import { type BasedAdditionalProps, type SelectBoxOption } from '../SelectBox.types';
/**
 * Flattens a (potentially) nested SelectBox options array into a single–level array of selectable options.
 *
 * Group options (objects that contain an `options` property) are traversed and their selectable child options are
 * collected. Only options that satisfy `isSelectableOption` (i.e. have a `value`) are included in the resulting
 * array.
 *
 * This utility is primarily used to simplify focus-management and keyboard-navigation logic inside the SelectBox
 * component.
 *
 * @param options - The (possibly nested) options array.
 *
 * @returns A flat array that contains only selectable options in the same order they appear visually.
 */
export declare function getFlatOptions<T extends string | number | undefined = string, AdditionalProps extends BasedAdditionalProps = BasedAdditionalProps>(options: (SelectBoxOption<T, AdditionalProps> | null | undefined)[]): Extract<SelectBoxOption<T, AdditionalProps>, {
    value?: T;
}>[];
/**
 * Escapes a string or number for use as a CSS attribute value selector.
 * Uses CSS.escape if available, otherwise falls back to a polyfill.
 * See: https://mathiasbynens.be/notes/css-escapes
 *
 * @param value - The value to escape for use in a CSS selector
 *
 * @returns The escaped string
 */
export declare function escapeAttributeSelector(value: string | number): string;