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Date: Thu, 14 Nov 2013 11:39:48 -0700
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Subject: Proposal: Type Casting User Classes
From: me@chrislondon.co (Chris London)

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Hey everyone,

I want to get a feel for something I would like to implement into PHP core.
 I would like to be able to cast objects to my own class types.  Similar to
already available PHP syntax:

$foo = (string) $bar;

The syntax would look like this:

$foo = (\My\FooObject) $bar;

It would also support:

$foo = ( (\My\FooObject) $bar )->myFooObjectFunction();

I'm still trying to decide what would happen internally and I would like
some feedback.  I'm thinking of 3 different things it could do:

1) Directly change the class type, functionally equivalent to:

    function castType($object, $type) {
        return unserialize(preg_replace("/^O:[0-9]+:\"[^\"]+\":/i",
    "O:".strlen($type).":\"$type\":", serialize($object)));
    }

2) Throw a fatal error if the object doesn't match the type trying to be
cast.

3) Add a new static magic method called __cast() that would allow the
developer to decide what happens. Like this:

namespace \My;

class FooObject {
    public static function __cast($foo) {
        // Do stuff here
        return new FooObject;
    }
}

I'm willing to implement this myself if everybody else likes this idea.
 Thanks!

Chris London

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