From: "Esteban Manchado Velázquez" <zoso@...>
Date: 2006-01-31T05:43:37+09:00
Subject: Re: inheritance from C object with different parameter count

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On Mon, Jan 30, 2006 at 06:12:13PM +0900, Geert Fannes wrote:
> Hello,
>=20
> I'm trying to create a derived class (ruby class) from a C-implemented
> class. Everything works fine, until I tried to add a parameter to the
> derived class. When I derive from a pure ruby base class, everything
> works as should be, extra parameter or not. Does someone know what is
> going on or what I am doing wrong?

    Hmmm... weird. If you comment the "super()" call in Derived#initialize,=
 it
dies with the exact same error. In fact, you don't even get the "init deriv=
ed"
message.

    After investigating a little, I found out that changing the definition =
of
new to:

    rb_define_singleton_method(cBase, "new", f_new0, -1);

makes it work. I don't know if that's entirely correct (I'm not very famili=
ar
with C extensions), but it works :-) I guess the problem is that, as you do=
n't
redefine the "new" method in the class Derived, you get the Base one, so it
chokes. I don't know if the usual thing here is always defining "new" metho=
ds
with any parameter count...

    HTH,

--=20
Esteban Manchado Vel=E1zquez <zoso@foton.es> - http://www.foton.es
EuropeSwPatentFree - http://EuropeSwPatentFree.hispalinux.es

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