Final by default?

[Jonathan M Davis]

On Friday, March 14, 2014 08:17:08 Andrei Alexandrescu wrote:
> On 3/14/14, 4:37 AM, Daniel Murphy wrote:
> > "Walter Bright" wrote in message news:lfu74a$8cr$1 at digitalmars.com...
> > 
> >> > No, it doesn't, because it is not usable if C introduces any virtual
> >> > methods.
> >> 
> >> That's what the !final storage class is for.
> > 
> > My mistake, I forgot you'd said you were in favor of this. Being able
> > to 'escape' final certainly gets us most of the way there.
> > 
> > !final is really rather hideous though.
> 
> A few possibilities discussed around here:
> 
> !final
> ~final
> final(false)
> @disable final
> 
> I've had an epiphany literally a few seconds ago that "final(false)" has
> the advantage of being generalizable to "final(bool)" taking any
> CTFE-able Boolean.
> 
> On occasion I needed a computed qualifier (I think there's code in
> Phobos like that) and the only way I could do it was through ugly code
> duplication or odd mixin-generated code. Allowing computed
> qualifiers/attributes would be a very elegant and general approach, and
> plays beautifully into the strength of D and our current investment in
> Boolean compile-time predicates.

That sounds like a good approach and could definitely reduce the number of 
static ifs in some generic code (though as Daniel points out, I'm not sure how 
common that really is).

- Jonathan M Davis