import type { IncomingMultipartFile, MultipartStorageEngine } from '../interfaces/index.js';
type NameCallback = (error: Error | null, value: string) => void;
type NameResolver = (req: any, file: IncomingMultipartFile, callback: NameCallback) => void;
/**
 * @publicApi
 */
export interface DiskStorageOptions {
    /**
     * The folder files are written to (Default: `os.tmpdir()`). A string is
     * created when the storage engine is; a function must return a folder that
     * already exists.
     */
    destination?: string | NameResolver;
    /** The file name within `destination` (Default: 32 random hex characters, no extension). */
    filename?: NameResolver;
}
/**
 * Writes each file to disk, with multer's `diskStorage` defaults and file
 * shape (`destination`, `filename`, `path`, `size`).
 *
 * @publicApi
 */
export declare function diskStorage(options?: DiskStorageOptions): MultipartStorageEngine;
export {};