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From: bwood (brass_at_[hidden])
Date: 2006-05-15 23:39:44


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David Abrahams wrote:
>bwood <brass_at_[hidden]> writes:
>
>> David Abrahams wrote:
>>>>"Le Chaud Lapin" <unoriginal_usern..._at_[hidden]> writes:
>>>>More than anything in programming, I depend on type to create form.

>>>>Versioning implies that types are semi-weak.
>>>
>>>
>>>If versioning in serialized form implies that, then so do revisions
of
>>>your type in a version control system. So, basically, once you
design
>>>a class, it never evolves?
>>>
>>
>> Along the lines of what Lapin is thinking, I think B.Ser's
"versioning"
>> support is problematic. For example, consider wanting to move (or
>> delete) a data member out of a type between versions 1.1 and 1.2.
>> B.Ser needs that member to remain in the type in order to support
1.1.
>
>No, you just read it and throw it away.
>
> if (version == 11)
> {
> type_of_deleted_member ignored;
> ar & ignored;
> }

Wait a minute. The code above looks like you may have focused on
deleting a member and not relocating it. "ignored" isn't coming
from anywhere else with a 1.1 client and it needs to be stored
somewhere. Also if a 1.2 server is sending to a 1.1 client,
it doesn't matter whether the member has been deleted or
relocated, it still has to send the right thing back.

Brian Wood
www.webEbenezer.net
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