import type { Arr } from '@toolbox-ts/types/defs/array';
/**
 * Returns a new array with duplicate values removed, preserving the original order.
 * - If a key function is provided, it is used to determine uniqueness.
 *
 * @important Uses `Set` for deduplication, which checks for strict equality (`===`). This means that for objects and arrays, only references are compared, not their contents.
 *
 * @important If a key function is provided and two items produce the same key, only the first is kept.
 *
 * @pure
 *
 * @example
 * ```ts
 * const arr1 = [1, 2, 2, 3, 1];
 * const uniqueArr = dedupe(arr1);
 * // uniqueArr is [1, 2, 3]
 *
 * const arr2 = [{a:1}, {b:2}, {a:1}];
 * const uniqueArr2 = dedupe(arr2);
 * // uniqueArr2 is [{a:1}, {b:2}, {a:1}] because the two {a:1} are different references
 * ```
 *
 * @example
 * ```ts
 * const arr = [
 *   { id: 1, name: 'Alice' },
 *   { id: 2, name: 'Bob' },
 *   { id: 1, name: 'Alice' }
 * ];
 * const uniqueArr = dedupeBy(arr, item => item.id);
 * // uniqueArr is [
 * //   { id: 1, name: 'Alice' },
 * //   { id: 2, name: 'Bob' }
 * // ]
 * ```
 */
export declare const dedupe: <T extends Arr = Arr, K = unknown>(a: T, keyFn?: (item: T[number]) => K) => T;
/**
 * Removes duplicate values from the array in place, preserving the original order.
 * - If a key function is provided, it is used to determine uniqueness.
 *
 * @important Uses `Set` for deduplication, which checks for strict equality (`===`). This means that for objects and arrays, only references are compared, not their contents.
 *
 * @important If a key function is provided and two items produce the same key, only the first is kept.
 *
 * @example
 * ```ts
 * const arr = [1, 2, 2, 3, 1];
 * dedupeInPlace(arr);
 * // arr is now [1, 2, 3]
 *
 * const arr2 = [{a:1}, {b:2}, {a:1}];
 * dedupeInPlace(arr2);
 * // arr2 is now [{a:1}, {b:2}, {a:1}] because the two {a:1} are different references
 * ```
 *
 * @example
 * ```ts
 * const arr = [
 *   { id: 1, name: 'Alice' },
 *   { id: 2, name: 'Bob' },
 *   { id: 1, name: 'Alice' }
 * ];
 * dedupeInPlace(arr, item => item.id);
 * // arr is now [
 * //   { id: 1, name: 'Alice' },
 * //   { id: 2, name: 'Bob' }
 * // ]
 * ```
 */
export declare const dedupeInPlace: <T extends unknown[] = unknown[], K = unknown>(a: T, keyFn?: (item: T[number]) => K) => T;