export type DeepReadonly<T> = T extends undefined | null | boolean | string | number | Function ? T : T extends [] ? readonly [] : T extends [infer U, ...infer Rest] ? readonly [DeepReadonly<U>, ...DeepReadonly<Rest>] : T extends Array<infer U> ? ReadonlyArray<DeepReadonly<U>> : T extends Map<infer K, infer V> ? ReadonlyMap<DeepReadonly<K>, DeepReadonly<V>> : T extends Set<infer U> ? ReadonlySet<DeepReadonly<U>> : {
    readonly [K in keyof T]: DeepReadonly<T[K]>;
};
export declare function has<P extends PropertyKey>(target: object, property: P): target is {
    [K in P]: unknown;
};