181ad6265SDimitry Andric //===----------------------------------------------------------------------===// 281ad6265SDimitry Andric // 381ad6265SDimitry Andric // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 481ad6265SDimitry Andric // See https://llvm.org/LICENSE.txt for license information. 581ad6265SDimitry Andric // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 681ad6265SDimitry Andric // 781ad6265SDimitry Andric //===----------------------------------------------------------------------===// 881ad6265SDimitry Andric 981ad6265SDimitry Andric #ifndef _LIBCPP___TYPE_TRAITS_DECAY_H 1081ad6265SDimitry Andric #define _LIBCPP___TYPE_TRAITS_DECAY_H 1181ad6265SDimitry Andric 1281ad6265SDimitry Andric #include <__config> 1381ad6265SDimitry Andric #include <__type_traits/add_pointer.h> 1481ad6265SDimitry Andric #include <__type_traits/conditional.h> 1581ad6265SDimitry Andric #include <__type_traits/is_array.h> 1681ad6265SDimitry Andric #include <__type_traits/is_function.h> 1781ad6265SDimitry Andric #include <__type_traits/is_referenceable.h> 1881ad6265SDimitry Andric #include <__type_traits/remove_cv.h> 1981ad6265SDimitry Andric #include <__type_traits/remove_extent.h> 2081ad6265SDimitry Andric #include <__type_traits/remove_reference.h> 2181ad6265SDimitry Andric 2281ad6265SDimitry Andric #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 2381ad6265SDimitry Andric # pragma GCC system_header 2481ad6265SDimitry Andric #endif 2581ad6265SDimitry Andric 2681ad6265SDimitry Andric _LIBCPP_BEGIN_NAMESPACE_STD 2781ad6265SDimitry Andric 281f571f87SDimitry Andric #if __has_builtin(__decay) 291f571f87SDimitry Andric template <class _Tp> 3006c3fb27SDimitry Andric using __decay_t _LIBCPP_NODEBUG = __decay(_Tp); 3106c3fb27SDimitry Andric 3206c3fb27SDimitry Andric template <class _Tp> 331f571f87SDimitry Andric struct decay { 3406c3fb27SDimitry Andric using type _LIBCPP_NODEBUG = __decay_t<_Tp>; 351f571f87SDimitry Andric }; 3606c3fb27SDimitry Andric 371f571f87SDimitry Andric #else 3881ad6265SDimitry Andric template <class _Up, bool> 3981ad6265SDimitry Andric struct __decay { 40bdd1243dSDimitry Andric typedef _LIBCPP_NODEBUG __remove_cv_t<_Up> type; 4181ad6265SDimitry Andric }; 4281ad6265SDimitry Andric 4381ad6265SDimitry Andric template <class _Up> 4481ad6265SDimitry Andric struct __decay<_Up, true> { 4581ad6265SDimitry Andric public: 4606c3fb27SDimitry Andric typedef _LIBCPP_NODEBUG typename conditional< 4781ad6265SDimitry Andric is_array<_Up>::value, 48bdd1243dSDimitry Andric __add_pointer_t<__remove_extent_t<_Up> >, 4906c3fb27SDimitry Andric typename conditional<is_function<_Up>::value, typename add_pointer<_Up>::type, __remove_cv_t<_Up> >::type >::type 5006c3fb27SDimitry Andric type; 5181ad6265SDimitry Andric }; 5281ad6265SDimitry Andric 5381ad6265SDimitry Andric template <class _Tp> 5406c3fb27SDimitry Andric struct _LIBCPP_TEMPLATE_VIS decay { 5581ad6265SDimitry Andric private: 56bdd1243dSDimitry Andric typedef _LIBCPP_NODEBUG __libcpp_remove_reference_t<_Tp> _Up; 5706c3fb27SDimitry Andric 5881ad6265SDimitry Andric public: 591f571f87SDimitry Andric typedef _LIBCPP_NODEBUG typename __decay<_Up, __libcpp_is_referenceable<_Up>::value>::type type; 6081ad6265SDimitry Andric }; 6106c3fb27SDimitry Andric 6206c3fb27SDimitry Andric template <class _Tp> 6306c3fb27SDimitry Andric using __decay_t = typename decay<_Tp>::type; 641f571f87SDimitry Andric #endif // __has_builtin(__decay) 6581ad6265SDimitry Andric 6606c3fb27SDimitry Andric #if _LIBCPP_STD_VER >= 14 6706c3fb27SDimitry Andric template <class _Tp> 6806c3fb27SDimitry Andric using decay_t = __decay_t<_Tp>; 6981ad6265SDimitry Andric #endif 7081ad6265SDimitry Andric 7181ad6265SDimitry Andric _LIBCPP_END_NAMESPACE_STD 7281ad6265SDimitry Andric 7381ad6265SDimitry Andric #endif // _LIBCPP___TYPE_TRAITS_DECAY_H 74