[boost] Re: serialization: automatic undo/redo

From: David Abrahams (dave_at_[hidden])
Date: 2004-01-05 05:17:55

Li Lirong <lirong_at_[hidden]> writes:

> Robert Ramey wrote:
>
>> Dave Abrahams
>
>>>What's the point of doing that when you could just keep the
>>>un-serialized objects in your undo stack?
>> Indeed.  I responded to the original question about how to
>> do it without considering why one would want to.  I would
>> like to hear from the original poster as to what his
>> motivation is.
>> 
>
> There are two reasons.
>
> First, the object is referenced elsewhere in the programme.  It is not
> safe to simply replace the pointer with another object.

I suspect that you'll find you face the same problem when
de-serializing the object for undo.  Give it some careful thought, and
especially consider the advantages of a no-throw undo mechanism when
it comes to rolling back partially-complete operations that fail.

> Second, the object itself keeps some pointers to other objects.

I don't see why that matters.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com