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Date: Sat, 06 Dec 2014 14:29:21 +0000
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Subject: Re: [PHP-DEV] Re: Only variables can be passed by reference
From: rowan.collins@gmail.com (Rowan Collins)

On 06/12/2014 11:00, Christoph Becker wrote:
> Yasuo Ohgaki wrote:
>
>> In languages, there are literal, constant and variable. Return value is
>> variable.
>> It's better to keep basic rule. IMHO.
>>
>> $top = array_pop(f2());
>>
>> is better than
>>
>> $v = f2();
>> $top = array_pop($v);
>>
>> Is there anyone who likes latter?
>> Are there any other languages behave like PHP?
> IMHO, the first snippet is confusing (the second as well, if $v is not
> used in the following code).  Actually, you don't want to pop the top of
> the stack, but you want to simply get it without altering the stack at
> all.  Therefore it seems reasonable to use a function called array_top()
> (or so) which takes its argument by value.

I think this hits the nail on the head: most times when you're trying to 
pass a literal or return to a by-ref parameter, it's because the 
function you're using isn't actually the right fit for what you're 
trying to do - either because it's badly designed (arguably the case 
with stream_select()) or because you're using it for a purpose it wasn't 
intended for (e.g. array_pop() if you're not going to use the rest of 
the stack).

For user-defined functions, one reaction to the E_STRICT notice might be 
to realise that you don't actually need a by-ref parameter there anyway, 
so you can remove the & in the declaration, and everything's fine. For 
internal functions, it may mean that we're lacking something useful 
(e.g. accessing first and last elements of arrays without side-effects).

-- 
Rowan Collins
[IMSoP]