xref: /freebsd/contrib/llvm-project/libcxx/include/__algorithm/upper_bound.h (revision a2fda816eb054d5873be223ef2461741dfcc253c)
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_UPPER_BOUND_H
10  #define _LIBCPP___ALGORITHM_UPPER_BOUND_H
11  
12  #include <__algorithm/comp.h>
13  #include <__algorithm/half_positive.h>
14  #include <__algorithm/iterator_operations.h>
15  #include <__config>
16  #include <__functional/identity.h>
17  #include <__functional/invoke.h>
18  #include <__iterator/advance.h>
19  #include <__iterator/distance.h>
20  #include <__iterator/iterator_traits.h>
21  #include <__type_traits/is_copy_constructible.h>
22  #include <__utility/move.h>
23  
24  #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
25  #  pragma GCC system_header
26  #endif
27  
28  _LIBCPP_PUSH_MACROS
29  #include <__undef_macros>
30  
31  _LIBCPP_BEGIN_NAMESPACE_STD
32  
33  template <class _AlgPolicy, class _Compare, class _Iter, class _Sent, class _Tp, class _Proj>
34  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter
35  __upper_bound(_Iter __first, _Sent __last, const _Tp& __value, _Compare&& __comp, _Proj&& __proj) {
36    auto __len = _IterOps<_AlgPolicy>::distance(__first, __last);
37    while (__len != 0) {
38      auto __half_len = std::__half_positive(__len);
39      auto __mid      = _IterOps<_AlgPolicy>::next(__first, __half_len);
40      if (std::__invoke(__comp, __value, std::__invoke(__proj, *__mid)))
41        __len = __half_len;
42      else {
43        __first = ++__mid;
44        __len -= __half_len + 1;
45      }
46    }
47    return __first;
48  }
49  
50  template <class _ForwardIterator, class _Tp, class _Compare>
51  _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator
52  upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value, _Compare __comp) {
53    static_assert(is_copy_constructible<_ForwardIterator>::value, "Iterator has to be copy constructible");
54    return std::__upper_bound<_ClassicAlgPolicy>(
55        std::move(__first), std::move(__last), __value, std::move(__comp), std::__identity());
56  }
57  
58  template <class _ForwardIterator, class _Tp>
59  _LIBCPP_NODISCARD_EXT inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator
60  upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
61    return std::upper_bound(std::move(__first), std::move(__last), __value, __less<>());
62  }
63  
64  _LIBCPP_END_NAMESPACE_STD
65  
66  _LIBCPP_POP_MACROS
67  
68  #endif // _LIBCPP___ALGORITHM_UPPER_BOUND_H
69