import { StringRuleChecker } from './string-rule-checker';
import { GuardResult } from '../../core/guard-result';
/**
 * Octal pattern:
 * - ECMAScript 2015 introduces OctalIntegerLiteral, prefixed with 0o or 0O (not supported by old browsers).
 */
export declare const OCTAL_PATTERN = "^(0(o|O))?[0-7]+$";
export declare class StringIsOctal extends StringRuleChecker<{
    type: 'isOctal';
}> {
    constructor(rule: {
        type: 'isOctal';
    }, value: string);
    /**
     * @override
     */
    exec(): GuardResult;
    private isOctal;
}