From fe59276f04a2894eaba048ce5dbba7a6050ae9ab Mon Sep 17 00:00:00 2001
From: Howard Hinnant <hhinnant@apple.com>
Date: Sat, 9 Jun 2012 20:01:23 +0000
Subject: [PATCH] Revert pair constructors back to using is_convertible instead
 of is_constructible.  This should pull things into alignment with the final
 draft.  Fixes http://llvm.org/bugs/show_bug.cgi?id=13063#add_comment.

git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@158280 91177308-0d34-0410-b5e6-96231b3b80d8
---
 include/utility | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/include/utility b/include/utility
index 279d4218..a0e16a7f 100644
--- a/include/utility
+++ b/include/utility
@@ -233,8 +233,8 @@ struct _LIBCPP_VISIBLE pair
         _LIBCPP_INLINE_VISIBILITY
         pair(const pair<_U1, _U2>& __p
 #ifndef _LIBCPP_HAS_NO_ADVANCED_SFINAE
-                 ,typename enable_if<is_constructible<_T1, _U1>::value &&
-                                    is_constructible<_T2, _U2>::value>::type* = 0
+                 ,typename enable_if<is_convertible<const _U1&, _T1>::value &&
+                                    is_convertible<const _U2&, _T2>::value>::type* = 0
 #endif
                                       )
             : first(__p.first), second(__p.second) {}
@@ -261,8 +261,8 @@ struct _LIBCPP_VISIBLE pair
 #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 
     template <class _U1, class _U2,
-              class = typename enable_if<is_constructible<first_type, _U1 >::value &&
-                                         is_constructible<second_type, _U2>::value>::type>
+              class = typename enable_if<is_convertible<_U1, first_type>::value &&
+                                         is_convertible<_U2, second_type>::value>::type>
         _LIBCPP_INLINE_VISIBILITY
         pair(_U1&& __u1, _U2&& __u2)
             : first(_VSTD::forward<_U1>(__u1)),
@@ -272,8 +272,8 @@ struct _LIBCPP_VISIBLE pair
     template<class _U1, class _U2>
         _LIBCPP_INLINE_VISIBILITY
         pair(pair<_U1, _U2>&& __p,
-                 typename enable_if<is_constructible<_T1, _U1>::value &&
-                                    is_constructible<_T2, _U2>::value>::type* = 0)
+                 typename enable_if<is_convertible<_U1, _T1>::value &&
+                                    is_convertible<_U2, _T2>::value>::type* = 0)
             : first(_VSTD::forward<_U1>(__p.first)),
               second(_VSTD::forward<_U2>(__p.second)) {}