import { type BasedAdditionalProps, type SelectBoxOption } from '../SelectBox.types';
/**
 * Builds a Map from option value to its index in flatOptions for O(1) lookup.
 *
 * @param flatOptions - The array of flat options to index.
 *
 * @returns Map of value to index.
 */
export declare function buildValueToIndexMap<T extends string | number | undefined = string, AdditionalProps extends BasedAdditionalProps = BasedAdditionalProps>(flatOptions: SelectBoxOption<T, AdditionalProps>[]): Map<string | number, number>;
/**
 * Finds the index of an option in flatOptions by matching the value property using a prebuilt map.
 * Returns -1 if not found or if the option has no value.
 *
 * @param valueToIndexMap - Map from value to index, built from flatOptions.
 *
 * @param option - The option whose value to match.
 */
export declare function findFlatOptionIndexByValue<T extends string | number | undefined = string, AdditionalProps extends BasedAdditionalProps = BasedAdditionalProps>(valueToIndexMap: Map<string | number, number>, option: SelectBoxOption<T, AdditionalProps>): number;