[boost] [extension]

From: Stephan Diederich (stephan.diederich_at_[hidden])
Date: 2007-05-09 13:29:29

Hi,

I've some questions regarding boost.extension which I think is  
currently prepared to review by Mariano Gabriel Consoni as one of the  
SoC Projects.

We want to use a plugin loading mechanism in one of our projects and  
have some ideas currently not included in the boost.extensions library.

- Some kind of versioning of interfaces and implementations.
The idea is to give an interface (whose implementation is loaded as  
an extension) a version, which can be later compared to the version  
of the loaded implementation. As one of boost.extension's goal is NOT  
to modify a class-header to make it loadable, this should possibly be  
an optional feature. Another option would be to give non versioned  
interfaces always version 0 or 1.

- It would be nice, if the plugin-loader provides functionality to  
"switch" the interface of an instance of an implementation.
IIRC, the zone object knows, which interfaces are implemented by a  
loadable class. (when the dll is loaded, the export-function  
registers all the possible interfaces of one class to the zone). With  
that information it should be possible to determine if a given  
instance of a loaded class can be casted to another interface. (I  
think that casting has to be done in the loaded extension, as this is  
the only place where the layout it known. )

Are there any plans to include above mentioned functionality in  
boost.extension?

Thanks in advance,
Stephan