From 493355d8e92ab00f0f6b787e4226c095ccd83a55 Mon Sep 17 00:00:00 2001
From: Michael Layzell <michael@thelayzells.com>
Date: Thu, 24 Sep 2015 18:19:23 -0400
Subject: [PATCH] Add unsafe Send and Sync impls to VecDeque's Drain<T>

---
 src/libcollections/vec_deque.rs                            | 3 +++
 src/test/run-pass/sync-send-iterators-in-libcollections.rs | 3 ++-
 2 files changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/libcollections/vec_deque.rs b/src/libcollections/vec_deque.rs
index 27a996055f5..807c02af6e1 100644
--- a/src/libcollections/vec_deque.rs
+++ b/src/libcollections/vec_deque.rs
@@ -1800,6 +1800,9 @@ pub struct Drain<'a, T: 'a> {
     deque: *mut VecDeque<T>,
 }
 
+unsafe impl<'a, T: Sync> Sync for Drain<'a, T> {}
+unsafe impl<'a, T: Send> Send for Drain<'a, T> {}
+
 #[stable(feature = "rust1", since = "1.0.0")]
 impl<'a, T: 'a> Drop for Drain<'a, T> {
     fn drop(&mut self) {
diff --git a/src/test/run-pass/sync-send-iterators-in-libcollections.rs b/src/test/run-pass/sync-send-iterators-in-libcollections.rs
index 8160fe56fd0..7fa592105c0 100644
--- a/src/test/run-pass/sync-send-iterators-in-libcollections.rs
+++ b/src/test/run-pass/sync-send-iterators-in-libcollections.rs
@@ -93,7 +93,8 @@ fn from_usize(v: usize) -> Foo {
     }
     all_sync_send!(EnumSet::<Foo>::new(), iter);
 
-    all_sync_send!(VecDeque::<usize>::new(), iter, iter_mut, drain, into_iter);
+    all_sync_send!(VecDeque::<usize>::new(), iter, iter_mut, into_iter);
+    is_sync_send!(VecDeque::<usize>::new(), drain(..));
 
     all_sync_send!(Vec::<usize>::new(), into_iter);
     is_sync_send!(Vec::<usize>::new(), drain(..));