On Sun, Jun 14, 2026, at 10:53 AM, Seifeddine Gmati wrote:
> Hello internals,
>
> Voting is now open on the Bound-Erased Generic Types RFC, as announced
> in the Intent to Vote message earlier this week.
>
> There are two votes on the RFC page:
>
> 1. Primary vote, requires a 2/3 majority: accept the RFC as proposed.
> 2. Secondary vote, simple majority, conditional on the primary
> passing: variance marker syntax, `+T` / `-T` (Hack, Scala) vs `in T` /
> `out T` (C#, Kotlin). Semantically identical; only the surface syntax
> differs.
>
> The vote started on 2026-06-14 at 16:50 UTC and ends on 2026-06-28 at 17:00 
> UTC.
>
> RFC: https://wiki.php.net/rfc/bound_erased_generic_types
> Discussion thread: https://news-web.php.net/php.internals/130816
> Implementation: https://github.com/php/php-src/pull/21969
>
> Cheers::<>,
> Seifeddine.

I already posted this in the discussion thread, but since many people don't 
read deep into a thread I'm reposting it here for visibility:

---

i strongly urge you to hold off on a vote.  Generics would be the biggest PHP 
feature in *years*, and would generate a lot of very positive buzz, both within 
the community and externally.  OTOH, generics getting voted down (for whatever 
reason) would be... very bad press, both within the community and externally.

I don't feel like Rob's additions have been adequately investigated and 
evaluated, nor is there a clear consensus on what would be "good enough" for it 
to be acceptable.  That is a problem that should be addressed directly.

Additionally, Rob has noted that the current RFC does allow for code that would 
be broken and change behavior should generics become enforced in the future.  
That is a landmine we do not want.  (And I reiterate, "if you care, use an SA 
tool" is an insufficient answer.)

We basically have three options:

1. Erased generics, with all the limitations and problems that implies 
(basically Seif's current RFC).
2. Monomorphized generics, with the performance hit that implies (basically 
Rob's patch, with some further development.)
3. Pass on generics, again.

In my mind, option 3 is the absolute worst option.  I can think of at least 
three core features that would benefit from or require generics to be done 
properly, so having *something* in core is, in my mind, critical.  Plus, as 
previously noted, "Internals rejects generics, even though basically everyone 
wants it" is going to be the headline (no matter how (in)accurate you feel that 
is).  The only people that win in that scenario are Node.js fanbois.

However, my read of the current discussion is that partially-erased generics 
(this RFC) is not going to pass.  I've been struggling with it for a while, and 
still not sure how I'm going to vote.  I really want to support it, but the 
gaps that Rob pointed out (around catch) are a problem.  And again, they're 
worse than just "oh it's the wrong type so you get a type error."  It 
completely changes the error pathway that gets executed.

If partially-erased generics doesn't pass, that will leave us with 
monomorphized/reified generics.  That always runs into the "but performance" 
problem, yet, there has never been a consensus as to what an acceptable CPU or 
memory hit would be.  Because *there is guaranteed to be one*.  If we want 
generics, then we either accept partial erasure or we accept some performance 
hit.  We're going to have to deal with one or the other, and pretending that 
some magic free-reified implementation will appear is a fool's errand.

So to anyone who plans to vote against the current RFC, please state what you 
would consider an acceptable performance hit for going all the way.  *We need 
to agree on that*, so that Rob or anyone else can see if we can hit it.  That's 
the step that hasn't been achieved yet (due in part to our current process 
having no way to handle that).  What Rob has expressed so far frankly seems 
like an acceptable cost to me already, but I know others disagree.  But holding 
out for zero-cost is simply impractical.

My recommendation, in fact, would be to get one or more additional people 
involved to help on the performance front, and put forward an equivalent 
enforced-generics RFC.  (Same syntax and semantics as the current one, which 
are pretty solid aside from the in/out question.)  Let's bang on that and get 
it right, and then we can pass that.  Given the timing, I would suggest such an 
RFC not target 8.6.  Instead, we can plan ahead that 8.6 (this year) will be 
the end of the 8.x series, PHP 2027 will be PHP 9.0, and will include whatever 
the result of that further generics work is.  

That gives us plenty of time to:
1. Ensure it's rock solid, and as performant as we can manage
2. Develop additional features for core that can leverage generics, so when 
they ship we have stuff already using it.  This also helps flush out any edge 
case bugs before it ships.
3. Gives us a clear path toward a major PR and press win (PHP 9.0, Now with 
Generics!), which the project desperately needs.

I want to reiterate: "Internals votes down generics" is the absolute worst 
outcome, for literally everyone who cares about PHP.  As we say in Chicago, 
"you don't call the vote until you know you have the votes."  Right now, I 
don't think we have the votes.  We need to take the time and do the work to get 
this *right*, and ensure not just passage, but broad support and endorsement, 
and the right tooling built on top of it.

Voting on the current RFC right now will not get us there.

--Larry Garfield

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