1--TEST--
2Invariant parameter and return types work with nullable types
3--FILE--
4<?php
5
6interface A {
7    function method(?int $i): ?int;
8}
9
10class B implements A {
11    function method(?int $i): ?int {
12        return $i;
13    }
14}
15
16$b = new B();
17var_dump($b->method(null));
18var_dump($b->method(1));
19?>
20--EXPECT--
21NULL
22int(1)
23