[C++-sig] Boost "From Python" Conversion and Template Classes

[Sean Ross-Ross]

I have a project where there is an internal reference count pointer  
to the objects passed through. And all of class methods are templated  
similar to:

	template<class ScalarType, class MV, class OP>
	class BasicEigenproblem : public virtual Eigenproblem<ScalarType,  
MV, OP> {
	....
		setOperator( const Teuchos::RefCountPtr<OP>& Op );
	....
	}

In the C++ code to call this method you must do:
	
	RefCountPtr< Matrix > A = rcp( new Matrix( ... ) );
	eigenproblem. setOperator(A);


I would like to have the methods in python be just:
	
	A = Matrix()
	eigenproblem. setOperator(A)

where I have templated BasicEigenproblem<double,object,object>.
And without dealing with the RefCountPtr, and have some method that  
calls in the background:

	RefCountPtr< object > RCPA = rcp(  A );


I have tried experimenting with the extraction methods with no luck:

8:	using namespace boost::python;

10:	typedef Teuchos::RefCountPtr<object> RCP;

12:	void* extract_rcp(PyObject* obj)
13:	{
14:	    RCP *r = new RCP( new object(handle<>(obj)), false );
15:	    return r;
16:	}

18:	converter::registry::insert ( &extract_rcp,  type_id<RCP>() );

I get a few errors with this at compile time:

	extraction.cpp:18: error: expected constructor, destructor, or type  
conversion before '(' token

I can not see to find a concrete example of how to do this. Am I one  
the right track, any Sugestions?

Thanks, and sorry for the long winded message.

~Sean