1// -*- C++ -*-
2//===--------------------------- cstddef ----------------------------------===//
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_CSTDDEF
11#define _LIBCPP_CSTDDEF
12
13/*
14    cstddef synopsis
15
16Macros:
17
18    offsetof(type,member-designator)
19    NULL
20
21namespace std
22{
23
24Types:
25
26    ptrdiff_t
27    size_t
28    max_align_t
29    nullptr_t
30    byte // C++17
31
32}  // std
33
34*/
35
36#include <__config>
37#include <version>
38
39#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
40#pragma GCC system_header
41#endif
42
43// Don't include our own <stddef.h>; we don't want to declare ::nullptr_t.
44#include_next <stddef.h>
45#include <__nullptr>
46
47_LIBCPP_BEGIN_NAMESPACE_STD
48
49using ::ptrdiff_t;
50using ::size_t;
51
52#if defined(__CLANG_MAX_ALIGN_T_DEFINED) || defined(_GCC_MAX_ALIGN_T) || \
53    defined(__DEFINED_max_align_t) || defined(__NetBSD__)
54// Re-use the compiler's <stddef.h> max_align_t where possible.
55using ::max_align_t;
56#else
57typedef long double max_align_t;
58#endif
59
60template <class _Tp> struct __libcpp_is_integral                     { enum { value = 0 }; };
61template <>          struct __libcpp_is_integral<bool>               { enum { value = 1 }; };
62template <>          struct __libcpp_is_integral<char>               { enum { value = 1 }; };
63template <>          struct __libcpp_is_integral<signed char>        { enum { value = 1 }; };
64template <>          struct __libcpp_is_integral<unsigned char>      { enum { value = 1 }; };
65template <>          struct __libcpp_is_integral<wchar_t>            { enum { value = 1 }; };
66#ifndef _LIBCPP_NO_HAS_CHAR8_T
67template <>          struct __libcpp_is_integral<char8_t>            { enum { value = 1 }; };
68#endif
69#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
70template <>          struct __libcpp_is_integral<char16_t>           { enum { value = 1 }; };
71template <>          struct __libcpp_is_integral<char32_t>           { enum { value = 1 }; };
72#endif  // _LIBCPP_HAS_NO_UNICODE_CHARS
73template <>          struct __libcpp_is_integral<short>              { enum { value = 1 }; };
74template <>          struct __libcpp_is_integral<unsigned short>     { enum { value = 1 }; };
75template <>          struct __libcpp_is_integral<int>                { enum { value = 1 }; };
76template <>          struct __libcpp_is_integral<unsigned int>       { enum { value = 1 }; };
77template <>          struct __libcpp_is_integral<long>               { enum { value = 1 }; };
78template <>          struct __libcpp_is_integral<unsigned long>      { enum { value = 1 }; };
79template <>          struct __libcpp_is_integral<long long>          { enum { value = 1 }; };
80template <>          struct __libcpp_is_integral<unsigned long long> { enum { value = 1 }; };
81#ifndef _LIBCPP_HAS_NO_INT128
82template <>          struct __libcpp_is_integral<__int128_t>         { enum { value = 1 }; };
83template <>          struct __libcpp_is_integral<__uint128_t>        { enum { value = 1 }; };
84#endif
85
86_LIBCPP_END_NAMESPACE_STD
87
88#if _LIBCPP_STD_VER > 14
89namespace std  // purposefully not versioned
90{
91enum class byte : unsigned char {};
92
93
94template <bool> struct __enable_if_integral_imp {};
95template <> struct __enable_if_integral_imp<true> { using type = byte; };
96template <class _Tp> using _EnableByteOverload = typename __enable_if_integral_imp<__libcpp_is_integral<_Tp>::value>::type;
97
98constexpr byte  operator| (byte  __lhs, byte __rhs) noexcept
99{
100    return static_cast<byte>(
101      static_cast<unsigned char>(
102         static_cast<unsigned int>(__lhs) | static_cast<unsigned int>(__rhs)
103    ));
104}
105
106constexpr byte& operator|=(byte& __lhs, byte __rhs) noexcept
107{ return __lhs = __lhs | __rhs; }
108
109constexpr byte  operator& (byte  __lhs, byte __rhs) noexcept
110{
111    return static_cast<byte>(
112      static_cast<unsigned char>(
113         static_cast<unsigned int>(__lhs) & static_cast<unsigned int>(__rhs)
114    ));
115}
116
117constexpr byte& operator&=(byte& __lhs, byte __rhs) noexcept
118{ return __lhs = __lhs & __rhs; }
119
120constexpr byte  operator^ (byte  __lhs, byte __rhs) noexcept
121{
122    return static_cast<byte>(
123      static_cast<unsigned char>(
124         static_cast<unsigned int>(__lhs) ^ static_cast<unsigned int>(__rhs)
125    ));
126}
127
128constexpr byte& operator^=(byte& __lhs, byte __rhs) noexcept
129{ return __lhs = __lhs ^ __rhs; }
130
131constexpr byte  operator~ (byte __b) noexcept
132{
133    return static_cast<byte>(
134      static_cast<unsigned char>(
135        ~static_cast<unsigned int>(__b)
136    ));
137}
138template <class _Integer>
139  constexpr _EnableByteOverload<_Integer> &
140  operator<<=(byte& __lhs, _Integer __shift) noexcept
141  { return __lhs = __lhs << __shift; }
142
143template <class _Integer>
144  constexpr _EnableByteOverload<_Integer>
145  operator<< (byte  __lhs, _Integer __shift) noexcept
146  { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) << __shift)); }
147
148template <class _Integer>
149  constexpr _EnableByteOverload<_Integer> &
150  operator>>=(byte& __lhs, _Integer __shift) noexcept
151  { return __lhs = __lhs >> __shift; }
152
153template <class _Integer>
154  constexpr _EnableByteOverload<_Integer>
155  operator>> (byte  __lhs, _Integer __shift) noexcept
156  { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) >> __shift)); }
157
158template <class _Integer, class = _EnableByteOverload<_Integer> >
159  constexpr _Integer
160  to_integer(byte __b) noexcept { return static_cast<_Integer>(__b); }
161}
162
163#endif
164
165#endif  // _LIBCPP_CSTDDEF
166