import { Compare, nat } from "../index.js";
export type RedBlackTree<E> = Red<E> | Black<E> | null;
export declare class Red<E> {
    elem: E;
    left: RedBlackTree<E>;
    right: RedBlackTree<E>;
    constructor(elem: E, left: RedBlackTree<E>, right: RedBlackTree<E>);
}
export declare class Black<E> {
    elem: E;
    left: RedBlackTree<E>;
    right: RedBlackTree<E>;
    constructor(elem: E, left: RedBlackTree<E>, right: RedBlackTree<E>);
}
export declare function isRed<E>(tree: RedBlackTree<E>): tree is Red<E>;
export declare function isEmpty<E>(tree: RedBlackTree<E>): tree is null;
export declare function empty<E>(): RedBlackTree<E>;
export declare function isElementOf<E>(order: Compare<E>, x: E, tree: RedBlackTree<E>): boolean;
export declare function findEqualElement<E>(order: Compare<E>, x: E, tree: RedBlackTree<E>): E | undefined;
export declare function findMinimumElement<E>(tree: RedBlackTree<E>): E | undefined;
export declare function findMaximumElement<E>(tree: RedBlackTree<E>): E | undefined;
/**
 * Inserts a new element into the tree. Returns undefined if the element is already part of the tree.
 */
export declare function insertElement<E>(order: Compare<E>, x: E, tree: RedBlackTree<E>): {
    result: RedBlackTree<E>;
    previous: E | undefined;
};
/**
 * Deletes an existing element from the tree. Returns undefined if the element is already part of the tree.
 */
export declare function deleteElement<E>(order: Compare<E>, x: E, tree: RedBlackTree<E>): {
    result: RedBlackTree<E>;
    deleted: E | undefined;
};
export declare function iterateElements<E>(tree: RedBlackTree<E>): Generator<E, void, void>;
export declare function blackHeight<E>(tree: RedBlackTree<E>): nat;