If having a c++ class with a pimpl using std::unique_ptr and solving the fact that the pimpl class is incomplete in the header by declaring my own destructor (I know i could also provide a custom deleter, but lets go with the dtor for this one). If following the rule of five, I guess I should then also go ahead and declare copy/move constructors/assignment operators. However, the reason usually (always?) given for rule of five is that declaring one of the special members might indicate that the class has some resource needing special attention, and that is not the case here.
Is it reasonable to make a departure from the rule of five in this scenario if I don't need the class to be copyable for instance?