Nikolas Klauser 3c56437eaf
[libc++] Refactor signed/unsigned integer traits (#142750)
This patch does a few things:
- `__libcpp_is_signed_integer` and `__libcpp_is_unsigned_integer` are
refactored to be variable templates instead of class templates.
- the two traits are merged into a single header
`<__type_traits/integer_traits.h>`.
- `__libcpp_signed_integer`, `__libcpp_unsigned_integer` and
`__libcpp_integer` are moved into the same header.
- The above mentioned concepts are renamed to `__signed_integer`,
`__unsigned_integer` and `__signed_or_unsigned_integer` respectively.
2025-06-11 14:31:13 +02:00

55 lines
1.6 KiB
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___BIT_BIT_CEIL_H
#define _LIBCPP___BIT_BIT_CEIL_H
#include <__assert>
#include <__bit/countl.h>
#include <__config>
#include <__type_traits/integer_traits.h>
#include <limits>
#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
# pragma GCC system_header
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if _LIBCPP_STD_VER >= 17
template <class _Tp>
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp __bit_ceil(_Tp __t) noexcept {
if (__t < 2)
return 1;
const unsigned __n = numeric_limits<_Tp>::digits - std::__countl_zero((_Tp)(__t - 1u));
_LIBCPP_ASSERT_ARGUMENT_WITHIN_DOMAIN(__n != numeric_limits<_Tp>::digits, "Bad input to bit_ceil");
if constexpr (sizeof(_Tp) >= sizeof(unsigned))
return _Tp{1} << __n;
else {
const unsigned __extra = numeric_limits<unsigned>::digits - numeric_limits<_Tp>::digits;
const unsigned __ret_val = 1u << (__n + __extra);
return (_Tp)(__ret_val >> __extra);
}
}
# if _LIBCPP_STD_VER >= 20
template <__unsigned_integer _Tp>
[[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr _Tp bit_ceil(_Tp __t) noexcept {
return std::__bit_ceil(__t);
}
# endif // _LIBCPP_STD_VER >= 20
#endif // _LIBCPP_STD_VER >= 17
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___BIT_BIT_CEIL_H