2 files changed, 44 insertions, 468 deletions

diff --git a/crates/hir_ty/src/traits/chalk.rs b/crates/hir_ty/src/traits/chalk.rs
index f03b92422..b8c390b2e 100644
--- a/crates/hir_ty/src/traits/chalk.rs
+++ b/crates/hir_ty/src/traits/chalk.rs
@@ -17,16 +17,14 @@ use super::ChalkContext;
 use crate::{
     db::HirDatabase,
     display::HirDisplay,
-    from_assoc_type_id,
+    from_assoc_type_id, make_only_type_binders,
     method_resolution::{TyFingerprint, ALL_FLOAT_FPS, ALL_INT_FPS},
     to_assoc_type_id, to_chalk_trait_id,
     utils::generics,
     AliasEq, AliasTy, BoundVar, CallableDefId, DebruijnIndex, FnDefId, ProjectionTy, Substitution,
-    TraitRef, Ty, TyBuilder, TyExt, TyKind, WhereClause,
-};
-use mapping::{
-    convert_where_clauses, generic_predicate_to_inline_bound, make_binders, TypeAliasAsValue,
+    TraitRef, TraitRefExt, Ty, TyBuilder, TyExt, TyKind, WhereClause,
 };
+use mapping::{convert_where_clauses, generic_predicate_to_inline_bound, TypeAliasAsValue};
 
 pub use self::interner::Interner;
 pub(crate) use self::interner::*;
@@ -86,7 +84,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         debug!("impls_for_trait {:?}", trait_id);
         let trait_: hir_def::TraitId = from_chalk(self.db, trait_id);
 
-        let ty: Ty = from_chalk(self.db, parameters[0].assert_ty_ref(&Interner).clone());
+        let ty: Ty = parameters[0].assert_ty_ref(&Interner).clone();
 
         fn binder_kind(
             ty: &Ty,
@@ -187,16 +185,11 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
                 let (datas, binders) = (*datas).as_ref().into_value_and_skipped_binders();
                 let data = &datas.impl_traits[idx as usize];
                 let bound = OpaqueTyDatumBound {
-                    bounds: make_binders(
-                        data.bounds
-                            .skip_binders()
-                            .iter()
-                            .cloned()
-                            .map(|b| b.to_chalk(self.db))
-                            .collect(),
+                    bounds: make_only_type_binders(
                         1,
+                        data.bounds.skip_binders().iter().cloned().collect(),
                     ),
-                    where_clauses: make_binders(vec![], 0),
+                    where_clauses: make_only_type_binders(0, vec![]),
                 };
                 chalk_ir::Binders::new(binders, bound)
             }
@@ -244,25 +237,25 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
                             .intern(&Interner),
                     });
                     let bound = OpaqueTyDatumBound {
-                        bounds: make_binders(
+                        bounds: make_only_type_binders(
+                            1,
                             vec![
-                                crate::wrap_empty_binders(impl_bound).to_chalk(self.db),
-                                crate::wrap_empty_binders(proj_bound).to_chalk(self.db),
+                                crate::wrap_empty_binders(impl_bound),
+                                crate::wrap_empty_binders(proj_bound),
                             ],
-                            1,
                         ),
-                        where_clauses: make_binders(vec![], 0),
+                        where_clauses: make_only_type_binders(0, vec![]),
                     };
                     // The opaque type has 1 parameter.
-                    make_binders(bound, 1)
+                    make_only_type_binders(1, bound)
                 } else {
                     // If failed to find Symbol’s value as variable is void: Future::Output, return empty bounds as fallback.
                     let bound = OpaqueTyDatumBound {
-                        bounds: make_binders(vec![], 0),
-                        where_clauses: make_binders(vec![], 0),
+                        bounds: make_only_type_binders(0, vec![]),
+                        where_clauses: make_only_type_binders(0, vec![]),
                     };
                     // The opaque type has 1 parameter.
-                    make_binders(bound, 1)
+                    make_only_type_binders(1, bound)
                 }
             }
         };
@@ -272,7 +265,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
 
