1// -*- C++ -*-
2//===--------------------------- __nullptr --------------------------------===//
3//
4// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
5// See https://llvm.org/LICENSE.txt for license information.
6// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7//
8//===----------------------------------------------------------------------===//
9
10#ifndef _LIBCPP_NULLPTR
11#define _LIBCPP_NULLPTR
12
13#include <__config>
14
15#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
16#pragma GCC system_header
17#endif
18
19#ifdef _LIBCPP_HAS_NO_NULLPTR
20
21_LIBCPP_BEGIN_NAMESPACE_STD
22
23struct _LIBCPP_TEMPLATE_VIS nullptr_t
24{
25 void* __lx;
26
27 struct __nat {int __for_bool_;};
28
29 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR nullptr_t() : __lx(0) {}
30 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR nullptr_t(int __nat::*) : __lx(0) {}
31
32 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR operator int __nat::*() const {return 0;}
33
34 template <class _Tp>
35 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR
36 operator _Tp* () const {return 0;}
37
38 template <class _Tp, class _Up>
39 _LIBCPP_INLINE_VISIBILITY
40 operator _Tp _Up::* () const {return 0;}
41
42 friend _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR bool operator==(nullptr_t, nullptr_t) {return true;}
43 friend _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR bool operator!=(nullptr_t, nullptr_t) {return false;}
44};
45
46inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR nullptr_t __get_nullptr_t() {return nullptr_t(0);}
47
48#define nullptr _VSTD::__get_nullptr_t()
49
50_LIBCPP_END_NAMESPACE_STD
51
52#else // _LIBCPP_HAS_NO_NULLPTR
53
54namespace std
55{
56 typedef decltype(nullptr) nullptr_t;
57}
58
59#endif // _LIBCPP_HAS_NO_NULLPTR
60
61#endif // _LIBCPP_NULLPTR
62