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diff --git a/src/rocksdb/util/cast_util.h b/src/rocksdb/util/cast_util.h
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+++ b/src/rocksdb/util/cast_util.h
@@ -0,0 +1,42 @@
+//  Copyright (c) 2011-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under both the GPLv2 (found in the
+//  COPYING file in the root directory) and Apache 2.0 License
+//  (found in the LICENSE.Apache file in the root directory).
+
+#pragma once
+
+#include <type_traits>
+
+#include "rocksdb/rocksdb_namespace.h"
+
+namespace ROCKSDB_NAMESPACE {
+// The helper function to assert the move from dynamic_cast<> to
+// static_cast<> is correct. This function is to deal with legacy code.
+// It is not recommended to add new code to issue class casting. The preferred
+// solution is to implement the functionality without a need of casting.
+template <class DestClass, class SrcClass>
+inline DestClass* static_cast_with_check(SrcClass* x) {
+  DestClass* ret = static_cast<DestClass*>(x);
+#ifdef ROCKSDB_USE_RTTI
+  assert(ret == dynamic_cast<DestClass*>(x));
+#endif
+  return ret;
+}
+
+// A wrapper around static_cast for lossless conversion between integral
+// types, including enum types. For example, this can be used for converting
+// between signed/unsigned or enum type and underlying type without fear of
+// stripping away data, now or in the future.
+template <typename To, typename From>
+inline To lossless_cast(From x) {
+  using FromValue = typename std::remove_reference<From>::type;
+  static_assert(
+      std::is_integral<FromValue>::value || std::is_enum<FromValue>::value,
+      "Only works on integral types");
+  static_assert(std::is_integral<To>::value || std::is_enum<To>::value,
+                "Only works on integral types");
+  static_assert(sizeof(To) >= sizeof(FromValue), "Must be lossless");
+  return static_cast<To>(x);
+}
+
+}  // namespace ROCKSDB_NAMESPACE