Foundation Classes - NCollection_Shared constructor passes arguments by copy

  Standard_Mutex aMutex;
  Handle(NCollection_Shared<Standard_Mutex::Sentry>) aLock
    = new NCollection_Shared<Standard_Mutex::Sentry> (aMutex);

  struct Dummy1 { Dummy1 (Standard_Mutex& , int ) {} };
  Handle(NCollection_Shared<Dummy1>) aLock1
    = new NCollection_Shared<Dummy1> (aMutex, 2);

  struct Dummy2 { Dummy2 (int , Standard_Mutex& ) {} };
  Handle(NCollection_Shared<Dummy2>) aLock2
    = new NCollection_Shared<Dummy2> (2, aMutex);

  struct Dummy3 { Dummy3 (int , const double& ) {} };
  Handle(NCollection_Shared<Dummy3>) aLock3
    = new NCollection_Shared<Dummy3> (2, 3);

  struct Dummy4 { Dummy4 (Standard_Mutex& , Standard_Mutex& ) {} };
  Handle(NCollection_Shared<Dummy4>) aLock4
    = new NCollection_Shared<Dummy4> (aMutex, aMutex);