DIP33: A standard exception hierarchy

[deadalnix]

On Wednesday, 3 April 2013 at 09:44:23 UTC, Lars T. Kyllingstad 
wrote:
> I don't see the incompatibility.  This is exactly the purpose 
> of final switch.  If the user didn't want to be forced to 
> handle a new error category, they'd use normal switch instead.
>

This is a good thing in your own code. But in phobos, this is a 
guarantee to break a lot of user code when adding to the enum.

> You have yet to specify the problems with switch in OOP.  Maybe 
> you meant something else, that final switch doesn't solve?
>

The idiomatic way to execute code depending on a value in OOP is 
virtual dispatch.