Remove Ty::substs{_mut}

Almost all uses actually only care about ADT substs, so it's better to
be explicit. The methods were a bad abstraction anyway since they
already didn't include the inner types of e.g. `TyKind::Ref` anymore.

4 files changed, 24 insertions, 41 deletions

diff --git a/crates/hir_ty/src/infer/expr.rs b/crates/hir_ty/src/infer/expr.rs
index 9ab0fa212..9841988c5 100644
--- a/crates/hir_ty/src/infer/expr.rs
+++ b/crates/hir_ty/src/infer/expr.rs
@@ -412,7 +412,10 @@ impl<'a> InferenceContext<'a> {
 
                 self.unify(&ty, &expected.ty);
 
-                let substs = ty.substs().cloned().unwrap_or_else(|| Substitution::empty(&Interner));
+                let substs = ty
+                    .as_adt()
+                    .map(|(_, s)| s.clone())
+                    .unwrap_or_else(|| Substitution::empty(&Interner));
                 let field_types = def_id.map(|it| self.db.field_types(it)).unwrap_or_default();
                 let variant_data = def_id.map(|it| it.variant_data(self.db.upcast()));
                 for field in fields.iter() {
diff --git a/crates/hir_ty/src/infer/pat.rs b/crates/hir_ty/src/infer/pat.rs
index e4813c87c..f88d5c5d3 100644
--- a/crates/hir_ty/src/infer/pat.rs
+++ b/crates/hir_ty/src/infer/pat.rs
@@ -33,7 +33,8 @@ impl<'a> InferenceContext<'a> {
         }
         self.unify(&ty, expected);
 
-        let substs = ty.substs().cloned().unwrap_or_else(|| Substitution::empty(&Interner));
+        let substs =
+            ty.as_adt().map(|(_, s)| s.clone()).unwrap_or_else(|| Substitution::empty(&Interner));
 
         let field_tys = def.map(|it| self.db.field_types(it)).unwrap_or_default();
         let (pre, post) = match ellipsis {
@@ -74,7 +75,8 @@ impl<'a> InferenceContext<'a> {
 
         self.unify(&ty, expected);
 
-        let substs = ty.substs().cloned().unwrap_or_else(|| Substitution::empty(&Interner));
+        let substs =
+            ty.as_adt().map(|(_, s)| s.clone()).unwrap_or_else(|| Substitution::empty(&Interner));
 
         let field_tys = def.map(|it| self.db.field_types(it)).unwrap_or_default();
         for subpat in subpats {
diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
index ae3987752..84645c435 100644
--- a/crates/hir_ty/src/lib.rs
+++ b/crates/hir_ty/src/lib.rs
@@ -198,34 +198,6 @@ impl Ty {
             _ => false,
         }
     }
-
-    /// Returns the type parameters of this type if it has some (i.e. is an ADT
-    /// or function); so if `self` is `Option<u32>`, this returns the `u32`.
-    pub fn substs(&self) -> Option<&Substitution> {
-        match self.kind(&Interner) {
-            TyKind::Adt(_, substs)
-            | TyKind::FnDef(_, substs)
-            | TyKind::Tuple(_, substs)
-            | TyKind::OpaqueType(_, substs)
-            | TyKind::AssociatedType(_, substs)
-            | TyKind::Closure(.., substs) => Some(substs),
-            TyKind::Function(FnPointer { substitution: substs, .. }) => Some(&substs.0),
-            _ => None,
-        }
-    }
-
-    fn substs_mut(&mut self) -> Option<&mut Substitution> {
-        match self.interned_mut() {
-            TyKind::Adt(_, substs)
-            | TyKind::FnDef(_, substs)
-            | TyKind::Tuple(_, substs)
-            | TyKind::OpaqueType(_, substs)
-            | TyKind::AssociatedType(_, substs)
-            | TyKind::Closure(.., substs) => Some(substs),
-            TyKind::Function(FnPointer { substitution: substs, .. }) => Some(&mut substs.0),
-            _ => None,
-        }
-    }
 }
 
 #[derive(Copy, Clone, PartialEq, Eq, Debug, Hash)]
diff --git a/crates/hir_ty/src/walk.rs b/crates/hir_ty/src/walk.rs
index 41ebf6137..91116dcda 100644
--- a/crates/hir_ty/src/walk.rs
+++ b/crates/hir_ty/src/walk.rs
@@ -162,13 +162,15 @@ impl TypeWalk for Ty {
             TyKind::Function(fn_pointer) => {
                 fn_pointer.substitution.0.walk(f);
             }
-            _ => {
-                if let Some(substs) = self.substs() {
-                    for t in substs.iter(&Interner) {
-                        t.walk(f);
-                    }
-                }
+            TyKind::Adt(_, substs)
+            | TyKind::FnDef(_, substs)
+            | TyKind::Tuple(_, substs)
+            | TyKind::OpaqueType(_, substs)
+            | TyKind::AssociatedType(_, substs)
+            | TyKind::Closure(.., substs) => {
+                substs.walk(f);
             }
+            _ => {}
         }
         f(self);
     }
@@ -199,11 +201,15 @@ impl TypeWalk for Ty {
             TyKind::Function(fn_pointer) => {
                 fn_pointer.substitution.0.walk_mut_binders(f, binders.shifted_in());
             }
-            _ => {
-                if let Some(substs) = self.substs_mut() {
-                    substs.walk_mut_binders(f, binders);
-                }
+            TyKind::Adt(_, substs)
+            | TyKind::FnDef(_, substs)
+            | TyKind::Tuple(_, substs)
+            | TyKind::OpaqueType(_, substs)
+            | TyKind::AssociatedType(_, substs)
+            | TyKind::Closure(.., substs) => {
+                substs.walk_mut_binders(f, binders);
             }
+            _ => {}
         }
         f(self, binders);
     }