import { ObjectShape } from 'yup/lib/object';
import { TReferenceProps } from '../../..';
import { IObjectProps, TObjectValidatorResult } from '../_types';
export interface IIsOptionalProps {
}
/**
 * Allow an `object` to be `undefined`.
 */
export declare const isOptional: <T extends ObjectShape = {}>(props?: TReferenceProps<IIsOptionalProps> & Omit<IObjectProps, 'message'>) => TObjectValidatorResult<T, import("../../../i18n/placeholder").IIntlShapeRich>;