Raoul Gough <RaoulGough@[...].uk>  wrote:
>  "Joel de Guzman" <djowel@[...].uk> writes:

Hi Raoul,

I'll reply to your other "ramblings" (;-) later. For now the most easiest
to reply to:

> > Following Pythion semantics, basically, we want this:
> > 
> >     val = c[i]
> >     c[i].m()
> >     val == c[i]
> > 
> > where m is a non-const (mutating) member function (method). Yet, we
> > also want this:
> > 
> >     val = c[i]
> >     del c[i]
> >     # do something with val
> > 
> > No dangling references == no return_internal_reference
> > 
> > 
> > A proxy is basically a smart-pointer that has a reference to a
> > container and an index. When *attached*, dereferencing the proxy
> > will index the container. A proxy can be detached from the
> > container. In the *detached* state, it holds the actual object which
> > it returns when dereferenced. A proxy will be detached whenever you
> > remove or replace that element from the container (e.g. del C[I],
> > C[0:I] = [a,b,c], C[I] = x).
> > 
> > The proxy_group manages the proxies and is responsible for detaching
> > a proxy appropriately when necessary.
>  
>  Well, I've got to admire that for dedication to Python semantics! I
>  can think of an alternative, though, that would simplify the suite
>  considerably: document a requirement that if the client code wants
>  Python-style semantics it should use a container of shared_ptr. This
>  obviously has some disadvantages over the proxies, but I think it
>  achieves the same semantics without any additional complexity in the
>  indexing suite.

Can't do. Remember, one of the main objectives of BPL is to (quoting the
manual):

" It is designed to wrap C++ interfaces non-intrusively, so that you should 
not have to change the C++ code at all in order to wrap it, making Boost
Python ideal for exposing 3rd-party libraries to Python.". 

Forcing the client to wrap containers of shared_ptr goes against this goal. 
As a matter of fact, what actually spurred the development of the indexing 
suite was because I needed to wrap some special vectors of objects. It is 
out of the question to go modifying the C++ code.

Cheers,
-- 
Joel de Guzman
http://www.boost-consulting.com
http://spirit.sf.net


_______________________________________________
C++-sig mailing list
C++-sig@[...].org
http://mail.python.org/mailman/listinfo/c++-sig