/**
 * String validation module for checking if a string represents a number
 * Provides validation functionality for checking if a string can be converted to a number
 */
import type { ValidateReturnType } from "../../Validate/type";
/**
 * Creates a validator for checking if a string represents a valid number
 * @param {string} [message] - Custom error message for validation failure
 * @returns {ValidateReturnType<string>} - Validator for number strings
 */
export declare const numberString: (message?: string) => ValidateReturnType<string>;