Online PHP editor | refs for m7AbZ

<?php interface ISingleton { public static function getInstance(): ISingleton; } abstract class Singleton implements ISingleton { private static $_instances = []; final private function __construct () {} final private function __clone() {} final private function __wakeup() {} final public static function getInstance() : ISingleton { self::$_instances[static::class] = self::$_instances[static::class] ?? new static(); return self::$_instances[static::class]; } } class Flextype extends Singleton { } var_export(Flextype::getInstance());