libcxx/include/__algorithm/set_intersection.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_SET_INTERSECTION_H
  10 #define _LIBCPP___ALGORITHM_SET_INTERSECTION_H
  11
  12 #include <__algorithm/comp.h>
  13 #include <__algorithm/comp_ref_type.h>
  14 #include <__algorithm/iterator_operations.h>
  15 #include <__config>
  16 #include <__iterator/iterator_traits.h>
  17 #include <__iterator/next.h>
  18 #include <__utility/move.h>
  19
  20 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  21 #  pragma GCC system_header
  22 #endif
  23
  24 _LIBCPP_BEGIN_NAMESPACE_STD
  25
  26 template <class _InIter1, class _InIter2, class _OutIter>
  27 struct __set_intersection_result {
  28   _InIter1 __in1_;
  29   _InIter2 __in2_;
  30   _OutIter __out_;
  31
  32   // need a constructor as C++03 aggregate init is hard
  33   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
  34   __set_intersection_result(_InIter1&& __in_iter1, _InIter2&& __in_iter2, _OutIter&& __out_iter)
  35       : __in1_(std::move(__in_iter1)), __in2_(std::move(__in_iter2)), __out_(std::move(__out_iter)) {}
  36 };
  37
  38 template <class _AlgPolicy, class _Compare, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
  39 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __set_intersection_result<_InIter1, _InIter2, _OutIter>
  40 __set_intersection(
  41     _InIter1 __first1, _Sent1 __last1, _InIter2 __first2, _Sent2 __last2, _OutIter __result, _Compare&& __comp) {
  42   while (__first1 != __last1 && __first2 != __last2) {
  43     if (__comp(*__first1, *__first2))
  44       ++__first1;
  45     else {
  46       if (!__comp(*__first2, *__first1)) {
  47         *__result = *__first1;
  48         ++__result;
  49         ++__first1;
  50       }
  51       ++__first2;
  52     }
  53   }
  54
  55   return __set_intersection_result<_InIter1, _InIter2, _OutIter>(
  56       _IterOps<_AlgPolicy>::next(std::move(__first1), std::move(__last1)),
  57       _IterOps<_AlgPolicy>::next(std::move(__first2), std::move(__last2)),
  58       std::move(__result));
  59 }
  60
  61 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
  62 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_intersection(
  63     _InputIterator1 __first1,
  64     _InputIterator1 __last1,
  65     _InputIterator2 __first2,
  66     _InputIterator2 __last2,
  67     _OutputIterator __result,
  68     _Compare __comp) {
  69   return std::__set_intersection<_ClassicAlgPolicy, __comp_ref_type<_Compare> >(
  70              std::move(__first1),
  71              std::move(__last1),
  72              std::move(__first2),
  73              std::move(__last2),
  74              std::move(__result),
  75              __comp)
  76       .__out_;
  77 }
  78
  79 template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
  80 inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_intersection(
  81     _InputIterator1 __first1,
  82     _InputIterator1 __last1,
  83     _InputIterator2 __first2,
  84     _InputIterator2 __last2,
  85     _OutputIterator __result) {
  86   return std::__set_intersection<_ClassicAlgPolicy>(
  87              std::move(__first1),
  88              std::move(__last1),
  89              std::move(__first2),
  90              std::move(__last2),
  91              std::move(__result),
  92              __less<>())
  93       .__out_;
  94 }
  95
  96 _LIBCPP_END_NAMESPACE_STD
  97
  98 #endif // _LIBCPP___ALGORITHM_SET_INTERSECTION_H