Unnamed repository; edit this file 'description' to name the repository.
| -rw-r--r-- | crates/hir-ty/src/next_solver/mapping.rs | 7 | ||||
| -rw-r--r-- | crates/hir-ty/src/tests/traits.rs | 32 |
2 files changed, 39 insertions, 0 deletions
diff --git a/crates/hir-ty/src/next_solver/mapping.rs b/crates/hir-ty/src/next_solver/mapping.rs index 4696cf479c..20cd8626f2 100644 --- a/crates/hir-ty/src/next_solver/mapping.rs +++ b/crates/hir-ty/src/next_solver/mapping.rs @@ -1148,6 +1148,13 @@ pub(crate) fn convert_ty_for_result<'db>(interner: DbInterner<'db>, ty: Ty<'db>) }), ); + // Rust and chalk have slightly different + // representation for trait objects. + // + // Chalk uses `for<T0> for<'a> T0: Trait<'a>` while rustc + // uses `ExistentialPredicate`s, which do not have a self ty. + // We need to shift escaping bound vars by 1 to accommodate + // the newly introduced `for<T0>` binder. let p = shift_vars(interner, p, 1); let where_clause = match p.skip_binder() { diff --git a/crates/hir-ty/src/tests/traits.rs b/crates/hir-ty/src/tests/traits.rs index 2e4346a869..9d72105624 100644 --- a/crates/hir-ty/src/tests/traits.rs +++ b/crates/hir-ty/src/tests/traits.rs @@ -4994,3 +4994,35 @@ fn main() { "#]], ); } + +#[test] +fn trait_object_binders() { + check_infer( + r#" +//- minicore: iterator, dispatch_from_dyn +fn main() { + struct Box<T: ?Sized>(*const T); + impl<I: Iterator + ?Sized> Iterator for Box<I> { + type Item = I::Item; + fn next(&mut self) -> Option<I::Item> { + loop {} + } + } + let iter: Box<dyn Iterator<Item = &[u8]> + 'static> = loop {}; + let _ = iter.into_iter(); +}"#, + expect![[r#" + 10..313 '{ ...r(); }': () + 223..227 'iter': Box<dyn Iterator<Item = &'? [u8]> + 'static> + 273..280 'loop {}': ! + 278..280 '{}': () + 290..291 '_': Box<dyn Iterator<Item = &'? [u8]> + 'static> + 294..298 'iter': Box<dyn Iterator<Item = &'? [u8]> + 'static> + 294..310 'iter.i...iter()': Box<dyn Iterator<Item = &'? [u8]> + 'static> + 152..156 'self': &'? mut Box<I> + 177..208 '{ ... }': Option<Iterator::Item<I>> + 191..198 'loop {}': ! + 196..198 '{}': () + "#]], + ); +} |