functions returning references to function calls

Hello. I found in PEAR DB class something that seemed like small BC issue. The package maintainer thought it sounded like bug. If anyone would comment? function &foo() { return new barclass; } gives error saying PHP Fatal error: Only variables or references can be returned by reference this is correct for php 5, yes? same as function &foo() { $a = array(1); return array_keys($a); } which gives same error in 5, but is acceptable in 4. Thank you.