libcxx/include/__algorithm/set_symmetric_difference.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_SYMMETRIC_DIFFERENCE_H
  10 #define _LIBCPP___ALGORITHM_SET_SYMMETRIC_DIFFERENCE_H
  11
  12 #include <__algorithm/comp.h>
  13 #include <__algorithm/comp_ref_type.h>
  14 #include <__algorithm/copy.h>
  15 #include <__algorithm/iterator_operations.h>
  16 #include <__config>
  17 #include <__iterator/iterator_traits.h>
  18 #include <__utility/move.h>
  19 #include <__utility/pair.h>
  20
  21 #if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
  22 #  pragma GCC system_header
  23 #endif
  24
  25 _LIBCPP_BEGIN_NAMESPACE_STD
  26
  27 template <class _InIter1, class _InIter2, class _OutIter>
  28 struct __set_symmetric_difference_result {
  29   _InIter1 __in1_;
  30   _InIter2 __in2_;
  31   _OutIter __out_;
  32
  33   // need a constructor as C++03 aggregate init is hard
  34   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
  35   __set_symmetric_difference_result(_InIter1&& __in_iter1, _InIter2&& __in_iter2, _OutIter&& __out_iter)
  36       : __in1_(std::move(__in_iter1)), __in2_(std::move(__in_iter2)), __out_(std::move(__out_iter)) {}
  37 };
  38
  39 template <class _AlgPolicy, class _Compare, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
  40 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __set_symmetric_difference_result<_InIter1, _InIter2, _OutIter>
  41 __set_symmetric_difference(
  42     _InIter1 __first1, _Sent1 __last1, _InIter2 __first2, _Sent2 __last2, _OutIter __result, _Compare&& __comp) {
  43   while (__first1 != __last1) {
  44     if (__first2 == __last2) {
  45       auto __ret1 = std::__copy<_AlgPolicy>(std::move(__first1), std::move(__last1), std::move(__result));
  46       return __set_symmetric_difference_result<_InIter1, _InIter2, _OutIter>(
  47           std::move(__ret1.first), std::move(__first2), std::move((__ret1.second)));
  48     }
  49     if (__comp(*__first1, *__first2)) {
  50       *__result = *__first1;
  51       ++__result;
  52       ++__first1;
  53     } else {
  54       if (__comp(*__first2, *__first1)) {
  55         *__result = *__first2;
  56         ++__result;
  57       } else {
  58         ++__first1;
  59       }
  60       ++__first2;
  61     }
  62   }
  63   auto __ret2 = std::__copy<_AlgPolicy>(std::move(__first2), std::move(__last2), std::move(__result));
  64   return __set_symmetric_difference_result<_InIter1, _InIter2, _OutIter>(
  65       std::move(__first1), std::move(__ret2.first), std::move((__ret2.second)));
  66 }
  67
  68 template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
  69 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_symmetric_difference(
  70     _InputIterator1 __first1,
  71     _InputIterator1 __last1,
  72     _InputIterator2 __first2,
  73     _InputIterator2 __last2,
  74     _OutputIterator __result,
  75     _Compare __comp) {
  76   return std::__set_symmetric_difference<_ClassicAlgPolicy, __comp_ref_type<_Compare> >(
  77              std::move(__first1),
  78              std::move(__last1),
  79              std::move(__first2),
  80              std::move(__last2),
  81              std::move(__result),
  82              __comp)
  83       .__out_;
  84 }
  85
  86 template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
  87 _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_symmetric_difference(
  88     _InputIterator1 __first1,
  89     _InputIterator1 __last1,
  90     _InputIterator2 __first2,
  91     _InputIterator2 __last2,
  92     _OutputIterator __result) {
  93   return std::set_symmetric_difference(
  94       std::move(__first1),
  95       std::move(__last1),
  96       std::move(__first2),
  97       std::move(__last2),
  98       std::move(__result),
  99       __less<>());
 100 }
 101
 102 _LIBCPP_END_NAMESPACE_STD
 103
 104 #endif // _LIBCPP___ALGORITHM_SET_SYMMETRIC_DIFFERENCE_H