Re: [Boost-users] [serialization] class versioning changes in boost 1.42

1 Mar 2010

      Robert Ramey  writes:
...
Robert Ramey wrote:
...
Jarl Lindrud wrote:
...
There is definitely a breaking archive format change in
basic_binary_iarchive.hpp:110 (1.42.0) - collection sizes serialized
as std::size_t rather than unsigned int.
The code in question is:
void load_override(serialization::collection_size_type & t, int){
    if (this->get_library_version() < 6) {
        unsigned int x=0;
        * this->This() >> x;
        t = serialization::collection_size_type(x);
    }
    else {
        std::size_t x=0;
        * this->This() >> x;
        t = serialization::collection_size_type(x);
    }
}
This indicates that if the serialization library version is less than 6, 
then
read the collection count as an unsigned int from the file.  Otherwise
read the collection count as an std::size_t from the file.  Thus, backward
compatibility is maintained through this change.
Sure. The point being made is that, contrary to your assumption, it is 
generally not possible for 1.35.0 based programs to read archives produced by 
1.42.0 based programs.

As the version number is 6, one might suspect that this isn't the only format 
change that's occurred.

Regards,
Jarl.