/**
 * Convert half-width alphanumeric characters to full-width characters.
 * Inverse of `toHalfWidth`; only digits, uppercase and lowercase ASCII
 * letters are converted.
 * @param {string} string_ - String to convert
 * @returns {string} - Converted string
 * @example
 * toFullWidth("Abc123"); // "Ａｂｃ１２３"
 */
export declare const toFullWidth: (string_: string) => string;