/**
 * Flattens array a single level deep.
 *
 * @param array - The array to flatten
 * @returns Returns the new flattened array
 *
 * @example
 * flatten([1, [2, [3, [4]], 5]]);
 * // => [1, 2, [3, [4]], 5]
 */
export declare function flatten<T>(array: readonly (T | readonly T[])[]): T[];
/**
 * Recursively flattens array.
 *
 * @param array - The array to flatten
 * @returns Returns the new flattened array
 *
 * @example
 * flattenDeep([1, [2, [3, [4]], 5]]);
 * // => [1, 2, 3, 4, 5]
 */
export declare function flattenDeep<T>(array: readonly any[]): T[];
/**
 * Recursively flatten array up to depth times.
 *
 * @param array - The array to flatten
 * @param depth - The maximum recursion depth
 * @returns Returns the new flattened array
 *
 * @example
 * flattenDepth([1, [2, [3, [4]], 5]], 1);
 * // => [1, 2, [3, [4]], 5]
 *
 * flattenDepth([1, [2, [3, [4]], 5]], 2);
 * // => [1, 2, 3, [4], 5]
 */
export declare function flattenDepth<T>(array: readonly any[], depth?: number): T[];
/**
 * Enhanced deep flatten that recursively flattens nested arrays of any depth.
 * This is an advanced utility beyond standard Lodash.
 *
 * @param array - The array to deeply flatten
 * @returns Returns the completely flattened array
 *
 * @example
 * deepFlatten([1, [2, [3, [4, [5, 6]]]], 7]);
 * // => [1, 2, 3, 4, 5, 6, 7]
 */
export declare function deepFlatten<T>(array: readonly any[]): T[];