1 files changed, 4 insertions, 0 deletions

diff --git a/crates/hir_ty/src/lib.rs b/crates/hir_ty/src/lib.rs
index c46529879..815bb8418 100644
--- a/crates/hir_ty/src/lib.rs
+++ b/crates/hir_ty/src/lib.rs
@@ -106,6 +106,10 @@ impl ProjectionTy {
         }
     }
 
+    pub fn self_type_parameter(&self) -> &Ty {
+        &self.substitution[0]
+    }
+
     fn trait_(&self, db: &dyn HirDatabase) -> TraitId {
         match from_assoc_type_id(self.associated_ty_id).lookup(db.upcast()).container {
             AssocContainerId::TraitId(it) => it,