Re: [Boost-users] Serialization and class versioning

Subject: Re: [Boost-users] Serialization and class versioning
From: Robert Ramey (ramey_at_[hidden])
Date: 2018-08-02 16:07:06

On 8/2/18 4:58 AM, Tim Burgess via Boost-users wrote:
> Hi,
> 
> I have an application that uses serialization for data 
> storage/retrieval, based on Boost 1.67.0. I’ve implemented class 
> versioning as per:
> 
> https://www.boost.org/doc/libs/1_67_0/libs/serialization/doc/tutorial.html#versioning
> 
> The overall archive stores a number of sub-classes, nested within the 
> XML. However, I get a run-time exception thrown that I can’t catch when 
> one of my sub-classes (DisplayDefinition) returns from being read in. A 
> bit of debugging found that the problem was caused by the class version 
> number having a value of 0, whilst the file being read had a version 
> number of 3 for the class in question.

A couple of possibilites

a) something else is messed up and the values get out of sync.  Using 
XML should be detected as it checks the end tags to be sure they match 
the start tags.  So this is not likely it.

b) determine how the input file got the version number 3 in the first 
place.  Did it previously have a version # of 3?  Did you change it back 
to 0 - lowering the version # would create this problem.

c) If it's showing up on newly create files - it's easy, just debug and 
find the place where the version # is being written.

Robert Ramey