void startServer(int port)
{
    Server server(port);
    server.run();
}

void handler(int)
{
    // What to do here to make sure the `Server` object
    // owned by the tread is properly destroyed?
    // Remember: when this code executes, the thread is probably
    // blocked by a call to accept().
}

int main(int argc, char **argv)
{
    signal(SIGINT, handler);
    std::thread serverThread(std::bind(startServer,
                             std::stoi(argv[1])));

    while (true)
    {
        // do work in main thread
    }
}