Introduce Ty::Alias

13 files changed, 105 insertions, 94 deletions

diff --git a/crates/hir_ty/src/autoderef.rs b/crates/hir_ty/src/autoderef.rs
index 21d1e5446..be1fd1f13 100644
--- a/crates/hir_ty/src/autoderef.rs
+++ b/crates/hir_ty/src/autoderef.rs
@@ -81,7 +81,7 @@ fn deref_by_trait(
 
     // Now do the assoc type projection
     let projection = super::traits::ProjectionPredicate {
-        ty: Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, ty.value.kinds.len())),
+        ty: Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, ty.value.kinds.len())),
         projection_ty: super::ProjectionTy { associated_ty: target, parameters },
     };
 
@@ -114,7 +114,8 @@ fn deref_by_trait(
             // new variables in that case
 
             for i in 1..vars.0.kinds.len() {
-                if vars.0.value[i - 1] != Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, i - 1))
+                if vars.0.value[i - 1]
+                    != Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, i - 1))
                 {
                     warn!("complex solution for derefing {:?}: {:?}, ignoring", ty.value, solution);
                     return None;
diff --git a/crates/hir_ty/src/diagnostics/unsafe_check.rs b/crates/hir_ty/src/diagnostics/unsafe_check.rs
index b439915c7..e77a20fea 100644
--- a/crates/hir_ty/src/diagnostics/unsafe_check.rs
+++ b/crates/hir_ty/src/diagnostics/unsafe_check.rs
@@ -110,7 +110,7 @@ fn walk_unsafe(
             }
         }
         Expr::UnaryOp { expr, op: UnaryOp::Deref } => {
-            if let Ty::RawPtr(..) = &infer[*expr] {
+            if let Ty::Raw(..) = &infer[*expr] {
                 unsafe_exprs.push(UnsafeExpr { expr: current, inside_unsafe_block });
             }
         }
diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index ff8211094..f3a4333cb 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -3,8 +3,9 @@
 use std::{borrow::Cow, fmt};
 
 use crate::{
-    db::HirDatabase, primitive, utils::generics, CallableDefId, CallableSig, GenericPredicate,
-    Lifetime, Obligation, OpaqueTy, OpaqueTyId, ProjectionTy, Scalar, Substs, TraitRef, Ty,
+    db::HirDatabase, primitive, utils::generics, AliasTy, CallableDefId, CallableSig,
+    GenericPredicate, Lifetime, Obligation, OpaqueTy, OpaqueTyId, ProjectionTy, Scalar, Substs,
+    TraitRef, Ty,
 };
 use arrayvec::ArrayVec;
 use hir_def::{
@@ -284,12 +285,12 @@ impl HirDisplay for Ty {
                 t.hir_fmt(f)?;
                 write!(f, "; _]")?;
             }
-            Ty::RawPtr(m, parameters) | Ty::Ref(m, parameters) => {
+            Ty::Raw(m, parameters) | Ty::Ref(m, parameters) => {
                 let t = parameters.as_single();
                 let ty_display =
                     t.into_displayable(f.db, f.max_size, f.omit_verbose_types, f.display_target);
 
-                if matches!(self, Ty::RawPtr(..)) {
+                if matches!(self, Ty::Raw(..)) {
                     write!(f, "*{}", m.as_keyword_for_ptr())?;
                 } else {
                     write!(f, "&{}", m.as_keyword_for_ref())?;
@@ -300,10 +301,10 @@ impl HirDisplay for Ty {
                     Ty::Dyn(predicates) if predicates.len() > 1 => {
                         Cow::Borrowed(predicates.as_ref())
                     }
-                    &Ty::Opaque(OpaqueTy {
+                    &Ty::Alias(AliasTy::Opaque(OpaqueTy {
                         opaque_ty_id: OpaqueTyId::ReturnTypeImplTrait(func, idx),
                         ref parameters,
-                    }) => {
+                    })) => {
                         datas =
                             f.db.return_type_impl_traits(func).expect("impl trait id without data");
                         let data = (*datas)
@@ -518,7 +519,6 @@ impl HirDisplay for Ty {
                     write!(f, "{{closure}}")?;
                 }
             }
-            Ty::Projection(p_ty) => p_ty.hir_fmt(f)?,
             Ty::Placeholder(id) => {
                 let generics = generics(f.db.upcast(), id.parent);
                 let param_data = &generics.params.types[id.local_id];
@@ -537,11 +537,12 @@ impl HirDisplay for Ty {
                     }
                 }
             }
-            Ty::Bound(idx) => write!(f, "?{}.{}", idx.debruijn.depth(), idx.index)?,
+            Ty::BoundVar(idx) => write!(f, "?{}.{}", idx.debruijn.depth(), idx.index)?,
             Ty::Dyn(predicates) => {
                 write_bounds_like_dyn_trait_with_prefix("dyn", predicates, f)?;
             }
-            Ty::Opaque(opaque_ty) => {
+            Ty::Alias(AliasTy::Projection(p_ty)) => p_ty.hir_fmt(f)?,
+            Ty::Alias(AliasTy::Opaque(opaque_ty)) => {
                 match opaque_ty.opaque_ty_id {
                     OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
                         let datas =
diff --git a/crates/hir_ty/src/infer.rs b/crates/hir_ty/src/infer.rs
index 1d78d1feb..18a4f5e8a 100644
--- a/crates/hir_ty/src/infer.rs
+++ b/crates/hir_ty/src/infer.rs
@@ -40,7 +40,7 @@ use super::{
     InEnvironment, ProjectionTy, Substs, TraitEnvironment, TraitRef, Ty, TypeWalk,
 };
 use crate::{
-    db::HirDatabase, infer::diagnostics::InferenceDiagnostic, lower::ImplTraitLoweringMode,
+    db::HirDatabase, infer::diagnostics::InferenceDiagnostic, lower::ImplTraitLoweringMode, AliasTy,
 };
 
