From 775d399da84776bfd8ae09af5f402874372e299c Mon Sep 17 00:00:00 2001
From: Oliver Middleton <olliemail27@gmail.com>
Date: Fri, 4 Nov 2016 18:47:32 +0000
Subject: [PATCH] Remove recursive call from Cow::to_mut

It seems to prevent it from being inlined.
---
 src/libcollections/borrow.rs | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/libcollections/borrow.rs b/src/libcollections/borrow.rs
index 8f9c357833791..30286fb243c1d 100644
--- a/src/libcollections/borrow.rs
+++ b/src/libcollections/borrow.rs
@@ -159,7 +159,10 @@ impl<'a, B: ?Sized> Cow<'a, B> where B: ToOwned {
         match *self {
             Borrowed(borrowed) => {
                 *self = Owned(borrowed.to_owned());
-                self.to_mut()
+                match *self {
+                    Borrowed(..) => unreachable!(),
+                    Owned(ref mut owned) => owned,
+                }
             }
             Owned(ref mut owned) => owned,
         }