import { Iterator } from "../../lazy";
import type { AnyObject, Options } from "../../types";
/**
 * Takes the documents returned by the aggregation pipeline and writes them to a specified collection.
 *
 * Unlike in MongoDB, this operator can appear in any position in the pipeline and is
 * useful for collecting intermediate results of an aggregation operation.
 *
 * Objects are deep cloned for output regardless of the processing mode.
 *
 * See {@link https://www.mongodb.com/docs/manual/reference/operator/aggregation/out/ usage}.
 */
export declare function $out(coll: Iterator, expr: string | AnyObject[], options: Options): Iterator;