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<?php class T { private $attr = [1,2,3]; } $t = function(){ var_dump($this->attr); return $this; }; $c1 = Closure::bind($t, new T(), 'T'); $c1(); var_dump($c1()); die; abstract class T { static public $instanses; final private function __construct(){ } public static function getInstance() { var_dump(static::$instanses); if (!(static::$instanses instanceof static)) { static::$instanses = new static; } var_dump(static::$instanses); return static::$instanses; } } class A extends T { static public $instanses; } class B extends A { static public $instanses; } $t = A::getInstance(); var_dump($t); $t1 = B::getInstance(); var_dump($t1); new B(); ?>
Output for 5.4.2 - 5.4.45, 5.5.24 - 5.5.35, 5.6.7 - 5.6.28, 7.0.0 - 7.0.20, 7.1.0 - 7.1.33, 7.2.0 - 7.2.33, 7.3.0 - 7.3.33, 7.4.0 - 7.4.33, 8.0.0 - 8.0.30, 8.1.0 - 8.1.28, 8.2.0 - 8.2.19, 8.3.0 - 8.3.7
array(3) { [0]=> int(1) [1]=> int(2) [2]=> int(3) } array(3) { [0]=> int(1) [1]=> int(2) [2]=> int(3) } object(T)#2 (1) { ["attr":"T":private]=> array(3) { [0]=> int(1) [1]=> int(2) [2]=> int(3) } }

preferences:
187.97 ms | 405 KiB | 275 Q