[C++-sig] problem chaning object state using a python class that inherits from c++ class

[David Abrahams]

"Alexis H. Rivera-Rios" <ahrivera at yahoo.com> writes:

> David,
>
> Im sending the email again, since I don't remember if
> I  have send it or not.  Please forgive the formatting
> since I don't know how to control that with yahoo
> mail.

THe formatting is okay, but...

 <snip code>

> Here is the pyste script 
>
> Class("Data","test.h")
> B = Class("B","test.h")
> use_shared_ptr(B)
>
> Class("C","test.h")
>
> D = Class("D","test.h")
> final(D.Update)

Sorry, but I don't know Jack about pyste, so please show me the code
it generates instead.

> Here is an example of the error:
>
> (test 1) works as expected

And please don't show me anything that works as expected.  That's just
a distraction from the problem.

> (test 2) fails when called from C
>>>> class E(B):
> ... 	def Update(self,data,val):
> ... 		data.a = 999
> ... 		data.b = 100
> ... 		
>>>> e = E()
>>>> cc = C()
>>>> cc.SetBptr(e)
>>>> cc.Update(1)
>>>> print cc.GetData_a()
> 6488163
>>>> print cc.GetData_b()
> 6.95352557184e-308

Please show me the result you were expecting, like I asked you to.
I'm guessing it was 999 and 100.0 ??

> Hope this illustrates the problem better,

Sorta.  This example could be smaller, couldn't it?  Do you really
need two data members to show it?

I really mean it: if you pare it down to the absolute minimum you'll
probably find the problem yourself.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com