On Sat, Dec 14, 2002 at 10:18:32AM -0800, Robert Ramey wrote: [snip]
> topic. It seems that there is a strong belief that there can be created a > generic system which will map an arbitrary set of C++ objects in a meaningful > way to another other format. Such a system will necessarily have to start > with a system of reflection that describes all aspects of data structures > that the system aspires to support. For example, if XML is to be supported, > items will have to have external names. Once this system of reflection (or >meta-data) > were specified, then importers/exporters to from/to each file format would be > created. There is at least one commercial product that does this (Data Junction) > This is a hugely ambitious undertaking that is only tenously related to >serialization. Yes, I agree. We should begin discussion of a reflection library. I will give the following suggestings regarding such a system: I think such a system should be based on providing an interface for accessing and assigning the value of any exposed field. I believe the following types are sufficient for representing anything that could be serialized: - built-in numeric types - fixed-length containers of a single type - variable length containers of a single type - container with a single value of variable type - character strings (note: these are included separate from variable length containers of a single type only because it is extremely common to handle them separately) - pointer or reference to a type - aggregate of zero or more of the above types In order to facilitate serialization/persistence, a name for each field as well as version history (i.e. the version in which it was added, and possibly a version in which it is removed). The same could be specified for base classes. I realize this is not much to go on, but please provide comments. - Jeremy Maitin-Shepard _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost
