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Cc: PHP Internals <internals@lists.php.net>
Date: Sat, 14 Feb 2015 12:33:23 +0000
To: Xinchen Hui <laruence@php.net>
Subject: Re: [PHP-DEV] [RFC] Void Return Type
From: ajf@ajf.me (Andrea Faulds)

Hi,

> On 14 Feb 2015, at 05:03, Xinchen Hui <laruence@php.net> wrote:
>=20
> Hey:
> be honest, I think it's only part of the idea is implemented.
>=20
> which make it useless.
>=20
> in PHP, even if you don't return anything, NULL is returned implicitly.
>=20
> even if a function is declared return nothing(void).
>=20
> like:
>=20
>   function a() : void {};
>=20
> following codes  still works:
>=20
>   $b =3D a();
>=20
> so, if you want a void return type, and if you want it to be a useful feat=
ure..
>=20
> above expr should be invalid with an error " a() return nothing"

I'm not sure about this. PHP has always made functions valid rvalues, for be=
tter or for worse. This RFC could make void functions "truly" void, but that=
 would be a massive change to support value-less function returns. It would a=
lso break existing code which assumes all functions return a value, which is=
n't good.

I think this RFC is enough: it would let you enforce that a function doesn't=
 return anything and makes code more self-documenting. It doesn't affect any=
thing trying to use the function's implicit return value of NULL, but IDEs a=
nd code linters would surely pick up on it for you. It's still useful even i=
f it doesn't bind the caller.

Thanks.