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> has_single_bit(_Tp __t)27[[nodiscard]] _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