From 7e12e67936dd2ad12e529278344dab369ccb75a0 Mon Sep 17 00:00:00 2001
From: Brian Anderson <banderson@mozilla.com>
Date: Thu, 4 Sep 2014 19:54:41 -0700
Subject: Optimize Slice::reverse

This makes the completely safe implementation of fannkuchredux perform
the same as C++. Yay, Rust.
---
 src/libcore/slice.rs | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

(limited to 'src/libcore')

diff --git a/src/libcore/slice.rs b/src/libcore/slice.rs
index c3c18e36617..cc2b01e3bb5 100644
--- a/src/libcore/slice.rs
+++ b/src/libcore/slice.rs
@@ -806,7 +806,12 @@ impl<'a,T> MutableSlice<'a, T> for &'a mut [T] {
         let mut i: uint = 0;
         let ln = self.len();
         while i < ln / 2 {
-            self.swap(i, ln - i - 1);
+            // Unsafe swap to avoid the bounds check in safe swap.
+            unsafe {
+                let pa: *mut T = self.unsafe_mut_ref(i);
+                let pb: *mut T = self.unsafe_mut_ref(ln - i - 1);
+                ptr::swap(pa, pb);
+            }
             i += 1;
         }
     }
-- 
cgit 1.4.1-3-g733a5