import { Observable } from 'rxjs';
export declare type UpdateValue<T> = {
    oldValue: T;
    newValue: T;
};
/** Reduces an array from sources that add, clear, remove or update that array.  */
export declare function arrayReducer<T>(observables: {
    add?: Observable<T>;
    clear?: Observable<any>;
    push?: Observable<any>;
    remove?: Observable<T>;
    update?: Observable<UpdateValue<T>>;
}): Observable<T[]>;