xref: /llvm-project-15.0.7/libcxx/include/__algorithm/ranges_binary_search.h (revision 295b951e)

//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#ifndef _LIBCPP___ALGORITHM_RANGES_BINARY_SEARCH_H
#define _LIBCPP___ALGORITHM_RANGES_BINARY_SEARCH_H

#include <__algorithm/iterator_operations.h>
#include <__algorithm/lower_bound.h>
#include <__config>
#include <__functional/identity.h>
#include <__functional/invoke.h>
#include <__functional/ranges_operations.h>
#include <__iterator/concepts.h>
#include <__iterator/projected.h>
#include <__ranges/access.h>
#include <__ranges/concepts.h>

#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
#  pragma GCC system_header
#endif

#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)

_LIBCPP_BEGIN_NAMESPACE_STD

namespace ranges {
namespace __binary_search {
struct __fn {
  template <forward_iterator _Iter, sentinel_for<_Iter> _Sent, class _Type, class _Proj = identity,
            indirect_strict_weak_order<const _Type*, projected<_Iter, _Proj>> _Comp = ranges::less>
  _LIBCPP_HIDE_FROM_ABI constexpr
  bool operator()(_Iter __first, _Sent __last, const _Type& __value, _Comp __comp = {}, _Proj __proj = {}) const {
    auto __ret = std::__lower_bound_impl<_RangeAlgPolicy>(__first, __last, __value, __comp, __proj);
    return __ret != __last && !std::invoke(__comp, __value, std::invoke(__proj, *__first));
  }

  template <forward_range _Range, class _Type, class _Proj = identity,
            indirect_strict_weak_order<const _Type*, projected<iterator_t<_Range>, _Proj>> _Comp = ranges::less>
  _LIBCPP_HIDE_FROM_ABI constexpr
  bool operator()(_Range&& __r, const _Type& __value, _Comp __comp = {}, _Proj __proj = {}) const {
    auto __first = ranges::begin(__r);
    auto __last = ranges::end(__r);
    auto __ret = std::__lower_bound_impl<_RangeAlgPolicy>(__first, __last, __value, __comp, __proj);
    return __ret != __last && !std::invoke(__comp, __value, std::invoke(__proj, *__first));
  }
};
} // namespace __binary_search

inline namespace __cpo {
  inline constexpr auto binary_search = __binary_search::__fn{};
} // namespace __cpo
} // namespace ranges

_LIBCPP_END_NAMESPACE_STD

#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)

#endif // _LIBCPP___ALGORITHM_RANGES_BINARY_SEARCH_H