import { ObjectId as ObjectIdClass } from 'bson';
import * as x from 'x-value';
export declare const objectIdSymbol: unique symbol;
export declare const ObjectId: x.AtomicType<typeof objectIdSymbol>;
/**
 * Unlike ObjectId, ObjectIdHexString is string in every medium.
 */
export declare const ObjectIdHexString: x.RefinedType<x.AtomicType<typeof x.stringTypeSymbol>, "object id", unknown, false>;
/**
 * BSON ObjectId in string.
 */
export type ObjectIdString = x.Nominal<'object id', string>;
export type BSONObjectIdConstructor = new <T extends ObjectIdString>(id?: T) => x.TransformNominal<T, BSONObjectId>;
export declare const BSONObjectId: BSONObjectIdConstructor;
export interface BSONObjectId extends ObjectIdClass {
    toHexString(): x.TransformNominal<this, ObjectIdString>;
}