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Date: Fri, 3 Aug 2018 19:47:24 +0100
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To: "Christoph M. Becker" <cmbecker69@gmx.de>
Cc: PHP internals <internals@lists.php.net>
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Subject: Re: On abstract methods defined on traits
From: mail@pmmaga.net (=?UTF-8?Q?Pedro_Magalh=C3=A3es?=)

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On Fri, Aug 3, 2018 at 7:22 PM Christoph M. Becker <cmbecker69@gmx.de>
wrote:

> On 03.08.2018 at 19:08, Pedro Magalh=C3=A3es wrote:
> > What currently happens is that (like with normal methods), the method o=
n
> > the receiving class is used and the method from the trait is simply
> ignored.
>
> Yes.  However, if the class using the trait would not implement the
> method, a compile time error would be thrown.
>

Not really, I mean, the error you get is that you are declaring an abstract
method in a non abstract class. If the receiving class is abstract, this
works as expected (https://3v4l.org/QdHBo) and nothing is imposed on the
receiving class.
I think this is also what Levi is referring to. (Correct me if I'm wrong)


> > Although this can be fixed, I wanted your opinion on it as this would b=
e
> > the only thing from traits that would impose anything on the receiving
> > class and conflicts with the normal precedence rules.
>
> Frankly, I don't understand what this bug report is about,
> <https://3v4l.org/38lmA> looks pretty much expected (note that the error
> message is totally different from what has been reported; there is no
> class D in the reproduce script).
>

Yes, the report is not very clear. But if we follow the docs logic,
A::values in your example should fail to compile as it doesn't have the
same signature (return type) as the method from the trait T.

Regards,
Pedro

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