import { Main } from '../..';
/**
 * @hidden
 */
export declare const testSymbol: unique symbol;
/**
 * @hidden
 */
export declare const isPredicate: (value: any) => value is BasePredicate<any>;
/**
 * @hidden
 */
export interface BasePredicate<T = any> {
    [testSymbol](value: T, main: Main, label: string | Function): void;
}