Expand the primary span of E0277 when the immediate unmet bound is not what the user wrote:
```
error[E0277]: the trait bound `i32: Bar` is not satisfied
--> f100.rs:6:6
|
6 | <i32 as Foo>::foo();
| ^^^ the trait `Bar` is not implemented for `i32`, which is required by `i32: Foo`
|
help: this trait has no implementations, consider adding one
--> f100.rs:2:1
|
2 | trait Bar {}
| ^^^^^^^^^
note: required for `i32` to implement `Foo`
--> f100.rs:3:14
|
3 | impl<T: Bar> Foo for T {}
| --- ^^^ ^
| |
| unsatisfied trait bound introduced here
```
Fix#40120.
Change the implicit `Sized` `Obligation` `Span` for call expressions to
include the whole expression. This aids the existing deduplication
machinery to reduce the number of errors caused by a single unsized
expression.
When we encounter a `dyn Trait` that isn't object safe, look for its
implementors. If there's one, mention using it directly If there are
less than 9, mention the possibility of creating a new enum and using
that instead.
Account for object unsafe `impl Trait on dyn Trait {}`. Make a
distinction between public and sealed traits.
Fix#80194.
In `report_fullfillment_errors` push back `T: Sized`, `T: WellFormed`
and coercion errors to the end of the list. The pre-existing
deduplication logic eliminates redundant errors better that way, keeping
the resulting output with fewer errors than before, while also having
more detail.
Correctly deny late-bound lifetimes from parent in anon consts and TAITs
Reuse the `AnonConstBoundary` scope (introduced in #108553, renamed in this PR to `LateBoundary`) to deny late-bound vars of *all* kinds (ty/const/lifetime) in anon consts and TAITs.
Side-note, but I would like to consolidate this with the error reporting for RPITs (E0657):
c4f25777a0/compiler/rustc_hir_analysis/src/collect/resolve_bound_vars.rs (L733-L754) but the semantics about what we're allowed to capture there are slightly different, so I'm leaving that untouched.
Fixes#115474
Instantiate instead of erasing binder when probing param methods
Fixes#108836
There is a really old comment saying that a `WhereClauseCandidate` probe candidate "should not contain any inference variables", but I'm not really confident that that comment applies anymore. In contrast, other candidates that we assemble during method probe contain inference variables in their substitutions (e.g. `InherentImplCandidate`)...
Since this change is made only to support a nightly feature, I'm happy to gate the new behavior behind this feature flag or discuss it further.
r? types
Deny capturing late-bound non-lifetime param in anon const
Introduce a new AnonConstBoundary so we can detect when we capture a late-bound non-lifetime param with `non_lifetime_binders` enabled.
In the future, we could technically do something like introduce an early-bound parameter on the anon const, and stick the late-bound param in its substs (kinda like how we turn late-bound lifetimes in opaques into early-bound ones). But for now, just deny it so we don't ICE.
Fixes#108191
Use DefKind to give more item kind information during BindingObligation note
The current label says "required by a bound in this". When I see that label, my immediate impression is "this... **what**?". It feels like it was cut short.
Alternative to this would be saying "in this item", but adding the item kind is strictly more informational and adds very little overhead to the existing error presentation.
