internal: intern `TypeBound`s

Doesn't save much memory (~2 mb), but interning things is generally a
good pattern to follow

2 files changed, 9 insertions, 1 deletions

diff --git a/crates/hir_ty/src/display.rs b/crates/hir_ty/src/display.rs
index 7bbd1a1f7..637bbc634 100644
--- a/crates/hir_ty/src/display.rs
+++ b/crates/hir_ty/src/display.rs
@@ -13,6 +13,7 @@ use hir_def::{
     db::DefDatabase,
     find_path,
     generics::TypeParamProvenance,
+    intern::{Internable, Interned},
     item_scope::ItemInNs,
     path::{Path, PathKind},
     type_ref::{TypeBound, TypeRef},
@@ -256,6 +257,12 @@ impl<T: HirDisplay> HirDisplay for &'_ T {
     }
 }
 
+impl<T: HirDisplay + Internable> HirDisplay for Interned<T> {
+    fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
+        HirDisplay::hir_fmt(self.as_ref(), f)
+    }
+}
+
 impl HirDisplay for ProjectionTy {
     fn hir_fmt(&self, f: &mut HirFormatter) -> Result<(), HirDisplayError> {
         if f.should_truncate() {
diff --git a/crates/hir_ty/src/lower.rs b/crates/hir_ty/src/lower.rs
index 8a375b973..1645ac533 100644
--- a/crates/hir_ty/src/lower.rs
+++ b/crates/hir_ty/src/lower.rs
@@ -10,6 +10,7 @@ use std::{iter, sync::Arc};
 
 use base_db::CrateId;
 use chalk_ir::{cast::Cast, fold::Shift, interner::HasInterner, Mutability, Safety};
+use hir_def::intern::Interned;
 use hir_def::{
     adt::StructKind,
     body::{Expander, LowerCtx},
@@ -843,7 +844,7 @@ impl<'a> TyLoweringContext<'a> {
             })
     }
 
-    fn lower_impl_trait(&self, bounds: &[TypeBound]) -> ReturnTypeImplTrait {
+    fn lower_impl_trait(&self, bounds: &[Interned<TypeBound>]) -> ReturnTypeImplTrait {
         cov_mark::hit!(lower_rpit);
         let self_ty =
             TyKind::BoundVar(BoundVar::new(DebruijnIndex::INNERMOST, 0)).intern(&Interner);