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

[Allen B. <al...@vr...>]

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 = 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 = 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 = 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 = 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) = 0;
>};
>
>class Father : public Grandpa
>{
>public:
>   virtual int gp_pure(int i);
>};
>
>class Son : public Father
>{
>public:
>};
>
>} // namespace test_ns
>  
>