diff options
3 files changed, 37 insertions, 1 deletions
diff --git a/compiler/rustc_hir_typeck/src/mem_categorization.rs b/compiler/rustc_hir_typeck/src/mem_categorization.rs index 7fb1dc2347e..9574da0212f 100644 --- a/compiler/rustc_hir_typeck/src/mem_categorization.rs +++ b/compiler/rustc_hir_typeck/src/mem_categorization.rs @@ -464,7 +464,7 @@ impl<'a, 'tcx> MemCategorizationContext<'a, 'tcx> { // Opaque types can't have field projections, but we can instead convert // the current place in-place (heh) to the hidden type, and then apply all // follow up projections on that. - if node_ty != place_ty && place_ty.has_opaque_types() { + if node_ty != place_ty && matches!(place_ty.kind(), ty::Alias(ty::Opaque, ..)) { projections.push(Projection { kind: ProjectionKind::OpaqueCast, ty: node_ty }); } projections.push(Projection { kind, ty }); diff --git a/tests/ui/impl-trait/opaque-cast-field-access-in-future.rs b/tests/ui/impl-trait/opaque-cast-field-access-in-future.rs new file mode 100644 index 00000000000..3e3bc09a62a --- /dev/null +++ b/tests/ui/impl-trait/opaque-cast-field-access-in-future.rs @@ -0,0 +1,27 @@ +// edition: 2021 + +use std::future::Future; + +async fn bop() { + fold(run(), |mut foo| async move { + &mut foo.bar; + }) +} + +fn fold<Fut, F, U>(_: Foo<U>, f: F) +where + F: FnMut(Foo<U>) -> Fut, +{ + loop {} +} + +struct Foo<F> { + bar: Vec<F>, +} + +fn run() -> Foo<impl Future<Output = ()>> { + //~^ ERROR type annotations needed + loop {} +} + +fn main() {} diff --git a/tests/ui/impl-trait/opaque-cast-field-access-in-future.stderr b/tests/ui/impl-trait/opaque-cast-field-access-in-future.stderr new file mode 100644 index 00000000000..ee4343b110f --- /dev/null +++ b/tests/ui/impl-trait/opaque-cast-field-access-in-future.stderr @@ -0,0 +1,9 @@ +error[E0282]: type annotations needed + --> $DIR/opaque-cast-field-access-in-future.rs:22:17 + | +LL | fn run() -> Foo<impl Future<Output = ()>> { + | ^^^^^^^^^^^^^^^^^^^^^^^^ cannot infer type + +error: aborting due to previous error + +For more information about this error, try `rustc --explain E0282`. |