Apple LWG 2067: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2012/n3318.html#2067 .  This is the only actionable change that has been made to the C++ draft since C++11.  In general it has not been decided exactly how libc++ will track changes made to C++11.  New features and design changes will probably be #ifdef'd, especially if they are not backwards compatible.  Defects and 'dumb mistakes' are more likely to just be put in.  Decisions on telling one from the other will be made on a case by case basis.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@160608 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/future b/include/future
index fa8dd8a..9b768e3 100644
--- a/include/future
+++ b/include/future
@@ -333,8 +333,8 @@
     ~packaged_task();
 
     // no copy
-    packaged_task(packaged_task&) = delete;
-    packaged_task& operator=(packaged_task&) = delete;
+    packaged_task(const packaged_task&) = delete;
+    packaged_task& operator=(const packaged_task&) = delete;
 
     // move support
     packaged_task(packaged_task&& other) noexcept;
@@ -1953,8 +1953,8 @@
     // ~packaged_task() = default;
 
     // no copy
-    packaged_task(packaged_task&) = delete;
-    packaged_task& operator=(packaged_task&) = delete;
+    packaged_task(const packaged_task&) = delete;
+    packaged_task& operator=(const packaged_task&) = delete;
 
     // move support
     _LIBCPP_INLINE_VISIBILITY
@@ -2068,8 +2068,8 @@
     // ~packaged_task() = default;
 
     // no copy
-    packaged_task(packaged_task&) = delete;
-    packaged_task& operator=(packaged_task&) = delete;
+    packaged_task(const packaged_task&) = delete;
+    packaged_task& operator=(const packaged_task&) = delete;
 
     // move support
     _LIBCPP_INLINE_VISIBILITY