---

yaml
---
r: 234789
b: refs/heads/tmp
c: 77f5da7
h: refs/heads/master
i:
  234787: f04acdf
v: v3

Author: whitequark

[refs]

@@ -25,7 +25,7 @@ refs/tags/0.11.0: e1247cb1d0d681be034adb4b558b5a0c0d5720f9
 refs/tags/0.12.0: f0c419429ef30723ceaf6b42f9b5a2aeb5d2e2d1
 refs/heads/beta: d2e13e822a73e0ea46ae9e21afdd3155fc997f6d
 refs/tags/1.0.0-alpha: e42bd6d93a1d3433c486200587f8f9e12590a4d7
-refs/heads/tmp: 6beb4ba1aaecb59fdfdc676434b5a3b17a4b5bfc
+refs/heads/tmp: 77f5da77a91af88130fcff3e726931934c71ba3f
 refs/tags/1.0.0-alpha.2: 4c705f6bc559886632d3871b04f58aab093bfa2f
 refs/tags/homu-tmp: ab792abf1fcc28afbd315426213f6428da25c085
 refs/tags/1.0.0-beta: 8cbb92b53468ee2b0c2d3eeb8567005953d40828

branches/tmp/src/libcollections/vec.rs

@@ -1323,6 +1323,8 @@ impl<T> Drop for Vec<T> {
         // don't need unsafe_no_drop_flag shenanigans anymore.
         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() {
                         drop_in_place(x);