import { IObservableCache } from '../IObservableCache';
import { Observable, OperatorFunction } from 'rxjs';
import { IChangeSet } from '../IChangeSet';
/**
 * Watches updates for a single value matching the specified key
 * @typeparam TObject The type of the object.
 * @typeparam TKey The type of the key.
 * @param cache The cache.
 * @param key The key.
 */
export declare function watchValue<TObject, TKey>(cache: IObservableCache<TObject, TKey>, key: TKey): Observable<TObject>;
/**
 * Watches updates for a single value matching the specified key
 * @typeparam TObject The type of the object.
 * @typeparam TKey The type of the key.
 * @param key The key.
 */
export declare function watchValue<TObject, TKey>(key: TKey): OperatorFunction<IChangeSet<TObject, TKey>, TObject>;