import { AsyncSequence } from "../../sequency";
export declare class ElementAtOrElse {
    /**
     * Returns the element at position `index` (zero-based). If `index` is out of bounds returns
     * the result of the given `defaultValue` function.
     *
     * @param {number} index
     * @param {(index: number) => Promise<T> | T} defaultValue
     * @returns {Promise<T>}
     */
    elementAtOrElse<T>(this: AsyncSequence<T>, index: number, defaultValue: (index: number) => Promise<T> | T): Promise<T>;
}