/**
 * Is the given argument a Set
 *
 * Works across realms (e.g. a Set created in an iframe), where `instanceof`
 * against the local realm's `Set` would fail.
 *
 * @param x - Argument to test
 *
 * @returns Whether the argument is a Set or not
 *
 * @example
 * ```ts
 * isSet(new Set()); // --> true
 * isSet(new Map()); // --> false
 * isSet([]); // --> false
 * ```
 */
export declare const isSet: (x: unknown) => x is Set<unknown>;
export default isSet;