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Date: Fri, 11 Sep 2015 18:19:21 -0600
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To: Ben Scholzen <mail@dasprids.de>
Cc: internals <internals@lists.php.net>
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Subject: Re: [PHP-DEV] Generic classes and methods RFC
From: levim@php.net (Levi Morrison)

(Please stop top-posting!)

On Fri, Sep 11, 2015 at 10:55 AM, Ben Scholzen <mail@dasprids.de> wrote:
> Well, with the example, there's a good reason to have them separated:
>
> class Factory
> {
>   public static function createFoo<T extends \SomeClass>()
>   {
>     return new Foo<T>();
>   }
>
>   public static function createBar<T extends \SomeOtherClass>()
>   {
>     return new Bar<T>();
>   }
> }
>
> class Foo<T extends \SomeClass> {}
> class Bar<T extends \SomeOtherClass> {}
>
> The factory instance does not know to need about <T>, this is purely a type
> for the method to be able to create another class, which requires that type.
> You couldn't put this definition on the Factory class.

What would prohibit this?

    class Factory<T> {
        public static function makeFoo() {
           return new Foo<T>();
        }
    }

It's perhaps less generic than what you posted, but this demonstrates
that that a Factory *could* hold the definition on the class and not
the method.

To be honest, I don't know why you would bother doing this anyway. I
am a fan of realistic examples and Factories that make Foos of type T
is pretty unrealistic.