import { BasePredicate } from 'ow';
import type { Constructor, MethodDecorator, Prototype } from "../etc/types";
/**
 * Provided an error, formats its message and returns it.
 */
export declare function formatMessage(err: any): string | undefined;
/**
 * Returns `true` if the provided value is an instance of Predicate.
 */
export declare function isPredicate(value: any): value is BasePredicate;
/**
 * Decorates the indicated class method using the provided function.
 */
export declare function decorateMethod<C extends Constructor<any>, M extends keyof C | keyof Prototype<C>>(ctor: C, methodName: M, decorator: MethodDecorator<C, M>): void;