[C++-sig] Re: Wrapping Just an Abstract Base

[David Abrahams]

Thomas Muldowney <temas at box5.net> writes:

> I'm having a mental breakdown on this one.  I have a factory returning a
> pointer to an abstract base class that I've wrapped.  


  Abstract* factory();

> However, I can't logically wrap the actual derived class because
> it's generated in a plugin.  

What do you mean by "plugin"?  Some other extension module?

> So, when I go to make a call on one of the abstract functions it
            "pure virtual"-------------------^^^^^^^^?
> fails with an AttributeError exception.  Is there anyway to handle
> this in a clean manner that keeps the API near the C++ API?  


  class_<Abstract, non_copyable>("Abstract", no_init)
       .def("pure_virtual_function1", &Abstract::pure_virtual_function1)
       .def("pure_virtual_function2", &Abstract::pure_virtual_function2)
       ...
       ;

??

> I've played around with writing wrapper functions (taking the base
> class pointer) that are defined on the class using the same name as
> the virtual function.  Sadly, from my mailing list searches on this
> subject it seems this is a bad idea and can possibly lead to lookup
> loops?  

Please post some code which illustrates what you're doing.  I'm sure
it's unneccessary, but I can't quite understand it either.

> It does seem to run properly, though.  Would love some feedback or a
> kick in the head if I'm missing something in the docs and sites.

Sorry, remote cranial kicks cost extra.

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