import { IterableX } from './iterablex';
/**
 * Returns an iterable sequence that invokes the specified factory function whenever a call to [Symbol.iterator] has been made.
 *
 * @export
 * @template TSource The type of the elements in the sequence returned by the factory function, and in the resulting sequence.
 * @param {(() => Iterable<TSource>)} factory iterable factory function to invoke for each call to [Symbol.iterator].
 * @returns {AsyncIterableX<TSource>} An iterable sequence whose observers trigger an invocation of the given iterable factory function.
 */
export declare function defer<TSource>(factory: () => Iterable<TSource>): IterableX<TSource>;