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

From: Robert Ramey (ramey_at_[hidden])
Date: 2007-01-10 11:55:04

Thorsten Ottosen wrote:
> Robert Ramey wrote:
(It is really hard to
> grasp why using a const-cast is really needed ... the connection is
> just to weak).

Actually, this is probably the heart of the problem.  Regeneration of
serialized pointers has a number of implications which are not at
all obvious until you think about it.  Among others is the fact
that tracking is required to implement this and that this
conflicts with other natural usages of serialization.  The "real"
solution would be cut down the functionality of the serialization
to narrow its application to a set of usages which can't conflict.
It's also possible that the "serialization traits" might have been
designed differently to make eliminate that they be "in sync"
or that other higher level traits might be designed instead
(e.g. "log", etc....).  Its also possible that implementation
of a well crafted set of serialization "concepts" could be helpful.

So I'm not totally unsympathetic to the complaints about this.
And I do concede that it is slightly odd.  Recognize
that the current solution does in fact address a real problem
and does force users to understand their choices in their
usage of the library at the time when it can actually help rather
than way after its too late.

On the other hand, I suspect that this is a problem mostly
for people who are not in the habit of using "const" everywhere
they can.  For those that are in this habit, the problem rarely
comes up and when it does its easy to address.  For those
who aren't in this habit - it requires some sort of "ugly" casting.
I confess I don't have much sympathy here. Why
should the rest of us give up a useful double check just because
other's don't use "const" enough.

For those that don't agree - well, they always have the &
operator to fall back on.  In the context of an archive, this
is identical to an << or >> without the "trap"

Robert Ramey

>
> -Thorsten