Just return Ty directly

Author: detrumi

chalk-integration/src/db.rs

@@ -97,7 +97,7 @@ impl RustIrDatabase<ChalkIr> for ChalkDatabase {
         self.program_ir().unwrap().opaque_ty_data(id)
     }
 
-    fn hidden_opaque_type(&self, id: OpaqueTyId<ChalkIr>) -> Arc<Ty<ChalkIr>> {
+    fn hidden_opaque_type(&self, id: OpaqueTyId<ChalkIr>) -> Ty<ChalkIr> {
         self.program_ir().unwrap().hidden_opaque_type(id)
     }
 

chalk-integration/src/program.rs

@@ -339,8 +339,8 @@ impl RustIrDatabase<ChalkIr> for Program {
         self.opaque_ty_data[&id].clone()
     }
 
-    fn hidden_opaque_type(&self, id: OpaqueTyId<ChalkIr>) -> Arc<Ty<ChalkIr>> {
-        self.hidden_opaque_types[&id].clone()
+    fn hidden_opaque_type(&self, id: OpaqueTyId<ChalkIr>) -> Ty<ChalkIr> {
+        (*self.hidden_opaque_types[&id]).clone()
     }
 
     fn adt_datum(&self, id: AdtId<ChalkIr>) -> Arc<AdtDatum<ChalkIr>> {

chalk-solve/src/clauses.rs

@@ -142,7 +142,7 @@ pub fn push_auto_trait_impls_opaque<I: Interner>(
         1
     );
 
-    let hidden_ty = (*builder.db.hidden_opaque_type(opaque_id)).clone();
+    let hidden_ty = builder.db.hidden_opaque_type(opaque_id);
     let binders = opaque_ty_datum.bound.clone();
     builder.push_binders(&binders, |builder, _| {
         let self_ty: Ty<_> = ApplicationTy {

chalk-solve/src/clauses/program_clauses.rs

@@ -151,7 +151,7 @@ impl<I: Interner> ToProgramClauses<I> for OpaqueTyDatum<I> {
                 DomainGoal::Holds(
                     AliasEq {
                         alias: alias.clone(),
-                        ty: (*builder.db.hidden_opaque_type(self.opaque_ty_id)).clone(),
+                        ty: builder.db.hidden_opaque_type(self.opaque_ty_id),
                     }
                     .cast(interner),
                 ),

chalk-solve/src/lib.rs

@@ -52,7 +52,7 @@ pub trait RustIrDatabase<I: Interner>: Debug {
     fn opaque_ty_data(&self, id: OpaqueTyId<I>) -> Arc<OpaqueTyDatum<I>>;
 
     /// Returns the "hidden type" corresponding with the opaque type.
-    fn hidden_opaque_type(&self, id: OpaqueTyId<I>) -> Arc<Ty<I>>;
+    fn hidden_opaque_type(&self, id: OpaqueTyId<I>) -> Ty<I>;
 
     /// Returns a list of potentially relevant impls for a given
     /// trait-id; we also supply the type parameters that we are