Re: [Boost-users] [serialization] serialization of a class as pointerand non-pointer

Subject: Re: [Boost-users] [serialization] serialization of a class as pointerand non-pointer
From: Robert Ramey (ramey_at_[hidden])
Date: 2011-10-10 12:40:12

Daniela Lambertz wrote:
> Now in the Serialization tutorial, I found that the adresses of
> objects with the tracking trait "track_selectively" are tracked if
> "an object of this type is anywhere in the program serialized through
> a pointer".
> Can this be the reason for my Energy-problem? If yes, is there a way
> to avoid this behaviour?

I believe you're speculation is correct here.  The library includes the
(too) clever optimization that code to serialize/deserialize pointers
is used only if the type is serialized anywhere as a pointer.  This will
lead to problems if the type is used in one program which serializes
the type via a pointer and the program is later changed (or a variant
is made) which doesn't do this.  there are a couple of fixes for this:

a) don't do that - that is make sure all programs do it the same way.
b) use "serialization traits" to explicitly specify which level of 
serialization
support you require.  Specifically, over-ride the default "track 
selectively"
with either "track always" or "track never".

This raises the very interesting and ultimately unresolvable dilema
about how a library should be designed.  On one hand one get's what
we have now - something the produces the optimal solution 99% of the
time and a nasty situation 1% of the time or something that produces
a suboptimal solution 50% of the time but no nasty situations.

After having seen the library in usage for several years now - I'm amazed
how well it's worked.  BUT, if I had nothing else to do, I see that
another pass - mostly on details such as this and a few other really
subtle issues - would be  in order.  It's hard to wind myself up for this
though.  The first pass exhausted me.

Robert Ramey