     fn hidden_opaque_type(&self, _id: chalk_ir::OpaqueTyId<Interner>) -> chalk_ir::Ty<Interner> {
         // FIXME: actually provide the hidden type; it is relevant for auto traits
-        TyKind::Error.intern(&Interner).to_chalk(self.db)
+        TyKind::Error.intern(&Interner)
     }
 
     fn is_object_safe(&self, _trait_id: chalk_ir::TraitId<Interner>) -> bool {
@@ -293,29 +286,28 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
         _closure_id: chalk_ir::ClosureId<Interner>,
         substs: &chalk_ir::Substitution<Interner>,
     ) -> chalk_ir::Binders<rust_ir::FnDefInputsAndOutputDatum<Interner>> {
-        let sig_ty: Ty =
-            from_chalk(self.db, substs.at(&Interner, 0).assert_ty_ref(&Interner).clone());
+        let sig_ty = substs.at(&Interner, 0).assert_ty_ref(&Interner).clone();
         let sig = &sig_ty.callable_sig(self.db).expect("first closure param should be fn ptr");
         let io = rust_ir::FnDefInputsAndOutputDatum {
-            argument_types: sig.params().iter().map(|ty| ty.clone().to_chalk(self.db)).collect(),
-            return_type: sig.ret().clone().to_chalk(self.db),
+            argument_types: sig.params().iter().cloned().collect(),
+            return_type: sig.ret().clone(),
         };
-        make_binders(io.shifted_in(&Interner), 0)
+        make_only_type_binders(0, io.shifted_in(&Interner))
     }
     fn closure_upvars(
         &self,
         _closure_id: chalk_ir::ClosureId<Interner>,
         _substs: &chalk_ir::Substitution<Interner>,
     ) -> chalk_ir::Binders<chalk_ir::Ty<Interner>> {
-        let ty = TyBuilder::unit().to_chalk(self.db);
-        make_binders(ty, 0)
+        let ty = TyBuilder::unit();
+        make_only_type_binders(0, ty)
     }
     fn closure_fn_substitution(
         &self,
         _closure_id: chalk_ir::ClosureId<Interner>,
         _substs: &chalk_ir::Substitution<Interner>,
     ) -> chalk_ir::Substitution<Interner> {
-        Substitution::empty(&Interner).to_chalk(self.db)
+        Substitution::empty(&Interner)
     }
 
     fn trait_name(&self, trait_id: chalk_ir::TraitId<Interner>) -> String {
@@ -410,10 +402,10 @@ pub(crate) fn associated_ty_data_query(
     let where_clauses = convert_where_clauses(db, type_alias.into(), &bound_vars);
     let bound_data = rust_ir::AssociatedTyDatumBound { bounds, where_clauses };
     let datum = AssociatedTyDatum {
-        trait_id: trait_.to_chalk(db),
+        trait_id: to_chalk_trait_id(trait_),
         id,
         name: type_alias,
-        binders: make_binders(bound_data, generic_params.len()),
+        binders: make_only_type_binders(generic_params.len(), bound_data),
     };
     Arc::new(datum)
 }
@@ -446,7 +438,7 @@ pub(crate) fn trait_datum_query(
         lang_attr(db.upcast(), trait_).and_then(|name| well_known_trait_from_lang_attr(&name));
     let trait_datum = TraitDatum {
         id: trait_id,
-        binders: make_binders(trait_datum_bound, bound_vars.len(&Interner)),
+        binders: make_only_type_binders(bound_vars.len(&Interner), trait_datum_bound),
         flags,
         associated_ty_ids,
         well_known,
@@ -515,7 +507,7 @@ pub(crate) fn struct_datum_query(
         // FIXME set ADT kind
         kind: rust_ir::AdtKind::Struct,
         id: struct_id,
-        binders: make_binders(struct_datum_bound, num_params),
+        binders: make_only_type_binders(num_params, struct_datum_bound),
         flags,
     };
     Arc::new(struct_datum)
@@ -563,7 +555,6 @@ fn impl_def_datum(
         trait_ref.display(db),
         where_clauses
     );
-    let trait_ref = trait_ref.to_chalk(db);
 
     let polarity = if negative { rust_ir::Polarity::Negative } else { rust_ir::Polarity::Positive };
 