 pub(crate) use unify::unify;
@@ -395,7 +395,7 @@ impl<'a> InferenceContext<'a> {
     fn normalize_associated_types_in(&mut self, ty: Ty) -> Ty {
         let ty = self.resolve_ty_as_possible(ty);
         ty.fold(&mut |ty| match ty {
-            Ty::Projection(proj_ty) => self.normalize_projection_ty(proj_ty),
+            Ty::Alias(AliasTy::Projection(proj_ty)) => self.normalize_projection_ty(proj_ty),
             _ => ty,
         })
     }
diff --git a/crates/hir_ty/src/infer/coerce.rs b/crates/hir_ty/src/infer/coerce.rs
index 667b26a76..c33d8c61e 100644
--- a/crates/hir_ty/src/infer/coerce.rs
+++ b/crates/hir_ty/src/infer/coerce.rs
@@ -73,19 +73,19 @@ impl<'a> InferenceContext<'a> {
         match (&mut from_ty, to_ty) {
             // `*mut T` -> `*const T`
             // `&mut T` -> `&T`
-            (Ty::RawPtr(m1, ..), Ty::RawPtr(m2 @ Mutability::Shared, ..))
+            (Ty::Raw(m1, ..), Ty::Raw(m2 @ Mutability::Shared, ..))
             | (Ty::Ref(m1, ..), Ty::Ref(m2 @ Mutability::Shared, ..)) => {
                 *m1 = *m2;
             }
             // `&T` -> `*const T`
             // `&mut T` -> `*mut T`/`*const T`
-            (Ty::Ref(.., substs), &Ty::RawPtr(m2 @ Mutability::Shared, ..))
-            | (Ty::Ref(Mutability::Mut, substs), &Ty::RawPtr(m2, ..)) => {
-                from_ty = Ty::RawPtr(m2, substs.clone());
+            (Ty::Ref(.., substs), &Ty::Raw(m2 @ Mutability::Shared, ..))
+            | (Ty::Ref(Mutability::Mut, substs), &Ty::Raw(m2, ..)) => {
+                from_ty = Ty::Raw(m2, substs.clone());
             }
 
             // Illegal mutability conversion
-            (Ty::RawPtr(Mutability::Shared, ..), Ty::RawPtr(Mutability::Mut, ..))
+            (Ty::Raw(Mutability::Shared, ..), Ty::Raw(Mutability::Mut, ..))
             | (Ty::Ref(Mutability::Shared, ..), Ty::Ref(Mutability::Mut, ..)) => return false,
 
