import { ArgumentProcessorContext, ParamType } from "./types";
import { InputHelper } from "./input-helper";
export interface FileFilter<ReqType, ResType> {
    (this: ArgumentProcessorContext<ReqType, ResType>, object: Express.Multer.File): boolean;
}
export declare class FileInputHelper<ReqType, ResType> extends InputHelper<ReqType, ResType> {
    private fileCount;
    toJSON(): ParamType<ReqType, ResType>;
    filter(fn: FileFilter<ReqType, ResType>): this;
    single(): this;
    multi(max?: number): this;
}