[C++-sig] Wrap a c++ function that returns boost::shared_ptr<> type?

[lin yun]

Actually I used return_range with element type of unsigned short. Python
interprets the element as int.

You mean it is not difficult to wrap a function that returns
vector<boost::shared_ptr<char>> then?

OK. Then the C++ class needs to take care of the memory when using
return_range. I am still a newbie in boost python. I am learning and making
progress. I hope I could write new call policies in the future like you did
for py++.:)

Thanks.



On Wed, Dec 17, 2008 at 11:32 PM, Roman Yakovenko <roman.yakovenko at gmail.com
> wrote:

> 2008/12/18 lin yun <yunlin07 at gmail.com>:
> >> Yes. I believe Py++ deals with boost::shared_ptr without invoking the
> >> user. Just use default call policy.
> > That's good news! How about vector<boost::shared_ptr<unsigned short *>> ?
>
> No :-(,  unsigned short is immutable type. You will have too write
> wrapper. Take a look on Py++ - ctypes functionality:
>
>
> http://language-binding.net/pyplusplus/documentation/ctypes/ctypes_integration.html
>
> >> Can you provide small example of what you are trying to do?
> >
> > I have a C++ function "imgreader" which reads an image and return a
> > "unsigned short *" pointer. I have another piece of Python code that
> calls
> > imgreader and gets the pointer to the image data. Where should I release
> the
> > memory of the image data when it is not needed any more? in python side
> or
> > C++ side?
>
> return_range call policy doesn't manage the memory. It assumes that
> the buffer is owned by C++ class.
>
> I guess you should use "as_tuple" call policy, with
> memory_managers::delete_ memory manager.
> This way you don't need to force user to manage the memory.
>
> May be you will have to create new call policy - hybrid of
> return_range and as_tuple:
> * efficiency of return_range
> * memory management ability of as_tuple
>
> HTH
>
> --
>  Roman Yakovenko
> C++ Python language binding
> http://www.language-binding.net/
> _______________________________________________
> Cplusplus-sig mailing list
> Cplusplus-sig at python.org
> http://mail.python.org/mailman/listinfo/cplusplus-sig
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.python.org/pipermail/cplusplus-sig/attachments/20081217/36e9db01/attachment.htm>