How can I get the port number from an RWSocket?

 int main() {        
  RWInetAddr local;        
  cout << 'initial local port #:'  << local.port() << endl;// ** Note 1 **              
  RWSocketListener listen(local);
 









     if( RWInetAddr::is(listen.socket().getsockname()))//**        Note  2 ** 
       {  
          RWInetAddr   check = RWInetAddr::as(listen.socket().getsockname()); // ** Note 3 **          
          cout <<  'RWInetAddr   port # is' << check.port() <<  endl;  // ** Note 4 **
       } 
     else { 
            cout << 'The RWSockAddr was no RWInetAddr!' << endl; 
       }
 
  cout  << 'final local  port #:' << local.port() <<  endl; // ** Note 5 **        
  return 0;      
} 
 

NOTES:

1. Default InetAddr has no port associated with it (yet), so this line will print a zero.
   
2. getsockname returns an RWSockAddr. Using the static method RWInetAddr::is(const RWSockAddr&), we can be sure we have an RWInetAddr. (In real code, this might not be as obvious as it is here!)
   
3. RWInetAddr::as(const RWSockAddr&) returns an RWInetAddr if it can legally do so.
   
4. From an RWInetAddr, we can discover the port number. This one should not be zero.
   
5. Just as a final check, note that the original RWInetAddr was not altered: RWSocketListener makes its own copy.