From b929de3c3d5c11d6136be1f59838788b8797ac12 Mon Sep 17 00:00:00 2001
From: Howard Hinnant <hhinnant@apple.com>
Date: Fri, 1 Jul 2011 20:12:51 +0000
Subject: [PATCH] Changed constraints on pair and tuple constructors from
 is_convertible to is_constructible.

llvm-svn: 134252
---
 libcxx/include/__tuple |  4 ----
 libcxx/include/utility | 12 ++++++------
 2 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/libcxx/include/__tuple b/libcxx/include/__tuple
index a9514c1e36f2..918656ed8386 100644
--- a/libcxx/include/__tuple
+++ b/libcxx/include/__tuple
@@ -214,11 +214,7 @@ struct __tuple_convertible_imp : public false_type {};
 template <class _Tp0, class ..._Tp, class _Up0, class ..._Up>
 struct __tuple_convertible_imp<true, __tuple_types<_Tp0, _Tp...>, __tuple_types<_Up0, _Up...> >
     : public integral_constant<bool,
-#if 1 // waiting on cwg 1170
-                               is_convertible<_Tp0, _Up0>::value &&
-#else
                                is_constructible<_Up0, _Tp0>::value &&
-#endif
                                __tuple_convertible_imp<true, __tuple_types<_Tp...>, __tuple_types<_Up...> >::value> {};
 
 template <>
diff --git a/libcxx/include/utility b/libcxx/include/utility
index 3850f8f3524a..d0aee559a310 100644
--- a/libcxx/include/utility
+++ b/libcxx/include/utility
@@ -227,8 +227,8 @@ struct _LIBCPP_VISIBLE pair
     template<class _U1, class _U2>
         _LIBCPP_INLINE_VISIBILITY
         pair(const pair<_U1, _U2>& __p,
-                 typename enable_if<is_convertible<_U1, _T1>::value &&
-                                    is_convertible<_U2, _T2>::value>::type* = 0)
+                 typename enable_if<is_constructible<_T1, _U1>::value &&
+                                    is_constructible<_T2, _U2>::value>::type* = 0)
             : first(__p.first), second(__p.second) {}
 
     _LIBCPP_INLINE_VISIBILITY
@@ -253,8 +253,8 @@ struct _LIBCPP_VISIBLE pair
 #ifndef _LIBCPP_HAS_NO_RVALUE_REFERENCES
 
     template <class _U1, class _U2,
-              class = typename enable_if<is_convertible<_U1, first_type >::value &&
-                                         is_convertible<_U2, second_type>::value>::type>
+              class = typename enable_if<is_constructible<first_type, _U1 >::value &&
+                                         is_constructible<second_type, _U2>::value>::type>
         _LIBCPP_INLINE_VISIBILITY
         pair(_U1&& __u1, _U2&& __u2)
             : first(_VSTD::forward<_U1>(__u1)),
@@ -264,8 +264,8 @@ struct _LIBCPP_VISIBLE pair
     template<class _U1, class _U2>
         _LIBCPP_INLINE_VISIBILITY
         pair(pair<_U1, _U2>&& __p,
-                 typename enable_if<is_convertible<_U1, _T1>::value &&
-                                    is_convertible<_U2, _T2>::value>::type* = 0)
+                 typename enable_if<is_constructible<_T1, _U1>::value &&
+                                    is_constructible<_T2, _U2>::value>::type* = 0)
             : first(_VSTD::forward<_U1>(__p.first)),
               second(_VSTD::forward<_U2>(__p.second)) {}
 
-- 
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