From d9fadbc04f5bbd520e4ce8665ac128288e9846c0 Mon Sep 17 00:00:00 2001
From: Nathaniel Herman <nherman@college.harvard.edu>
Date: Sun, 26 Jan 2014 11:24:34 -0500
Subject: Make mut_last return Option instead of failing on empty vector (and
 add a test for mut_last)

---
 src/libsyntax/opt_vec.rs | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'src/libsyntax')

diff --git a/src/libsyntax/opt_vec.rs b/src/libsyntax/opt_vec.rs
index ce3042cb9cd..c575e170bef 100644
--- a/src/libsyntax/opt_vec.rs
+++ b/src/libsyntax/opt_vec.rs
@@ -62,10 +62,10 @@ impl<T> OptVec<T> {
         }
     }
 
-    pub fn mut_last<'a>(&'a mut self) -> &'a mut T {
+    pub fn mut_last<'a>(&'a mut self) -> Option<&'a mut T> {
         match *self {
             Vec(ref mut v) => v.mut_last(),
-            Empty => fail!("mut_last on empty opt_vec")
+            Empty => None
         }
     }
 
-- 
cgit 1.4.1-3-g733a5