has_single_bit.h 980 B

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  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. #ifndef _LIBCPP___BIT_HAS_SINGLE_BIT_H
  9. #define _LIBCPP___BIT_HAS_SINGLE_BIT_H
  10. #include <__concepts/arithmetic.h>
  11. #include <__config>
  12. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  13. # pragma GCC system_header
  14. #endif
  15. _LIBCPP_PUSH_MACROS
  16. #include <__undef_macros>
  17. #if _LIBCPP_STD_VER >= 20
  18. _LIBCPP_BEGIN_NAMESPACE_STD
  19. template <__libcpp_unsigned_integer _Tp>
  20. _LIBCPP_HIDE_FROM_ABI constexpr bool has_single_bit(_Tp __t) noexcept {
  21. return __t != 0 && (((__t & (__t - 1)) == 0));
  22. }
  23. _LIBCPP_END_NAMESPACE_STD
  24. #endif // _LIBCPP_STD_VER >= 20
  25. _LIBCPP_POP_MACROS
  26. #endif // _LIBCPP___BIT_HAS_SINGLE_BIT_H