//===----------------------------------------------------------------------===//
//
// 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___ITERATOR_MOVE_SENTINEL_H
#define _LIBCUDACXX___ITERATOR_MOVE_SENTINEL_H

#include <cuda/std/detail/__config>

#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 <cuda/std/__concepts/assignable.h>
#include <cuda/std/__concepts/convertible_to.h>
#include <cuda/std/__concepts/semiregular.h>
#include <cuda/std/__utility/move.h>

_LIBCUDACXX_BEGIN_NAMESPACE_STD

#if !defined(_CCCL_NO_CONCEPTS)
template <semiregular _Sent>
#else // ^^^ !_CCCL_NO_CONCEPTS ^^^ / vvv _CCCL_NO_CONCEPTS vvv
template <class _Sent, enable_if_t<semiregular<_Sent>, int> = 0>
#endif // _CCCL_NO_CONCEPTS
class _CCCL_TYPE_VISIBILITY_DEFAULT move_sentinel
{
public:
  _CCCL_HIDE_FROM_ABI constexpr move_sentinel() = default;

  _LIBCUDACXX_HIDE_FROM_ABI constexpr explicit move_sentinel(_Sent __s)
      : __last_(_CUDA_VSTD::move(__s))
  {}

  _CCCL_TEMPLATE(class _S2)
  _CCCL_REQUIRES(convertible_to<const _S2&, _Sent>)
  _LIBCUDACXX_HIDE_FROM_ABI constexpr move_sentinel(const move_sentinel<_S2>& __s)
      : __last_(__s.base())
  {}

  _CCCL_TEMPLATE(class _S2)
  _CCCL_REQUIRES(assignable_from<const _S2&, _Sent>)
  _LIBCUDACXX_HIDE_FROM_ABI constexpr move_sentinel& operator=(const move_sentinel<_S2>& __s)
  {
    __last_ = __s.base();
    return *this;
  }

  _LIBCUDACXX_HIDE_FROM_ABI constexpr _Sent base() const
  {
    return __last_;
  }

private:
  _Sent __last_ = _Sent();
};

_LIBCUDACXX_END_NAMESPACE_STD

#endif // _LIBCUDACXX___ITERATOR_MOVE_SENTINEL_H
