/// <reference types="mongoose/types/aggregate" />
/// <reference types="mongoose/types/callback" />
/// <reference types="mongoose/types/collection" />
/// <reference types="mongoose/types/connection" />
/// <reference types="mongoose/types/cursor" />
/// <reference types="mongoose/types/document" />
/// <reference types="mongoose/types/error" />
/// <reference types="mongoose/types/expressions" />
/// <reference types="mongoose/types/helpers" />
/// <reference types="mongoose/types/middlewares" />
/// <reference types="mongoose/types/indexes" />
/// <reference types="mongoose/types/models" />
/// <reference types="mongoose/types/mongooseoptions" />
/// <reference types="mongoose/types/pipelinestage" />
/// <reference types="mongoose/types/populate" />
/// <reference types="mongoose/types/query" />
/// <reference types="mongoose/types/schemaoptions" />
/// <reference types="mongoose/types/schematypes" />
/// <reference types="mongoose/types/session" />
/// <reference types="mongoose/types/types" />
/// <reference types="mongoose/types/utility" />
/// <reference types="mongoose/types/validation" />
/// <reference types="mongoose/types/virtuals" />
/// <reference types="mongoose/types/inferschematype" />
/// <reference types="mongoose/types/inferrawdoctype" />
import mongoose from 'mongoose';
import type { IndexOptions } from './types';
/**
 * Defines a index for this Class which will then be added to the Schema.
 * @param fields Which fields to index (if multiple fields are set, it will be a compound index)
 * @param options Options to pass to MongoDB driver's createIndex() function
 * @example Example:
 * ```ts
 * @index({ article: 1, user: 1 }, { unique: true })
 * class ClassName {}
 * ```
 */
export declare function index(fields: mongoose.IndexDefinition, options?: IndexOptions): ClassDecorator;
export { index as Index };