Don't ICE on missing Unsize impl
#72194
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| @@ -283,6 +283,8 @@ impl<'a, 'tcx> InferCtxtExt<'tcx> for InferCtxt<'a, 'tcx> { | |||
| .unwrap_or(false); | |||
| let is_from = format!("{}", trait_ref.print_only_trait_path()) | |||
| .starts_with("std::convert::From<"); | |||
| let is_unsize = | |||
| { Some(trait_ref.def_id()) == self.tcx.lang_items().unsize_trait() }; | |||
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Are the braces needed? Have you ran x.py fmt?
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Not strictly necessary, but I ran ./x.py fmt
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I can remove if you think that's better?
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Na, if it's fine with fmt it's fine with me.
|
@bors r+ rollup |
|
📌 Commit f6aa161 has been approved by |
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…tebank
Don't ICE on missing `Unsize` impl
Previously code of the form
```rust
#![feature(unsize, dispatch_from_dyn)]
use std::marker::Unsize;
use std::ops::DispatchFromDyn;
pub struct Foo<'a, T: ?Sized> {
_inner: &'a &'a T,
}
impl<'a, T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<Foo<'a, U>> for Foo<'a, T> {}
```
would generate an ICE due to the missing `Unsize` impl being run through the `suggest_change_mut` suggestion. This PR adds an early exit and a pointer to the appropriate docs regarding `Unsize` instead:
```
error[E0277]: the trait bound `&'a T: std::marker::Unsize<&'a U>` is not satisfied
--> src/test/ui/issues/issue-71036.rs:11:1
|
11 | impl<'a, T: ?Sized + Unsize<U>, U: ?Sized> DispatchFromDyn<Foo<'a, U>> for Foo<'a, T> {}
| ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ the trait `std::marker::Unsize<&'a U>` is not implemented for `&'a T`
|
= note: all implementations of `Unsize` are provided automatically by the compiler, see <https://doc.rust-lang.org/stable/std/marker/trait.Unsize.html> for more information
= note: required because of the requirements on the impl of `std::ops::DispatchFromDyn<&'a &'a U>` for `&'a &'a T`
error: aborting due to previous error
For more information about this error, try `rustc --explain E0277`.
```
r? @estebank
Resolves rust-lang#71036
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Rollup of 8 pull requests Successful merges: - rust-lang#71910 (Fix unused_parens false positive when using binary operations) - rust-lang#72087 (Fix hang in lexical_region_resolve) - rust-lang#72126 (Change `WorkProduct::saved_files` to an `Option`.) - rust-lang#72127 (add long error explanation for E0228) - rust-lang#72141 (Warn against thread::sleep in async fn) - rust-lang#72170 (use `require_lang_item` over `unwrap`.) - rust-lang#72191 (Clean up E0589 explanation) - rust-lang#72194 (Don't ICE on missing `Unsize` impl) Failed merges: r? @ghost
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Previously code of the form
would generate an ICE due to the missing
Unsizeimpl being run through thesuggest_change_mutsuggestion. This PR adds an early exit and a pointer to the appropriate docs regardingUnsizeinstead:r? @estebank
Resolves #71036