Re: [pygccxml-development] 2 Questions

[Roman Y. <rom...@gm...>]

On 9/12/06, Allen Bierbaum <al...@vr...> wrote:
> I have two questions that I am surprised I haven't run into before. I
> hope that both have easy answers.
>
> 1. Base class virtual ignored, but coming in inside derived class wrappers.
>
> I have a base class and derived class like:
>
> struct Base
> {
>    virtual const int* getData() const = 0;
> };
>
> struct Child : public Base
> { }
>
> struct GrandChild : public Child
> {
>    virtual const int* getData() const;
> }
>
> In my py++ generation script I ignore the getData decl in the Base class
> (and the GrandChild).  But py++ still ends up generating wrapper code
> for getData for the Child class.  To make matters worse, since it is not
> a decl for getData in the Child class I can not ignore it there.  It is
> almost like Py++ is seeing the virtual method and deciding that it needs
> to provide a wrapper for it in Child even though it is ignored in Base.
> Is this a bug in Py++ or is there some way that I can take care of this.

Do you know how hard I work to implement this? Basically this is because
wrapper classes could not be abstract. Also untill now I didn't have use case
where user ignore some method. May be I will have to take a look on it.

>
> 2. The alternative option would be to just wrap the method correctly,
> but how can I wrap returning a memory buffer (array) of arbitrary length?
>
> Is there a way to wrap this method so it will return a const wrapper
> around this data buffer to make it look like a python list?  If so what
> is the easiest way to do it and do I really need to wait for MB's method
> transformer code to do it right?

You don't have to wait, you can join and help :-). Take a look on TnFOX Python
bindings, they deal with the same problem ( image classes ). It uses indexing
suite v2 to solve the problem.


-- 
Roman Yakovenko
C++ Python language binding
http://www.language-binding.net/