Upgrade to 2022-era LLVM LIBCXX

third_party/libcxx/__algorithm/set_union.h

@@ -0,0 +1,101 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP___ALGORITHM_SET_UNION_H
+#define _LIBCPP___ALGORITHM_SET_UNION_H
+
+#include <__algorithm/comp.h>
+#include <__algorithm/comp_ref_type.h>
+#include <__algorithm/copy.h>
+#include <__algorithm/iterator_operations.h>
+#include <__config>
+#include <__iterator/iterator_traits.h>
+#include <__utility/move.h>
+#include <__utility/pair.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _InIter1, class _InIter2, class _OutIter>
+struct __set_union_result {
+  _InIter1 __in1_;
+  _InIter2 __in2_;
+  _OutIter __out_;
+
+  // need a constructor as C++03 aggregate init is hard
+  _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
+  __set_union_result(_InIter1&& __in_iter1, _InIter2&& __in_iter2, _OutIter&& __out_iter)
+      : __in1_(std::move(__in_iter1)), __in2_(std::move(__in_iter2)), __out_(std::move(__out_iter)) {}
+};
+
+template <class _AlgPolicy, class _Compare, class _InIter1, class _Sent1, class _InIter2, class _Sent2, class _OutIter>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 __set_union_result<_InIter1, _InIter2, _OutIter> __set_union(
+    _InIter1 __first1, _Sent1 __last1, _InIter2 __first2, _Sent2 __last2, _OutIter __result, _Compare&& __comp) {
+  for (; __first1 != __last1; ++__result) {
+    if (__first2 == __last2) {
+      auto __ret1 = std::__copy<_AlgPolicy>(std::move(__first1), std::move(__last1), std::move(__result));
+      return __set_union_result<_InIter1, _InIter2, _OutIter>(
+          std::move(__ret1.first), std::move(__first2), std::move((__ret1.second)));
+    }
+    if (__comp(*__first2, *__first1)) {
+      *__result = *__first2;
+      ++__first2;
+    } else {
+      if (!__comp(*__first1, *__first2)) {
+        ++__first2;
+      }
+      *__result = *__first1;
+      ++__first1;
+    }
+  }
+  auto __ret2 = std::__copy<_AlgPolicy>(std::move(__first2), std::move(__last2), std::move(__result));
+  return __set_union_result<_InIter1, _InIter2, _OutIter>(
+      std::move(__first1), std::move(__ret2.first), std::move((__ret2.second)));
+}
+
+template <class _InputIterator1, class _InputIterator2, class _OutputIterator, class _Compare>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_union(
+    _InputIterator1 __first1,
+    _InputIterator1 __last1,
+    _InputIterator2 __first2,
+    _InputIterator2 __last2,
+    _OutputIterator __result,
+    _Compare __comp) {
+  return std::__set_union<_ClassicAlgPolicy, __comp_ref_type<_Compare> >(
+             std::move(__first1),
+             std::move(__last1),
+             std::move(__first2),
+             std::move(__last2),
+             std::move(__result),
+             __comp)
+      .__out_;
+}
+
+template <class _InputIterator1, class _InputIterator2, class _OutputIterator>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _OutputIterator set_union(
+    _InputIterator1 __first1,
+    _InputIterator1 __last1,
+    _InputIterator2 __first2,
+    _InputIterator2 __last2,
+    _OutputIterator __result) {
+  return std::set_union(
+      std::move(__first1),
+      std::move(__last1),
+      std::move(__first2),
+      std::move(__last2),
+      std::move(__result),
+      __less<typename iterator_traits<_InputIterator1>::value_type,
+             typename iterator_traits<_InputIterator2>::value_type>());
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP___ALGORITHM_SET_UNION_H