   c++ templates
  ciao.I'm still suding the templates but i'm not understand also where is better to use they instead of the common classes.What are the features in that you advice me to use templates?Have you a link or two word for clarify my ideas?thanks.   
  Look at how the standard library uses them.  Templates are good when you need to express a generic idea where a common base class would be to intrusive. Consider the case of std::vector.  How would you implement this with out templates?  You would more or less end up writing an implementation for each type that needed a vector.  You would probably write a bunch of helper functions that worked on void* and sizeof.   