Implement the std::pair parts of "Improving pair and tuple". Completes N4387.
llvm-svn: 276605
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 4927c295777f49ad518a809a85dc31c3e250680f
diff --git a/include/__tuple b/include/__tuple
index cc9fbbe..3cafbde 100644
--- a/include/__tuple
+++ b/include/__tuple
@@ -146,6 +146,12 @@
template <class... _Tp> struct __tuple_like<tuple<_Tp...> > : true_type {};
+template <class ..._Tp>
+class _LIBCPP_TYPE_VIS_ONLY tuple_size<tuple<_Tp...> >
+ : public integral_constant<size_t, sizeof...(_Tp)>
+{
+};
+
template <size_t _Ip, class ..._Tp>
_LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX11
typename tuple_element<_Ip, tuple<_Tp...> >::type&
@@ -431,8 +437,48 @@
>
{};
+
+template <size_t _Ip, class ..._Tp>
+class _LIBCPP_TYPE_VIS_ONLY tuple_element<_Ip, tuple<_Tp...> >
+{
+public:
+ typedef typename tuple_element<_Ip, __tuple_types<_Tp...> >::type type;
+};
+
+#if _LIBCPP_STD_VER > 11
+template <size_t _Ip, class ..._Tp>
+using tuple_element_t = typename tuple_element <_Ip, _Tp...>::type;
+#endif
+
#endif // _LIBCPP_HAS_NO_VARIADICS
+#ifndef _LIBCPP_CXX03_LANG
+template <bool _IsTuple, class _SizeTrait, size_t _Expected>
+struct __tuple_like_with_size_imp : false_type {};
+
+template <class _SizeTrait, size_t _Expected>
+struct __tuple_like_with_size_imp<true, _SizeTrait, _Expected>
+ : integral_constant<bool, _SizeTrait::value == _Expected> {};
+
+template <class _Tuple, size_t _ExpectedSize,
+ class _RawTuple = typename __uncvref<_Tuple>::type>
+using __tuple_like_with_size = __tuple_like_with_size_imp<
+ __tuple_like<_RawTuple>::value,
+ tuple_size<_RawTuple>, _ExpectedSize
+ >;
+
+struct _LIBCPP_TYPE_VIS __check_tuple_constructor_fail {
+ template <class ...>
+ static constexpr bool __enable_default() { return false; }
+ template <class ...>
+ static constexpr bool __enable_explicit() { return false; }
+ template <class ...>
+ static constexpr bool __enable_implicit() { return false; }
+ template <class ...>
+ static constexpr bool __enable_assign() { return false; }
+};
+#endif
+
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___TUPLE