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