import { AccumulatorOperator } from "../../core";
/**
 * Returns the population standard deviation of the input values.
 *
 * @param {Array} collection The input array
 * @param {AnyObject} expr The right-hand side expression value of the operator
 * @param {Options} options The options to use for this operation
 * @return {Number}
 */
export declare const $stdDevPop: AccumulatorOperator;
