import { StatefulZirconValidator } from "../StatefulZirconValidator";
import { ZirconValidator } from "../ZirconTypeValidator";
export declare class OptionalValidator<T, U = T> extends StatefulZirconValidator<T | undefined, U | undefined> {
    private innerValidator;
    constructor(innerValidator: ZirconValidator<T, U>);
    Validate(value: unknown): value is T | undefined;
    Transform(value: T): U | undefined;
}