Re: [pygccxml-development] Bug in virtual function wrapping with pyplusplus

[Roman Y. <rom...@gm...>]

Allen, there is no work around for this bug, so I work on it right now.
I believe you will have an answer pretty soon.

On 5/23/06, Allen Bierbaum <al...@vr...> wrote:
> I should also have mentioned that as of yet I have not found a work
> around for this bug.
>
> I tried to work around it by "finalizing" the Son class, but I can't
> find a reliable way to finalize a class with pyplusplus.  Until then I
> think I am at an impass. :(
>
> -Allen
>
>
> Allen Bierbaum wrote:
>
> > I think I have found a bug in the handling of virtual methods with
> > pyplusplus.
> >
> > I have attached a set of test classes and the generated bindings.
> >
> > The problem seems to be that when you have 3 classes derived from each
> > other as:
> >
> > class Grandpa
> > class Father : public Grandpa
> > class Son : public Father
> >
> > And Grandpa declares a pure virtual method that is defined in Father
> > but just used in Son, the wrapper for Son still thinks it is a pure
> > virtual and doesn't know to generate code with the default
> > implementation in Father.  (See the attached code, it really makes
> > more sense with an example)
> >
> > -Allen
> >
> >------------------------------------------------------------------------
> >
> >// This file has been generated by pyplusplus.
> >
> >#include "boost/python.hpp"
> >
> >#include "/home/allenb/temp/pypp_test/Classes.h"
> >
> >namespace bp =3D boost::python;
> >
> >struct Grandpa_wrapper : test_ns::Grandpa, bp::wrapper< test_ns::Grandpa=
 > {
> >
> >    Grandpa_wrapper()
> >    : test_ns::Grandpa()
> >      , bp::wrapper< test_ns::Grandpa >()
> >    {}
> >
> >    virtual int gp_pure( int i ){
> >        bp::override func_gp_pure =3D this->get_override( "gp_pure" );
> >        return func_gp_pure( i );
> >    }
> >
> >};
> >
> >struct Father_wrapper : test_ns::Father, bp::wrapper< test_ns::Father > =
{
> >
> >    Father_wrapper(test_ns::Father const & arg )
> >    : test_ns::Father( arg )
> >      , bp::wrapper< test_ns::Father >()
> >    {}
> >
> >    Father_wrapper()
> >    : test_ns::Father()
> >      , bp::wrapper< test_ns::Father >()
> >    {}
> >
> >    virtual int gp_pure( int i ) {
> >        if( bp::override func_gp_pure =3D this->get_override( "gp_pure" =
) )
> >            return func_gp_pure( i );
> >        else
> >            return test_ns::Father::gp_pure( i );
> >    }
> >
> >
> >    virtual int default_gp_pure( int i ) {
> >        return test_ns::Father::gp_pure( i );
> >    }
> >
> >};
> >
> >struct Son_wrapper : test_ns::Son, bp::wrapper< test_ns::Son > {
> >
> >    Son_wrapper(test_ns::Son const & arg )
> >    : test_ns::Son( arg )
> >      , bp::wrapper< test_ns::Son >()
> >    {}
> >
> >    Son_wrapper()
> >    : test_ns::Son()
> >      , bp::wrapper< test_ns::Son >()
> >    {}
> >
> >    virtual int gp_pure( int i ){
> >        bp::override func_gp_pure =3D this->get_override( "gp_pure" );
> >        return func_gp_pure( i );
> >    }
> >
> >};
> >
> >BOOST_PYTHON_MODULE(_test){
> >    bp::class_< Grandpa_wrapper, boost::noncopyable >( "Grandpa" )
> >        .def("gp_pure"
> >                , bp::pure_virtual( &::test_ns::Grandpa::gp_pure )
> >                , ( bp::arg("i") )
> >                , bp::default_call_policies() );
> >
> >    bp::class_< Father_wrapper, bp::bases< test_ns::Grandpa > >( "Father=
" )
> >        .def("gp_pure"
> >                , &::test_ns::Father::gp_pure
> >                , &Father_wrapper::default_gp_pure
> >                , ( bp::arg("i") )
> >                , bp::default_call_policies() );
> >
> >    bp::class_< Son_wrapper, bp::bases< test_ns::Father > >( "Son" )
> >        .def("gp_pure"
> >                , bp::pure_virtual( &::test_ns::Grandpa::gp_pure )
> >                , ( bp::arg("i") )
> >                , bp::default_call_policies() );
> >}
> >
> >
> >------------------------------------------------------------------------
> >
> >
> >namespace test_ns
> >{
> >class Grandpa
> >{
> >public:
> >   virtual int gp_pure(int i) =3D 0;
> >};
> >
> >class Father : public Grandpa
> >{
> >public:
> >   virtual int gp_pure(int i);
> >};
> >
> >class Son : public Father
> >{
> >public:
> >};
> >
> >} // namespace test_ns
> >
> >
>
>
>
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--=20
Roman Yakovenko
C++ Python language binding
http://www.language-binding.net/