import { Result } from "../types";
/**
 * Tests if the value is an instance of the specified object.
 *
 * ### Example
 * ```
 * expect(isInstanceOf(new Date(0), Date).value).toBeTruthy()
 * ```
 *
 * @param value The value array being checked.
 * @param target The target type constructor
 */
export declare function isInstanceOf(value: any, target: new (...args: any[]) => any): Result<boolean | undefined>;