import { StateOperator } from '@ngxs/store';
import { EntityStateModel, IdProvider } from '../models';
/**
 * Adds or replaces the given entities to the state.
 * For each entity an ID will be calculated, based on the given provider.
 * This operator ensures that the calculated ID is added to the entity, at the specified id-field.
 * The `lastUpdated` timestamp will be updated.
 * @param entities the new entities to add or replace
 * @param idKey key of the id-field of an entity
 * @param idProvider function to provide an ID for the given entity
 */
export declare function addOrReplace<T>(entities: T | T[], idKey: string, idProvider: IdProvider<T>): StateOperator<EntityStateModel<T>>;