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run code in 300+ PHP versions simultaneously
<?php class CC { private static $bt; public function run(&$a) { self::$bt[] = debug_backtrace(); $a = 222; } } function n(&$a) { (new CC())->run($a); } $a = [ 'a' => 1, 'b' => 2, 'c' => 3 ]; n($a['b']); echo '<pre>'; var_dump($a);

preferences:
30.15 ms | 402 KiB | 5 Q