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#elif defined(__ANDROID__) && !__LP64__
53// If compiler doesn't have max_align_t (ie. clang), and it's on 32-bit Android, typedef max_align_t to
54// "long long" instead of "long double" because 32-bit Android treats "long double" the same as "double"
55// which is smaller than "long long"
56typedef long long max_align_t;
57#else
58typedef long double max_align_t;
59#endif
60
61#ifdef _LIBCPP_HAS_NO_NULLPTR
62
63struct _LIBCPP_TYPE_VIS_ONLY nullptr_t
64{
65    void* __lx;
66
67    struct __nat {int __for_bool_;};
68
69    _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t() : __lx(0) {}
70    _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t(int __nat::*) : __lx(0) {}
71
72    _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR operator int __nat::*() const {return 0;}
73
74    template <class _Tp>
75        _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR
76        operator _Tp* () const {return 0;}
77
78    template <class _Tp, class _Up>
79        _LIBCPP_ALWAYS_INLINE
80        operator _Tp _Up::* () const {return 0;}
81
82    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator==(nullptr_t, nullptr_t) {return true;}
83    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator!=(nullptr_t, nullptr_t) {return false;}
84    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator<(nullptr_t, nullptr_t) {return false;}
85    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator<=(nullptr_t, nullptr_t) {return true;}
86    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator>(nullptr_t, nullptr_t) {return false;}
87    friend _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR bool operator>=(nullptr_t, nullptr_t) {return true;}
88};
89
90inline _LIBCPP_ALWAYS_INLINE _LIBCPP_CONSTEXPR nullptr_t __get_nullptr_t() {return nullptr_t(0);}
91
92#define nullptr _VSTD::__get_nullptr_t()
93
94#endif  // _LIBCPP_HAS_NO_NULLPTR
95
96_LIBCPP_END_NAMESPACE_STD
97
98#ifndef _LIBCPP_HAS_NO_NULLPTR
99
100namespace std
101{
102    typedef decltype(nullptr) nullptr_t;
103}
104
105#endif  // _LIBCPP_HAS_NO_NULLPTR
106
107#endif  // _LIBCPP_CSTDDEF
108