Re: [boost] [serialization] Enhancing Archives with Archve Adaptors

From: David Abrahams (dave_at_[hidden])
Date: 2005-12-08 16:52:19

Matthias Troyer <troyer_at_[hidden]> writes:

> I see two ways how this can be implemented and wanted to discuss what  
> option is best in your opinion:
>
> i) the load function for std::vector could dispatch to either version  
> A or B depending on the type traits has_trivial_constructor<T>

  ia) define the has_default_constructor<T> trait, which by default 
      is derived from has_trivial_constructor<T> on implementations
      without magic compiler support.

> ii) one could leave std::vector serialization untouched, meaning  
> always use version A, and use the optimized version B only in the  
> archive wrapper for archives implementing fast array serialization.  
> The advantage of this is that these archives know for which types  
> they provide fast array serialization, and could override the  
> std::vector serialization just for these types.

That one scares me a lot.  The archive author doesn't know the full
range of element types T for which vector<T> can be
fast-array-serialized, does he?  What happens when I invent a new POD
that I want to stick in vectors that will be serialized?  Do I have to
go modify the archive?  Or have I misundestood this altogether?

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com