Hi, > You only declared constructors and destructors for the classes, but did > not define them. You could write A() {}; ~A() {}; instead to define > empty constructor and destructor. Thanks, it's work! > HTH, > Pavel. I placed the wrong example. I used an example for don't send complete code. The real problem is in my small application. Could someone help me? Only executing a simple "make". My application is: http://www.felicio.com.br/mcast.tar.gz It is a simple multimedia server multicast using RTP. Thank you.