E.g.
```
trait Trait {
type Item: SomeOtherTrait;
}
```
Note that these don't simply desugar to where clauses; as I understand it, where
clauses have to be proved by the *user* of the trait, but these bounds are proved
by the *implementor*. (Also, where clauses on associated types are unstable.)
Like `Iterator<Item: SomeTrait>`.
This is an unstable feature, but it's used in the standard library e.g. in the
definition of Flatten, so we can't get away with not implementing it :)
This fixes the a bug when merging imports from the second line when it already has a comma it would previously insert a comma.
There's probably a better way to check for a COMMA.
This also ends up with a weird indentation, but rust-fmt can easily deal with it so I'm not sure how to resolve that.
Closes#3832
3938: fix missing match arm false positive r=flodiebold a=JoshMcguigan
This fixes#3932 by skipping the missing match arm diagnostic in the case any of the match arms don't type check properly against the match expression.
I think this is the appropriate behavior for this diagnostic, since `is_useful` relies on all match arms being well formed, and the case of a malformed match arm should probably be handled by a different diagnostic.
Co-authored-by: Josh Mcguigan <joshmcg88@gmail.com>
3955: Align grammar for record patterns and literals r=matklad a=matklad
The grammar now looks like this
[name_ref :] pat
bors r+
🤖
Co-authored-by: Aleksey Kladov <aleksey.kladov@gmail.com>
3925: Implement assist "Reorder field names" r=matklad a=geoffreycopin
This PR implements the "Reorder record fields" assist as discussed in issue #3821 .
Adding a `RecordFieldPat` variant to the `Pat` enum seemed like the easiest way to handle the `RecordPat` children as a single sequence of elements, maybe there is a better way ?
Co-authored-by: Geoffrey Copin <copin.geoffrey@gmail.com>
3944: Look up trait impls by self type r=matklad a=flodiebold
This speeds up inference in analysis-stats by ~30% (even more with the recursive solver).
There's a slight difference in inferred types, which I think comes from pre-existing wrong handling of error types in impls, so I think it's fine.
Co-authored-by: Florian Diebold <flodiebold@gmail.com>
