import { ModelClass } from '../modelShared/BaseModelShared';
declare const Ref_base: import('..')._Model<unknown, {
    /**
     * Reference id.
     */
    id: import('..').MaybeOptionalModelProp<string> & {
        $storedValueType: string;
        $storedCreationValueType: string;
    };
}, never, never>;
/**
 * A reference model base type.
 * Use `customRef` to create a custom ref constructor.
 */
export declare abstract class Ref<T extends object> extends Ref_base {
    protected abstract resolve(): T | undefined;
    /**
     * The object this reference points to, or `undefined` if the reference is currently invalid.
     */
    get maybeCurrent(): T | undefined;
    /**
     * If the reference is currently valid.
     */
    get isValid(): boolean;
    /**
     * The object this reference points to, or throws if invalid.
     */
    get current(): T;
    /**
     * Ensures back references for this ref are up to date.
     * This only needs to be called if you need to get the most up to date
     * back references while both still inside an action and while the reference
     * is not a child of the same root than the target.
     */
    abstract forceUpdateBackRefs(): void;
}
/**
 * @ignore
 */
export declare const customRefTypeSymbol: unique symbol;
/** A ref constructor for custom refs */
export interface RefConstructor<T extends object> {
    <TE extends T>(valueOrID: TE | string): Ref<TE>;
    refClass: ModelClass<Ref<T>>;
    [customRefTypeSymbol]: T;
}
/**
 * Checks if a ref object is of a given ref type.
 *
 * @template T Referenced object type.
 * @param ref Reference object.
 * @param refType Reference type.
 * @returns `true` if it is of the given type, false otherwise.
 */
export declare function isRefOfType<T extends object>(ref: Ref<object>, refType: RefConstructor<T>): ref is Ref<T>;
export {};