From: dblack@...
Date: 2006-02-15T07:38:47+09:00
Subject: Re: undefining Class.inherited makes class not subclassable anymore

Hi --

On Wed, 15 Feb 2006, Tilman Sauerbeck wrote:

> Hi,
> 1.) cFoo = rb_define_class ("Foo", rb_cObject);
> 2.) rb_define_singleton_method (cFoo, "inherited", ...)
> 3.) rb_undef_method (rb_singleton_class (foo, "inherited"))
> 4.) rb_define_class (c, "Bar", cFoo)
>
> The fourth call will lead to an error saying:
>  "Undefined method 'inherited'"
>
> Is there a way to restore the default Class.inherited method on Foo, so
> I can still inherit from Foo, but not call the original inherited method
> I defined in step 2?

A semi-guess, but I think you could use rb_remove_method instead of
rb_undef_method.  On the Ruby side, at least (and I assume the C
side), remove_method removes the method from the class or module but
still allows earlier ones to be called, whereas undef_method causes
instances (singleton or otherwise) not to be able to call the method
at all.


David

-- 
David A. Black (dblack@wobblini.net)
Ruby Power and Light (http://www.rubypowerandlight.com)

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