/**
 * Returns previous state value, useful for diff comparison
 * @example
 * const [count, setCount] = useState(0)
 * const prevCount = usePrevious(value)
 *
 * return (
 *      <button onClick={() => setValue(current => current + 1)}>
 *          Diff: {count - prevCount}
 *      </button>
 * )
 */
declare function usePrevious<T>(state: T): T | undefined;

export { usePrevious };