scope(exit) with expected library

[Paul Backus]

On Wednesday, 25 August 2021 at 14:42:07 UTC, Steven 
Schveighoffer wrote:
>
> I think it's possible to work with some mechanics that aren't 
> necessarily desirable. Something like:
>
> ```d
> ErrorHandler error = registerErrorHandler;
> error.onFailure({writeln("division failed");});
> error.onSuccess({writeln("division succeeded");});
>
> ...
> ```

This is kind of like what Common Lisp has with its condition 
system. One downside of this approach in D is that it would not 
work well with static analysis features like `@safe`, `nothrow`, 
etc., since the handlers are not known until runtime. But it does 
offer a lot more flexibility than traditional exceptions.