Re: Interface design question

Hello,

       Have a design related question and hope to hear some insights.

       Interfaces using abstract classes impose restriction(s) on it's derived implementations.
         - The most widely used restriction is to IMPLEMENT Function(s)

       Question:
         Is it permissible to have similar kind of restriction for any data members in the interface?
         In a way that if some one wants to implement the interface it also must initialize certain variable.

      Ex:

         Say for a TCP/IP it absolutely necessary to have peer's IP address and Port number.
         So, is wise to impose a restriction to pass above variable to initialize the class.

         class IP4Connection
         {
                public:
                     explicit IP4Connection( string ip, uint port);
                     virtual int send() = 0;
                     virtual int listen() = 0;
                     virtual int reconnect() = 0;
                protected:
                     std::string ip;
                     uint port;
         };

Thanks,
Siva.