Multiple inherittance in plugins

[fullmetalcoder]

Strange, because Qt uses the exact same method for providing widget plugins for Designer... And as far as I know other component technologies (like COM) use that approach as well...

All the dependencies are NOT in Qt Designer itself but in Qt libs, including QtDesigner and QtDesignerComponents library...

But where does my approach violate any of the above mentioned statements? I don't see a problem for "Blah" being an abstract class declared in the same file as "SomeInterface"...

It will be OK as long as Blah inherits ONLY from Qt classes, or other external libraries BTW, (thus accessible from the plugin without the need to create an intermediary library) AND does not implement any method of its own (except inline methods and possibly, but might depend on compiler, methods implemented inside the header file).