From 9f7ed2f054c72dd0989b42ed3e6a839e64d9fa1a Mon Sep 17 00:00:00 2001
From: Tim Chevalier <chevalier@alum.wellesley.edu>
Date: Tue, 30 Aug 2011 17:17:42 -0700
Subject: [PATCH] Add a total version of vec::last that has a precondition

---
 src/lib/vec.rs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/lib/vec.rs b/src/lib/vec.rs
index daa1d499d58..8a20345b864 100644
--- a/src/lib/vec.rs
+++ b/src/lib/vec.rs
@@ -97,6 +97,11 @@ fn last<@T>(v: &[mutable? T]) -> option::t<T> {
     ret some(v[len(v) - 1u]);
 }
 
+/// Returns the last element of a non-empty vector `v`.
+fn last_total<@T>(v: &[mutable? T]) : is_not_empty(v) -> T {
+    ret v[len(v) - 1u];
+}
+
 /// Returns a copy of the elements from [`start`..`end`) from `v`.
 fn slice<@T>(v: &[mutable? T], start: uint, end: uint) -> [T] {
     assert (start <= end);