/**
 * String Expression Operators: https://docs.mongodb.com/manual/reference/operator/aggregation/#string-expression-operators
 */
import { Options } from '../../../core';
/**
 * Splits a string into substrings based on a delimiter.
 * If the delimiter is not found within the string, returns an array containing the original string.
 *
 * @param  {Object} obj
 * @param  {Array} expr
 * @return {Array} Returns an array of substrings.
 */
export declare function $split(obj: object, expr: any, options: Options): any;