[C++-sig] BPL and Py_Clear()

[Niall Douglas]

On 12 Jun 2005 at 15:25, David Abrahams wrote:

> > As it turned out, pyste already supported auto_ptr. And it also
> > seems that BPL treats auto_ptr quite sensibly, so it "just works".
> > Wish I had known as it would have saved me a day's work :(
> 
> You could have taken my word for it :)

Unfortunately Dave what's easy to you is not so easy for the rest of 
us mere mortals. You have previously told me to do things which I am 
sure are very easy for you, but took me days of head scratching. 
Hence you see my hesitation!

> > My current problem is when running through virtual function wrappers
> > in that call_method<> tries converting an unsigned int * to an
> > unsigned int which I don't want. I tried putting ptr() round it like
> > this:
> >
> >     void setData(FX::FXColor* p0, FX::FXuint p1) {
> >         call_method< void >(py_self, "setData", ptr(p0), p1);
> >     }
> >
> > (here FXColor is a typedef for unsigned int)
> >
> > ... but BPL won't take pointers to integral types in ptr(), and thus
> > I can't see how to pass the pointer as-is.
> >
> >
> > Why doesn't BPL's ptr() accept pointers to integral types?
> 
> Think about how you would implement such a thing.  What would a
> an overriden virtual function written in Python see?

A single item of whatever type eg; long * would mean the python code 
sees a python integer.

Sure, it's not very useful to the python code itself. However, the 
python code could go call some C which produces an iterable list from 
the pointer which saves having to pack and unpack such a list through 
each and every virtual function invocation.

Cheers,
Niall