xref: /llvm-project/libcxx/include/__algorithm/ranges_binary_search.h (revision d10dc5a06fac4dcabf2264c64c8672c6f6ae36fb)
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___ALGORITHM_RANGES_BINARY_SEARCH_H
10 #define _LIBCPP___ALGORITHM_RANGES_BINARY_SEARCH_H
11 
12 #include <__algorithm/iterator_operations.h>
13 #include <__algorithm/lower_bound.h>
14 #include <__config>
15 #include <__functional/identity.h>
16 #include <__functional/invoke.h>
17 #include <__functional/ranges_operations.h>
18 #include <__iterator/concepts.h>
19 #include <__iterator/projected.h>
20 #include <__ranges/access.h>
21 #include <__ranges/concepts.h>
22 
23 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
24 #  pragma GCC system_header
25 #endif
26 
27 _LIBCPP_PUSH_MACROS
28 #include <__undef_macros>
29 
30 #if _LIBCPP_STD_VER >= 20
31 
32 _LIBCPP_BEGIN_NAMESPACE_STD
33 
34 namespace ranges {
35 struct __binary_search {
36   template <forward_iterator _Iter,
37             sentinel_for<_Iter> _Sent,
38             class _Type,
39             class _Proj                                                             = identity,
40             indirect_strict_weak_order<const _Type*, projected<_Iter, _Proj>> _Comp = ranges::less>
41   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool
42   operator()(_Iter __first, _Sent __last, const _Type& __value, _Comp __comp = {}, _Proj __proj = {}) const {
43     auto __ret = std::__lower_bound<_RangeAlgPolicy>(__first, __last, __value, __comp, __proj);
44     return __ret != __last && !std::invoke(__comp, __value, std::invoke(__proj, *__ret));
45   }
46 
47   template <forward_range _Range,
48             class _Type,
49             class _Proj                                                                          = identity,
50             indirect_strict_weak_order<const _Type*, projected<iterator_t<_Range>, _Proj>> _Comp = ranges::less>
51   [[nodiscard]] _LIBCPP_HIDE_FROM_ABI constexpr bool
52   operator()(_Range&& __r, const _Type& __value, _Comp __comp = {}, _Proj __proj = {}) const {
53     auto __first = ranges::begin(__r);
54     auto __last  = ranges::end(__r);
55     auto __ret   = std::__lower_bound<_RangeAlgPolicy>(__first, __last, __value, __comp, __proj);
56     return __ret != __last && !std::invoke(__comp, __value, std::invoke(__proj, *__ret));
57   }
58 };
59 
60 inline namespace __cpo {
61 inline constexpr auto binary_search = __binary_search{};
62 } // namespace __cpo
63 } // namespace ranges
64 
65 _LIBCPP_END_NAMESPACE_STD
66 
67 #endif // _LIBCPP_STD_VER >= 20
68 
69 _LIBCPP_POP_MACROS
70 
71 #endif // _LIBCPP___ALGORITHM_RANGES_BINARY_SEARCH_H
72