[Boost-users] class initialization problem

Subject: [Boost-users] class initialization problem
From: Christopher Pisz (cpisz_at_[hidden])
Date: 2011-09-30 19:07:23

I have a Server class inherited from a Listener class, with the latter being 
bases on the boost::asio example code.

My problem is that the Listener class requires am boost::asio::io_service & in 
order to initialize its member variables.

I wanted the Server class to be responsible for starting a thread, owning the 
io_service, and running it.

It seems I cannot do that!

class Server : public Listener
{
public:
   Server()
      :
      Listener(ioService_)
   {
   }
   
   // Snip

protected:

   boost::asio::io_service ioService_;
};

class Listener
{
public:

   Listener(boost::asio::io_service & ioService)
      :
      socket_(ioService)
   {
   }

   // Snip

protected:
   boot::asio::ip::tcp::socket socket_;
};

The above throws an unhandled exception in the initialization of the derived 
class.

I suppose this is because ioService_ is not constructed yet? Since the C++ 
rules, if I remember correctly, say the base class gets constructed before the 
members of the derived?

So, I tried:

Server()
      :
      ioService_(),
      Listener(ioService_)
   {
   }

to try and force it, but it still throws an exception.

The only way to get it to not throw an exception is to create the instance to 
io-service in main() and then pass it as a reference into the class 
constructor. If I do that, then there is no way for any class in my 
inheritance hierarchy to own the io_service. As such, I cannot start and stop 
it either.

Is there any way to get ownership of the io_service in my class hierarchy?