import { PipelineOperator } from "../../core";
/**
 * Categorizes incoming documents into a specific number of groups, called buckets, based on a specified expression.
 * Bucket boundaries are automatically determined in an attempt to evenly distribute the documents into the specified number of buckets.
 *
 * See {@link https://docs.mongodb.com/manual/reference/operator/aggregation/bucketAuto/ usage}.
 *
 * @param collection
 * @param expr
 * @param options
 * @returns
 */
export declare const $bucketAuto: PipelineOperator;