//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// SPDX-FileCopyrightText: Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES.
//
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCUDACXX___TYPE_TRAITS_EXTENT_H
#define _LIBCUDACXX___TYPE_TRAITS_EXTENT_H

#ifndef __cuda_std__
#include <__config>
#endif // __cuda_std__

#if defined(_CCCL_IMPLICIT_SYSTEM_HEADER_GCC)
#  pragma GCC system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_CLANG)
#  pragma clang system_header
#elif defined(_CCCL_IMPLICIT_SYSTEM_HEADER_MSVC)
#  pragma system_header
#endif // no system header

#include "../__type_traits/integral_constant.h"
#include "../cstddef"

_LIBCUDACXX_BEGIN_NAMESPACE_STD

#if defined(_LIBCUDACXX_ARRAY_EXTENT) && !defined(_LIBCUDACXX_USE_ARRAY_EXTENT_FALLBACK)

template<class _Tp, size_t _Dim = 0>
struct _LIBCUDACXX_TEMPLATE_VIS extent
    : integral_constant<size_t, _LIBCUDACXX_ARRAY_EXTENT(_Tp, _Dim)> { };

#if _CCCL_STD_VER > 2011 && !defined(_LIBCUDACXX_HAS_NO_VARIABLE_TEMPLATES)
template <class _Tp, unsigned _Ip = 0>
_LIBCUDACXX_INLINE_VAR constexpr size_t extent_v = _LIBCUDACXX_ARRAY_EXTENT(_Tp, _Ip);
#endif

#else

template <class _Tp, unsigned _Ip = 0> struct _LIBCUDACXX_TEMPLATE_VIS extent
    : public integral_constant<size_t, 0> {};
template <class _Tp> struct _LIBCUDACXX_TEMPLATE_VIS extent<_Tp[], 0>
    : public integral_constant<size_t, 0> {};
template <class _Tp, unsigned _Ip> struct _LIBCUDACXX_TEMPLATE_VIS extent<_Tp[], _Ip>
    : public integral_constant<size_t, extent<_Tp, _Ip-1>::value> {};
template <class _Tp, size_t _Np> struct _LIBCUDACXX_TEMPLATE_VIS extent<_Tp[_Np], 0>
    : public integral_constant<size_t, _Np> {};
template <class _Tp, size_t _Np, unsigned _Ip> struct _LIBCUDACXX_TEMPLATE_VIS extent<_Tp[_Np], _Ip>
    : public integral_constant<size_t, extent<_Tp, _Ip-1>::value> {};

#if _CCCL_STD_VER > 2011 && !defined(_LIBCUDACXX_HAS_NO_VARIABLE_TEMPLATES)
template <class _Tp, unsigned _Ip = 0>
_LIBCUDACXX_INLINE_VAR constexpr size_t extent_v = extent<_Tp, _Ip>::value;
#endif

#endif // defined(_LIBCUDACXX_ARRAY_EXTENT) && !defined(_LIBCUDACXX_USE_ARRAY_EXTENT_FALLBACK)

_LIBCUDACXX_END_NAMESPACE_STD

#endif // _LIBCUDACXX___TYPE_TRAITS_EXTENT_H
