martin.ecker@tab.at wrote:
Hi,
Robert Ramey wrote:
For what its worth, my thoughts along these lines are something like:
calss helper_base { virtual ~helper_base() = 0; }
class text_iarchive ... std::list<helpbase *> helper_list; text_iarchive(){ for(it = help_list.begin();it != helper_list.end();++it) delete *it; } };
This is a good idea, although it shouldn't be part of text_iarchive, but some base class of it instead,
Of course, this was only an example/sketch for illustrative purposes.
so that all archive types can use these 'helpers' as you call them. Some time ago, this was one of our feature requests for boost::serialization and we've implemented this in our version of the library. We currently call these 'helpers' 'archive state', for the lack of a better word. Basically, this mechanism allows applications to associate arbitrary objects with archives that can be accessed from serialization code. These objects are basically per-instance variables of an archive. This is not only useful for shared_ptr serialization, but for other things as well, such as integrating boost::serialization with a serialization system of a 3rd party library. Another thing we use this mechanism for is when de-serialized objects need to register themselves with some kind of global registry or other type of manager object. So we strongly encourage adding such a feature to boost::serialization.
Your experience suggests this is on the right track. I would like to see this kicked around a while to see that it would really satisfy those who are unhappy about this aspect of serialization. Its also possible that someone can invent a more elegant, transparent, and typesafe way of doing I can live with it - question is can everyone else? Robert Ramey