import { IterableX } from '../iterable';
/**
 * Creates an enumerable sequence based on an iterable factory function.
 * @param {function(): Iterable<T>} factory Iterable factory function.
 * @return {Iterable<T>} Sequence that will invoke the iterable factory upon a call to [Symbol.iterator]().
 */
export declare function defer<TSource>(factory: () => Iterable<TSource>): IterableX<TSource>;