[libcxx] LWG2485: get() should be overloaded for const tuple&&. Patch from K-Ballo.

Review: http://reviews.llvm.org/D14839
llvm-svn: 255941
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 545b8861fc40bb194d6e8daa382f9d6d4659a13b
diff --git a/include/__tuple b/include/__tuple
index 57581e8..8c31759 100644
--- a/include/__tuple
+++ b/include/__tuple
@@ -86,6 +86,11 @@
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 typename tuple_element<_Ip, tuple<_Tp...> >::type&&
 get(tuple<_Tp...>&&) _NOEXCEPT;
+
+template <size_t _Ip, class ..._Tp>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const typename tuple_element<_Ip, tuple<_Tp...> >::type&&
+get(const tuple<_Tp...>&&) _NOEXCEPT;
 #endif
 
 // pair specializations
@@ -109,6 +114,11 @@
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
 get(pair<_T1, _T2>&&) _NOEXCEPT;
+
+template <size_t _Ip, class _T1, class _T2>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const typename tuple_element<_Ip, pair<_T1, _T2> >::type&&
+get(const pair<_T1, _T2>&&) _NOEXCEPT;
 #endif
 
 // array specializations
@@ -132,6 +142,11 @@
 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
 _Tp&&
 get(array<_Tp, _Size>&&) _NOEXCEPT;
+
+template <size_t _Ip, class _Tp, size_t _Size>
+_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
+const _Tp&&
+get(const array<_Tp, _Size>&&) _NOEXCEPT;
 #endif
 
 #if !defined(_LIBCPP_HAS_NO_VARIADICS)