@@ -585,7 +576,7 @@ fn impl_def_datum(
         .collect();
     debug!("impl_datum: {:?}", impl_datum_bound);
     let impl_datum = ImplDatum {
-        binders: make_binders(impl_datum_bound, bound_vars.len(&Interner)),
+        binders: make_only_type_binders(bound_vars.len(&Interner), impl_datum_bound),
         impl_type,
         polarity,
         associated_ty_value_ids,
@@ -624,7 +615,7 @@ fn type_alias_associated_ty_value(
         .associated_type_by_name(&type_alias_data.name)
         .expect("assoc ty value should not exist"); // validated when building the impl data as well
     let (ty, binders) = db.ty(type_alias.into()).into_value_and_skipped_binders();
-    let value_bound = rust_ir::AssociatedTyValueBound { ty: ty.to_chalk(db) };
+    let value_bound = rust_ir::AssociatedTyValueBound { ty };
     let value = rust_ir::AssociatedTyValue {
         impl_id: impl_id.to_chalk(db),
         associated_ty_id: to_assoc_type_id(assoc_ty),
@@ -645,13 +636,13 @@ pub(crate) fn fn_def_datum_query(
     let where_clauses = convert_where_clauses(db, callable_def.into(), &bound_vars);
     let bound = rust_ir::FnDefDatumBound {
         // Note: Chalk doesn't actually use this information yet as far as I am aware, but we provide it anyway
-        inputs_and_output: make_binders(
+        inputs_and_output: make_only_type_binders(
+            0,
             rust_ir::FnDefInputsAndOutputDatum {
-                argument_types: sig.params().iter().map(|ty| ty.clone().to_chalk(db)).collect(),
-                return_type: sig.ret().clone().to_chalk(db),
+                argument_types: sig.params().iter().cloned().collect(),
+                return_type: sig.ret().clone(),
             }
             .shifted_in(&Interner),
-            0,
         ),
         where_clauses,
     };
diff --git a/crates/hir_ty/src/traits/chalk/mapping.rs b/crates/hir_ty/src/traits/chalk/mapping.rs
index 84abd99b2..7818f6387 100644
--- a/crates/hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/hir_ty/src/traits/chalk/mapping.rs
@@ -3,233 +3,20 @@
 //! Chalk (in both directions); plus some helper functions for more specialized
 //! conversions.
 
-use chalk_ir::{cast::Cast, interner::HasInterner};
+use chalk_ir::cast::Cast;
 use chalk_solve::rust_ir;
 
 use base_db::salsa::InternKey;
 use hir_def::{GenericDefId, TypeAliasId};
 
 use crate::{
-    chalk_ext::ProjectionTyExt, db::HirDatabase, static_lifetime, AliasTy, CallableDefId,
-    Canonical, ConstrainedSubst, DomainGoal, FnPointer, GenericArg, InEnvironment, OpaqueTy,
-    ProjectionTy, QuantifiedWhereClause, Substitution, TraitRef, Ty, TypeWalk, WhereClause,
+    db::HirDatabase, AliasTy, CallableDefId, ProjectionTyExt, QuantifiedWhereClause, Substitution,
+    Ty, WhereClause,
 };
 
 use super::interner::*;
 use super::*;
 
