import { ExtendedMap } from './collections/ExtendedMap';
/**
 * Provides few additional utility methods for array modification, immutable, all operations create new instance
 */
export declare class ExtendedArray<T> {
    private readonly values;
    constructor(values: T[]);
    static of<T>(values: T[]): ExtendedArray<T>;
    joinWith<R, Y>(second: R[], joinFn: (x: T, y: R) => Y, predicate?: (x: T, y: R) => boolean): ExtendedArray<Y>;
    distinct(key?: (x: T) => any): ExtendedArray<T>;
    toArray(): T[];
    flatMap<R>(f: (el: T) => R[]): ExtendedArray<R>;
    toMap<K, V>(keyFn: (v: T) => K, vFn: (v: T) => V): ExtendedMap<K, V>;
}