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 <__config>
15 #include <__iterator/advance.h>
16 #include <__iterator/distance.h>
17 #include <__iterator/iterator_traits.h>
18 
19 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
20 #  pragma GCC system_header
21 #endif
22 
23 _LIBCPP_BEGIN_NAMESPACE_STD
24 
25 template <class _Compare, class _ForwardIterator, class _Tp>
26 _LIBCPP_CONSTEXPR_AFTER_CXX17 _ForwardIterator
27 __upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
28 {
29     typedef typename iterator_traits<_ForwardIterator>::difference_type difference_type;
30     difference_type __len = _VSTD::distance(__first, __last);
31     while (__len != 0)
32     {
33         difference_type __l2 = _VSTD::__half_positive(__len);
34         _ForwardIterator __m = __first;
35         _VSTD::advance(__m, __l2);
36         if (__comp(__value_, *__m))
37             __len = __l2;
38         else
39         {
40             __first = ++__m;
41             __len -= __l2 + 1;
42         }
43     }
44     return __first;
45 }
46 
47 template <class _ForwardIterator, class _Tp, class _Compare>
48 _LIBCPP_NODISCARD_EXT inline
49 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
50 _ForwardIterator
51 upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_, _Compare __comp)
52 {
53     return _VSTD::__upper_bound<_Compare&>(__first, __last, __value_, __comp);
54 }
55 
56 template <class _ForwardIterator, class _Tp>
57 _LIBCPP_NODISCARD_EXT inline
58 _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
59 _ForwardIterator
60 upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value_)
61 {
62     return _VSTD::upper_bound(__first, __last, __value_,
63                              __less<_Tp, typename iterator_traits<_ForwardIterator>::value_type>());
64 }
65 
66 _LIBCPP_END_NAMESPACE_STD
67 
68 #endif // _LIBCPP___ALGORITHM_UPPER_BOUND_H
69