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tags: weekly-meeting
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# 2022-06-03 Planning meeting

## Updates

### RPITIT refactoring

It's "done". We've a PR open to replace the old implementation with the new one. Did a perf run which came back with no regressions, but I think we don't exercise async fns or RPITIT that much in perf tests and we have also done a crater run which came back with 4 errors. 2 of those are already fixed, @spastorino is working on the other 2.
We need to decide how to land this feature because although it's under a feature flag it's used by async fns in traits, so we don't want to produce a massive breakage.

### AFIT/RPITIT stabilization

### TAITs

* some folk expressed a preference for `#[defines]`, which the lang team said requires a separate RFC and that they are not in favor of at present. Could become a separate feature in the future.
* new soundness bugs found
* demonstrated the "most minimal (forward compatible) still useful TAIT implementation": https://github.com/rust-lang/rust/pull/113169

### a-mir-formality

* implemented const generics (not merged yet)

### Subtyping refactor

### Implied bounds

### Trait solver refactor

with https://github.com/rust-lang/rust/pull/112869 we're finally completely independent of the old solver: https://github.com/rust-lang/rust/commit/e0c9cb6cfe9b8649a01835d0d1df8587a27213b4.

Intent to write an internals blogpost about the current state over the new few weeks.

### Trait object upcasting

### Negative impls

- continue having weekly meetings
- considering to land an impl only using the new trait solver
- still working on the rfc?

### Polonius

### chalk-ty

## Nominated issues

2 open: https://github.com/rust-lang/rust/labels/I-types-nominated

### [Do not substitute nonexistent lifetime in RPIT in recursive function](https://github.com/rust-lang/rust/pull/110844)

Previously discussed: https://rust-lang.zulipchat.com/#narrow/stream/326132-t-types.2Fmeetings/topic/2023-06-05.20planning.20meeting/near/363737597

### [Account for late-bound lifetimes in generics](https://github.com/rust-lang/rust/pull/103448)

## Types FCPs

2 ongoing: https://github.com/rust-lang/rust/issues?q=is%3Aopen+label%3AT-types+label%3Aproposed-final-comment-period

### [stop adding dropck outlives requirements for [T; 0] ](https://github.com/rust-lang/rust/issues/110288)

### [Resolve inherent associated functions & constants defined on function pointer types](https://github.com/rust-lang/rust/pull/108347)

### [Remove chalk support from Rust](https://github.com/rust-lang/types-team/issues/93)

## Deep dive planning

14 proposals: https://github.com/rust-lang/types-team/issues?q=is%3Aissue+is%3Aopen+label%3Adeep-dive-proposal