/**
 * Get the index to use for pluralization.
 * The plural rules are derived from code of the Zend Framework.
 *
 * @category    Zend
 * @package     Zend_Locale
 * @public      https://github.com/zendframework/zf1/blob/master/library/Zend/Translate/Plural.php
 * @copyright   2005-2015 Zend Technologies USA Inc. http://www.zend.com
 * @license     http://framework.zend.com/license     New BSD License
 *
 * @param  {String}  locale
 * @param  {Number}  number
 * @return {Number}
 */
export declare function getPluralIndex(locale: string, number: number): 3 | 0 | 1 | 2 | 4 | 5;