Implement LWG Paper n3887: Consistent Metafunction Aliases. This adds std::tuple_element_t<> as an alias for tuple_element<>::type. Clean up the synopsis for tuple_element in <utility> as well. git-svn-id: https://llvm.org/svn/llvm-project/libcxx/trunk@202673 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/tuple b/include/tuple index 30a958a..3a1752e 100644 --- a/include/tuple +++ b/include/tuple
@@ -82,13 +82,15 @@ template <class... T> class tuple_size<tuple<T...>>; template <intsize_t I, class T> class tuple_element; // undefined template <intsize_t I, class... T> class tuple_element<I, tuple<T...>>; +template <size_t _Ip, class ..._Tp> + using tuple_element_t = typename tuple_element <_Ip, _Tp...>::type; // C++14 // 20.4.1.5, element access: template <intsize_t I, class... T> typename tuple_element<I, tuple<T...>>::type& get(tuple<T...>&) noexcept; // constexpr in C++14 template <intsize_t I, class... T> - typename tuple_element<I, tuple<T...>>::type const& + typename const tuple_element<I, tuple<T...>>::type & get(const tuple<T...>&) noexcept; // constexpr in C++14 template <intsize_t I, class... T> typename tuple_element<I, tuple<T...>>::type&& @@ -152,6 +154,11 @@ 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 + // __tuple_leaf template <size_t _Ip, class _Hp, bool=is_empty<_Hp>::value
