Description:
------------
---
From manual page: https://php.net/migration70.new-features
---
I really don't know - is this a bug or a feature? Is this a safe behavior? Can I count on this behavior and use it in the future?
Thank you for your answer!

Test script:
---------------
<?php
ini_set('error_reporting', E_ALL);
ini_set('display_errors', 1);
ini_set('display_startup_errors', 1);

class A {
    public function test()
    {
        return [];
    }
}

$obj = new A();
$result = $obj->test()[0] ?? null;
var_dump($result);



Expected result:
----------------
PHP Notice:  Undefined offset: 0 in /directory/file on line 15

Actual result:
--------------
NULL