From fda71d676d07415f78c7835a6fa67b6aacb62c97 Mon Sep 17 00:00:00 2001
From: LingMan <LingMan@users.noreply.github.com>
Date: Fri, 12 Feb 2021 10:27:08 +0100
Subject: [PATCH] Push a `char` instead of a `str` with len one into a String

---
 compiler/rustc_typeck/src/check/upvar.rs | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compiler/rustc_typeck/src/check/upvar.rs b/compiler/rustc_typeck/src/check/upvar.rs
index 04a9e65e664..4f90f2877ed 100644
--- a/compiler/rustc_typeck/src/check/upvar.rs
+++ b/compiler/rustc_typeck/src/check/upvar.rs
@@ -1211,7 +1211,7 @@ fn construct_place_string(tcx: TyCtxt<'_>, place: &Place<'tcx>) -> String {
             ProjectionKind::Subslice => String::from("Subslice"),
         };
         if i != 0 {
-            projections_str.push_str(",");
+            projections_str.push(',');
         }
         projections_str.push_str(proj.as_str());
     }