             // `{function_type}` -> `fn()`
diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
index 928ad37a3..7852b3d23 100644
--- a/crates/hir_ty/src/infer/expr.rs
+++ b/crates/hir_ty/src/infer/expr.rs
@@ -479,7 +479,7 @@ impl<'a> InferenceContext<'a> {
                 };
                 let inner_ty = self.infer_expr_inner(*expr, &expectation);
                 match rawness {
-                    Rawness::RawPtr => Ty::RawPtr(*mutability, Substs::single(inner_ty)),
+                    Rawness::RawPtr => Ty::Raw(*mutability, Substs::single(inner_ty)),
                     Rawness::Ref => Ty::Ref(*mutability, Substs::single(inner_ty)),
                 }
             }
diff --git a/crates/hir_ty/src/infer/unify.rs b/crates/hir_ty/src/infer/unify.rs
index b481aa1b3..99a89a7f3 100644
--- a/crates/hir_ty/src/infer/unify.rs
+++ b/crates/hir_ty/src/infer/unify.rs
@@ -68,7 +68,7 @@ impl<'a, 'b> Canonicalizer<'a, 'b> {
                     } else {
                         let root = self.ctx.table.var_unification_table.find(inner);
                         let position = self.add(InferenceVar::from_inner(root), kind);
-                        Ty::Bound(BoundVar::new(binders, position))
+                        Ty::BoundVar(BoundVar::new(binders, position))
                     }
                 }
                 _ => ty,
@@ -110,7 +110,7 @@ impl<T> Canonicalized<T> {
     pub(super) fn decanonicalize_ty(&self, mut ty: Ty) -> Ty {
         ty.walk_mut_binders(
             &mut |ty, binders| {
-                if let &mut Ty::Bound(bound) = ty {
+                if let &mut Ty::BoundVar(bound) = ty {
                     if bound.debruijn >= binders {
                         let (v, k) = self.free_vars[bound.index];
                         *ty = Ty::InferenceVar(v, k);
@@ -168,7 +168,7 @@ pub(crate) fn unify(tys: &Canonical<(Ty, Ty)>) -> Option<Substs> {
     // (kind of hacky)
     for (i, var) in vars.iter().enumerate() {
         if &*table.resolve_ty_shallow(var) == var {
-            table.unify(var, &Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, i)));
+            table.unify(var, &Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, i)));
         }
     }
     Some(
diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
index 1131eaf92..9bcaf6fa7 100644
--- a/crates/hir_ty/src/lib.rs
+++ b/crates/hir_ty/src/lib.rs
@@ -111,6 +111,19 @@ pub struct FnPointer {
     pub substs: Substs,
 }
 
+#[derive(Clone, PartialEq, Eq, Debug, Hash)]
+pub enum AliasTy {
+    /// A "projection" type corresponds to an (unnormalized)
+    /// projection like `<P0 as Trait<P1..Pn>>::Foo`. Note that the
+    /// trait and all its parameters are fully known.
+    Projection(ProjectionTy),
+    /// An opaque type (`impl Trait`).
+    ///
+    /// This is currently only used for return type impl trait; each instance of
+    /// `impl Trait` in a return type gets its own ID.
+    Opaque(OpaqueTy),
+}
+
 /// A type.
 ///
 /// See also the `TyKind` enum in rustc (librustc/ty/sty.rs), which represents
@@ -141,7 +154,7 @@ pub enum Ty {
     Slice(Substs),
 
     /// A raw pointer. Written as `*mut T` or `*const T`
-    RawPtr(Mutability, Substs),
+    Raw(Mutability, Substs),
 
     /// A reference; a pointer with an associated lifetime. Written as
     /// `&'a mut T` or `&'a T`.
@@ -193,16 +206,11 @@ pub enum Ty {
     /// ```
     Function(FnPointer),
 
-    /// A "projection" type corresponds to an (unnormalized)
-    /// projection like `<P0 as Trait<P1..Pn>>::Foo`. Note that the
-    /// trait and all its parameters are fully known.
-    Projection(ProjectionTy),
-
-    /// An opaque type (`impl Trait`).
-    ///
-    /// This is currently only used for return type impl trait; each instance of
-    /// `impl Trait` in a return type gets its own ID.
-    Opaque(OpaqueTy),
+    /// An "alias" type represents some form of type alias, such as:
+    /// - An associated type projection like `<T as Iterator>::Item`
+    /// - `impl Trait` types
+    /// - Named type aliases like `type Foo<X> = Vec<X>`
+    Alias(AliasTy),
 
     /// A placeholder for a type parameter; for example, `T` in `fn f<T>(x: T)
     /// {}` when we're type-checking the body of that function. In this
@@ -215,7 +223,7 @@ pub enum Ty {
     /// parameters get turned into variables; during trait resolution, inference
     /// variables get turned into bound variables and back; and in `Dyn` the
     /// `Self` type is represented with a bound variable as well.
-    Bound(BoundVar),
+    BoundVar(BoundVar),
 
     /// A type variable used during type checking.
     InferenceVar(InferenceVar, TyVariableKind),
@@ -299,7 +307,7 @@ impl Substs {
             generic_params
                 .iter()
                 .enumerate()
-                .map(|(idx, _)| Ty::Bound(BoundVar::new(debruijn, idx)))
+                .map(|(idx, _)| Ty::BoundVar(BoundVar::new(debruijn, idx)))
                 .collect(),
         )
     }
@@ -347,7 +355,7 @@ impl SubstsBuilder {
     }
 
     pub fn fill_with_bound_vars(self, debruijn: DebruijnIndex, starting_from: usize) -> Self {
-        self.fill((starting_from..).map(|idx| Ty::Bound(BoundVar::new(debruijn, idx))))
+        self.fill((starting_from..).map(|idx| Ty::BoundVar(BoundVar::new(debruijn, idx))))
     }
 
