binary_search.h 1.6 KB

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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___ALGORITHM_BINARY_SEARCH_H
  9. #define _LIBCPP___ALGORITHM_BINARY_SEARCH_H
  10. #include <__algorithm/comp.h>
  11. #include <__algorithm/comp_ref_type.h>
  12. #include <__algorithm/lower_bound.h>
  13. #include <__config>
  14. #include <__iterator/iterator_traits.h>
  15. #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  16. # pragma GCC system_header
  17. #endif
  18. _LIBCPP_BEGIN_NAMESPACE_STD
  19. template <class _ForwardIterator, class _Tp, class _Compare>
  20. _LIBCPP_NODISCARD_EXT inline
  21. _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
  22. bool
  23. binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value, _Compare __comp)
  24. {
  25. using _Comp_ref = typename __comp_ref_type<_Compare>::type;
  26. __first = std::lower_bound<_ForwardIterator, _Tp, _Comp_ref>(__first, __last, __value, __comp);
  27. return __first != __last && !__comp(__value, *__first);
  28. }
  29. template <class _ForwardIterator, class _Tp>
  30. _LIBCPP_NODISCARD_EXT inline
  31. _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
  32. bool
  33. binary_search(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value)
  34. {
  35. return std::binary_search(__first, __last, __value,
  36. __less<typename iterator_traits<_ForwardIterator>::value_type, _Tp>());
  37. }
  38. _LIBCPP_END_NAMESPACE_STD
  39. #endif // _LIBCPP___ALGORITHM_BINARY_SEARCH_H