message: mempool: apply rule of 5 to epochguard.h, fix compiler warnings
diff: @@ -40,6 +40,9 @@ public:
  Epoch() = default;
  Epoch(const Epoch&) = delete;
  Epoch& operator=(const Epoch&) = delete;
  + Epoch(Epoch&&) = delete;
  + Epoch& operator=(Epoch&&) = delete;
  + ~Epoch() = default;
  bool guarded() const { return m_guarded; }
  @@ -51,6 +54,13 @@ public:
  // only allow modification via Epoch member functions
  friend class Epoch;
  Marker& operator=(const Marker&) = delete;
  +
  + public:
  + Marker() = default;
  + Marker(const Marker&) = default;
  + Marker(Marker&&) = delete;
  + Marker& operator=(Marker&&) = delete;
  + ~Marker() = default;
  };
  class SCOPED_LOCKABLE Guard
  