-impl ToChalk for Ty {
-    type Chalk = chalk_ir::Ty<Interner>;
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Ty<Interner> {
-        match self.into_inner() {
-            TyKind::Ref(m, lt, ty) => {
-                chalk_ir::TyKind::Ref(m, lt, ty.to_chalk(db)).intern(&Interner)
-            }
-            TyKind::Array(ty, size) => {
-                chalk_ir::TyKind::Array(ty.to_chalk(db), size).intern(&Interner)
-            }
-            TyKind::Function(FnPointer { sig, substitution: substs, num_binders }) => {
-                let substitution = chalk_ir::FnSubst(substs.0.to_chalk(db));
-                chalk_ir::TyKind::Function(chalk_ir::FnPointer { num_binders, sig, substitution })
-                    .intern(&Interner)
-            }
-            TyKind::AssociatedType(assoc_type_id, substs) => {
-                let substitution = substs.to_chalk(db);
-                chalk_ir::TyKind::AssociatedType(assoc_type_id, substitution).intern(&Interner)
-            }
-
-            TyKind::OpaqueType(id, substs) => {
-                let substitution = substs.to_chalk(db);
-                chalk_ir::TyKind::OpaqueType(id, substitution).intern(&Interner)
-            }
-
-            TyKind::Foreign(id) => chalk_ir::TyKind::Foreign(id).intern(&Interner),
-
-            TyKind::Scalar(scalar) => chalk_ir::TyKind::Scalar(scalar).intern(&Interner),
-
-            TyKind::Tuple(cardinality, substs) => {
-                let substitution = substs.to_chalk(db);
-                chalk_ir::TyKind::Tuple(cardinality, substitution).intern(&Interner)
-            }
-            TyKind::Raw(mutability, ty) => {
-                let ty = ty.to_chalk(db);
-                chalk_ir::TyKind::Raw(mutability, ty).intern(&Interner)
-            }
-            TyKind::Slice(ty) => chalk_ir::TyKind::Slice(ty.to_chalk(db)).intern(&Interner),
-            TyKind::Str => chalk_ir::TyKind::Str.intern(&Interner),
-            TyKind::FnDef(id, substs) => {
-                let substitution = substs.to_chalk(db);
-                chalk_ir::TyKind::FnDef(id, substitution).intern(&Interner)
-            }
-            TyKind::Never => chalk_ir::TyKind::Never.intern(&Interner),
-
-            TyKind::Closure(closure_id, substs) => {
-                let substitution = substs.to_chalk(db);
-                chalk_ir::TyKind::Closure(closure_id, substitution).intern(&Interner)
-            }
-
-            TyKind::Adt(adt_id, substs) => {
-                let substitution = substs.to_chalk(db);
-                chalk_ir::TyKind::Adt(adt_id, substitution).intern(&Interner)
-            }
-            TyKind::Alias(AliasTy::Projection(proj_ty)) => {
-                chalk_ir::AliasTy::Projection(proj_ty.to_chalk(db))
-                    .cast(&Interner)
-                    .intern(&Interner)
-            }
-            TyKind::Alias(AliasTy::Opaque(opaque_ty)) => {
-                chalk_ir::AliasTy::Opaque(opaque_ty.to_chalk(db)).cast(&Interner).intern(&Interner)
-            }
-            TyKind::Placeholder(idx) => idx.to_ty::<Interner>(&Interner),
-            TyKind::BoundVar(idx) => chalk_ir::TyKind::BoundVar(idx).intern(&Interner),
-            TyKind::InferenceVar(..) => panic!("uncanonicalized infer ty"),
-            TyKind::Dyn(dyn_ty) => {
