rust/compiler/rustc_hir_analysis
bors b4c4664167 Auto merge of #118118 - spastorino:do-not-erase-late-bound-regions-on-iat, r=compiler-errors
Do not erase late bound regions when selecting inherent associated types

In the fix for #97156 we would want the following code:

```rust
#![feature(inherent_associated_types)]
#![allow(incomplete_features)]

struct Foo<T>(T);

impl Foo<fn(&'static ())> {
    type Assoc = u32;
}

trait Other {}
impl Other for u32 {}

// FIXME(inherent_associated_types): Avoid emitting two diagnostics (they only differ in span).
// FIXME(inherent_associated_types): Enhancement: Spruce up the diagnostic by saying something like
// "implementation is not general enough" as is done for traits via
// `try_report_trait_placeholder_mismatch`.

fn bar(_: Foo<for<'a> fn(&'a ())>::Assoc) {}
//~^ ERROR mismatched types
//~| ERROR mismatched types

fn main() {}
```

to fail with ...

```
error[E0220]: associated type `Assoc` not found for `Foo<for<'a> fn(&'a ())>` in the current scope
  --> tests/ui/associated-inherent-types/issue-109789.rs:18:36
   |
4  | struct Foo<T>(T);
   | ------------- associated item `Assoc` not found for this struct
...
18 | fn bar(_: Foo<for<'a> fn(&'a ())>::Assoc) {}
   |                                    ^^^^^ associated item not found in `Foo<for<'a> fn(&'a ())>`
   |
   = note: the associated type was found for
           - `Foo<fn(&'static ())>`

error: aborting due to previous error

For more information about this error, try `rustc --explain E0220`.
```

This PR fixes the ICE we are currently getting "was a subtype of Foo<Binder(fn(&ReStatic ()), [])> during selection but now it is not"

Also fixes #112631

r? `@lcnr`
2023-11-27 17:11:35 +00:00
..
src Auto merge of #118118 - spastorino:do-not-erase-late-bound-regions-on-iat, r=compiler-errors 2023-11-27 17:11:35 +00:00
Cargo.toml Clean up rustc_*/Cargo.toml. 2023-10-30 08:46:02 +11:00
messages.ftl Detect object safety errors when assoc type is missing 2023-10-30 22:12:07 +00:00
README.md

For high-level intro to how type checking works in rustc, see the type checking chapter of the rustc dev guide.