1 files changed, 90 insertions, 0 deletions
diff --git a/contrib/llvm-project/libcxx/include/__algorithm/partition.h b/contrib/llvm-project/libcxx/include/__algorithm/partition.h
new file mode 100644
index 000000000000..824e49b9ec21
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+++ b/contrib/llvm-project/libcxx/include/__algorithm/partition.h
@@ -0,0 +1,90 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_PARTITION_H
+#define _LIBCPP___ALGORITHM_PARTITION_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_PUSH_MACROS
+#include <__undef_macros>
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+template <class _Predicate, class _AlgPolicy, class _ForwardIterator, class _Sentinel>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_ForwardIterator, _ForwardIterator>
+__partition_impl(_ForwardIterator __first, _Sentinel __last, _Predicate __pred, forward_iterator_tag) {
+  while (true) {
+    if (__first == __last)
+      return std::make_pair(std::move(__first), std::move(__first));
+    if (!__pred(*__first))
+      break;
+    ++__first;
+  }
+
+  _ForwardIterator __p = __first;
+  while (++__p != __last) {
+    if (__pred(*__p)) {
+      _IterOps<_AlgPolicy>::iter_swap(__first, __p);
+      ++__first;
+    }
+  }
+  return std::make_pair(std::move(__first), std::move(__p));
+}
+
+template <class _Predicate, class _AlgPolicy, class _BidirectionalIterator, class _Sentinel>
+_LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_BidirectionalIterator, _BidirectionalIterator>
+__partition_impl(_BidirectionalIterator __first, _Sentinel __sentinel, _Predicate __pred, bidirectional_iterator_tag) {
+  _BidirectionalIterator __original_last = _IterOps<_AlgPolicy>::next(__first, __sentinel);
+  _BidirectionalIterator __last          = __original_last;
+
+  while (true) {
+    while (true) {
+      if (__first == __last)
+        return std::make_pair(std::move(__first), std::move(__original_last));
+      if (!__pred(*__first))
+        break;
+      ++__first;
+    }
+    do {
+      if (__first == --__last)
+        return std::make_pair(std::move(__first), std::move(__original_last));
+    } while (!__pred(*__last));
+    _IterOps<_AlgPolicy>::iter_swap(__first, __last);
+    ++__first;
+  }
+}
+
+template <class _AlgPolicy, class _ForwardIterator, class _Sentinel, class _Predicate, class _IterCategory>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 pair<_ForwardIterator, _ForwardIterator>
+__partition(_ForwardIterator __first, _Sentinel __last, _Predicate&& __pred, _IterCategory __iter_category) {
+  return std::__partition_impl<__remove_cvref_t<_Predicate>&, _AlgPolicy>(
+      std::move(__first), std::move(__last), __pred, __iter_category);
+}
+
+template <class _ForwardIterator, class _Predicate>
+inline _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 _ForwardIterator
+partition(_ForwardIterator __first, _ForwardIterator __last, _Predicate __pred) {
+  using _IterCategory = typename iterator_traits<_ForwardIterator>::iterator_category;
+  auto __result = std::__partition<_ClassicAlgPolicy>(std::move(__first), std::move(__last), __pred, _IterCategory());
+  return __result.first;
+}
+
+_LIBCPP_END_NAMESPACE_STD
+
+_LIBCPP_POP_MACROS
+
+#endif // _LIBCPP___ALGORITHM_PARTITION_H