dolfin team mailing list archive

[Johan Hake <hake@xxxxxxxxx>]

On Wednesday 07 January 2009 10:29:52 Martin Sandve Alnæs wrote:
> On Wed, Jan 7, 2009 at 10:22 AM, Johan Hake <hake@xxxxxxxxx> wrote:
> > On Wednesday 07 January 2009 00:29:52 Garth N. Wells wrote:
> >> Johan Hake wrote:
> >> > Hello!
> >> >
> >> > I have now got some of the shared_ptr stuff combined with python up
> >> > and going.
> >> >
> >> > The function interface, with shared functions and function_space
> >> > should just work. This includes compiled functions. The nice thing
> >> > with these is they only refer to our own library, i.e., Py/DOLFIN and
> >> > they don't have to be compatible with other Py-library.
> >> >
> >> > I havn't looked into the la objects yet. I lack a good example of
> >> > where it is used.
> >>
> >> demo/la/trilinos/python/demo.py
> >>
> >> All la stuff in pure dolfin library use wants a GenericMatrix, (right?)
> >>
> >> > and as far as I am concerned we cannot use a shared Epetra_FECrsMatrix
> >> > or Epetra_FeVector in the PyTrilinos interface.
> >>
> >> What isn't this possible?
> >
> > Short answer, no.
> >
> > Long answer:
> >
> > PyTrilinos need to be compiled with shared_ptr support. If the underlying
> > library does not have a shared_ptr interface, which I am quite sure
> > Trilinos does not have, it is that libraries responsability to include a
> > shared_ptr typemaps to handle situations where it get this type. These
> > typemaps is what I am about to include for PyDOLFIN, i.e., making it
> > possible to pass a python objects that are stored using shared_ptr to
> > function accepting pointers, references, or shared_ptr, but I doubt
> > PyTrilinos is compiled with this support.
> >
> > Johan
>
> And to complicate further PyTrilinos has wrapper classes around the
> C++ Epetra classes...

That's true. 

But if PyTrilinos was swigged using shared_ptr typemaps it should in theory 
just work. Then we could for example %import this interface while swigging 
DOLFIN, and produce full fledged swigwrapped Epetra objects, using 
shared_ptrs, which then could be passed to the PyTrilinos library.

Johan