-                let (bounds, binders) = dyn_ty.bounds.into_value_and_skipped_binders();
-                let where_clauses = chalk_ir::QuantifiedWhereClauses::from_iter(
-                    &Interner,
-                    bounds.interned().iter().cloned().map(|p| p.to_chalk(db)),
-                );
-                let bounded_ty = chalk_ir::DynTy {
-                    bounds: chalk_ir::Binders::new(binders, where_clauses),
-                    lifetime: dyn_ty.lifetime,
-                };
-                chalk_ir::TyKind::Dyn(bounded_ty).intern(&Interner)
-            }
-            TyKind::Error => chalk_ir::TyKind::Error.intern(&Interner),
-        }
-    }
-    fn from_chalk(db: &dyn HirDatabase, chalk: chalk_ir::Ty<Interner>) -> Self {
-        match chalk.data(&Interner).kind.clone() {
-            chalk_ir::TyKind::Error => TyKind::Error,
-            chalk_ir::TyKind::Array(ty, size) => TyKind::Array(from_chalk(db, ty), size),
-            chalk_ir::TyKind::Placeholder(idx) => TyKind::Placeholder(idx),
-            chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Projection(proj)) => {
-                TyKind::Alias(AliasTy::Projection(from_chalk(db, proj)))
-            }
-            chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Opaque(opaque_ty)) => {
-                TyKind::Alias(AliasTy::Opaque(from_chalk(db, opaque_ty)))
-            }
-            chalk_ir::TyKind::Function(chalk_ir::FnPointer {
-                num_binders,
-                sig,
-                substitution,
-                ..
-            }) => {
-                assert_eq!(num_binders, 0);
-                let substs = crate::FnSubst(from_chalk(db, substitution.0));
-                TyKind::Function(FnPointer { num_binders, sig, substitution: substs })
-            }
-            chalk_ir::TyKind::BoundVar(idx) => TyKind::BoundVar(idx),
-            chalk_ir::TyKind::InferenceVar(_iv, _kind) => TyKind::Error,
-            chalk_ir::TyKind::Dyn(dyn_ty) => {
-                assert_eq!(dyn_ty.bounds.binders.len(&Interner), 1);
-                let (bounds, binders) = dyn_ty.bounds.into_value_and_skipped_binders();
-                let where_clauses = crate::QuantifiedWhereClauses::from_iter(
-                    &Interner,
-                    bounds.interned().iter().cloned().map(|p| from_chalk(db, p)),
-                );
-                TyKind::Dyn(crate::DynTy {
-                    bounds: crate::Binders::new(binders, where_clauses),
-                    // HACK: we sometimes get lifetime variables back in solutions
-                    // from Chalk, and don't have the infrastructure to substitute
-                    // them yet. So for now we just turn them into 'static right
-                    // when we get them
-                    lifetime: static_lifetime(),
-                })
-            }
-
-            chalk_ir::TyKind::Adt(adt_id, subst) => TyKind::Adt(adt_id, from_chalk(db, subst)),
-            chalk_ir::TyKind::AssociatedType(type_id, subst) => {
-                TyKind::AssociatedType(type_id, from_chalk(db, subst))
-            }
-
-            chalk_ir::TyKind::OpaqueType(opaque_type_id, subst) => {
-                TyKind::OpaqueType(opaque_type_id, from_chalk(db, subst))
-            }
-
-            chalk_ir::TyKind::Scalar(scalar) => TyKind::Scalar(scalar),
