-std::map<uint32_t, USER>::iterator userIt(users.begin());
-for (it = pollFds.begin(); it != pollFds.end(); ++it)
+std::vector<std::pair<uint32_t, USER> >::iterator userIt;
+for (it = pollFds.begin(), userIt = users.begin(); it != pollFds.end() && userIt != users.end(); ++it, ++userIt)