inheritance - Make a copy of an unknown concrete type in c++ -

Assume that we have the following category hierarchies:

  class base. .}} Category Derived1: Public Base {...}; Category Derived2: Public Base {...}; Looking at the   
  base *  which can indicate the  Derived1  or  Derived2  object how can I I can do a copy of the real object that this concrete type is unknown. I had thought about defining the copy constructor, but I do not think it is possible without the actual type involved. The only solution is to define a  clone ()  method on each type of hierarchy. Does anyone feel more elegant? 
 

Unfortunately, a virtual clone / duplication pattern is your only real choice

in it There are differences, but essentially they all come down to write down each type of work which can return a new copy.