/**
 * @module array
 */
/**
 *
 * Calls a function on every item in an array and concatenates the resulting arrays into a single flat array.
 *
 * @typeparam TValue The type of items in the input array
 * @typeparam TNext the type of items in the output array
 * @param array The input array to be mapped
 * @param fn The functions used to generate the new items
 * @return A flat array of the resulting values
 *
 * @example
 * ```typescript
 *
 * const items = flatMap(['foo', 'bar'], word => word.split())
 * // Returns ['f', 'o', 'o', 'b', 'a', 'r']
 * ```
 *
 */
export default function flatMap<TValue, TNext>(array: TValue[], fn: (value: TValue, index?: number) => TNext[]): TNext[];