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To: "Anthony Ferrara" <ircmaxell@gmail.com>, Laruence <laruence@php.net>
Cc: internals@lists.php.net
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Subject: Re: [PHP-DEV] Object Casting - An Alternative to Type Hinting
From: glopes@nebm.ist.utl.pt ("Gustavo Lopes")

On Sun, 26 Feb 2012 16:39:10 +0100, Laruence <laruence@php.net> wrote:

> On Sun, Feb 26, 2012 at 10:57 PM, Anthony Ferrara <ircmaxell@gmail.com>  
> wrote:
>
> I have to say, it doesn't get work, thinking this:
>
> $mixed1 = new Interger(2);
> $mixed2 = new Interge(3);
> $guess_what_type_is = $mixed1 + $mixed2;
>

Actually, this part of the problem can be pretty much be implemented today  
for internal classes with the cast_object[1] or get[2] handlers. There are  
of course some difficulties, like the nonexistence of a numeric cast,  
which, by the way, has caused some trouble because the Zend Engine  
defaults to cast to an integer in a numerical situation instead of a  
float. This has causes a known bug in SimpleXML:

<?php
$xml = <<<XML
<a>6.5</a>
XML;

$sxml = new simplexmlelement($xml);
$r = 4 + $sxml;
echo $r; //10, not 10.5

The other side (cast from) is more problematic, not entirely satisfactory  
to the people that have proposed autoboxing in the past, which would like  
to be able to do $a = 1;  $a->blah().

[1] https://wiki.php.net/internals/engine/objects#cast_object
[2] https://wiki.php.net/internals/engine/objects#get


-- 
Gustavo Lopes