There are two possible solutions to the problem. The first one is to fix
Boost.Python library: pointer_holder.hpp.patch . The patch was contributed
to the library ( 8-December-2006 ) and some day it will be committed to the CVS.
It is also possible to solve the problem, without changing Boost.Python library:
namespace boost{
template<class T>
inline T* get_pointer( boost::shared_ptr<const T> const& p ){
return const_cast< T* >( p.get() );
}
}
namespace boost{ namespace python{
template<class T>
struct pointee< boost::shared_ptr<T const> >{
typedef T type;
};
} } //boost::python
namespace utils{
template< class T >
register_shared_ptrs_to_python(){
namespace bpl = boost::python;
bpl::register_ptr_to_python< boost::shared_ptr< T > >();
bpl::register_ptr_to_python< boost::shared_ptr< const T > >();
bpl::implicitly_convertible< boost::shared_ptr< T >, boost::shared_ptr< const T > >();
}
}
BOOST_PYTHON_MODULE(...){
class_< YourClass >( "YourClass" )
...;
utils::register_shared_ptrs_to_python< YourClass >();
}
The second approach is a little bit "evil" because it redefines get_pointer
function for all shared pointer class instantiations. So you should be careful.
- solution.cpp file contains definition of a class and few functions, which
have shared_ptr< T > and shared_ptr< const T> as return type or as an
argument. The file also contains source code that exposes the defined
functionality to Python.
- sconstruct file contains build instructions for scons build tool.
- test.py file contains complete unit tests for the exposed classes
- pointer_holder.hpp.patch file contains patch for the library
All files contain comments, which describe what and why was done.
