import type { Arr, WithoutFalsy, WithoutNull, WithoutNullish, WithoutUndefined } from '@toolbox-ts/types/defs/array';
/**
 * Removes all `null` and `undefined` values from the array.
 *
 * @param a - The array to compact.
 *
 * @example
 * ```ts
 * const arr = [1, null, 2, undefined, 3];
 * const compacted = compact(arr); // [1, 2, 3]
 * ```
 */
export declare const compact: <T extends Arr = Arr>(a: T) => WithoutNullish<T>;
/**
 * Removes all falsy values from the array.
 *
 * @param a - The array to compact.
 *
 * @example
 * ```ts
 * const arr = [0, 1, false, 2, '', 3];
 * const compacted = compactFalsy(arr); // [1, 2, 3]
 * ```
 */
export declare const compactFalsy: <T extends Arr = Arr>(a: T) => WithoutFalsy<T>;
/**
 * Removes all `null` values from the array.
 *
 * @param a - The array to compact.
 *
 * @example
 * ```ts
 * const arr = [1, null, 2, null, 3];
 * const compacted = compactNull(arr); // [1, 2, 3]
 * ```
 */
export declare const compactNull: <T extends Arr = Arr>(a: T) => WithoutNull<T>;
/**
 * Removes all `undefined` values from the array.
 *
 * @param a - The array to compact.
 *
 * @example
 * ```ts
 * const arr = [1, undefined, 2, undefined, 3];
 * const compacted = compactUndefined(arr); // [1, 2, 3]
 * ```
 */
export declare const compactUndefined: <T extends Arr = Arr>(a: T) => WithoutUndefined<T>;