diff options
| -rw-r--r-- | compiler/rustc_middle/src/ty/error.rs | 15 | ||||
| -rw-r--r-- | src/test/ui/type-alias-impl-trait/issue-89686.rs | 24 | ||||
| -rw-r--r-- | src/test/ui/type-alias-impl-trait/issue-89686.stderr | 34 |
3 files changed, 68 insertions, 5 deletions
diff --git a/compiler/rustc_middle/src/ty/error.rs b/compiler/rustc_middle/src/ty/error.rs index 08b4d3aecda..bac681bd96f 100644 --- a/compiler/rustc_middle/src/ty/error.rs +++ b/compiler/rustc_middle/src/ty/error.rs @@ -769,11 +769,16 @@ fn foo(&self) -> Self::T { String::new() } ) -> bool { let assoc = self.associated_item(proj_ty.item_def_id); if let ty::Opaque(def_id, _) = *proj_ty.self_ty().kind() { - let opaque_local_def_id = def_id.expect_local(); - let opaque_hir_id = self.hir().local_def_id_to_hir_id(opaque_local_def_id); - let opaque_hir_ty = match &self.hir().expect_item(opaque_hir_id).kind { - hir::ItemKind::OpaqueTy(opaque_hir_ty) => opaque_hir_ty, - _ => bug!("The HirId comes from a `ty::Opaque`"), + let opaque_local_def_id = def_id.as_local(); + let opaque_hir_ty = if let Some(opaque_local_def_id) = opaque_local_def_id { + let hir = self.hir(); + let opaque_hir_id = hir.local_def_id_to_hir_id(opaque_local_def_id); + match &hir.expect_item(opaque_hir_id).kind { + hir::ItemKind::OpaqueTy(opaque_hir_ty) => opaque_hir_ty, + _ => bug!("The HirId comes from a `ty::Opaque`"), + } + } else { + return false; }; let (trait_ref, assoc_substs) = proj_ty.trait_ref_and_own_substs(self); diff --git a/src/test/ui/type-alias-impl-trait/issue-89686.rs b/src/test/ui/type-alias-impl-trait/issue-89686.rs new file mode 100644 index 00000000000..2b6ce49e7e2 --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/issue-89686.rs @@ -0,0 +1,24 @@ +// edition:2018 + +#![feature(type_alias_impl_trait)] + +use std::future::Future; + +type G<'a, T> = impl Future<Output = ()>; +//~^ ERROR: type mismatch resolving `<impl Future as Future>::Output == ()` +//~| ERROR: the trait bound `T: Trait` is not satisfied + +trait Trait { + type F: Future<Output = ()>; + + fn f(&self) -> Self::F; + + fn g<'a>(&'a self) -> G<'a, Self> + where + Self: Sized, + { + async move { self.f().await } + } +} + +fn main() {} diff --git a/src/test/ui/type-alias-impl-trait/issue-89686.stderr b/src/test/ui/type-alias-impl-trait/issue-89686.stderr new file mode 100644 index 00000000000..accc84d30a7 --- /dev/null +++ b/src/test/ui/type-alias-impl-trait/issue-89686.stderr @@ -0,0 +1,34 @@ +error[E0271]: type mismatch resolving `<impl Future as Future>::Output == ()` + --> $DIR/issue-89686.rs:7:17 + | +LL | type G<'a, T> = impl Future<Output = ()>; + | ^^^^^^^^^^^^^^^^^^^^^^^^ expected `()`, found associated type +... +LL | async move { self.f().await } + | ------------------ the found `async` block + | + ::: $SRC_DIR/core/src/future/mod.rs:LL:COL + | +LL | pub const fn from_generator<T>(gen: T) -> impl Future<Output = T::Return> + | ------------------------------- the found opaque type + | + = note: expected unit type `()` + found associated type `<impl Future as Future>::Output` + = help: consider constraining the associated type `<impl Future as Future>::Output` to `()` + = note: for more information, visit https://doc.rust-lang.org/book/ch19-03-advanced-traits.html + +error[E0277]: the trait bound `T: Trait` is not satisfied + --> $DIR/issue-89686.rs:7:17 + | +LL | type G<'a, T> = impl Future<Output = ()>; + | ^^^^^^^^^^^^^^^^^^^^^^^^ the trait `Trait` is not implemented for `T` + | +help: consider restricting type parameter `T` + | +LL | type G<'a, T: Trait> = impl Future<Output = ()>; + | +++++++ + +error: aborting due to 2 previous errors + +Some errors have detailed explanations: E0271, E0277. +For more information about an error, try `rustc --explain E0271`. |