1--TEST-- 2Test that a mixed parameter type can't be overridden by a union of all built-in types 3--FILE-- 4<?php 5 6class Foo 7{ 8 public function method(mixed $a) {} 9} 10 11class Bar extends Foo 12{ 13 public function method(bool|int|float|string|array|object|null $a) {} 14} 15 16?> 17--EXPECTF-- 18Fatal error: Declaration of Bar::method(object|array|string|int|float|bool|null $a) must be compatible with Foo::method(mixed $a) in %s on line %d 19