Re: [pygccxml-development] Abstract Classes

[Lakin W. <lak...@gm...>]

Maybe I was not clear.  I'm talking about pure virtual functions.  You
had mentioned at some point that I may have to take care of these in a
certain way.

For instance:

g++ `pkg-config --cflags OGRE` -I/usr/include/python2.4
-DBOOST_PYTHON_MAX_ARITY=16 -O0 -g -I./ -fPIC -Ibuild -c -o
build/RenderWindow.pypp.os build/RenderWindow.pypp.cpp
/usr/include/boost/python/object/value_holder.hpp: In instantiation of
'boost::python::objects::value_holder<RenderWindow_wrapper>':
/usr/include/boost/type_traits/alignment_of.hpp:52:   instantiated
from 'const size_t
boost::detail::alignment_of_impl<boost::python::objects::value_holder<RenderWindow_wrapper>
>::value'
/usr/include/boost/type_traits/alignment_of.hpp:61:   instantiated
from 'boost::alignment_of<boost::python::objects::value_holder<RenderWindow_wrapper>
>'
/usr/include/boost/python/object/instance.hpp:30:   instantiated from
'boost::python::objects::instance<boost::python::objects::value_holder<RenderWindow_wrapper>
>'
/usr/include/boost/python/object/instance.hpp:44:   instantiated from
'const size_t boost::python::objects::additional_instance_size<boost::python::objects::value_holder<RenderWindow_wrapper>
>::value'
/usr/include/boost/python/class.hpp:499:   instantiated from 'void
boost::python::class_<T, X1, X2, X3>::initialize(const DefVisitor&)
[with DefVisitor = boost::python::init<mpl_::void_, mpl_::void_,
mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_,
mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_,
mpl_::void_, mpl_::void_, mpl_::void_, mpl_::void_>, W =
RenderWindow_wrapper, X1 = boost::noncopyable_::noncopyable, X2 =
boost::python::detail::not_specified, X3 =
boost::python::detail::not_specified]'
/usr/include/boost/python/class.hpp:629:   instantiated from
'boost::python::class_<T, X1, X2, X3>::class_(const char*, const
char*) [with W = RenderWindow_wrapper, X1 =
boost::noncopyable_::noncopyable, X2 =
boost::python::detail::not_specified, X3 =
boost::python::detail::not_specified]'
build/RenderWindow.pypp.cpp:158:   instantiated from here
/usr/include/boost/python/object/value_holder.hpp:66: error: cannot
declare field 'boost::python::objects::value_holder<RenderWindow_wrapper>::m_held'
to be of abstract type 'RenderWindow_wrapper'
build/RenderWindow.pypp.cpp:18: note:   because the following virtual
functions are pure within 'RenderWindow_wrapper':
/home/lakin/.local/include/OGRE/OgreRenderTarget.h:267: note:  virtual
void Ogre::RenderTarget::writeContentsToFile(const Ogre::String&)
/home/lakin/.local/include/OGRE/OgreRenderTarget.h:273: note:  virtual
bool Ogre::RenderTarget::requiresTextureFlipping() cons


Lakin

On 5/30/06, Roman Yakovenko <rom...@gm...> wrote:
> On 5/31/06, Lakin Wecker <lak...@gm...> wrote:
> > In Ogre, a frequent design used is to define an abstract base class,
> > (Say RenderWindow).  Along with a Manager/Factory that creates that
> > window for you.  Then the platform specific implementations of those
> > classes are built to actually do the work.
> >
> > However, the API dictates that you ask the Manager/Factory for an
> > implementation of RenderWindow (you don't care which), and you then
> > use it as a generic RenderWindow interface.
> >
> >
> > In py++, how do I model this?  I don't want to expose the platform
> > specific implementations of the classes, as they're not needed. But I
> > do need to somehow let the python run time know about the
> > AbstractClass so that when I ask the Manager for one, I can use it
> > from Python.
> >
> > When I directly include the class in the ouput, I get a compile error
> > because of the lack of implementations ... of some methods.
>
> I could be wrong, but it should work out of the box. I will check this at home.
>
> > Anyways, I'm going to sleep now.  See you all in a few hours.
>
> Good night
>
> > Lakin
>
>
> --
> Roman Yakovenko
> C++ Python language binding
> http://www.language-binding.net/
>