xref: /llvm-project-15.0.7/libcxx/include/cstddef (revision 7e69bd9b)

// -*- C++ -*-
//===----------------------------------------------------------------------===//
//
// 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 <__assert> // all public C++ headers provide the assertion handler
#include <__config>
#include <__type_traits/enable_if.h>
#include <__type_traits/integral_constant.h>
#include <__type_traits/is_integral.h>
#include <stddef.h>
#include <version>

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

_LIBCPP_BEGIN_NAMESPACE_STD

using ::nullptr_t;
using ::ptrdiff_t _LIBCPP_USING_IF_EXISTS;
using ::size_t _LIBCPP_USING_IF_EXISTS;

#if !defined(_LIBCPP_CXX03_LANG)
using ::max_align_t _LIBCPP_USING_IF_EXISTS;
#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)
    ));
}

template <class _Tp>
using _EnableByteOverload = __enable_if_t<is_integral<_Tp>::value, byte>;

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); }

} // namespace std

#endif

#endif // _LIBCPP_CSTDDEF