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Reply-To: zeev@zend.com
Message-ID: <5.1.0.14.2.20030802004433.070f2620@localhost>
Date: Sat, 02 Aug 2003 00:48:12 +0300
To: Brad Bulger <tater@potatoe.com>
Cc: internals@lists.php.net,alan@akbkhome.com
In-Reply-To: <3F2A5E1A.9060500@potatoe.com>
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Subject: Re: [PHP-DEV] functions returning references to function calls
From: zeev@zend.com (Zeev Suraski)
References: <3F2A5E1A.9060500@potatoe.com>

At 15:33 01/08/2003, Brad Bulger wrote:
>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.

It's problematic in both versions, in PHP 4 it's going to create memory 
corruption (which may or may not lead to visible symptoms), and in PHP 5 
it's currently caught and avoided.  We plan on trying to fix it so that it 
works in PHP 5.

If you want to write code that will work across versions, my recommendation 
is that you use a temporary variable for now, e.g.:

function &foo()
{
         $rv =& new barclass;
         return $rv;
}

Ugly, but works.

Zeev