libcxx/include/__algorithm/upper_bound.h

   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/invoke.h>
  22 #include <__type_traits/is_callable.h>
  23 #include <__type_traits/is_constructible.h>
  24 #include <__utility/move.h>
  25
  26 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  27 #  pragma GCC system_header
  28 #endif
  29
  30 _LIBCPP_PUSH_MACROS
  31 #include <__undef_macros>
  32
  33 _LIBCPP_BEGIN_NAMESPACE_STD
  34
  35 template <class _AlgPolicy, class _Compare, class _Iter, class _Sent, class _Tp, class _Proj>
  36 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _Iter
  37 __upper_bound(_Iter __first, _Sent __last, const _Tp& __value, _Compare&& __comp, _Proj&& __proj) {
  38   auto __len = _IterOps<_AlgPolicy>::distance(__first, __last);
  39   while (__len != 0) {
  40     auto __half_len = std::__half_positive(__len);
  41     auto __mid      = _IterOps<_AlgPolicy>::next(__first, __half_len);
  42     if (std::__invoke(__comp, __value, std::__invoke(__proj, *__mid)))
  43       __len = __half_len;
  44     else {
  45       __first = ++__mid;
  46       __len -= __half_len + 1;
  47     }
  48   }
  49   return __first;
  50 }
  51
  52 template <class _ForwardIterator, class _Tp, class _Compare>
  53 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator
  54 upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value, _Compare __comp) {
  55   static_assert(__is_callable<_Compare&, const _Tp&, decltype(*__first)>::value, "The comparator has to be callable");
  56   static_assert(is_copy_constructible<_ForwardIterator>::value, "Iterator has to be copy constructible");
  57   return std::__upper_bound<_ClassicAlgPolicy>(
  58       std::move(__first), std::move(__last), __value, std::move(__comp), std::__identity());
  59 }
  60
  61 template <class _ForwardIterator, class _Tp>
  62 [[__nodiscard__]] inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator
  63 upper_bound(_ForwardIterator __first, _ForwardIterator __last, const _Tp& __value) {
  64   return std::upper_bound(std::move(__first), std::move(__last), __value, __less<>());
  65 }
  66
  67 _LIBCPP_END_NAMESPACE_STD
  68
  69 _LIBCPP_POP_MACROS
  70
  71 #endif // _LIBCPP___ALGORITHM_UPPER_BOUND_H