From aff153a8cd0119ef9e60d2c01760796f938f7c9a Mon Sep 17 00:00:00 2001
From: Eric Fiselier <eric@efcs.ca>
Date: Fri, 28 Aug 2015 05:07:06 +0000
Subject: [PATCH] [libcxx] Constrain unique_ptr::operator=(unique_ptr<Tp, Dp>)
 in C++03 mode

Summary:
This patch properly constrains the converting assignment operator in C++03. It also fixes a bug where std::forward was given the wrong type.
The following two tests begin passing in C++03:

* `unique_ptr.single.asgn/move_convert.pass.cpp`
* `unique_ptr.single.asgn/move_convert13.fail.cpp`

Reviewers: mclow.lists

Subscribers: cfe-commits

Differential Revision: http://reviews.llvm.org/D12173

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@246272 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/memory | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

diff --git a/include/memory b/include/memory
index 9d214beb..4ed33084 100644
--- a/include/memory
+++ b/include/memory
@@ -2668,10 +2668,17 @@ public:
         : __ptr_(__u->release(), _VSTD::forward<deleter_type>(__u->get_deleter())) {}
 
     template <class _Up, class _Ep>
-    _LIBCPP_INLINE_VISIBILITY unique_ptr& operator=(unique_ptr<_Up, _Ep> __u)
+    _LIBCPP_INLINE_VISIBILITY
+    typename enable_if<
+        !is_array<_Up>::value &&
+        is_convertible<typename unique_ptr<_Up, _Ep>::pointer, pointer>::value &&
+        is_assignable<deleter_type&, _Ep&>::value,
+        unique_ptr&
+    >::type
+    operator=(unique_ptr<_Up, _Ep> __u)
     {
         reset(__u.release());
-        __ptr_.second() = _VSTD::forward<deleter_type>(__u.get_deleter());
+        __ptr_.second() = _VSTD::forward<_Ep>(__u.get_deleter());
         return *this;
     }