diff --git a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs index 1f912894ccc..b2f010e674e 100644 --- a/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs +++ b/compiler/rustc_trait_selection/src/traits/select/candidate_assembly.rs @@ -779,7 +779,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { match (source.kind(), target.kind()) { // Trait+Kx+'a -> Trait+Ky+'b (upcasts). - (&ty::Dynamic(ref data_a, _, ty::Dyn), &ty::Dynamic(ref data_b, _, ty::Dyn)) => { + (&ty::Dynamic(ref data_a, _, dyn_a), &ty::Dynamic(ref data_b, _, dyn_b)) + if dyn_a == dyn_b => + { // Upcast coercions permit several things: // // 1. Dropping auto traits, e.g., `Foo + Send` to `Foo` diff --git a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs index f132fbc2e40..16960146473 100644 --- a/compiler/rustc_trait_selection/src/traits/select/confirmation.rs +++ b/compiler/rustc_trait_selection/src/traits/select/confirmation.rs @@ -919,7 +919,9 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { let mut nested = vec![]; match (source.kind(), target.kind()) { // Trait+Kx+'a -> Trait+Ky+'b (auto traits and lifetime subtyping). - (&ty::Dynamic(ref data_a, r_a, ty::Dyn), &ty::Dynamic(ref data_b, r_b, ty::Dyn)) => { + (&ty::Dynamic(ref data_a, r_a, dyn_a), &ty::Dynamic(ref data_b, r_b, dyn_b)) + if dyn_a == dyn_b => + { // See `assemble_candidates_for_unsizing` for more info. // We already checked the compatibility of auto traits within `assemble_candidates_for_unsizing`. let iter = data_a @@ -938,7 +940,7 @@ impl<'cx, 'tcx> SelectionContext<'cx, 'tcx> { .map(ty::Binder::dummy), ); let existential_predicates = tcx.mk_poly_existential_predicates(iter); - let source_trait = tcx.mk_dynamic(existential_predicates, r_b, ty::Dyn); + let source_trait = tcx.mk_dynamic(existential_predicates, r_b, dyn_a); // Require that the traits involved in this upcast are **equal**; // only the **lifetime bound** is changed.