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<?php //simulatiing a similar situation class PDO2{} class DB{ public static function connection(){ //I know it's not something like this, but that isn't what we're concerned here return new class { public function getPdo(){ return new PDO2(); } }; } }; class Test { protected $pdo; public function __construct(PDO2 $pdo) { $this->pdo = $pdo; } } var_dump(new Test($pdo = DB::connection()->getPdo()));
Output for 7.1.25 - 7.3.1
object(Test)#1 (1) { ["pdo":protected]=> object(PDO2)#3 (0) { } }