import { CollectionItem } from './collection-item.js';
declare class FlatResult<T> {
    items: T[];
    depths: number[];
}
/**
 * Quickly flattens a deeply nested `CollectionItem` array.
 * @param items Collection of nested items to flatten
 * @return Flattened array of Collection Items
 */
export declare const flatten: <T extends CollectionItem = CollectionItem>(items: T[]) => FlatResult<T>;
export {};