cstddef revision 278724 
1// -*- C++ -*-
2//===--------------------------- cstddef ----------------------------------===//
3//
4//                     The LLVM Compiler Infrastructure
5//
6// This file is dual licensed under the MIT and the University of Illinois Open
7// Source Licenses. See LICENSE.TXT for details.
8//
9//===----------------------------------------------------------------------===//
10
11#ifndef _LIBCPP_CSTDDEF
12#define _LIBCPP_CSTDDEF
13
14/*
15    cstddef synopsis
16
17Macros:
18
19    offsetof(type,member-designator)
20    NULL
21
22namespace std
23{
24
25Types:
26
27    ptrdiff_t
28    size_t
29    max_align_t
30    nullptr_t
31
32}  // std
33
34*/
35
36#include <__config>
37
38#include <stddef.h>
39
40#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
41#pragma GCC system_header
42#endif
43
44_LIBCPP_BEGIN_NAMESPACE_STD
45
46using ::ptrdiff_t;
47using ::size_t;
48
49#if defined(__CLANG_MAX_ALIGN_T_DEFINED) || defined(_GCC_MAX_ALIGN_T)
50// Re-use the compiler's <stddef.h> max_align_t where possible.
51using ::max_align_t;
52#else
53typedef long double max_align_t;
54#endif
55
56#ifdef _LIBCPP_HAS_NO_NULLPTR
57
58struct _LIBCPP_TYPE_VIS_ONLY nullptr_t
59{
60    void* __lx;
61
62    struct __nat {int __for_bool_;};
63
64    _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t() : __lx(0) {}
65    _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t(int __nat::*) : __lx(0) {}
66
67    _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR operator int __nat::*() const {return 0;}
68
69    template <class _Tp>
70        _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR
71        operator _Tp* () const {return 0;}
72
73    template <class _Tp, class _Up>
74        _LIBCPP_ALWAYS_INLINE
75        operator _Tp _Up::* () const {return 0;}
76
77    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator==(nullptr_t, nullptr_t) {return true;}
78    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator!=(nullptr_t, nullptr_t) {return false;}
79    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator<(nullptr_t, nullptr_t) {return false;}
80    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator<=(nullptr_t, nullptr_t) {return true;}
81    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator>(nullptr_t, nullptr_t) {return false;}
82    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator>=(nullptr_t, nullptr_t) {return true;}
83};
84
85inline _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t __get_nullptr_t() {return nullptr_t(0);}
86
87#define nullptr _VSTD::__get_nullptr_t()
88
89#endif  // _LIBCPP_HAS_NO_NULLPTR
90
91_LIBCPP_END_NAMESPACE_STD
92
93#ifndef _LIBCPP_HAS_NO_NULLPTR
94
95namespace std
96{
97    typedef decltype(nullptr) nullptr_t;
98}
99
100#endif  // _LIBCPP_HAS_NO_NULLPTR
101
102#endif  // _LIBCPP_CSTDDEF
103