From 6493e6b86e10805814a85e278b363232696da2bb Mon Sep 17 00:00:00 2001
From: Tyler Mandry <tmandry@gmail.com>
Date: Thu, 10 Oct 2019 16:38:53 -0700
Subject: [PATCH] Only expand types that contain projections

---
 src/librustc/ty/util.rs | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/librustc/ty/util.rs b/src/librustc/ty/util.rs
index 131a4ed312731..acf6f2845d2af 100644
--- a/src/librustc/ty/util.rs
+++ b/src/librustc/ty/util.rs
@@ -745,8 +745,10 @@ impl<'tcx> TyCtxt<'tcx> {
             fn fold_ty(&mut self, t: Ty<'tcx>) -> Ty<'tcx> {
                 if let ty::Opaque(def_id, substs) = t.kind {
                     self.expand_opaque_ty(def_id, substs).unwrap_or(t)
-                } else {
+                } else if t.has_projections() {
                     t.super_fold_with(self)
+                } else {
+                    t
                 }
             }
         }