xref: /freebsd/contrib/llvm-project/libcxx/include/cstddef (revision 2fb4f839f3fc72ce2bab12f9ba4760f97f73e97f)
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 <__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 _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
56template <class _Tp> struct __libcpp_is_integral                     { enum { value = 0 }; };
57template <>          struct __libcpp_is_integral<bool>               { enum { value = 1 }; };
58template <>          struct __libcpp_is_integral<char>               { enum { value = 1 }; };
59template <>          struct __libcpp_is_integral<signed char>        { enum { value = 1 }; };
60template <>          struct __libcpp_is_integral<unsigned char>      { enum { value = 1 }; };
61#ifndef _LIBCPP_HAS_NO_WIDE_CHARACTERS
62template <>          struct __libcpp_is_integral<wchar_t>            { enum { value = 1 }; };
63#endif
64#ifndef _LIBCPP_HAS_NO_CHAR8_T
65template <>          struct __libcpp_is_integral<char8_t>            { enum { value = 1 }; };
66#endif
67#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
68template <>          struct __libcpp_is_integral<char16_t>           { enum { value = 1 }; };
69template <>          struct __libcpp_is_integral<char32_t>           { enum { value = 1 }; };
70#endif
71template <>          struct __libcpp_is_integral<short>              { enum { value = 1 }; };
72template <>          struct __libcpp_is_integral<unsigned short>     { enum { value = 1 }; };
73template <>          struct __libcpp_is_integral<int>                { enum { value = 1 }; };
74template <>          struct __libcpp_is_integral<unsigned int>       { enum { value = 1 }; };
75template <>          struct __libcpp_is_integral<long>               { enum { value = 1 }; };
76template <>          struct __libcpp_is_integral<unsigned long>      { enum { value = 1 }; };
77template <>          struct __libcpp_is_integral<long long>          { enum { value = 1 }; };
78template <>          struct __libcpp_is_integral<unsigned long long> { enum { value = 1 }; };
79#ifndef _LIBCPP_HAS_NO_INT128
80template <>          struct __libcpp_is_integral<__int128_t>         { enum { value = 1 }; };
81template <>          struct __libcpp_is_integral<__uint128_t>        { enum { value = 1 }; };
82#endif
83
84_LIBCPP_END_NAMESPACE_STD
85
86#if _LIBCPP_STD_VER > 14
87namespace std  // purposefully not versioned
88{
89enum class byte : unsigned char {};
90
91
92template <bool> struct __enable_if_integral_imp {};
93template <> struct __enable_if_integral_imp<true> { using type = byte; };
94template <class _Tp> using _EnableByteOverload = typename __enable_if_integral_imp<__libcpp_is_integral<_Tp>::value>::type;
95
96constexpr byte  operator| (byte  __lhs, byte __rhs) noexcept
97{
98    return static_cast<byte>(
99      static_cast<unsigned char>(
100         static_cast<unsigned int>(__lhs) | static_cast<unsigned int>(__rhs)
101    ));
102}
103
104constexpr byte& operator|=(byte& __lhs, byte __rhs) noexcept
105{ return __lhs = __lhs | __rhs; }
106
107constexpr byte  operator& (byte  __lhs, byte __rhs) noexcept
108{
109    return static_cast<byte>(
110      static_cast<unsigned char>(
111         static_cast<unsigned int>(__lhs) & static_cast<unsigned int>(__rhs)
112    ));
113}
114
115constexpr byte& operator&=(byte& __lhs, byte __rhs) noexcept
116{ return __lhs = __lhs & __rhs; }
117
118constexpr byte  operator^ (byte  __lhs, byte __rhs) noexcept
119{
120    return static_cast<byte>(
121      static_cast<unsigned char>(
122         static_cast<unsigned int>(__lhs) ^ static_cast<unsigned int>(__rhs)
123    ));
124}
125
126constexpr byte& operator^=(byte& __lhs, byte __rhs) noexcept
127{ return __lhs = __lhs ^ __rhs; }
128
129constexpr byte  operator~ (byte __b) noexcept
130{
131    return static_cast<byte>(
132      static_cast<unsigned char>(
133        ~static_cast<unsigned int>(__b)
134    ));
135}
136template <class _Integer>
137  constexpr _EnableByteOverload<_Integer> &
138  operator<<=(byte& __lhs, _Integer __shift) noexcept
139  { return __lhs = __lhs << __shift; }
140
141template <class _Integer>
142  constexpr _EnableByteOverload<_Integer>
143  operator<< (byte  __lhs, _Integer __shift) noexcept
144  { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) << __shift)); }
145
146template <class _Integer>
147  constexpr _EnableByteOverload<_Integer> &
148  operator>>=(byte& __lhs, _Integer __shift) noexcept
149  { return __lhs = __lhs >> __shift; }
150
151template <class _Integer>
152  constexpr _EnableByteOverload<_Integer>
153  operator>> (byte  __lhs, _Integer __shift) noexcept
154  { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) >> __shift)); }
155
156template <class _Integer, class = _EnableByteOverload<_Integer> >
157  _LIBCPP_NODISCARD_EXT constexpr _Integer
158  to_integer(byte __b) noexcept { return static_cast<_Integer>(__b); }
159
160} // namespace std
161
162#endif
163
164#endif // _LIBCPP_CSTDDEF
165