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

32 lines
996 B
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_LOG2_H
#define _LIBCPP___BIT_BIT_LOG2_H
#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
template <class _Tp>
_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX14 _Tp __bit_log2(_Tp __t) _NOEXCEPT {
static_assert(__is_unsigned_integer_v<_Tp>, "__bit_log2 requires an unsigned integer type");
return numeric_limits<_Tp>::digits - 1 - std::__countl_zero(__t);
}
_LIBCPP_END_NAMESPACE_STD
#endif // _LIBCPP___BIT_BIT_LOG2_H