Singleton extend class

Singleton.php

<?php

class singleton
{
	/**
	 * protect the construct
	 */
	protected function __construct()
	{
	}

	/**
	 * get instance
	 *
	 * @return static
	 */
	public static function instance()
	{
		static $instances = array(); // all instances for different classes are saved in this array

		$calledClass = get_called_class(); // gets the name of the class

		if (!isset($instances[$calledClass])) { // create a new one if not set
			$instances[$calledClass] = new $calledClass();
		}

		return $instances[$calledClass];
	}

	/**
	 * protected the call function
	 *
	 * @param string $function
	 * @param array $args
	 * @return void
	 */
	protected function __call($function, $args)
	{
	}
}