     pub fn fill_with_unknown(self) -> Self {
@@ -627,7 +635,7 @@ impl Ty {
             Ty::Ref(mutability, parameters) => {
                 Some((parameters.as_single(), Rawness::Ref, *mutability))
             }
-            Ty::RawPtr(mutability, parameters) => {
+            Ty::Raw(mutability, parameters) => {
                 Some((parameters.as_single(), Rawness::RawPtr, *mutability))
             }
             _ => None,
@@ -688,9 +696,7 @@ impl Ty {
                 expr == expr2 && def == def2
             }
             (Ty::Ref(mutability, ..), Ty::Ref(mutability2, ..))
-            | (Ty::RawPtr(mutability, ..), Ty::RawPtr(mutability2, ..)) => {
-                mutability == mutability2
-            }
+            | (Ty::Raw(mutability, ..), Ty::Raw(mutability2, ..)) => mutability == mutability2,
             (
                 Ty::Function(FnPointer { num_args, sig, .. }),
                 Ty::Function(FnPointer { num_args: num_args2, sig: sig2, .. }),
@@ -721,7 +727,7 @@ impl Ty {
     fn builtin_deref(&self) -> Option<Ty> {
         match self {
             Ty::Ref(.., parameters) => Some(Ty::clone(parameters.as_single())),
-            Ty::RawPtr(.., parameters) => Some(Ty::clone(parameters.as_single())),
+            Ty::Raw(.., parameters) => Some(Ty::clone(parameters.as_single())),
             _ => None,
         }
     }
@@ -757,7 +763,7 @@ impl Ty {
             Ty::Adt(_, substs)
             | Ty::Slice(substs)
             | Ty::Array(substs)
-            | Ty::RawPtr(_, substs)
+            | Ty::Raw(_, substs)
             | Ty::Ref(_, substs)
             | Ty::FnDef(_, substs)
             | Ty::Function(FnPointer { substs, .. })
@@ -780,7 +786,7 @@ impl Ty {
             Ty::Adt(_, substs)
             | Ty::Slice(substs)
             | Ty::Array(substs)
-            | Ty::RawPtr(_, substs)
+            | Ty::Raw(_, substs)
             | Ty::Ref(_, substs)
             | Ty::FnDef(_, substs)
             | Ty::Function(FnPointer { substs, .. })
@@ -797,7 +803,7 @@ impl Ty {
             Ty::Adt(_, substs)
             | Ty::Slice(substs)
             | Ty::Array(substs)
-            | Ty::RawPtr(_, substs)
+            | Ty::Raw(_, substs)
             | Ty::Ref(_, substs)
             | Ty::FnDef(_, substs)
             | Ty::Function(FnPointer { substs, .. })
@@ -834,7 +840,7 @@ impl Ty {
                     OpaqueTyId::ReturnTypeImplTrait(..) => None,
                 }
             }
-            Ty::Opaque(opaque_ty) => {
+            Ty::Alias(AliasTy::Opaque(opaque_ty)) => {
                 let predicates = match opaque_ty.opaque_ty_id {
                     OpaqueTyId::ReturnTypeImplTrait(func, idx) => {
                         db.return_type_impl_traits(func).map(|it| {
@@ -878,7 +884,7 @@ impl Ty {
                     _ => None,
                 }
             }
-            Ty::Projection(projection_ty) => {
+            Ty::Alias(AliasTy::Projection(projection_ty)) => {
                 match projection_ty.associated_ty.lookup(db.upcast()).container {
                     AssocContainerId::TraitId(trait_id) => Some(trait_id),
                     _ => None,
@@ -956,7 +962,7 @@ pub trait TypeWalk {
     {
         self.walk_mut_binders(
             &mut |ty, binders| {
-                if let &mut Ty::Bound(bound) = ty {
+                if let &mut Ty::BoundVar(bound) = ty {
                     if bound.debruijn >= binders {
                         *ty = substs.0[bound.index].clone().shift_bound_vars(binders);
                     }
@@ -974,8 +980,8 @@ pub trait TypeWalk {
     {
         self.fold_binders(
             &mut |ty, binders| match ty {
-                Ty::Bound(bound) if bound.debruijn >= binders => {
-                    Ty::Bound(bound.shifted_in_from(n))
+                Ty::BoundVar(bound) if bound.debruijn >= binders => {
+                    Ty::BoundVar(bound.shifted_in_from(n))
                 }
                 ty => ty,
             },
@@ -987,21 +993,21 @@ pub trait TypeWalk {
 impl TypeWalk for Ty {
     fn walk(&self, f: &mut impl FnMut(&Ty)) {
         match self {
-            Ty::Projection(p_ty) => {
+            Ty::Alias(AliasTy::Projection(p_ty)) => {
                 for t in p_ty.parameters.iter() {
                     t.walk(f);
                 }
             }
+            Ty::Alias(AliasTy::Opaque(o_ty)) => {
+                for t in o_ty.parameters.iter() {
+                    t.walk(f);
+                }
+            }
             Ty::Dyn(predicates) => {
                 for p in predicates.iter() {
                     p.walk(f);
                 }
             }
-            Ty::Opaque(o_ty) => {
-                for t in o_ty.parameters.iter() {
-                    t.walk(f);
-                }
-            }
             _ => {
                 if let Some(substs) = self.substs() {
                     for t in substs.iter() {
@@ -1019,7 +1025,7 @@ impl TypeWalk for Ty {
         binders: DebruijnIndex,
     ) {
         match self {
-            Ty::Projection(p_ty) => {
+            Ty::Alias(AliasTy::Projection(p_ty)) => {
                 p_ty.parameters.walk_mut_binders(f, binders);
             }
             Ty::Dyn(predicates) => {
@@ -1027,7 +1033,7 @@ impl TypeWalk for Ty {
                     p.walk_mut_binders(f, binders.shifted_in());
                 }
             }
-            Ty::Opaque(o_ty) => {
+            Ty::Alias(AliasTy::Opaque(o_ty)) => {
                 o_ty.parameters.walk_mut_binders(f, binders);
             }
             _ => {
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index 44bd95a9a..ca06c9fe2 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -31,8 +31,8 @@ use crate::{
         all_super_trait_refs, associated_type_by_name_including_super_traits, generics,
         make_mut_slice, variant_data,
     },
-    Binders, BoundVar, CallableSig, DebruijnIndex, FnPointer, FnSig, GenericPredicate, OpaqueTy,
-    OpaqueTyId, PolyFnSig, ProjectionPredicate, ProjectionTy, ReturnTypeImplTrait,
+    AliasTy, Binders, BoundVar, CallableSig, DebruijnIndex, FnPointer, FnSig, GenericPredicate,
+    OpaqueTy, OpaqueTyId, PolyFnSig, ProjectionPredicate, ProjectionTy, ReturnTypeImplTrait,
     ReturnTypeImplTraits, Substs, TraitEnvironment, TraitRef, Ty, TypeWalk,
 };
 
