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In-Reply-To: <05aa01d7db0e$783fa120$68bee360$@webkr.de>
Date: Fri, 19 Nov 2021 21:22:40 +0700
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Message-ID: <A73273D0-4194-4780-B5E4-DEE6003E6AD7@koalephant.com>
References: <05aa01d7db0e$783fa120$68bee360$@webkr.de>
To: =?utf-8?B?QW5kcsOpIEjDpG5zZWw=?= <andre@webkr.de>
Subject: Re: [PHP-DEV] Is there an RFC/discussion for ::class being a specific
 type?
From: php-lists@koalephant.com (Stephen Reay)



> On 17 Nov 2021, at 00:22, Andr=C3=A9 H=C3=A4nsel <andre@webkr.de> =
wrote:
>=20
> It is common (with DI systems for example) and to my knowledge not
> particularly discouraged to have function parameters that are supposed =
to
> accept something like Foo::class, which currently is a string.
>=20
> It seems logical to ask for a special type that can hold class names, =
so
> that parameters that can accept a class name can be type hinted more
> specifically than just (any) "string".
>=20
> Regardless of whether or not such a proposal would be accepted or =
declined
> (for complexity reasons maybe) I couldn't even find any such proposal. =
Has
> this really never been asked?
>=20
> --=20
> PHP Internals - PHP Runtime Development Mailing List
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>=20
Hi Andr=C3=A9,

I=E2=80=99ve wondered about this kind of functionality myself, but IMO =
to be particularly useful it=E2=80=99d need to support the ability to =
accept a classname that is a subtype of a parent class or interface. I =
can=E2=80=99t think of too many places where I=E2=80=99d want to know =
something is a classname reference, and not also want to know that it's =
a subclass or implementation of something specific.


This typeof functionality could support some very expressive solutions, =
when combined with union types, and anonymous classes.=20




Cheers

Stephen=20=