Re: [boost] Re: Re: [multi_index] announce: serialization support

From: JOAQUIN LOPEZ MU?Z (joaquin_at_[hidden])
Date: 2004-12-01 16:54:17

----- Mensaje original -----
De: Robert Ramey <ramey_at_[hidden]>
Fecha: Miércoles, Diciembre 1, 2004 10:15 pm
Asunto: [boost] Re: Re: [multi_index] announce: serialization support

[snip]
 
> If you guarentee that the container itself is always serialized 
> before your
> indices, then de-serialization of the indices would automatically 
> be reduced
> to providing the original (tracked) pointer.  In such a case, I 
> would think
> the whole isse would never appear and that the implementation 
> would be very
> straight forward.
> 

I think this is not correct (but I'd like to be
proven wrong, that'd mean I could simplify my code.)
Consider this:

struct foo
{
  std::list<std::string> cont;
  std::string*           pos; // pos points to an element of cont

private:
  friend class boost::serialization::access;

  template<class Archive>
  void serialize(Archive & ar, const unsigned int)
  {
    ar&cont; // before pos, as you suggest
    ar&pos;
  }
};

My thesis is that loading a foo will get it
wrong --pos won't be pointing to an element of cont,
but rather to some random address in stack memory.
I'll check it out on my compiler tomorrow, but I was
already through this when designing multi_index
serialization. See my point now? Am I missing something?

Joaquín M López Muñoz
Telefónica, Investigación y Desarrollo