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___TYPE_TRAITS_EXTENT_H 10 #define _LIBCPP___TYPE_TRAITS_EXTENT_H 11 12 #include <__config> 13 #include <__type_traits/integral_constant.h> 14 #include <cstddef> 15 16 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER) 17 # pragma GCC system_header 18 #endif 19 20 _LIBCPP_BEGIN_NAMESPACE_STD 21 22 #if __has_builtin(__array_extent) 23 24 template <class _Tp, size_t _Dim = 0> 25 struct _LIBCPP_TEMPLATE_VIS extent : integral_constant<size_t, __array_extent(_Tp, _Dim)> {}; 26 27 # if _LIBCPP_STD_VER >= 17 28 template <class _Tp, unsigned _Ip = 0> 29 inline constexpr size_t extent_v = __array_extent(_Tp, _Ip); 30 # endif 31 32 #else // __has_builtin(__array_extent) 33 34 template <class _Tp, unsigned _Ip = 0> 35 struct _LIBCPP_TEMPLATE_VIS extent : public integral_constant<size_t, 0> {}; 36 template <class _Tp> 37 struct _LIBCPP_TEMPLATE_VIS extent<_Tp[], 0> : public integral_constant<size_t, 0> {}; 38 template <class _Tp, unsigned _Ip> 39 struct _LIBCPP_TEMPLATE_VIS extent<_Tp[], _Ip> : public integral_constant<size_t, extent<_Tp, _Ip - 1>::value> {}; 40 template <class _Tp, size_t _Np> 41 struct _LIBCPP_TEMPLATE_VIS extent<_Tp[_Np], 0> : public integral_constant<size_t, _Np> {}; 42 template <class _Tp, size_t _Np, unsigned _Ip> 43 struct _LIBCPP_TEMPLATE_VIS extent<_Tp[_Np], _Ip> : public integral_constant<size_t, extent<_Tp, _Ip - 1>::value> {}; 44 45 # if _LIBCPP_STD_VER >= 17 46 template <class _Tp, unsigned _Ip = 0> 47 inline constexpr size_t extent_v = extent<_Tp, _Ip>::value; 48 # endif 49 50 #endif // __has_builtin(__array_extent) 51 52 _LIBCPP_END_NAMESPACE_STD 53 54 #endif // _LIBCPP___TYPE_TRAITS_EXTENT_H 55