
    fn node(&mut self) -> &mut AvlNode<T> {
        match self {
            Null => panic!("Error: Empty tree!"),
            Tree(node) => node,
        }
    }

    // 获取左右子树
    fn left_subtree(&mut self) -> &mut Self {