Re: [Boost-users] operators << and >> on boost serialization

From: Thorsten Ottosen (thorsten.ottosen_at_[hidden])
Date: 2007-01-08 18:11:47

Robert Ramey wrote:
> Since we've implemented this we do get a complaint on a regular basis - but 
> we've not had a problem which had cropped up a couple of times before - 
> creation of archives which cannot
> be read.
> 
> For those that use "const" on a regular basis this issue hardly every crops 
> up. To
> accomodate the rest of us I might be convinced to implement:
> 
> BOOST_SERIALIZATION_NO_CONST_CHECKING which
> would suppress the check.  This would help those who have an issue
> with using "const" but it wouldn't cut down the frequency of the
> incidences such as that started this thread.

Hm. I have a certain feeling that the "trap" is somewhat misplaced.

First of, any solution that is **so** complicated to explain as
http://www.boost.org/libs/serialization/doc/rationale.html#trap
tells my intuition that something is not clearly understood yet.

Question: what is the real problem here?

Is it that one programmer serializes an object and another a pointer?
Probably not.

Could it be this: the default tracking behavior is "track_selectively".
Possibly.

Your looong example ends with this text: "Eventually, after some code 
restructuring, the differing requirements of serializating 
construct_from are reconciled."

But what do the programmers end up doing? I'm very curious? Is it not 
possible to what the programmers in the example is trying?
(I'm too stupid here, but I thought it might be possible!)

Anyway, it might be worth considering this procedure:

1. There is no default tracking level. It must be set explxitly for all 
classes. It should be part of a class' public interface that you know it 
is serializable and that you know *explicitly* what tracking it 
supports. Maybe this can be implemented as a macro that must expand 
inside the class, so it can only be provided with the declaration of the 
class.

AFAICT (*), with that in place, there is not need for "traps".

cheers

-Thosten

(*) It's been a long day of 10 hours work and 3 hours helping my 
big-brother with marketing assignment, so my brain might not work 
properly anymore :-)