-            chalk_ir::TyKind::Tuple(cardinality, subst) => {
-                TyKind::Tuple(cardinality, from_chalk(db, subst))
-            }
-            chalk_ir::TyKind::Raw(mutability, ty) => TyKind::Raw(mutability, from_chalk(db, ty)),
-            chalk_ir::TyKind::Slice(ty) => TyKind::Slice(from_chalk(db, ty)),
-            chalk_ir::TyKind::Ref(mutability, _lifetime, ty) => {
-                // HACK: we sometimes get lifetime variables back in solutions
-                // from Chalk, and don't have the infrastructure to substitute
-                // them yet. So for now we just turn them into 'static right
-                // when we get them
-                TyKind::Ref(mutability, static_lifetime(), from_chalk(db, ty))
-            }
-            chalk_ir::TyKind::Str => TyKind::Str,
-            chalk_ir::TyKind::Never => TyKind::Never,
-
-            chalk_ir::TyKind::FnDef(fn_def_id, subst) => {
-                TyKind::FnDef(fn_def_id, from_chalk(db, subst))
-            }
-
-            chalk_ir::TyKind::Closure(id, subst) => TyKind::Closure(id, from_chalk(db, subst)),
-
-            chalk_ir::TyKind::Foreign(foreign_def_id) => TyKind::Foreign(foreign_def_id),
-            chalk_ir::TyKind::Generator(_, _) => unimplemented!(), // FIXME
-            chalk_ir::TyKind::GeneratorWitness(_, _) => unimplemented!(), // FIXME
-        }
-        .intern(&Interner)
-    }
-}
-
-impl ToChalk for GenericArg {
-    type Chalk = chalk_ir::GenericArg<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> Self::Chalk {
-        match self.interned() {
-            crate::GenericArgData::Ty(ty) => ty.clone().to_chalk(db).cast(&Interner),
-        }
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self {
-        match chalk.interned() {
-            chalk_ir::GenericArgData::Ty(ty) => Ty::from_chalk(db, ty.clone()).cast(&Interner),
-            chalk_ir::GenericArgData::Lifetime(_) => unimplemented!(),
-            chalk_ir::GenericArgData::Const(_) => unimplemented!(),
-        }
-    }
-}
-
-impl ToChalk for Substitution {
-    type Chalk = chalk_ir::Substitution<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Substitution<Interner> {
-        chalk_ir::Substitution::from_iter(
-            &Interner,
-            self.iter(&Interner).map(|ty| ty.clone().to_chalk(db)),
-        )
-    }
-
-    fn from_chalk(
-        db: &dyn HirDatabase,
-        parameters: chalk_ir::Substitution<Interner>,
-    ) -> Substitution {
-        let tys = parameters.iter(&Interner).map(|p| from_chalk(db, p.clone())).collect();
-        Substitution::intern(tys)
-    }
-}
-
-impl ToChalk for TraitRef {
-    type Chalk = chalk_ir::TraitRef<Interner>;
-
-    fn to_chalk(self: TraitRef, db: &dyn HirDatabase) -> chalk_ir::TraitRef<Interner> {
-        let trait_id = self.trait_id;
-        let substitution = self.substitution.to_chalk(db);
-        chalk_ir::TraitRef { trait_id, substitution }
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, trait_ref: chalk_ir::TraitRef<Interner>) -> Self {
-        let trait_id = trait_ref.trait_id;
-        let substs = from_chalk(db, trait_ref.substitution);
-        TraitRef { trait_id, substitution: substs }
-    }
-}
-
 impl ToChalk for hir_def::TraitId {
     type Chalk = TraitId;
 