@@ -157,7 +157,7 @@ impl Ty {
             }
             TypeRef::RawPtr(inner, mutability) => {
                 let inner_ty = Ty::from_hir(ctx, inner);
-                Ty::RawPtr(*mutability, Substs::single(inner_ty))
+                Ty::Raw(*mutability, Substs::single(inner_ty))
             }
             TypeRef::Array(inner) => {
                 let inner_ty = Ty::from_hir(ctx, inner);
@@ -181,7 +181,7 @@ impl Ty {
                 })
             }
             TypeRef::DynTrait(bounds) => {
-                let self_ty = Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0));
+                let self_ty = Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0));
                 let predicates = ctx.with_shifted_in(DebruijnIndex::ONE, |ctx| {
                     bounds
                         .iter()
@@ -225,7 +225,10 @@ impl Ty {
                         let impl_trait_id = OpaqueTyId::ReturnTypeImplTrait(func, idx);
                         let generics = generics(ctx.db.upcast(), func.into());
                         let parameters = Substs::bound_vars(&generics, ctx.in_binders);
-                        Ty::Opaque(OpaqueTy { opaque_ty_id: impl_trait_id, parameters })
+                        Ty::Alias(AliasTy::Opaque(OpaqueTy {
+                            opaque_ty_id: impl_trait_id,
+                            parameters,
+                        }))
                     }
                     ImplTraitLoweringMode::Param => {
                         let idx = ctx.impl_trait_counter.get();
@@ -256,7 +259,7 @@ impl Ty {
                             } else {
                                 (0, 0, 0, 0)
                             };
-                        Ty::Bound(BoundVar::new(
+                        Ty::BoundVar(BoundVar::new(
                             ctx.in_binders,
                             idx as usize + parent_params + self_params + list_params,
                         ))
@@ -328,7 +331,7 @@ impl Ty {
             TypeNs::TraitId(trait_) => {
                 // if this is a bare dyn Trait, we'll directly put the required ^0 for the self type in there
                 let self_ty = if remaining_segments.len() == 0 {
-                    Some(Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0)))
+                    Some(Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)))
                 } else {
                     None
                 };
@@ -344,10 +347,10 @@ impl Ty {
                     match found {
                         Some((super_trait_ref, associated_ty)) => {
                             // FIXME handle type parameters on the segment
-                            Ty::Projection(ProjectionTy {
+                            Ty::Alias(AliasTy::Projection(ProjectionTy {
                                 associated_ty,
                                 parameters: super_trait_ref.substs,
-                            })
+                            }))
                         }
                         None => {
                             // FIXME: report error (associated type not found)
@@ -371,7 +374,7 @@ impl Ty {
                     TypeParamLoweringMode::Placeholder => Ty::Placeholder(param_id),
                     TypeParamLoweringMode::Variable => {
                         let idx = generics.param_idx(param_id).expect("matching generics");
-                        Ty::Bound(BoundVar::new(ctx.in_binders, idx))
+                        Ty::BoundVar(BoundVar::new(ctx.in_binders, idx))
                     }
                 }
             }
@@ -469,10 +472,10 @@ impl Ty {
                         // associated_type_shorthand_candidates does not do that
                         let substs = substs.shift_bound_vars(ctx.in_binders);
                         // FIXME handle type parameters on the segment
-                        return Some(Ty::Projection(ProjectionTy {
+                        return Some(Ty::Alias(AliasTy::Projection(ProjectionTy {
                             associated_ty,
                             parameters: substs,
-                        }));
+                        })));
                     }
 
