export interface Validator {
    predictor: Predictor;
    message: string;
    args?: object;
}
export interface FunctionPredictor {
    (value: string): boolean;
}
export interface AsyncFunctionPredictor {
    (value: string): Promise<boolean>;
}
export declare type Predictor = RegExp | FunctionPredictor | AsyncFunctionPredictor;
export declare function validate(validator: Validator, value: any): Promise<string>;