import { RefProxy } from './ref-proxy.js';
/**
 * Ref proxy traps answer this module-private key, so a user object shaped
 * like a ref proxy is never mistaken for one.
 */
export declare const REF_PROXY_BRAND: unique symbol;
/** The brand a ref proxy answers, or undefined for any other value. */
export declare function readRefProxyBrand(value: unknown): unknown;
export declare function isRefProxy(value: any): value is RefProxy;