1 files changed, 14 insertions, 2 deletions

diff --git a/crates/hir_ty/src/traits/chalk/mapping.rs b/crates/hir_ty/src/traits/chalk/mapping.rs
index 0536b934e..84abd99b2 100644
--- a/crates/hir_ty/src/traits/chalk/mapping.rs
+++ b/crates/hir_ty/src/traits/chalk/mapping.rs
@@ -11,8 +11,8 @@ use hir_def::{GenericDefId, TypeAliasId};
 
 use crate::{
     chalk_ext::ProjectionTyExt, db::HirDatabase, static_lifetime, AliasTy, CallableDefId,
-    Canonical, DomainGoal, FnPointer, GenericArg, InEnvironment, OpaqueTy, ProjectionTy,
-    QuantifiedWhereClause, Substitution, TraitRef, Ty, TypeWalk, WhereClause,
+    Canonical, ConstrainedSubst, DomainGoal, FnPointer, GenericArg, InEnvironment, OpaqueTy,
+    ProjectionTy, QuantifiedWhereClause, Substitution, TraitRef, Ty, TypeWalk, WhereClause,
 };
 
 use super::interner::*;
@@ -459,6 +459,18 @@ where
     }
 }
 
+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>,