On Wed, Feb 4, 2009 at 8:49 PM, Paul Melis
<pyplusp...@assumetheposition.nl> wrote:
> Hello,
>
> Classes with protected destructors (as found when custom reference
> counting is used) seem to cause some trouble when using bp::wrapper<>
> containing a method that takes a const reference to a refcounted class.
>
> Say I have:
>
> #include <cstdio>
> #include <boost/python.hpp>
>
> namespace bp = boost::python;
>
> class Thing
> {
> protected:
> virtual ~Thing() {}
> };
>
> class Callback
> {
> public:
> Callback() { }
> virtual void execute(const Thing& t) { }
> protected:
> virtual ~Callback() {}
> };
>
> And I want to add a wrapper class so that Callback can be derived from
> in Python and its execute() method overridden.
Try the following code:
#include "boost/python.hpp"
namespace bp = boost::python;
struct Callback_wrapper : Callback, bp::wrapper< Callback > {
Callback_wrapper( )
: Callback( )
, bp::wrapper< Callback >(){
// null constructor
}
virtual void execute( ::Thing const & t ) {
if( bp::override func_execute = this->get_override( "execute" ) )
func_execute( boost::ref(t) );
else
this->Callback::execute( boost::ref(t) );
}
void default_execute( ::Thing const & t ) {
Callback::execute( boost::ref(t) );
}
};
BOOST_PYTHON_MODULE(pyplusplus){
bp::class_< Callback_wrapper, boost::noncopyable >( "Callback",
bp::no_init )
.def( bp::init< >() )
.def(
"execute"
, (void ( ::Callback::* )( ::Thing const & ) )(&::Callback::execute)
, (void ( Callback_wrapper::* )( ::Thing const & )
)(&Callback_wrapper::default_execute)
, ( bp::arg("t") ) );
bp::class_< Thing, boost::noncopyable >( "Thing", bp::no_init );
}
It was generated by Py++ and I believe it exposes your use case correctly.
--
Roman Yakovenko
C++ Python language binding
http://www.language-binding.net/
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