Newsgroups: php.internals
Path: news.php.net
Xref: news.php.net php.internals:129518
Feedback-ID: ifab94697:Fastmail
Precedence: list
MIME-Version: 1.0
Date: Tue, 02 Dec 2025 23:23:06 +0100
To: internals@lists.php.net
Message-ID: <87e9d1bf-e407-45c1-9fad-d8759405ab8b@app.fastmail.com>
Subject: [PHP-DEV] [RFC] Type Aliases
Content-Type: multipart/alternative;
 boundary=b499d03129fc4e0789a517efd61ef786
From: rob@bottled.codes ("Rob Landers")

--b499d03129fc4e0789a517efd61ef786
Content-Type: text/plain; charset=utf-8
Content-Transfer-Encoding: quoted-printable

Hello Internals,

I=E2=80=99d like to request your comments on type aliases (not to be con=
fused with typedefs) at https://wiki.php.net/rfc/typed-aliases

TL;DR (it=E2=80=99s actually rather short):

Following the same syntax as other use'ing statements, you can alias a t=
ype:

use type int|float as Number;

function sum(Number $a, Number $b): Number { return $a + $b; }

You can also include types, with some restrictions:

include types 'math-types.php';

function sum(Number $a, Number $b): Number { return $a + $b; }

These are compile-time replacements that serve to make code more readabl=
e and reduce repetition with no runtime overhead. Type aliases follow th=
e same scoping rules as other use imports.

=E2=80=94 Rob
--b499d03129fc4e0789a517efd61ef786
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: quoted-printable

<!DOCTYPE html><html><head><title></title></head><body><div>Hello Intern=
als,</div><div><br></div><div>I=E2=80=99d like to request your comments =
on type aliases (not to be confused with typedefs) at&nbsp;<a href=3D"ht=
tps://wiki.php.net/rfc/typed-aliases">https://wiki.php.net/rfc/typed-ali=
ases</a><br></div><div><br></div><div>TL;DR (it=E2=80=99s actually rathe=
r short):</div><div><br></div><div>Following the same syntax as other us=
e'ing statements, you can alias a type:</div><div><br></div><pre style=3D=
"border-top-width:1px;border-right-width:1px;border-bottom-width:1px;bor=
der-left-width:1px;border-top-style:solid;border-right-style:solid;borde=
r-bottom-style:solid;border-left-style:solid;border-top-color:#ccc;borde=
r-right-color:#ccc;border-bottom-color:#ccc;border-left-color:#ccc;borde=
r-image-source:initial;border-image-slice:initial;border-image-width:ini=
tial;border-image-outset:initial;border-image-repeat:initial;border-top-=
left-radius:3px;border-top-right-radius:3px;border-bottom-right-radius:3=
px;border-bottom-left-radius:3px;background-image:initial;background-pos=
ition-x:initial;background-position-y:initial;background-size:initial;ba=
ckground-repeat:initial;background-attachment:initial;background-origin:=
initial;background-clip:initial;background-color:#f6f6f6;font-family:men=
lo, consolas, monospace;font-size:90%;margin-top:7px;margin-right:0px;ma=
rgin-bottom:7px;margin-left:0px;padding-top:7px;padding-right:10px;paddi=
ng-bottom:7px;padding-left:10px;white-space-collapse:preserve;text-wrap-=
mode:wrap;overflow-wrap:break-word;">use type int|float as Number;=0A=0A=
function sum(Number $a, Number $b): Number { return $a + $b; }</pre><div=
><br></div><div>You can also include types, with some restrictions:</div=
><div><br></div><pre style=3D"border-top-width:1px;border-right-width:1p=
x;border-bottom-width:1px;border-left-width:1px;border-top-style:solid;b=
order-right-style:solid;border-bottom-style:solid;border-left-style:soli=
d;border-top-color:#ccc;border-right-color:#ccc;border-bottom-color:#ccc=
;border-left-color:#ccc;border-image-source:initial;border-image-slice:i=
nitial;border-image-width:initial;border-image-outset:initial;border-ima=
ge-repeat:initial;border-top-left-radius:3px;border-top-right-radius:3px=
;border-bottom-right-radius:3px;border-bottom-left-radius:3px;background=
-image:initial;background-position-x:initial;background-position-y:initi=
al;background-size:initial;background-repeat:initial;background-attachme=
nt:initial;background-origin:initial;background-clip:initial;background-=
color:#f6f6f6;font-family:menlo, consolas, monospace;font-size:90%;margi=
n-top:7px;margin-right:0px;margin-bottom:7px;margin-left:0px;padding-top=
:7px;padding-right:10px;padding-bottom:7px;padding-left:10px;white-space=
-collapse:preserve;text-wrap-mode:wrap;overflow-wrap:break-word;">includ=
e types 'math-types.php';=0A=0Afunction sum(Number $a, Number $b): Numbe=
r { return $a + $b; }</pre><div><br></div><div>These are compile-time re=
placements that serve to make code more readable and reduce repetition w=
ith no runtime overhead. Type aliases follow the same scoping rules as o=
ther use imports.</div><div><br></div><div id=3D"sig121229152">=E2=80=94=
 Rob</div></body></html>
--b499d03129fc4e0789a517efd61ef786--