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diff --git a/src/rocksdb/third-party/folly/folly/Indestructible.h b/src/rocksdb/third-party/folly/folly/Indestructible.h
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+++ b/src/rocksdb/third-party/folly/folly/Indestructible.h
@@ -0,0 +1,166 @@
+//  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 <cassert>
+#include <type_traits>
+#include <utility>
+
+#include <folly/Traits.h>
+
+namespace folly {
+
+/***
+ *  Indestructible
+ *
+ *  When you need a Meyers singleton that will not get destructed, even at
+ *  shutdown, and you also want the object stored inline.
+ *
+ *  Use like:
+ *
+ *      void doSomethingWithExpensiveData();
+ *
+ *      void doSomethingWithExpensiveData() {
+ *        static const Indestructible<map<string, int>> data{
+ *          map<string, int>{{"key1", 17}, {"key2", 19}, {"key3", 23}},
+ *        };
+ *        callSomethingTakingAMapByRef(*data);
+ *      }
+ *
+ *  This should be used only for Meyers singletons, and, even then, only when
+ *  the instance does not need to be destructed ever.
+ *
+ *  This should not be used more generally, e.g., as member fields, etc.
+ *
+ *  This is designed as an alternative, but with one fewer allocation at
+ *  construction time and one fewer pointer dereference at access time, to the
+ *  Meyers singleton pattern of:
+ *
+ *    void doSomethingWithExpensiveData() {
+ *      static const auto data =  // never `delete`d
+ *          new map<string, int>{{"key1", 17}, {"key2", 19}, {"key3", 23}};
+ *      callSomethingTakingAMapByRef(*data);
+ *    }
+ */
+
+template <typename T>
+class Indestructible final {
+ public:
+  template <typename S = T, typename = decltype(S())>
+  constexpr Indestructible() noexcept(noexcept(T())) {}
+
+  /**
+   * Constructor accepting a single argument by forwarding reference, this
+   * allows using list initialzation without the overhead of things like
+   * in_place, etc and also works with std::initializer_list constructors
+   * which can't be deduced, the default parameter helps there.
+   *
+   *    auto i = folly::Indestructible<std::map<int, int>>{{{1, 2}}};
+   *
+   * This provides convenience
+   *
+   * There are two versions of this constructor - one for when the element is
+   * implicitly constructible from the given argument and one for when the
+   * type is explicitly but not implicitly constructible from the given
+   * argument.
+   */
+  template <
+      typename U = T,
+      _t<std::enable_if<std::is_constructible<T, U&&>::value>>* = nullptr,
+      _t<std::enable_if<
+          !std::is_same<Indestructible<T>, remove_cvref_t<U>>::value>>* =
+          nullptr,
+      _t<std::enable_if<!std::is_convertible<U&&, T>::value>>* = nullptr>
+  explicit constexpr Indestructible(U&& u) noexcept(
+      noexcept(T(std::declval<U>())))
+      : storage_(std::forward<U>(u)) {}
+  template <
+      typename U = T,
+      _t<std::enable_if<std::is_constructible<T, U&&>::value>>* = nullptr,
+      _t<std::enable_if<
+          !std::is_same<Indestructible<T>, remove_cvref_t<U>>::value>>* =
+          nullptr,
+      _t<std::enable_if<std::is_convertible<U&&, T>::value>>* = nullptr>
+  /* implicit */ constexpr Indestructible(U&& u) noexcept(
+      noexcept(T(std::declval<U>())))
+      : storage_(std::forward<U>(u)) {}
+
+  template <typename... Args, typename = decltype(T(std::declval<Args>()...))>
+  explicit constexpr Indestructible(Args&&... args) noexcept(
+      noexcept(T(std::declval<Args>()...)))
+      : storage_(std::forward<Args>(args)...) {}
+  template <
+      typename U,
+      typename... Args,
+      typename = decltype(
+          T(std::declval<std::initializer_list<U>&>(),
+            std::declval<Args>()...))>
+  explicit constexpr Indestructible(std::initializer_list<U> il, Args... args) noexcept(
+      noexcept(
+          T(std::declval<std::initializer_list<U>&>(),
+            std::declval<Args>()...)))
+      : storage_(il, std::forward<Args>(args)...) {}
+
+  ~Indestructible() = default;
+
+  Indestructible(Indestructible const&) = delete;
+  Indestructible& operator=(Indestructible const&) = delete;
+
+  Indestructible(Indestructible&& other) noexcept(
+      noexcept(T(std::declval<T>())))
+      : storage_(std::move(other.storage_.value)) {
+    other.erased_ = true;
+  }
+  Indestructible& operator=(Indestructible&& other) noexcept(
+      noexcept(T(std::declval<T>()))) {
+    storage_.value = std::move(other.storage_.value);
+    other.erased_ = true;
+  }
+
+  T* get() noexcept {
+    check();
+    return &storage_.value;
+  }
+  T const* get() const noexcept {
+    check();
+    return &storage_.value;
+  }
+  T& operator*() noexcept {
+    return *get();
+  }
+  T const& operator*() const noexcept {
+    return *get();
+  }
+  T* operator->() noexcept {
+    return get();
+  }
+  T const* operator->() const noexcept {
+    return get();
+  }
+
+ private:
+  void check() const noexcept {
+    assert(!erased_);
+  }
+
+  union Storage {
+    T value;
+
+    template <typename S = T, typename = decltype(S())>
+    constexpr Storage() noexcept(noexcept(T())) : value() {}
+
+    template <typename... Args, typename = decltype(T(std::declval<Args>()...))>
+    explicit constexpr Storage(Args&&... args) noexcept(
+        noexcept(T(std::declval<Args>()...)))
+        : value(std::forward<Args>(args)...) {}
+
+    ~Storage() {}
+  };
+
+  Storage storage_{};
+  bool erased_{false};
+};
+} // namespace folly