Index: /Sources/LLVM/libcxx/include/utility
===================================================================
--- /Sources/LLVM/libcxx/include/utility	(revision 186344)
+++ /Sources/LLVM/libcxx/include/utility	(working copy)
@@ -66,10 +66,10 @@
     pair(const pair&) = default;
     pair(pair&&) = default;
     constexpr pair();
-    pair(const T1& x, const T2& y);
-    template <class U, class V> pair(U&& x, V&& y);
-    template <class U, class V> pair(const pair<U, V>& p);
-    template <class U, class V> pair(pair<U, V>&& p);
+    pair(const T1& x, const T2& y);                          // constexpr in C++14
+    template <class U, class V> pair(U&& x, V&& y);          // constexpr in C++14
+    template <class U, class V> pair(const pair<U, V>& p);   // constexpr in C++14
+    template <class U, class V> pair(pair<U, V>&& p);        // constexpr in C++14
     template <class... Args1, class... Args2>
         pair(piecewise_construct_t, tuple<Args1...> first_args,
              tuple<Args2...> second_args);
@@ -83,14 +83,14 @@
                                 noexcept(swap(second, p.second)));
 };
 
-template <class T1, class T2> bool operator==(const pair<T1,T2>&, const pair<T1,T2>&);
-template <class T1, class T2> bool operator!=(const pair<T1,T2>&, const pair<T1,T2>&);
-template <class T1, class T2> bool operator< (const pair<T1,T2>&, const pair<T1,T2>&);
-template <class T1, class T2> bool operator> (const pair<T1,T2>&, const pair<T1,T2>&);
-template <class T1, class T2> bool operator>=(const pair<T1,T2>&, const pair<T1,T2>&);
-template <class T1, class T2> bool operator<=(const pair<T1,T2>&, const pair<T1,T2>&);
+template <class T1, class T2> bool operator==(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
+template <class T1, class T2> bool operator!=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
+template <class T1, class T2> bool operator< (const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
+template <class T1, class T2> bool operator> (const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
+template <class T1, class T2> bool operator>=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
+template <class T1, class T2> bool operator<=(const pair<T1,T2>&, const pair<T1,T2>&); // constexpr in C++14
 
-template <class T1, class T2> pair<V1, V2> make_pair(T1&&, T2&&);
+template <class T1, class T2> pair<V1, V2> make_pair(T1&&, T2&&);   // constexpr in C++14
 template <class T1, class T2>
 void
 swap(pair<T1, T2>& x, pair<T1, T2>& y) noexcept(noexcept(x.swap(y)));
@@ -258,11 +258,12 @@
 
     _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR pair() : first(), second() {}
 
-    _LIBCPP_INLINE_VISIBILITY pair(const _T1& __x, const _T2& __y)
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+    pair(const _T1& __x, const _T2& __y)
         : first(__x), second(__y) {}
 
     template<class _U1, class _U2>
-        _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
         pair(const pair<_U1, _U2>& __p
 #ifndef _LIBCPP_HAS_NO_ADVANCED_SFINAE
                  ,typename enable_if<is_convertible<const _U1&, _T1>::value &&
@@ -271,7 +272,7 @@
                                       )
             : first(__p.first), second(__p.second) {}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
     pair(const pair& __p)
         _NOEXCEPT_(is_nothrow_copy_constructible<first_type>::value &&
                    is_nothrow_copy_constructible<second_type>::value)
@@ -295,21 +296,21 @@
     template <class _U1, class _U2,
               class = typename enable_if<is_convertible<_U1, first_type>::value &&
                                          is_convertible<_U2, second_type>::value>::type>
-        _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
         pair(_U1&& __u1, _U2&& __u2)
             : first(_VSTD::forward<_U1>(__u1)),
               second(_VSTD::forward<_U2>(__u2))
             {}
 
     template<class _U1, class _U2>
-        _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
         pair(pair<_U1, _U2>&& __p,
                  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)) {}
 
-    _LIBCPP_INLINE_VISIBILITY
+    _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
     pair(pair&& __p) _NOEXCEPT_(is_nothrow_move_constructible<first_type>::value &&
                                 is_nothrow_move_constructible<second_type>::value)
         : first(_VSTD::forward<first_type>(__p.first)),
@@ -331,7 +332,7 @@
 
     template<class _Tuple,
              class = typename enable_if<__tuple_convertible<_Tuple, pair>::value>::type>
-        _LIBCPP_INLINE_VISIBILITY
+        _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
         pair(_Tuple&& __p)
             : first(_VSTD::forward<typename tuple_element<0,
                                   typename __make_tuple_types<_Tuple>::type>::type>(get<0>(__p))),
@@ -387,7 +388,7 @@
 };
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 bool
 operator==(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
 {
@@ -395,7 +396,7 @@
 }
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 bool
 operator!=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
 {
@@ -403,7 +404,7 @@
 }
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 bool
 operator< (const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
 {
@@ -411,7 +412,7 @@
 }
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 bool
 operator> (const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
 {
@@ -419,7 +420,7 @@
 }
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 bool
 operator>=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
 {
@@ -427,7 +428,7 @@
 }
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 bool
 operator<=(const pair<_T1,_T2>& __x, const pair<_T1,_T2>& __y)
 {
@@ -472,7 +473,7 @@
 };
 
 template <class _T1, class _T2>
-inline _LIBCPP_INLINE_VISIBILITY
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 pair<typename __make_pair_return<_T1>::type, typename __make_pair_return<_T2>::type>
 make_pair(_T1&& __t1, _T2&& __t2)
 {
Index: /Sources/LLVM/libcxx/test/utilities/utility/pairs/pair.astuple/get_const.pass.cpp
===================================================================
--- /Sources/LLVM/libcxx/test/utilities/utility/pairs/pair.astuple/get_const.pass.cpp	(revision 186319)
+++ /Sources/LLVM/libcxx/test/utilities/utility/pairs/pair.astuple/get_const.pass.cpp	(working copy)
@@ -26,4 +26,27 @@
         assert(std::get<0>(p) == 3);
         assert(std::get<1>(p) == 4);
     }
+
+#if __cplusplus > 201103L
+        typedef std::pair<int, short> P;
+    {
+        constexpr P p1(3, 4);
+        static_assert(p1.first == 3, "" );
+        static_assert(p1.second == 4, "" );
+//         static_assert(std::get<0>(p1) == 3, "");
+//         static_assert(std::get<1>(p1) == 4, "");
+
+		constexpr P p2 = std::make_pair<int, short> (5, 6);
+        static_assert(p2.first == 5, "" );
+        static_assert(p2.second == 6, "" );
+		
+	//  make sure all the comparison operators are constexpr
+		static_assert ( !(p1 == p2), "" );
+		static_assert (  (p1 != p2), "" );
+		static_assert ( !(p1 >  p2), "" );
+		static_assert ( !(p1 >= p2), "" );
+		static_assert (  (p1 <  p2), "" );
+		static_assert (  (p1 <= p2), "" );
+    }
+#endif
 }