From ddb77185d36985aeac85094cb4742da93a7e821d Mon Sep 17 00:00:00 2001
From: Jorge Aparicio <japaricious@gmail.com>
Date: Thu, 27 Nov 2014 09:04:20 -0500
Subject: [PATCH] impl Clone for Cow

---
 src/libcore/borrow.rs | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/libcore/borrow.rs b/src/libcore/borrow.rs
index 06fda8d60928f..0bfa3dac1b0ee 100644
--- a/src/libcore/borrow.rs
+++ b/src/libcore/borrow.rs
@@ -137,6 +137,18 @@ pub enum Cow<'a, T, Sized? B: 'a> where B: ToOwned<T> {
     Owned(T)
 }
 
+impl<'a, T, Sized? B> Clone for Cow<'a, T, B> where B: ToOwned<T> {
+    fn clone(&self) -> Cow<'a, T, B> {
+        match *self {
+            Borrowed(b) => Borrowed(b),
+            Owned(ref o) => {
+                let b: &B = BorrowFrom::borrow_from(o);
+                Owned(b.to_owned())
+            },
+        }
+    }
+}
+
 impl<'a, T, Sized? B> Cow<'a, T, B> where B: ToOwned<T> {
     /// Acquire a mutable reference to the owned form of the data.
     ///