---
# System prepended metadata

title: T-spec meeting 2025-01-23
tags: [T-spec, meeting, minutes]

---

---
title: T-spec meeting 2025-01-23
tags: ["T-spec", "meeting", "minutes"]
date: 2025-01-23
discussion: https://rust-lang.zulipchat.com/#narrow/stream/399173-t-spec/topic/Meeting.202025-01-23
url: https://hackmd.io/UiT2quGZRxGnFh-P3638Yg
---

Attendees: 
- Joel Marcey (30 minutes only), Connor Horman, Eric Huss, Pierre-Emmanuel Patry, TC, Mara, Niko Matasakis (30 minutes)

Regrets:

Agenda:

- Quick Rust specification testing goal revisit
- (ehuss) Stabilizing target_feature_11 https://github.com/rust-lang/rust/pull/134090
- Adding `t-spec` participation in other project goals
- T-Spec tagged GitHub Issues for Reference
- (ehuss) panic runtimes


## Rust Specification Testing Goal

At the last meeting, it was concluded that the [Rust Specification Testing goal](https://rust-lang.github.io/rust-project-goals/2025h1/spec-testing.html) didn't have the alignment amongst the team to be worked on as an official project goal in its current state. 

Since this was Connor's goal, and he was not here to discuss it last week, he wanted the chance to understand this decision.

Connor: Will withdraw the goal as it is and work through the LCCC and hopefully sometime that could be integrated into the Project somehow.

## Stablizing target_feature_11

https://github.com/rust-lang/rust/pull/134090

Eric: Looking for two things. Can we pause on stabilizing until the documentation is ready? And who can help with the documentation?

Connor will have a look at puttinp a PR.

eric: PR https://github.com/rust-lang/reference/pull/1181 is up, but needs some updating.

TC: I've left a note on the issue and tagged it so it won't be merged until the PR has approved.

## Formalizing `t-spec` participation in project goals

At the last meeting, we agreed that `t-spec` should have involvement in other project goals. Who will officially make the PRs/edits to add `t-spec` to those goals?

Niko: Will try to do this sometime after this meeting and will ping Joel if needs some help.

> Niko: reviewing the list of things for which spec edits might be good
> 
> Process note:
> 
> * we should add "submit first draft of spec" to the metadata
>     * assign a spec reviewer to do the rest of the work
>     * liaison should not need to be content expert
>     * members of the spec team:
>         * m-ou-se, ehuss, traviscross, nikomatsakis, JoelMarcey
>     * and spec team should check "who will be authoring it"
> * stabilization requested
>     * [Return type notation](https://rust-lang.github.io/rust-project-goals/2025h1/async.html#ownership-and-team-asks)
>         * our team will review
>         * complex but driven by errs/tmandry/nikomatsakis
>     * [Implement restrictions, prepare for stabilization](https://rust-lang.github.io/rust-project-goals/2025h1/restrictions.html#ownership-and-team-asks)
>         * our team will review -- seems straightforward [rfc 3323](https://github.com/rust-lang/rfcs/pull/3323)
>     * [macro_rules! attributes](https://rust-lang.github.io/rust-project-goals/2025h1/macro-improvements.html#ownership-and-team-asks) and friends
>     * trait aliases --
>         * not listed, niko thinks it's important, had half a mind to propose
>         * our team would review
>         * complex but driven by errs/tmandry/nikomatsakis
> * stabilization not requested
>     * [const traits](https://rust-lang.github.io/rust-project-goals/2025h1/const-trait.html#ownership-and-team-asks)
>         * oli can author
>         * team can review
>     * [unsafe fields](https://rust-lang.github.io/rust-project-goals/2025h1/unsafe-fields.html#ownership-and-team-asks)
>         * jswrenn can author
>         * team can review
>     * [pin reborrowing](https://rust-lang.github.io/rust-project-goals/2025h1/async.html#ownership-and-team-asks)
>         * eholk could author
>         * team can review

## Reference: T-Spec GitHub Issues

https://github.com/rust-lang/reference/issues?q=label%3A%22T-spec%22+is%3Aopen

Connor: 1662. I think it can be closed.