                     None
@@ -673,7 +676,7 @@ impl GenericPredicate {
                             TypeParamLoweringMode::Placeholder => Ty::Placeholder(param_id),
                             TypeParamLoweringMode::Variable => {
                                 let idx = generics.param_idx(param_id).expect("matching generics");
-                                Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, idx))
+                                Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, idx))
                             }
                         }
                     }
@@ -747,7 +750,7 @@ fn assoc_type_bindings_from_type_bound<'a>(
                 preds.extend(GenericPredicate::from_type_bound(
                     ctx,
                     bound,
-                    Ty::Projection(projection_ty.clone()),
+                    Ty::Alias(AliasTy::Projection(projection_ty.clone())),
                 ));
             }
             preds
@@ -757,7 +760,7 @@ fn assoc_type_bindings_from_type_bound<'a>(
 impl ReturnTypeImplTrait {
     fn from_hir(ctx: &TyLoweringContext, bounds: &[TypeBound]) -> Self {
         mark::hit!(lower_rpit);
-        let self_ty = Ty::Bound(BoundVar::new(DebruijnIndex::INNERMOST, 0));
+        let self_ty = Ty::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0));
         let predicates = ctx.with_shifted_in(DebruijnIndex::ONE, |ctx| {
             bounds
                 .iter()
@@ -981,7 +984,7 @@ pub(crate) fn generic_defaults_query(
             // Each default can only refer to previous parameters.
             ty.walk_mut_binders(
                 &mut |ty, binders| match ty {
-                    Ty::Bound(BoundVar { debruijn, index }) if *debruijn == binders => {
+                    Ty::BoundVar(BoundVar { debruijn, index }) if *debruijn == binders => {
                         if *index >= idx {
                             // type variable default referring to parameter coming
                             // after it. This is forbidden (FIXME: report
diff --git a/crates/hir_ty/src/method_resolution.rs b/crates/hir_ty/src/method_resolution.rs
index 8b1717873..dd5109d4e 100644
--- a/crates/hir_ty/src/method_resolution.rs
+++ b/crates/hir_ty/src/method_resolution.rs
@@ -51,7 +51,7 @@ impl TyFingerprint {
             &Ty::Scalar(scalar) => TyFingerprint::Scalar(scalar),
             &Ty::Adt(adt, _) => TyFingerprint::Adt(adt),
             &Ty::Tuple(cardinality, _) => TyFingerprint::Tuple(cardinality),
-            &Ty::RawPtr(mutability, ..) => TyFingerprint::RawPtr(mutability),
+            &Ty::Raw(mutability, ..) => TyFingerprint::RawPtr(mutability),
             &Ty::ForeignType(alias_id, ..) => TyFingerprint::ForeignType(alias_id),
             &Ty::Function(FnPointer { num_args, sig, .. }) => TyFingerprint::FnPtr(num_args, sig),
             Ty::Dyn(_) => ty.dyn_trait().map(|trait_| TyFingerprint::Dyn(trait_))?,
@@ -251,8 +251,8 @@ impl Ty {
             }
             Ty::Str => lang_item_crate!("str_alloc", "str"),
             Ty::Slice(_) => lang_item_crate!("slice_alloc", "slice"),
-            Ty::RawPtr(Mutability::Shared, _) => lang_item_crate!("const_ptr"),
-            Ty::RawPtr(Mutability::Mut, _) => lang_item_crate!("mut_ptr"),
+            Ty::Raw(Mutability::Shared, _) => lang_item_crate!("const_ptr"),
+            Ty::Raw(Mutability::Mut, _) => lang_item_crate!("mut_ptr"),
             Ty::Dyn(_) => {
                 return self.dyn_trait().and_then(|trait_| {
                     mod_to_crate_ids(GenericDefId::TraitId(trait_).module(db.upcast()))
@@ -683,7 +683,7 @@ pub(crate) fn inherent_impl_substs(
 fn fallback_bound_vars(s: Substs, num_vars_to_keep: usize) -> Substs {
     s.fold_binders(
         &mut |ty, binders| {
-            if let Ty::Bound(bound) = &ty {
+            if let Ty::BoundVar(bound) = &ty {
                 if bound.index >= num_vars_to_keep && bound.debruijn >= binders {
                     Ty::Unknown
                 } else {
diff --git a/crates/hir_ty/src/traits.rs b/crates/hir_ty/src/traits.rs
index dfa51896b..e4cdb6d53 100644
--- a/crates/hir_ty/src/traits.rs
+++ b/crates/hir_ty/src/traits.rs
@@ -129,7 +129,7 @@ pub(crate) fn trait_solve_query(
     log::info!("trait_solve_query({})", goal.value.value.display(db));
 
