From ef54251a84b976a17ce7a9cc8e55e644f090c6dc Mon Sep 17 00:00:00 2001
From: Howard Hinnant <hhinnant@apple.com>
Date: Sun, 22 May 2011 15:07:43 +0000
Subject: [PATCH] Fix const correctness bug in bind involving reference_wrapper
 found by Jonathan Sauer

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@131852 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/functional | 22 ++++++++++++----------
 1 file changed, 12 insertions(+), 10 deletions(-)

diff --git a/include/functional b/include/functional
index aa2b4924d..03e2c8162 100644
--- a/include/functional
+++ b/include/functional
@@ -1567,24 +1567,31 @@ __mu(_Ti& __ti, _Uj& __uj)
     return __ti;
 }
 
-template <class _Ti, bool IsBindEx, bool IsPh, class _TupleUj>
+template <class _Ti, bool IsReferenceWrapper, bool IsBindEx, bool IsPh,
+          class _TupleUj>
 struct ____mu_return;
 
 template <class _Ti, class ..._Uj>
-struct ____mu_return<_Ti, true, false, tuple<_Uj...> >
+struct ____mu_return<_Ti, false, true, false, tuple<_Uj...> >
 {
     typedef typename __invoke_of<_Ti&, _Uj...>::type type;
 };
 
 template <class _Ti, class _TupleUj>
-struct ____mu_return<_Ti, false, true, _TupleUj>
+struct ____mu_return<_Ti, false, false, true, _TupleUj>
 {
     typedef typename tuple_element<is_placeholder<_Ti>::value - 1,
                                    _TupleUj>::type&& type;
 };
 
 template <class _Ti, class _TupleUj>
-struct ____mu_return<_Ti, false, false, _TupleUj>
+struct ____mu_return<_Ti, true, false, false, _TupleUj>
+{
+    typedef typename _Ti::type& type;
+};
+
+template <class _Ti, class _TupleUj>
+struct ____mu_return<_Ti, false, false, false, _TupleUj>
 {
     typedef _Ti& type;
 };
@@ -1592,18 +1599,13 @@ struct ____mu_return<_Ti, false, false, _TupleUj>
 template <class _Ti, class _TupleUj>
 struct __mu_return
     : public ____mu_return<_Ti,
+                           __is_reference_wrapper<_Ti>::value,
                            is_bind_expression<_Ti>::value,
                            0 < is_placeholder<_Ti>::value,
                            _TupleUj>
 {
 };
 
-template <class _Ti, class _TupleUj>
-struct __mu_return<reference_wrapper<_Ti>, _TupleUj>
-{
-    typedef _Ti& type;
-};
-
 template <class _F, class _BoundArgs, class _TupleUj>
 struct __bind_return;