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Cc: Craig Duncan <php@duncanc.co.uk>, Niklas Keller <me@kelunik.com>,
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Date: Thu, 17 Nov 2016 12:59:49 +0100
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Subject: Re: [PHP-DEV] How to detect classes with a count_elements handler in
 userland?
From: cmbecker69@gmx.de ("Christoph M. Becker")

On 16.11.2016 at 22:02, Nikita Popov wrote:

> On Mon, Nov 14, 2016 at 2:22 PM, Christoph M. Becker <cmbecker69@gmx.de>
> wrote:
> 
>> On 13.11.2016 at 22:10, Craig Duncan wrote:
>>
>>>> How about just making those classes implement the interface instead?
>>>
>>> Christoph pointed out that there may be classes in extensions that use
>>> count_elements.
>>
>> Furthermore, letting those classes implement Countable could break BC.
> 
> How would this break BC?
> 
> SXE even already has a count() method, and count_elements respects
> overrides of that method. Clearly SXE is supposed to implement Countable,
> it was simply forgotten.

Thinking about it, we most likely don't have to be concerned with some
*theoretic* BC break (such as `!(instance of Countable)`).

Thanks!

-- 
Christoph M. Becker