1 //===----------------------------------------------------------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #ifndef _LIBCPP___BIT_HAS_SINGLE_BIT_H
10 #define _LIBCPP___BIT_HAS_SINGLE_BIT_H
11 
12 #include <__concepts/arithmetic.h>
13 #include <__config>
14 
15 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
16 #  pragma GCC system_header
17 #endif
18 
19 _LIBCPP_PUSH_MACROS
20 #include <__undef_macros>
21 
22 #if _LIBCPP_STD_VER >= 20
23 
24 _LIBCPP_BEGIN_NAMESPACE_STD
25 
26 template <__libcpp_unsigned_integer _Tp>
27 _LIBCPP_NODISCARD_EXT _LIBCPP_HIDE_FROM_ABI constexpr bool has_single_bit(_Tp __t) noexcept {
28   return __t != 0 && (((__t & (__t - 1)) == 0));
29 }
30 
31 _LIBCPP_END_NAMESPACE_STD
32 
33 #endif // _LIBCPP_STD_VER >= 20
34 
35 _LIBCPP_POP_MACROS
36 
37 #endif // _LIBCPP___BIT_HAS_SINGLE_BIT_H
38