about the state of TAIT:
- It's been split into two features: `type_alias_impl_trait` and `impl_trait_in_assoc_type`
- the latter has an [open stabilization PR](https://github.com/rust-lang/rust/pull/120700) that is likely to go through soon ... hopefully.
- there was a lang team meeting that discussed [#107645](https://github.com/rust-lang/rust/issues/107645), the conclusion was mostly "implicit defining scope doesn't work well, we need `#[defines]`. minutes are [here](https://hackmd.io/CDj92gZdTzilDWORdKhLQA) even though they're not very good.
- It's pending on actually implementing `#[defines]`.