@@ -283,208 +70,6 @@ impl ToChalk for TypeAliasAsValue {
     }
 }
 
-impl ToChalk for WhereClause {
-    type Chalk = chalk_ir::WhereClause<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::WhereClause<Interner> {
-        match self {
-            WhereClause::Implemented(trait_ref) => {
-                chalk_ir::WhereClause::Implemented(trait_ref.to_chalk(db))
-            }
-            WhereClause::AliasEq(alias_eq) => chalk_ir::WhereClause::AliasEq(alias_eq.to_chalk(db)),
-        }
-    }
-
-    fn from_chalk(
-        db: &dyn HirDatabase,
-        where_clause: chalk_ir::WhereClause<Interner>,
-    ) -> WhereClause {
-        match where_clause {
-            chalk_ir::WhereClause::Implemented(tr) => WhereClause::Implemented(from_chalk(db, tr)),
-            chalk_ir::WhereClause::AliasEq(alias_eq) => {
-                WhereClause::AliasEq(from_chalk(db, alias_eq))
-            }
-
-            chalk_ir::WhereClause::LifetimeOutlives(_) => {
-                // we shouldn't get these from Chalk
-                panic!("encountered LifetimeOutlives from Chalk")
-            }
-
-            chalk_ir::WhereClause::TypeOutlives(_) => {
-                // we shouldn't get these from Chalk
-                panic!("encountered TypeOutlives from Chalk")
-            }
-        }
-    }
-}
-
-impl ToChalk for ProjectionTy {
-    type Chalk = chalk_ir::ProjectionTy<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::ProjectionTy<Interner> {
-        chalk_ir::ProjectionTy {
-            associated_ty_id: self.associated_ty_id,
-            substitution: self.substitution.to_chalk(db),
-        }
-    }
-
-    fn from_chalk(
-        db: &dyn HirDatabase,
-        projection_ty: chalk_ir::ProjectionTy<Interner>,
-    ) -> ProjectionTy {
-        ProjectionTy {
-            associated_ty_id: projection_ty.associated_ty_id,
-            substitution: from_chalk(db, projection_ty.substitution),
-        }
-    }
-}
-impl ToChalk for OpaqueTy {
-    type Chalk = chalk_ir::OpaqueTy<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> Self::Chalk {
-        chalk_ir::OpaqueTy {
-            opaque_ty_id: self.opaque_ty_id,
-            substitution: self.substitution.to_chalk(db),
-        }
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self {
-        OpaqueTy {
-            opaque_ty_id: chalk.opaque_ty_id,
-            substitution: from_chalk(db, chalk.substitution),
-        }
-    }
-}
-
-impl ToChalk for AliasTy {
-    type Chalk = chalk_ir::AliasTy<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> Self::Chalk {
-        match self {
-            AliasTy::Projection(projection_ty) => {
-                chalk_ir::AliasTy::Projection(projection_ty.to_chalk(db))
-            }
-            AliasTy::Opaque(opaque_ty) => chalk_ir::AliasTy::Opaque(opaque_ty.to_chalk(db)),
-        }
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self {
-        match chalk {
-            chalk_ir::AliasTy::Projection(projection_ty) => {
-                AliasTy::Projection(from_chalk(db, projection_ty))
-            }
-            chalk_ir::AliasTy::Opaque(opaque_ty) => AliasTy::Opaque(from_chalk(db, opaque_ty)),
-        }
-    }
-}
-
-impl ToChalk for AliasEq {
-    type Chalk = chalk_ir::AliasEq<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::AliasEq<Interner> {
-        chalk_ir::AliasEq { alias: self.alias.to_chalk(db), ty: self.ty.to_chalk(db) }
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, alias_eq: chalk_ir::AliasEq<Interner>) -> Self {
-        AliasEq { alias: from_chalk(db, alias_eq.alias), ty: from_chalk(db, alias_eq.ty) }
-    }
-}
-
-impl ToChalk for DomainGoal {
-    type Chalk = chalk_ir::DomainGoal<Interner>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::DomainGoal<Interner> {
-        match self {
-            DomainGoal::Holds(WhereClause::Implemented(tr)) => tr.to_chalk(db).cast(&Interner),
-            DomainGoal::Holds(WhereClause::AliasEq(alias_eq)) => {
-                alias_eq.to_chalk(db).cast(&Interner)
-            }
-        }
-    }
-
-    fn from_chalk(_db: &dyn HirDatabase, _goal: chalk_ir::DomainGoal<Interner>) -> Self {
-        unimplemented!()
-    }
-}
-
-impl<T> ToChalk for Canonical<T>
-where
-    T: ToChalk,
-    T::Chalk: HasInterner<Interner = Interner>,
-{
-    type Chalk = chalk_ir::Canonical<T::Chalk>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Canonical<T::Chalk> {
-        let value = self.value.to_chalk(db);
-        chalk_ir::Canonical { value, binders: self.binders }
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, canonical: chalk_ir::Canonical<T::Chalk>) -> Canonical<T> {
-        Canonical { binders: canonical.binders, value: from_chalk(db, canonical.value) }
-    }
-}
-
-impl<T: ToChalk> ToChalk for InEnvironment<T>
