always use `anonymize_bound_vars`
Unless this is perf-sensitive, it's probably best to always use one anonymize function that does the right thing for all bound vars.
r? types
Highlight conflicting param-env candidates, again
Un-reverts #98794 (i.e. reverts #99290).
The previous time I attempted to land this PR, it was because of an incremental issue (#99233). The repro instructions in the issue is no longer manifest the ICE -- I think it's because this ambiguity code was refactored (I think by `@lcnr)` to no longer store the ambiguities in the fulfillment error, but instead recompute them on the fly.
The main motivation for trying to re-land this is that it fixes#105131 by highlighting the root-cause of the issue, which is conflicting param-env candidates:
```
error[E0283]: type annotations needed: cannot satisfy `Self: Gen<'source>`
|
note: multiple `impl`s or `where` clauses satisfying `Self: Gen<'source>` found
--> $DIR/conflicting-bounds.rs:3:1
|
LL | pub trait Gen<'source> {
| ^^^^^^^^^^^^^^^^^^^^^^
...
LL | Self: for<'s> Gen<'s, Output = T>;
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^
error: aborting due to previous error
For more information about this error, try `rustc --explain E0283`.
```
Fixes#105131.
Fixes (again) #98786
Combine `ty::Projection` and `ty::Opaque` into `ty::Alias`
Implements https://github.com/rust-lang/types-team/issues/79.
This PR consolidates `ty::Projection` and `ty::Opaque` into a single `ty::Alias`, with an `AliasKind` and `AliasTy` type (renamed from `ty::ProjectionTy`, which is the inner data of `ty::Projection`) defined as so:
```
enum AliasKind {
Projection,
Opaque,
}
struct AliasTy<'tcx> {
def_id: DefId,
substs: SubstsRef<'tcx>,
}
```
Since we don't have access to `TyCtxt` in type flags computation, and because repeatedly calling `DefKind` on the def-id is expensive, these two types are distinguished with `ty::AliasKind`, conveniently glob-imported into `ty::{Projection, Opaque}`. For example:
```diff
match ty.kind() {
- ty::Opaque(..) =>
+ ty::Alias(ty::Opaque, ..) => {}
_ => {}
}
```
This PR also consolidates match arms that treated `ty::Opaque` and `ty::Projection` identically.
r? `@ghost`
Rollup of 7 pull requests
Successful merges:
- #105147 (Allow unsafe through inline const)
- #105438 (Move some codegen-y methods from `rustc_hir_analysis::collect` -> `rustc_codegen_ssa`)
- #105464 (Support #[track_caller] on async closures)
- #105476 (Change pattern borrowing suggestions to be verbose and remove invalid suggestion)
- #105500 (Make some diagnostics not depend on the source of what they reference being available)
- #105628 (Small doc fixes)
- #105659 (Don't require owned data in `MaybeStorageLive`)
Failed merges:
r? `@ghost`
`@rustbot` modify labels: rollup
Remove previously existing fallback that tried to give a good turbofish
suggestion, `need_type_info` is already good enough.
Special case `::<Vec<_>` suggestion for `Iterator::collect`.