Joel: Are we not documenting anything from the standard library.

Eric: Pietro mentioned they were documenting things for the FLS. Where do things stand, specifically around core

Joel: Can ask Pietro.

Eric: There is significant overlap sometimes between the standard library and the FLS.

Eric: Crystializing on how we document these things would be valuable?

## Panic Runtimes

Eric: Struggling with documenting panics is what is a panic runtime?

Niko: On the Rust side of it.

Connor: Know enough to know that it is not clearly defined.

Connor: The issue could be correct in two ways - the runtime is the definition of the panic handler, or it is -c pass to rustc. There is nothing that clarifies between those two.

Mara: Can help. Understands the context but not how to separate.

Connor: This needs a decision to define what a panic runtime is. A `t-lang` decision.

Mara: Whatever decision that we come up with as a definition makes sense with the edge cases. Can help out.

Eric: Will keep poking people.

Mara: Can set up a meeting to discuss. Can help to fill in gaps.

TC: Is there any scenario where the panic runtime is not called by the panic handler (if it is called at all)?

Mara: Kind of no.

Mara: Panic runtimes are not always called from the panic handler.

Mara: Do we want to promise anything for the panic runtime in the reference? Is it just implementation detail?

Eric: Leaning that way - not saying anything about the panic runtime.

## Other issues

Connor: Would like to see the type layout and values and representation merged.

Eric: Would like to see these in broken up into smaller, different PRs.

## Chat

https://hackmd.io/UiT2quGZRxGnFh-P3638Yg
 
8:02
avatar
Connor Horman
Connor Horman says:(In re. the meeting: project-ffi-unwind should probably be brought in) 

Mara
Mara says:
https://private-user-images.githubusercontent.com/783247/269543409-ca92beb3-045f-4e05-87a7-4ca37b1cc29d.png?jwt=eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpc3MiOiJnaXRodWIuY29tIiwiYXVkIjoicmF3LmdpdGh1YnVzZXJjb250ZW50LmNvbSIsImtleSI6ImtleTUiLCJleHAiOjE3Mzc2NDkyNzksIm5iZiI6MTczNzY0ODk3OSwicGF0aCI6Ii83ODMyNDcvMjY5NTQzNDA5LWNhOTJiZWIzLTA0NWYtNGUwNS04N2E3LTRjYTM3YjFjYzI5ZC5wbmc_WC1BbXotQWxnb3JpdGhtPUFXUzQtSE1BQy1TSEEyNTYmWC1BbXotQ3JlZGVudGlhbD1BS0lBVkNPRFlMU0E1M1BRSzRaQSUyRjIwMjUwMTIzJTJGdXMtZWFzdC0xJTJGczMlMkZhd3M0X3JlcXVlc3QmWC1BbXotRGF0ZT0yMDI1MDEyM1QxNjE2MTlaJlgtQW16LUV4cGlyZXM9MzAwJlgtQW16LVNpZ25hdHVyZT0xZjY0MDE1M2Y2Mjg2ZTgwYTVhMTYwZmZlNmRlMmI3ZWYyNjZiZGRlMjU5ZjdjZjVhM2IyZDM3ZjRjMGQ3NmJmJlgtQW16LVNpZ25lZEhlYWRlcnM9aG9zdCJ9.37_lMm7VWIwRRGs-QIxsvtKWn_3QSggqXx5iMoSWBpQ
 
https://github.com/rust-lang/rust/issues/116005
 
8:16

Eric Huss
Eric Huss says:thanks mara, that picture is great! 

Niko Matsakis
Niko Matsakis says:love a good diagram 

I'm having connectivity issues but I think I ntd a bit earlier anyway 
8:22
Niko Matsakis says:ttyal 