import { Struct } from 'superstruct';
export declare const message: <T>(struct: Struct<T, any>, message: string) => Struct<T, any>;
export declare const notFutureDate: Struct<unknown, null>;
export declare const afterDate: (date: Date, parser?: (v: string) => Date) => Struct<unknown, null>;
export declare const zipString: () => Struct<string, null>;
export declare const email: () => Struct<string, null>;
export declare const empty: () => Struct<any, null>;