import * as zjson from '../zjson';
import { EncodeStream } from '../encode-stream';
import { TypeUnion } from '../types/type-union';
import { Type } from '../types/types';
import { Value } from './types';
export declare class Union implements Value {
    type: TypeUnion;
    innerType: Type;
    index: number | null;
    value: Value | null;
    constructor(type: TypeUnion, innerType: Type, index: number | null, value: Value | null);
    toString(): string;
    serialize(stream: EncodeStream): zjson.UnionValue | null;
    isUnset(): boolean;
    toJS(): any;
}