llvm-project/libcxx/include/cstddef

// -*- C++ -*-
//===--------------------------- cstddef ----------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_CSTDDEF
#define _LIBCPP_CSTDDEF

/*
    cstddef synopsis

Macros:

    offsetof(type,member-designator)
    NULL

namespace std
{

Types:

    ptrdiff_t
    size_t
    max_align_t // C++11
    nullptr_t
    byte // C++17

}  // std

*/

#include <__config>
#include <version>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#pragma GCC system_header
#endif

// Don't include our own <stddef.h>; we don't want to declare ::nullptr_t.
#include_next <stddef.h>
#include <__nullptr>

_LIBCPP_BEGIN_NAMESPACE_STD

using ::ptrdiff_t;
using ::size_t;

#if !defined(_LIBCPP_CXX03_LANG)
using ::max_align_t;
#endif

template <class _Tp> struct __libcpp_is_integral                     { enum { value = 0 }; };
template <>          struct __libcpp_is_integral<bool>               { enum { value = 1 }; };
template <>          struct __libcpp_is_integral<char>               { enum { value = 1 }; };
template <>          struct __libcpp_is_integral<signed char>        { enum { value = 1 }; };
template <>          struct __libcpp_is_integral<unsigned char>      { enum { value = 1 }; };
template <>          struct __libcpp_is_integral<wchar_t>            { enum { value = 1 }; };
#ifndef _LIBCPP_HAS_NO_CHAR8_T
template <>          struct __libcpp_is_integral<char8_t>            { enum { value = 1 }; };
#endif
#ifndef _LIBCPP_HAS_NO_UNICODE_CHARS
template <>          struct __libcpp_is_integral<char16_t>           { enum { value = 1 }; };
template <>          struct __libcpp_is_integral<char32_t>           { enum { value = 1 }; };
#endif // _LIBCPP_HAS_NO_UNICODE_CHARS
template <>          struct __libcpp_is_integral<short>              { enum { value = 1 }; };
template <>          struct __libcpp_is_integral<unsigned short>     { enum { value = 1 }; };
template <>          struct __libcpp_is_integral<int>                { enum { value = 1 }; };
template <>          struct __libcpp_is_integral<unsigned int>       { enum { value = 1 }; };
template <>          struct __libcpp_is_integral<long>               { enum { value = 1 }; };
template <>          struct __libcpp_is_integral<unsigned long>      { enum { value = 1 }; };
template <>          struct __libcpp_is_integral<long long>          { enum { value = 1 }; };
template <>          struct __libcpp_is_integral<unsigned long long> { enum { value = 1 }; };
#ifndef _LIBCPP_HAS_NO_INT128
template <>          struct __libcpp_is_integral<__int128_t>         { enum { value = 1 }; };
template <>          struct __libcpp_is_integral<__uint128_t>        { enum { value = 1 }; };
#endif

_LIBCPP_END_NAMESPACE_STD

#if _LIBCPP_STD_VER > 14
namespace std  // purposefully not versioned
{
enum class byte : unsigned char {};


template <bool> struct __enable_if_integral_imp {};
template <> struct __enable_if_integral_imp<true> { using type = byte; };
template <class _Tp> using _EnableByteOverload = typename __enable_if_integral_imp<__libcpp_is_integral<_Tp>::value>::type;

constexpr byte  operator| (byte  __lhs, byte __rhs) noexcept
{
    return static_cast<byte>(
      static_cast<unsigned char>(
         static_cast<unsigned int>(__lhs) | static_cast<unsigned int>(__rhs)
    ));
}

constexpr byte& operator|=(byte& __lhs, byte __rhs) noexcept
{ return __lhs = __lhs | __rhs; }

constexpr byte  operator& (byte  __lhs, byte __rhs) noexcept
{
    return static_cast<byte>(
      static_cast<unsigned char>(
         static_cast<unsigned int>(__lhs) & static_cast<unsigned int>(__rhs)
    ));
}

constexpr byte& operator&=(byte& __lhs, byte __rhs) noexcept
{ return __lhs = __lhs & __rhs; }

constexpr byte  operator^ (byte  __lhs, byte __rhs) noexcept
{
    return static_cast<byte>(
      static_cast<unsigned char>(
         static_cast<unsigned int>(__lhs) ^ static_cast<unsigned int>(__rhs)
    ));
}

constexpr byte& operator^=(byte& __lhs, byte __rhs) noexcept
{ return __lhs = __lhs ^ __rhs; }

constexpr byte  operator~ (byte __b) noexcept
{
    return static_cast<byte>(
      static_cast<unsigned char>(
        ~static_cast<unsigned int>(__b)
    ));
}
template <class _Integer>
  constexpr _EnableByteOverload<_Integer> &
  operator<<=(byte& __lhs, _Integer __shift) noexcept
  { return __lhs = __lhs << __shift; }

template <class _Integer>
  constexpr _EnableByteOverload<_Integer>
  operator<< (byte  __lhs, _Integer __shift) noexcept
  { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) << __shift)); }

template <class _Integer>
  constexpr _EnableByteOverload<_Integer> &
  operator>>=(byte& __lhs, _Integer __shift) noexcept
  { return __lhs = __lhs >> __shift; }

template <class _Integer>
  constexpr _EnableByteOverload<_Integer>
  operator>> (byte  __lhs, _Integer __shift) noexcept
  { return static_cast<byte>(static_cast<unsigned char>(static_cast<unsigned int>(__lhs) >> __shift)); }

template <class _Integer, class = _EnableByteOverload<_Integer> >
  _LIBCPP_NODISCARD_EXT constexpr _Integer
  to_integer(byte __b) noexcept { return static_cast<_Integer>(__b); }
}

#endif

#endif // _LIBCPP_CSTDDEF