     if let Obligation::Projection(pred) = &goal.value.value {
-        if let Ty::Bound(_) = &pred.projection_ty.parameters[0] {
+        if let Ty::BoundVar(_) = &pred.projection_ty.parameters[0] {
             // Hack: don't ask Chalk to normalize with an unknown self type, it'll say that's impossible
             return Some(Solution::Ambig(Guidance::Unknown));
         }
diff --git a/crates/hir_ty/src/traits/chalk.rs b/crates/hir_ty/src/traits/chalk.rs
index 3f5f5091f..e513fa8f4 100644
--- a/crates/hir_ty/src/traits/chalk.rs
+++ b/crates/hir_ty/src/traits/chalk.rs
@@ -90,7 +90,7 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
             ty: &Ty,
             binders: &CanonicalVarKinds<Interner>,
         ) -> Option<chalk_ir::TyVariableKind> {
-            if let Ty::Bound(bv) = ty {
+            if let Ty::BoundVar(bv) = ty {
                 let binders = binders.as_slice(&Interner);
                 if bv.debruijn == DebruijnIndex::INNERMOST {
                     if let chalk_ir::VariableKind::Ty(tk) = binders[bv.index].kind {
@@ -220,18 +220,18 @@ impl<'a> chalk_solve::RustIrDatabase<Interner> for ChalkContext<'a> {
                     let impl_bound = GenericPredicate::Implemented(TraitRef {
                         trait_: future_trait,
                         // Self type as the first parameter.
-                        substs: Substs::single(Ty::Bound(BoundVar {
+                        substs: Substs::single(Ty::BoundVar(BoundVar {
                             debruijn: DebruijnIndex::INNERMOST,
                             index: 0,
                         })),
                     });
                     let proj_bound = GenericPredicate::Projection(ProjectionPredicate {
                         // The parameter of the opaque type.
-                        ty: Ty::Bound(BoundVar { debruijn: DebruijnIndex::ONE, index: 0 }),
+                        ty: Ty::BoundVar(BoundVar { debruijn: DebruijnIndex::ONE, index: 0 }),
                         projection_ty: ProjectionTy {
                             associated_ty: future_output,
                             // Self type as the first parameter.
-                            parameters: Substs::single(Ty::Bound(BoundVar::new(
+                            parameters: Substs::single(Ty::BoundVar(BoundVar::new(
                                 DebruijnIndex::INNERMOST,
                                 0,
                             ))),
@@ -392,7 +392,7 @@ pub(crate) fn associated_ty_data_query(
     let resolver = hir_def::resolver::HasResolver::resolver(type_alias, db.upcast());
     let ctx = crate::TyLoweringContext::new(db, &resolver)
         .with_type_param_mode(crate::lower::TypeParamLoweringMode::Variable);
-    let self_ty = Ty::Bound(crate::BoundVar::new(crate::DebruijnIndex::INNERMOST, 0));
+    let self_ty = Ty::BoundVar(crate::BoundVar::new(crate::DebruijnIndex::INNERMOST, 0));
     let bounds = type_alias_data
         .bounds
         .iter()
diff --git a/crates/hir_ty/src/traits/chalk/mapping.rs b/crates/hir_ty/src/traits/chalk/mapping.rs
index 995ff6a9a..6e6055d80 100644
--- a/crates/hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/hir_ty/src/traits/chalk/mapping.rs
@@ -16,8 +16,8 @@ use crate::{
     db::HirDatabase,
     primitive::UintTy,
     traits::{Canonical, Obligation},
-    CallableDefId, FnPointer, FnSig, GenericPredicate, InEnvironment, OpaqueTy, OpaqueTyId,
-    ProjectionPredicate, ProjectionTy, Scalar, Substs, TraitEnvironment, TraitRef, Ty,
+    AliasTy, CallableDefId, FnPointer, FnSig, GenericPredicate, InEnvironment, OpaqueTy,
+    OpaqueTyId, ProjectionPredicate, ProjectionTy, Scalar, Substs, TraitEnvironment, TraitRef, Ty,
 };
 
