Re: Wrapping variable argument functions

[José Alburquerque <jaalburquerque cox net>]

José Alburquerque wrote:
> José Alburquerque wrote:
>   
> > José Alburquerque wrote:
> >   
> >     
> > > Murray Cumming wrote:
> > >     
> > >       
> > > > On Wed, 2008-02-06 at 14:32 -0500, José Alburquerque wrote:
> > > >  
> > > >       
> > > >         
> > > > > Hi.  I have a general question about gmmproc:  Can it wrap methods 
> > > > > with variable arguments?  For example would  _WRAP_METHOD(void 
> > > > > method(int field1, ...), c_function) work if the c_function accepts 
> > > > > the same variable argument list as the method?  Thanks.
> > > > >     
> > > > >         
> > > > >           
> > > > No. These are generally convenience functions for C, which usually
> > > > repeatedly call other functions that we do wrap. We don't generally
> > > > want ... arguments in C++ because they are not at all type-safe.
> > > >
> > > >   
> > > >       
> > > >         
> > > I'm looking at two functions in gstreamer (the GstCaps 
> > > gst_caps_set_simple and the GstStructure gst_structure_set functions) 
> > > that are giving me a bit of trouble.  They're meant to set a series of 
> > > fields in the Caps and Structure.  What would I do in a case like 
> > > this?  Thanks.
> > >
> > > -Jose
> > >
> > >     
> > >       
> > In both cases, they seem to call a ..._set_valist() related function do 
> > I use these?
> >
> >   
> >     
> You know, I think I'll do something like what happens with 
> Gst::Element::link() which returns the element so another link can be 
> called right after, as in:
>
> element->link(one)->link(two);
>
> So the syntax would look like:
>
> pad->set(f1)->set(f2).  Would this work?  Thanks.
>   
I mean caps->set(f1)->set(f2).  I'll go with this for now.  Thanks.

-Jose