Add experimental container alias templates for PMRs

llvm-svn: 268841
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 522a7f953522bf8c133bc51b305f52c29c5d6595
diff --git a/include/experimental/set b/include/experimental/set
new file mode 100644
index 0000000..20cf6d4
--- /dev/null
+++ b/include/experimental/set
@@ -0,0 +1,57 @@
+// -*- C++ -*-
+//===--------------------------- list ------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_EXPERIMENTAL_SET
+#define _LIBCPP_EXPERIMENTAL_SET
+/*
+    experimental/set synopsis
+
+// C++1z
+namespace std {
+namespace experimental {
+inline namespace fundamentals_v1 {
+namespace pmr {
+
+  template <class Key, class T, class Compare = less<Key>>
+  using set = std::set<Key, T, Compare,
+                       polymorphic_allocator<pair<const Key,T>>>;
+
+  template <class Key, class T, class Compare = less<Key>>
+  using multiset = std::multiset<Key, T, Compare,
+                                 polymorphic_allocator<pair<const Key,T>>>;
+
+} // namespace pmr
+} // namespace fundamentals_v1
+} // namespace experimental
+} // namespace std
+
+ */
+
+#include <experimental/__config>
+#include <set>
+#include <experimental/memory_resource>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_LFTS_PMR
+
+template <class _Value, class  _Compare = less<_Value>>
+using set = _VSTD::set<_Value, _Compare,
+                        polymorphic_allocator<_Value>>;
+
+template <class _Value, class  _Compare = less<_Value>>
+using multiset = _VSTD::multiset<_Value, _Compare,
+                        polymorphic_allocator<_Value>>;
+
+_LIBCPP_END_NAMESPACE_LFTS_PMR
+
+#endif /* _LIBCPP_EXPERIMENTAL_SET */