Sealed classes - would you want them in D?

[H. S. Teoh]

On Fri, May 11, 2018 at 04:14:43PM -0700, Walter Bright via Digitalmars-d wrote:
> On 5/10/2018 6:22 AM, Piotr Mitana wrote:
> > For those who never coded Scala and don't know sealed classes: a
> > sealed class is a class which can be only extended in the same
> > source file.
> > 
> >      sealed class MyClass {}
> > 
> > Translating to D, a sealed class would could only be extended in the
> > same module.
> 
>   private class MyClass { }
> 
> should do the trick.

It doesn't; if you do this, you can't pass MyClass outside the module
and have other modules invoke its methods.  They will get an essentially
opaque object.  You'll have to resort to ugly wrapper types (defined in
the same module) in order to make this work.


T

-- 
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