// -*- C++ -*-
//===--------------------------- __nullptr --------------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCUDACXX_NULLPTR
#define _LIBCUDACXX_NULLPTR

#include <__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

#ifdef _LIBCUDACXX_HAS_NO_NULLPTR

_LIBCUDACXX_BEGIN_NAMESPACE_STD

struct _LIBCUDACXX_TEMPLATE_VIS nullptr_t
{
    void* __lx;

    struct __nat {int __for_bool_;};

    _LIBCUDACXX_INLINE_VISIBILITY constexpr nullptr_t() : __lx(0) {}
    _LIBCUDACXX_INLINE_VISIBILITY constexpr nullptr_t(int __nat::*) : __lx(0) {}

    _LIBCUDACXX_INLINE_VISIBILITY constexpr operator int __nat::*() const {return 0;}

    template <class _Tp>
        _LIBCUDACXX_INLINE_VISIBILITY constexpr
        operator _Tp* () const {return 0;}

    template <class _Tp, class _Up>
        _LIBCUDACXX_INLINE_VISIBILITY
        operator _Tp _Up::* () const {return 0;}

    friend _LIBCUDACXX_INLINE_VISIBILITY constexpr bool operator==(nullptr_t, nullptr_t) {return true;}
    friend _LIBCUDACXX_INLINE_VISIBILITY constexpr bool operator!=(nullptr_t, nullptr_t) {return false;}
};

inline _LIBCUDACXX_INLINE_VISIBILITY constexpr nullptr_t __get_nullptr_t() {return nullptr_t(0);}

#define nullptr _CUDA_VSTD::__get_nullptr_t()

_LIBCUDACXX_END_NAMESPACE_STD

#else  // _LIBCUDACXX_HAS_NO_NULLPTR

namespace std
{
    typedef decltype(nullptr) nullptr_t;
}

#endif  // _LIBCUDACXX_HAS_NO_NULLPTR

#endif  // _LIBCUDACXX_NULLPTR