/**
 * Applies the given selector to all elements of the provided collection and
 * returns the max value of all elements. If an empty array is provided the
 * function will return undefined.
 *
 * @typeParam T The type of the elements in the array.
 *
 * @param array The array to find the maximum element in.
 * @param selector The function to get the value to compare from each element.
 * The function receives the element and its index.
 *
 * @returns The largest value of the given function or undefined if there are no
 * elements.
 *
 * @example Basic usage
 * ```ts
 * import { maxOf } from "max_of.ts";
 * import { assertEquals } from "../assert/mod.ts";
 *
 * const inventory = [
 *   { name: "mustard", count: 2 },
 *   { name: "soy", count: 4 },
 *   { name: "tomato", count: 32 },
 * ];
 *
 * const maxCount = maxOf(inventory, (item) => item.count);
 *
 * assertEquals(maxCount, 32);
 * ```
 *
 * @example Using the index parameter
 * ```ts
 * import { maxOf } from "max_of.ts";
 * import { assertEquals } from "../assert/mod.ts";
 *
 * const array = [4, 3, 2, 1];
 * const result = maxOf(array, (_, index) => index);
 *
 * assertEquals(result, 3);
 * ```
 */
export declare function maxOf<T>(
  array: Iterable<T>,
  selector: (el: T, index: number) => number,
): number | undefined;
/**
 * Applies the given selector to all elements of the provided collection and
 * returns the max value of all elements. If an empty array is provided the
 * function will return undefined.
 *
 * @typeParam T The type of the elements in the array.
 *
 * @param array The array to find the maximum element in.
 * @param selector The function to get the value to compare from each element.
 * The function receives the element and its index.
 *
 * @returns The first element that is the largest value of the given function or
 * undefined if there are no elements.
 *
 * @example Basic usage
 * ```ts
 * import { maxOf } from "max_of.ts";
 * import { assertEquals } from "../assert/mod.ts";
 *
 * const inventory = [
 *   { name: "mustard", count: 2n },
 *   { name: "soy", count: 4n },
 *   { name: "tomato", count: 32n },
 * ];
 *
 * const maxCount = maxOf(inventory, (i) => i.count);
 *
 * assertEquals(maxCount, 32n);
 * ```
 */
export declare function maxOf<T>(
  array: Iterable<T>,
  selector: (el: T, index: number) => bigint,
): bigint | undefined;