1pub struct Node<T> { 2 is_red: bool, 3 size: usize, 4 pub(crate) v: T, 5 l: ON<T>, 6 r: ON<T>, 7} 8 9type N<T> = Box<Node<T>>; 10 11type ON<T> = Option<Box<Node<T>>>; 12 13#[cfg(test)] 14 15mod tests { 16 17 #[test] 18 19 fn test() {} 20}