-where
-    T::Chalk: chalk_ir::interner::HasInterner<Interner = Interner>,
-{
-    type Chalk = chalk_ir::InEnvironment<T::Chalk>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::InEnvironment<T::Chalk> {
-        chalk_ir::InEnvironment { environment: self.environment, goal: self.goal.to_chalk(db) }
-    }
-
-    fn from_chalk(
-        _db: &dyn HirDatabase,
-        _in_env: chalk_ir::InEnvironment<T::Chalk>,
-    ) -> InEnvironment<T> {
-        unimplemented!()
-    }
-}
-
-impl<T: ToChalk> ToChalk for crate::Binders<T>
-where
-    T::Chalk: chalk_ir::interner::HasInterner<Interner = Interner>,
-{
-    type Chalk = chalk_ir::Binders<T::Chalk>;
-
-    fn to_chalk(self, db: &dyn HirDatabase) -> chalk_ir::Binders<T::Chalk> {
-        let (value, binders) = self.into_value_and_skipped_binders();
-        chalk_ir::Binders::new(binders, value.to_chalk(db))
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, binders: chalk_ir::Binders<T::Chalk>) -> crate::Binders<T> {
-        let (v, b) = binders.into_value_and_skipped_binders();
-        crate::Binders::new(b, from_chalk(db, v))
-    }
-}
-
-impl ToChalk for crate::ConstrainedSubst {
-    type Chalk = chalk_ir::ConstrainedSubst<Interner>;
-
-    fn to_chalk(self, _db: &dyn HirDatabase) -> Self::Chalk {
-        unimplemented!()
-    }
-
-    fn from_chalk(db: &dyn HirDatabase, chalk: Self::Chalk) -> Self {
-        ConstrainedSubst { subst: from_chalk(db, chalk.subst) }
-    }
-}
-
-pub(super) fn make_binders<T>(value: T, num_vars: usize) -> chalk_ir::Binders<T>
-where
-    T: HasInterner<Interner = Interner>,
-{
-    chalk_ir::Binders::new(
-        chalk_ir::VariableKinds::from_iter(
-            &Interner,
-            std::iter::repeat(chalk_ir::VariableKind::Ty(chalk_ir::TyVariableKind::General))
-                .take(num_vars),
-        ),
-        value,
-    )
-}
-
 pub(super) fn convert_where_clauses(
     db: &dyn HirDatabase,
     def: GenericDefId,
@@ -493,7 +78,7 @@ pub(super) fn convert_where_clauses(
     let generic_predicates = db.generic_predicates(def);
     let mut result = Vec::with_capacity(generic_predicates.len());
     for pred in generic_predicates.iter() {
-        result.push(pred.clone().substitute(&Interner, substs).to_chalk(db));
+        result.push(pred.clone().substitute(&Interner, substs));
     }
     result
 }
@@ -505,33 +90,33 @@ pub(super) fn generic_predicate_to_inline_bound(
 ) -> Option<chalk_ir::Binders<rust_ir::InlineBound<Interner>>> {
     // An InlineBound is like a GenericPredicate, except the self type is left out.
     // We don't have a special type for this, but Chalk does.
-    let self_ty_shifted_in = self_ty.clone().shifted_in_from(DebruijnIndex::ONE);
+    let self_ty_shifted_in = self_ty.clone().shifted_in_from(&Interner, DebruijnIndex::ONE);
     let (pred, binders) = pred.as_ref().into_value_and_skipped_binders();
     match pred {
         WhereClause::Implemented(trait_ref) => {
-            if trait_ref.self_type_parameter(&Interner) != &self_ty_shifted_in {
+            if trait_ref.self_type_parameter(&Interner) != self_ty_shifted_in {
                 // we can only convert predicates back to type bounds if they
                 // have the expected self type
                 return None;
             }
             let args_no_self = trait_ref.substitution.interned()[1..]
                 .iter()
-                .map(|ty| ty.clone().to_chalk(db).cast(&Interner))
+                .map(|ty| ty.clone().cast(&Interner))
                 .collect();
             let trait_bound = rust_ir::TraitBound { trait_id: trait_ref.trait_id, args_no_self };
             Some(chalk_ir::Binders::new(binders, rust_ir::InlineBound::TraitBound(trait_bound)))
         }
         WhereClause::AliasEq(AliasEq { alias: AliasTy::Projection(projection_ty), ty }) => {
-            if projection_ty.self_type_parameter(&Interner) != &self_ty_shifted_in {
+            if projection_ty.self_type_parameter(&Interner) != self_ty_shifted_in {
                 return None;
             }
             let trait_ = projection_ty.trait_(db);
             let args_no_self = projection_ty.substitution.interned()[1..]
                 .iter()
-                .map(|ty| ty.clone().to_chalk(db).cast(&Interner))
+                .map(|ty| ty.clone().cast(&Interner))
                 .collect();
             let alias_eq_bound = rust_ir::AliasEqBound {
-                value: ty.clone().to_chalk(db),
+                value: ty.clone(),
                 trait_bound: rust_ir::TraitBound { trait_id: trait_.to_chalk(db), args_no_self },
                 associated_ty_id: projection_ty.associated_ty_id,
                 parameters: Vec::new(), // FIXME we don't support generic associated types yet