1// -*- C++ -*-
2//===----------------------------------------------------------------------===//
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 // C++11
29    nullptr_t
30    byte // C++17
31
32}  // std
33
34*/
35
36#include <__assert> // all public C++ headers provide the assertion handler
37#include <__config>
38#include <__type_traits/is_integral.h>
39#include <stddef.h>
40#include <version>
41
42#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
43#  pragma GCC system_header
44#endif
45
46_LIBCPP_BEGIN_NAMESPACE_STD
47
48using ::nullptr_t;
49using ::ptrdiff_t _LIBCPP_USING_IF_EXISTS;
50using ::size_t _LIBCPP_USING_IF_EXISTS;
51
52#if !defined(_LIBCPP_CXX03_LANG)
53using ::max_align_t _LIBCPP_USING_IF_EXISTS;
54#endif
55
56_LIBCPP_END_NAMESPACE_STD
57
58#if _LIBCPP_STD_VER > 14
59namespace std  // purposefully not versioned
60{
61enum class byte : unsigned char {};
62
63
64template <bool> struct __enable_if_integral_imp {};
65template <> struct __enable_if_integral_imp<true> { using type = byte; };
66template <class _Tp> using _EnableByteOverload = typename __enable_if_integral_imp<__libcpp_is_integral<_Tp>::value>::type;
67
68constexpr byte  operator| (byte  __lhs, byte __rhs) noexcept
69{
70    return static_cast<byte>(
71      static_cast<unsigned char>(
72         static_cast<unsigned int>(__lhs) | static_cast<unsigned int>(__rhs)
73    ));
74}
75
76constexpr byte& operator|=(byte& __lhs, byte __rhs) noexcept
77{ return __lhs = __lhs | __rhs; }
78
79constexpr byte  operator& (byte  __lhs, byte __rhs) noexcept
80{
81    return static_cast<byte>(
82      static_cast<unsigned char>(
83         static_cast<unsigned int>(__lhs) & static_cast<unsigned int>(__rhs)
84    ));
85}
86
87constexpr byte& operator&=(byte& __lhs, byte __rhs) noexcept
88{ return __lhs = __lhs & __rhs; }
89
90constexpr byte  operator^ (byte  __lhs, byte __rhs) noexcept
91{
92    return static_cast<byte>(
93      static_cast<unsigned char>(
94         static_cast<unsigned int>(__lhs) ^ static_cast<unsigned int>(__rhs)
95    ));
96}
97
98constexpr byte& operator^=(byte& __lhs, byte __rhs) noexcept
99{ return __lhs = __lhs ^ __rhs; }
100
101constexpr byte  operator~ (byte __b) noexcept
102{
103    return static_cast<byte>(
104      static_cast<unsigned char>(
105        ~static_cast<unsigned int>(__b)
106    ));
107}
108template <class _Integer>
109  constexpr _EnableByteOverload<_Integer> &
110  operator<<=(byte& __lhs, _Integer __shift) noexcept
111  { return __lhs = __lhs << __shift; }
112
113template <class _Integer>
114  constexpr _EnableByteOverload<_Integer>
115  operator<< (byte  __lhs, _Integer __shift) noexcept
116  { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) << __shift)); }
117
118template <class _Integer>
119  constexpr _EnableByteOverload<_Integer> &
120  operator>>=(byte& __lhs, _Integer __shift) noexcept
121  { return __lhs = __lhs >> __shift; }
122
123template <class _Integer>
124  constexpr _EnableByteOverload<_Integer>
125  operator>> (byte  __lhs, _Integer __shift) noexcept
126  { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) >> __shift)); }
127
128template <class _Integer, class = _EnableByteOverload<_Integer> >
129  _LIBCPP_NODISCARD_EXT constexpr _Integer
130  to_integer(byte __b) noexcept { return static_cast<_Integer>(__b); }
131
132} // namespace std
133
134#endif
135
136#endif // _LIBCPP_CSTDDEF
137