//===----------------------------------------------------------------------===//
//
// 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___UTILITY_CMP_H
#define _LIBCUDACXX___UTILITY_CMP_H

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

#include "../__utility/forward.h"
#include "../__utility/move.h"
#include "../__type_traits/disjunction.h"
#include "../__type_traits/is_integral.h"
#include "../__type_traits/is_same.h"
#include "../__type_traits/is_signed.h"
#include "../__type_traits/make_unsigned.h"
#include "../limits"

#ifndef __cuda_std__
#include <__pragma_push>
#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

_LIBCUDACXX_BEGIN_NAMESPACE_STD

#if _LIBCUDACXX_STD_VER > 17
template<class _Tp, class... _Up>
struct _IsSameAsAny : _Or<_IsSame<_Tp, _Up>...> {};

template<class _Tp>
concept __is_safe_integral_cmp = is_integral_v<_Tp> &&
                      !_IsSameAsAny<_Tp, bool, char, char16_t, char32_t
#ifndef _LIBCUDACXX_NO_HAS_CHAR8_T
                                    , char8_t
#endif
#ifndef _LIBCUDACXX_HAS_NO_WIDE_CHARACTERS
                                    , wchar_t
#endif
                                    >::value;

template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
_LIBCUDACXX_INLINE_VISIBILITY constexpr
bool cmp_equal(_Tp __t, _Up __u) noexcept
{
  if constexpr (is_signed_v<_Tp> == is_signed_v<_Up>)
    return __t == __u;
  else if constexpr (is_signed_v<_Tp>)
    return __t < 0 ? false : make_unsigned_t<_Tp>(__t) == __u;
  else
    return __u < 0 ? false : __t == make_unsigned_t<_Up>(__u);
}

template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
_LIBCUDACXX_INLINE_VISIBILITY constexpr
bool cmp_not_equal(_Tp __t, _Up __u) noexcept
{
  return !_CUDA_VSTD::cmp_equal(__t, __u);
}

template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
_LIBCUDACXX_INLINE_VISIBILITY constexpr
bool cmp_less(_Tp __t, _Up __u) noexcept
{
  if constexpr (is_signed_v<_Tp> == is_signed_v<_Up>)
    return __t < __u;
  else if constexpr (is_signed_v<_Tp>)
    return __t < 0 ? true : make_unsigned_t<_Tp>(__t) < __u;
  else
    return __u < 0 ? false : __t < make_unsigned_t<_Up>(__u);
}

template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
_LIBCUDACXX_INLINE_VISIBILITY constexpr
bool cmp_greater(_Tp __t, _Up __u) noexcept
{
  return _CUDA_VSTD::cmp_less(__u, __t);
}

template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
_LIBCUDACXX_INLINE_VISIBILITY constexpr
bool cmp_less_equal(_Tp __t, _Up __u) noexcept
{
  return !_CUDA_VSTD::cmp_greater(__t, __u);
}

template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
_LIBCUDACXX_INLINE_VISIBILITY constexpr
bool cmp_greater_equal(_Tp __t, _Up __u) noexcept
{
  return !_CUDA_VSTD::cmp_less(__t, __u);
}

template<__is_safe_integral_cmp _Tp, __is_safe_integral_cmp _Up>
_LIBCUDACXX_INLINE_VISIBILITY constexpr
bool in_range(_Up __u) noexcept
{
  return _CUDA_VSTD::cmp_less_equal(__u, numeric_limits<_Tp>::max()) &&
         _CUDA_VSTD::cmp_greater_equal(__u, numeric_limits<_Tp>::min());
}
#endif // _LIBCUDACXX_STD_VER > 17

_LIBCUDACXX_END_NAMESPACE_STD

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

#endif // _LIBCUDACXX___UTILITY_CMP_H
