boost-users-bounces@lists.boost.org wrote:

As I can see from the documentation the library has only a forward compatibility. 3. Independent versioning for each class definition. That is, when a class definition changed, older files can still be imported to the new version of the class. Is there any way to achieve a backward compatibility?

Hi Oleg, in August I bothered the group with pretty much the same question. Here is the answer the author of the serialization library gave - I think there might be a follow up with some more details but you will have to look that up if you're interested in it. Robert Ramey wrote:

Pfligersdorffer, Christian wrote:

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Hello Robert, hello all,

I know it is stated in the boost::serialization library documentation that per definition always the latest version of a class goes to the archive. I wonder if there is a way to change this behaviour and choose the version number for my class at runtime. Obviously this feature would be useful in a system of two dependent modules where either the producer or the consumer could by updated to a newer version without the other one being neccessarily updated too. Maybe this has already been discussed but I could not find anything about it on the web. However my strong suspicion is that there is no such option within the library and I will have to provide a solution within the affected classes.

I dismissed this issue when it was recently brought up for the first time. I had never intended to provide an option for making "backward compatible" so I had presumed that it wasn't going to be possible.

Well, some people kept bugging me and I did a little investigation and found that it would be quite possible with just a little bit of tweaking - and an amplified section in the documentation. So I guess it will be done with 1.35. FYI, the reason its doable is just a side effect of the fact that I leaned hard on "symetry" (I know I'm an atrocious speller) in order to conserve brain surface area. I suppose there is a lesson in there somewhere.