xref: /aosp_15_r20/external/libcxx/include/cstddef (revision 58b9f456b02922dfdb1fad8a988d5fd8765ecb80)

// -*- C++ -*-
//===--------------------------- cstddef ----------------------------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP_CSTDDEF
#define _LIBCPP_CSTDDEF

/*
    cstddef synopsis

Macros:

    offsetof(type,member-designator)
    NULL

namespace std
{

Types:

    ptrdiff_t
    size_t
    max_align_t
    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(__CLANG_MAX_ALIGN_T_DEFINED) || defined(_GCC_MAX_ALIGN_T) || \
    defined(__DEFINED_max_align_t) || defined(__NetBSD__)
// Re-use the compiler's <stddef.h> max_align_t where possible.
using ::max_align_t;
#else
typedef long double max_align_t;
#endif

_LIBCPP_END_NAMESPACE_STD

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

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)
    ));
}

}

#include <type_traits>  // rest of byte
#endif

#endif  // _LIBCPP_CSTDDEF