1 files changed, 45 insertions, 0 deletions
diff --git a/Utilities/std/cm/unordered_set b/Utilities/std/cm/unordered_set
new file mode 100644
index 0000000..9debac4
--- /dev/null
+++ b/Utilities/std/cm/unordered_set
@@ -0,0 +1,45 @@
+// -*-c++-*-
+// vim: set ft=cpp:
+
+/* Distributed under the OSI-approved BSD 3-Clause License.  See accompanying
+   file Copyright.txt or https://cmake.org/licensing for details.  */
+#ifndef cm_unordered_set
+#define cm_unordered_set
+
+#include <unordered_set> // IWYU pragma: export
+
+#include <cm/bits/erase_if.hxx>
+
+namespace cm {
+
+// should be updated when C++20 is finalized
+#if (__cplusplus > 201703L ||                                                 \
+     (defined(_MSVC_LANG) && _MSVC_LANG > 201703)) &&                         \
+  defined(__cpp_lib_erase_if)
+
+using std::erase_if;
+
+#else
+
+template <typename Key, typename Hash, typename KeyEqual, typename Allocator,
+          typename Predicate>
+inline void erase_if(std::unordered_set<Key, Hash, KeyEqual, Allocator>& cont,
+                     Predicate pred)
+{
+  internals::erase_if(cont, pred);
+}
+
+template <typename Key, typename Hash, typename KeyEqual, typename Allocator,
+          typename Predicate>
+inline void erase_if(
+  std::unordered_multiset<Key, Hash, KeyEqual, Allocator>& cont,
+  Predicate pred)
+{
+  internals::erase_if(cont, pred);
+}
+
+#endif
+
+} // namespace cm
+
+#endif