1 //===----------------------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 9 #ifndef _LIBCPP___TUPLE_TUPLE_ELEMENT_H 10 #define _LIBCPP___TUPLE_TUPLE_ELEMENT_H 11 12 #include <__config> 13 #include <__cstddef/size_t.h> 14 #include <__tuple/tuple_indices.h> 15 #include <__tuple/tuple_types.h> 16 17 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 18 # pragma GCC system_header 19 #endif 20 21 _LIBCPP_BEGIN_NAMESPACE_STD 22 23 template <size_t _Ip, class _Tp> 24 struct _LIBCPP_TEMPLATE_VIS tuple_element; 25 26 template <size_t _Ip, class _Tp> 27 struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const _Tp> { 28 using type _LIBCPP_NODEBUG = const typename tuple_element<_Ip, _Tp>::type; 29 }; 30 31 template <size_t _Ip, class _Tp> 32 struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, volatile _Tp> { 33 using type _LIBCPP_NODEBUG = volatile typename tuple_element<_Ip, _Tp>::type; 34 }; 35 36 template <size_t _Ip, class _Tp> 37 struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, const volatile _Tp> { 38 using type _LIBCPP_NODEBUG = const volatile typename tuple_element<_Ip, _Tp>::type; 39 }; 40 41 #ifndef _LIBCPP_CXX03_LANG 42 43 template <size_t _Ip, class... _Types> 44 struct _LIBCPP_TEMPLATE_VIS tuple_element<_Ip, __tuple_types<_Types...> > { 45 static_assert(_Ip < sizeof...(_Types), "tuple_element index out of range"); 46 using type _LIBCPP_NODEBUG = __type_pack_element<_Ip, _Types...>; 47 }; 48 49 # if _LIBCPP_STD_VER >= 14 50 template <size_t _Ip, class... _Tp> 51 using tuple_element_t _LIBCPP_NODEBUG = typename tuple_element<_Ip, _Tp...>::type; 52 # endif 53 54 #endif // _LIBCPP_CXX03_LANG 55 56 _LIBCPP_END_NAMESPACE_STD 57 58 #endif // _LIBCPP___TUPLE_TUPLE_ELEMENT_H 59