diff --git a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs index 95ffd07e397..f7e8dc62a62 100644 --- a/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs +++ b/compiler/rustc_trait_selection/src/traits/error_reporting/suggestions.rs @@ -3628,17 +3628,19 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { is_derivable_trait && // Ensure all fields impl the trait. adt.all_fields().all(|field| { - let field_ty = field.ty(self.tcx, args); + let field_ty = ty::GenericArg::from(field.ty(self.tcx, args)); let trait_args = match diagnostic_name { sym::PartialEq | sym::PartialOrd => { Some(field_ty) } _ => None, }; + // Also add host param, if present + let host = self.tcx.generics_of(trait_pred.def_id()).host_effect_index.map(|idx| trait_pred.skip_binder().trait_ref.args[idx]); let trait_pred = trait_pred.map_bound_ref(|tr| ty::TraitPredicate { trait_ref: ty::TraitRef::new(self.tcx, trait_pred.def_id(), - [field_ty].into_iter().chain(trait_args), + [field_ty].into_iter().chain(trait_args).chain(host), ), ..*tr }); @@ -3659,6 +3661,7 @@ impl<'tcx> TypeErrCtxtExt<'tcx> for TypeErrCtxt<'_, 'tcx> { trait_pred.skip_binder().self_ty(), diagnostic_name, ), + // FIXME(effects, const_trait_impl) derive_const as suggestion? format!("#[derive({diagnostic_name})]\n"), Applicability::MaybeIncorrect, );