Function put

src/tree/binary/rb2.rs:201–217

insert the element in the subtree rooted at h

(h: Option<NonNull<Node<K, V>>>, key: K, val: V)

/// insert the element in the subtree rooted at h
fn put<K, V>(h: Option<NonNull<Node<K, V>>>, key: K, val: V) -> Option<NonNull<Node<K, V>>>
where
    K: Ord,
{
    let mut h = NodeQuery::new(h);

    match h.get_key() {
        None => return Some(Node::new_leaf(key, Some(val), None)),
        Some(h_key) => match key.cmp(h_key) {
            Ordering::Equal => h.set_entry((key, Some(val))), // update val
            Ordering::Less => h.set_left(put(h.left().node, key, val)),
            Ordering::Greater => h.set_right(put(h.right().node, key, val)),
        },
    }

    balance(h.node)
}

/// delete the min element rooted at h
fn del_min<K, V>(h: Option<NonNull<Node<K, V>>>) -> Option<NonNull<Node<K, V>>> {