Assert in apply_substs that the number of parameters doesn't change

... and fix a small bug revealed by that.

1 files changed, 1 insertions, 1 deletions

diff --git a/crates/ra_hir/src/ty/infer.rs b/crates/ra_hir/src/ty/infer.rs
index be74b9fa6..bf42befbb 100644
--- a/crates/ra_hir/src/ty/infer.rs
+++ b/crates/ra_hir/src/ty/infer.rs
@@ -817,7 +817,7 @@ impl<'a, D: HirDatabase> InferenceContext<'a, D> {
                             Some(func.generic_params(self.db)),
                         )
                     }
-                    None => (Ty::Unknown, receiver_ty, None),
+                    None => (receiver_ty, Ty::Unknown, None),
                 };
                 let substs = self.substs_for_method_call(def_generics, generic_args);
                 let method_ty = method_ty.apply_substs(substs);