import Sequence from "./Sequence";
export declare class ToSet {
    /**
     * Returns all elements of the sequence as set. If a `set` is passed
     * the elements are added to this set.
     *
     * @param {Set<T>} set
     * @returns {Set<T>}
     */
    toSet<T>(this: Sequence<T>, set?: Set<T>): Set<T>;
}