Re: [Boost-users] [serialization] skipping data

From: Joel de Guzman (joel_at_[hidden])
Date: 2006-07-10 19:49:23

Peter Dimov wrote:
> Joel de Guzman wrote:
>> Peter Dimov wrote:
>>
>>> I can't help but wonder: if some parts of your v1 format are so
>>> completely redundant as to allow you to reconstruct the original
>>> data even if you skip them, what was the point of writing them in
>>> the first place? 
>> Here's one scenario (I'm sure there are others): Your class uses a
>> 3rd party library called Y. Later, you decide to replace it with
>> a better engine using a library called Z.
> 
> Still not getting it. Do you have an example?

That was the example ;)... Ok let me see if I can clarify...
With version 1 you have a class A with this structure:

     class A { W, w, X x; Y rep; };

Now with version 2, you want to use a new engine to replace Y:

     class A { W, w, X x; Z rep; };

Z is so different from Y that it does not need any of its data.
It is also plausible that W,X,Y and Z get some data from other
external sources. So, in effect, Z starts with a default data and
gets filled as the app runs.

Regards,
-- 
Joel de Guzman
http://www.boost-consulting.com
http://spirit.sf.net