import { StringRuleChecker } from './string-rule-checker';
import { GuardResult } from '../../core/guard-result';
/**
 * Hex pattern:
 * - ECMAScript 2015 introduces HexIntegerLiteral, prefixed with 0x or 0X (not supported by old browsers).
 * - Not case sensitive.
 */
export declare const HEX_PATTERN = "^(0(x|X))?[a-fA-F\\d]+$";
export declare class StringIsHex extends StringRuleChecker<{
    type: 'isHex';
}> {
    constructor(rule: {
        type: 'isHex';
    }, value: string);
    /**
     * @override
     */
    exec(): GuardResult;
    private isHex;
}