---

yaml
---
r: 272751
b: refs/heads/beta
c: f6e125f
h: refs/heads/master
i:
  272749: e048122
  272747: 6b9748e
  272743: e534909
  272735: cad5a66

Author: bors

[refs]

@@ -23,7 +23,7 @@ refs/tags/0.9: 36870b185fc5f5486636d4515f0e22677493f225
 refs/tags/0.10: ac33f2b15782272ae348dbd7b14b8257b2148b5a
 refs/tags/0.11.0: e1247cb1d0d681be034adb4b558b5a0c0d5720f9
 refs/tags/0.12.0: f0c419429ef30723ceaf6b42f9b5a2aeb5d2e2d1
-refs/heads/beta: 37ba66a66e07ce62a743b61f83d1b7bf38f1f88b
+refs/heads/beta: f6e125f04a54ec65eac0ecd3cb68e180210a06fa
 refs/tags/1.0.0-alpha: e42bd6d93a1d3433c486200587f8f9e12590a4d7
 refs/heads/tmp: e06d2ad9fcd5027bcaac5b08fc9aa39a49d0ecd3
 refs/tags/1.0.0-alpha.2: 4c705f6bc559886632d3871b04f58aab093bfa2f

branches/beta/src/libcollections/vec.rs

@@ -66,7 +66,7 @@ use borrow::ToOwned;
 use core::cmp::Ordering;
 use core::fmt;
 use core::hash::{self, Hash};
-use core::intrinsics::{arith_offset, assume, needs_drop};
+use core::intrinsics::{arith_offset, assume};
 use core::iter::FromIterator;
 use core::mem;
 use core::ops::{Index, IndexMut};
@@ -497,10 +497,11 @@ impl<T> Vec<T> {
         unsafe {
             // drop any extra elements
             while len < self.len {
-                // decrement len before the read(), so a panic on Drop doesn't
-                // re-drop the just-failed value.
+                // decrement len before the drop_in_place(), so a panic on Drop
+                // doesn't re-drop the just-failed value.
                 self.len -= 1;
-                ptr::read(self.get_unchecked(self.len));
+                let len = self.len;
+                ptr::drop_in_place(self.get_unchecked_mut(len));
             }
         }
     }
@@ -1471,13 +1472,8 @@ impl<T> Drop for Vec<T> {
     fn drop(&mut self) {
         if self.buf.unsafe_no_drop_flag_needs_drop() {
             unsafe {
-                // The branch on needs_drop() is an -O1 performance optimization.
-                // Without the branch, dropping Vec<u8> takes linear time.
-                if needs_drop::<T>() {
-                    for x in self.iter_mut() {
-                        ptr::drop_in_place(x);
-                    }
-                }
+                // use drop for [T]
+                ptr::drop_in_place(&mut self[..]);
             }
         }
         // RawVec handles deallocation

branches/beta/src/libcollections/vec_deque.rs

@@ -70,7 +70,12 @@ impl<T: Clone> Clone for VecDeque<T> {
 impl<T> Drop for VecDeque<T> {
     #[unsafe_destructor_blind_to_params]
     fn drop(&mut self) {
-        self.clear();
+        let (front, back) = self.as_mut_slices();
+        unsafe {
+            // use drop for [T]
+            ptr::drop_in_place(front);
+            ptr::drop_in_place(back);
+        }
         // RawVec handles deallocation
     }
 }