/**
 * Builds all possible orders of all elements in the given array
 * Ignores equality of elements, meaning this will always return the same
 * number of permutations for a given length of input.
 *
 * Example:
 *
 * ```ts
 * import { permutations } from "https://deno.land/std@$STD_VERSION/collections/mod.ts";
 * import { assertEquals } from "https://deno.land/std@$STD_VERSION/testing/asserts.ts";
 *
 * const numbers = [ 1, 2 ]
 * const windows = permutations(numbers)
 *
 * assertEquals(windows, [
 *     [ 1, 2 ],
 *     [ 2, 1 ],
 * ])
 * ```
 */
export declare function permutations<T>(inputArray: readonly T[]): T[][];