Re: [boost] [serialization] The constant object problem

From: Robert Ramey (ramey_at_[hidden])
Date: 2005-08-24 10:41:46

Martin Slater wrote:
> I just ported all our code using Boost.Serialization over to 1.33
> today and came across similar problems so I thought I'd add some
> comments as additional data points. In all cases the problems were
> trivial to fix (making Save() member functions const for example) and
> only came across a single case of serialising a local variable in our
> code, the fix there was also relatively trivial, so all in all this
> didn't cause us much grief at all.

OK - good to know - one more data point.  I wonder if that local variable 
was being tracked.  In this case you fixed a potential error.

>The bigger problem I have is with
> the added included dependancy order (archives must be included before
> any other serialisation files) which caused a big rearrangment of our
> headers and was a pain to deal with. Luckily for us these were all
> internal headers but it just reminds me of the problems with header
> dependancy that boost\serialisation\shared_ptr.hpp had and that have
> been happily resolved in this release. This is a much bigger issue
> for me and something that really should be readdressed.

This is caused by two circumstances:

a) for boost/serialization/export.hpp relies on previious inclusion of 
archive headers to know what archives to instantiate code for.  This the 
same as version 1.32

b) The new requirement to support auto-linking.  Auto-linking is forced by 
including a header whether or not the code is actually needed.  The new 
headers skip those portions which provoke auto-linking if no archive headers 
are included.  This permits headers to include serialization and still be 
included in other programs which don't use serialization without required 
link in a library which is not used.

I've resolve to make the rule "include archive headers before serialization 
headers\" conditional on the usage of auto-linking.  I'm not sure this is a 
great thing.  It will address the concerns of those who have had an issue 
with this.  But it will also require that a program which is developed on 
say GCC will have to suppress auto-linking with a compile time define when 
the program is compiled on a VC or borland.  I'm still mulling this over.

Robert Ramey