 use super::interner::*;
@@ -63,7 +63,7 @@ impl ToChalk for Ty {
                 let substitution = substs.to_chalk(db);
                 chalk_ir::TyKind::Tuple(cardinality.into(), substitution).intern(&Interner)
             }
-            Ty::RawPtr(mutability, substs) => {
+            Ty::Raw(mutability, substs) => {
                 let ty = substs[0].clone().to_chalk(db);
                 chalk_ir::TyKind::Raw(mutability.to_chalk(db), ty).intern(&Interner)
             }
@@ -88,7 +88,7 @@ impl ToChalk for Ty {
                 let substitution = substs.to_chalk(db);
                 chalk_ir::TyKind::Adt(chalk_ir::AdtId(adt_id), substitution).intern(&Interner)
             }
-            Ty::Projection(proj_ty) => {
+            Ty::Alias(AliasTy::Projection(proj_ty)) => {
                 let associated_ty_id = TypeAliasAsAssocType(proj_ty.associated_ty).to_chalk(db);
                 let substitution = proj_ty.parameters.to_chalk(db);
                 chalk_ir::AliasTy::Projection(chalk_ir::ProjectionTy {
@@ -106,7 +106,7 @@ impl ToChalk for Ty {
                 }
                 .to_ty::<Interner>(&Interner)
             }
-            Ty::Bound(idx) => chalk_ir::TyKind::BoundVar(idx).intern(&Interner),
+            Ty::BoundVar(idx) => chalk_ir::TyKind::BoundVar(idx).intern(&Interner),
             Ty::InferenceVar(..) => panic!("uncanonicalized infer ty"),
             Ty::Dyn(predicates) => {
                 let where_clauses = chalk_ir::QuantifiedWhereClauses::from_iter(
@@ -119,7 +119,7 @@ impl ToChalk for Ty {
                 };
                 chalk_ir::TyKind::Dyn(bounded_ty).intern(&Interner)
             }
-            Ty::Opaque(opaque_ty) => {
+            Ty::Alias(AliasTy::Opaque(opaque_ty)) => {
                 let opaque_ty_id = opaque_ty.opaque_ty_id.to_chalk(db);
                 let substitution = opaque_ty.parameters.to_chalk(db);
                 chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Opaque(chalk_ir::OpaqueTy {
@@ -146,12 +146,12 @@ impl ToChalk for Ty {
                 let associated_ty =
                     from_chalk::<TypeAliasAsAssocType, _>(db, proj.associated_ty_id).0;
                 let parameters = from_chalk(db, proj.substitution);
-                Ty::Projection(ProjectionTy { associated_ty, parameters })
+                Ty::Alias(AliasTy::Projection(ProjectionTy { associated_ty, parameters }))
             }
             chalk_ir::TyKind::Alias(chalk_ir::AliasTy::Opaque(opaque_ty)) => {
                 let impl_trait_id = from_chalk(db, opaque_ty.opaque_ty_id);
                 let parameters = from_chalk(db, opaque_ty.substitution);
-                Ty::Opaque(OpaqueTy { opaque_ty_id: impl_trait_id, parameters })
+                Ty::Alias(AliasTy::Opaque(OpaqueTy { opaque_ty_id: impl_trait_id, parameters }))
             }
             chalk_ir::TyKind::Function(chalk_ir::FnPointer {
                 num_binders,
@@ -170,7 +170,7 @@ impl ToChalk for Ty {
                     substs,
                 })
             }
-            chalk_ir::TyKind::BoundVar(idx) => Ty::Bound(idx),
+            chalk_ir::TyKind::BoundVar(idx) => Ty::BoundVar(idx),
             chalk_ir::TyKind::InferenceVar(_iv, _kind) => Ty::Unknown,
             chalk_ir::TyKind::Dyn(where_clauses) => {
                 assert_eq!(where_clauses.bounds.binders.len(&Interner), 1);
@@ -198,7 +198,7 @@ impl ToChalk for Ty {
                 Ty::Tuple(cardinality, from_chalk(db, subst))
             }
             chalk_ir::TyKind::Raw(mutability, ty) => {
-                Ty::RawPtr(from_chalk(db, mutability), Substs::single(from_chalk(db, ty)))
+                Ty::Raw(from_chalk(db, mutability), Substs::single(from_chalk(db, ty)))
             }
             chalk_ir::TyKind::Slice(ty) => Ty::Slice(Substs::single(from_chalk(db, ty))),
             chalk_ir::TyKind::Ref(mutability, _lifetime, ty) => {