import { NotifyPropertyChangedType } from '../../notify/notifyPropertyChangedSymbol';
import { Observable } from 'rxjs';
export declare type PropertyValue<TObject, TProperty extends keyof TObject> = {
    sender: TObject;
    value: TObject[TProperty];
};
export declare function whenChanged<TObject, TProperty extends keyof TObject>(value: TObject, key: TProperty, notifyInitial?: boolean, fallbackValue?: () => TObject[TProperty]): Observable<NotifyPropertyChangedType<TObject>[TProperty]>;