1 files changed, 73 insertions, 0 deletions
diff --git a/libcxx/include/__algorithm/ranges_inplace_merge.h b/libcxx/include/__algorithm/ranges_inplace_merge.h
new file mode 100644
index 000000000000..a0867e486c3a
--- /dev/null
+++ b/libcxx/include/__algorithm/ranges_inplace_merge.h
@@ -0,0 +1,73 @@
+//===----------------------------------------------------------------------===//
+//
+// 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_RANGES_INPLACE_MERGE_H
+#define _LIBCPP___ALGORITHM_RANGES_INPLACE_MERGE_H
+
+#include <__algorithm/inplace_merge.h>
+#include <__algorithm/make_projected.h>
+#include <__config>
+#include <__functional/identity.h>
+#include <__functional/invoke.h>
+#include <__functional/ranges_operations.h>
+#include <__iterator/concepts.h>
+#include <__iterator/iterator_traits.h>
+#include <__iterator/projected.h>
+#include <__iterator/sortable.h>
+#include <__ranges/access.h>
+#include <__ranges/concepts.h>
+#include <__ranges/dangling.h>
+#include <__utility/forward.h>
+#include <__utility/move.h>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#  pragma GCC system_header
+#endif
+
+#if _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+namespace ranges {
+namespace __inplace_merge {
+
+struct __fn {
+
+  template <bidirectional_iterator _Iter, sentinel_for<_Iter> _Sent, class _Comp = ranges::less, class _Proj = identity>
+  requires sortable<_Iter, _Comp, _Proj>
+  _LIBCPP_HIDE_FROM_ABI
+  _Iter operator()(_Iter __first, _Iter __middle, _Sent __last, _Comp __comp = {}, _Proj __proj = {}) const {
+    // TODO: implement
+    (void)__first; (void)__middle; (void)__last; (void)__comp; (void)__proj;
+    return {};
+  }
+
+  template <bidirectional_range _Range, class _Comp = ranges::less, class _Proj = identity>
+  requires sortable<iterator_t<_Range>, _Comp, _Proj>
+  _LIBCPP_HIDE_FROM_ABI
+  borrowed_iterator_t<_Range> operator()(_Range&& __range, iterator_t<_Range> __middle,
+                                            _Comp __comp = {}, _Proj __proj = {}) const {
+    // TODO: implement
+    (void)__range; (void)__middle; (void)__comp; (void)__proj;
+    return {};
+  }
+
+};
+
+} // namespace __inplace_merge
+
+inline namespace __cpo {
+  inline constexpr auto inplace_merge = __inplace_merge::__fn{};
+} // namespace __cpo
+} // namespace ranges
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif // _LIBCPP_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_INCOMPLETE_RANGES)
+
+#endif // _LIBCPP___ALGORITHM_RANGES_INPLACE_MERGE_H