include/__nullptr

// -*- C++ -*-
//===--------------------------- __nullptr --------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_NULLPTR
#define _LIBCPP_NULLPTR

#include <__config>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif

#ifdef _LIBCPP_HAS_NO_NULLPTR

_LIBCPP_BEGIN_NAMESPACE_STD

struct _LIBCPP_TYPE_VIS_ONLY nullptr_t
{
 void* __lx;

 struct __nat {int __for_bool_;};

 _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t() : __lx(0) {}
 _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t(int __nat::*) : __lx(0) {}

 _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR operator int __nat::*() const {return 0;}

 template <class _Tp>
 _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR
 operator _Tp* () const {return 0;}

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

 friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator==(nullptr_t, nullptr_t) {return true;}
 friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator!=(nullptr_t, nullptr_t) {return false;}
};

inline _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t __get_nullptr_t() {return nullptr_t(0);}

#define nullptr _VSTD::__get_nullptr_t()

_LIBCPP_END_NAMESPACE_STD

#else // _LIBCPP_HAS_NO_NULLPTR

namespace std
{
 typedef decltype(nullptr) nullptr_t;
}

#endif // _LIBCPP_HAS_NO_NULLPTR

#endif // _LIBCPP_NULLPTR