1*4bdff4beSrobert //===----------------------------------------------------------------------===//
2*4bdff4beSrobert //
3*4bdff4beSrobert // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4*4bdff4beSrobert // See https://llvm.org/LICENSE.txt for license information.
5*4bdff4beSrobert // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6*4bdff4beSrobert //
7*4bdff4beSrobert //===----------------------------------------------------------------------===//
8*4bdff4beSrobert 
9*4bdff4beSrobert #ifndef _LIBCPP___BIT_BIT_WIDTH_H
10*4bdff4beSrobert #define _LIBCPP___BIT_BIT_WIDTH_H
11*4bdff4beSrobert 
12*4bdff4beSrobert #include <__bit/bit_log2.h>
13*4bdff4beSrobert #include <__concepts/arithmetic.h>
14*4bdff4beSrobert #include <__config>
15*4bdff4beSrobert 
16*4bdff4beSrobert #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
17*4bdff4beSrobert #  pragma GCC system_header
18*4bdff4beSrobert #endif
19*4bdff4beSrobert 
20*4bdff4beSrobert #if _LIBCPP_STD_VER >= 20
21*4bdff4beSrobert 
22*4bdff4beSrobert _LIBCPP_BEGIN_NAMESPACE_STD
23*4bdff4beSrobert 
24*4bdff4beSrobert template <__libcpp_unsigned_integer _Tp>
bit_width(_Tp __t)25*4bdff4beSrobert _LIBCPP_HIDE_FROM_ABI constexpr int bit_width(_Tp __t) noexcept {
26*4bdff4beSrobert   return __t == 0 ? 0 : std::__bit_log2(__t) + 1;
27*4bdff4beSrobert }
28*4bdff4beSrobert 
29*4bdff4beSrobert _LIBCPP_END_NAMESPACE_STD
30*4bdff4beSrobert 
31*4bdff4beSrobert #endif // _LIBCPP_STD_VER >= 20
32*4bdff4beSrobert 
33*4bdff4beSrobert #endif // _LIBCPP___BIT_BIT_WIDTH_H
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