Re: [Discuss-gnuradio] Q's regarding C++ <-> SWIG <-> Python

[Michael Dickens]

> > Yes yes, standard C++ ;-)  In the context of how SWIG interprets the
> > declarations for the friend method(s), that's my question.  I tried
> > having the last 3 arguments of the friend method have defaults (of 7,
> > so 4 required, 3 optional), but then the instantiation from Python
> > doesn't work.  Could be that I messed up something else along the
> > way, but this was the last change I made (removing the 3 default
> > values) and -poof- things worked again.
>
> Should work OK.  Be sure that the C++ .h and the .i files agree.

Yup.  This works OK now .. it was the probably the multiple  
constructors which were the primary problem ... could have had other  
issues as well.

> > > Yes, you can have multiple constructors, but they need to have
> > > different names.  (If they have the same name, C++ can sort them out
> > > at compile time based on argument type at the calling site, but  
> > > Python
> > > can't do that because of its dynamic typing.)
> >
> > Ah, so just name the friend method differently than that of the
> > "default" friend method?  Hmmm, I'll try that tomorrow when I have a
> > chance.  Clearly for a given C++ class, the constructor names will be
> > the same but with different arguments ... so the difference has to
> > come in the friend naming.  I would guess it would require it's own
> > GR_SWIG_BLOCK_MAGIC stuff too, with the different friend name?
>
> The second constructor will require a subset of what's in
> GR_SWIG_BLOCK_MAGIC.  Probably just the renaming part.

OK.  I'll look into it. - MLD