The Status of Const

[Jonathan M Davis]

On Monday, August 16, 2010 15:31:23 Steven Schveighoffer wrote:
> We can move onto the next test:
> 
> Given:
> 
> class C {}
> 
> class D : C {}
> 
> convert Array!D into Array!(const C)
> 
> OK, maybe this is a more advanced test :)
> 
> I'd be happy with just proper factoring of const to be honest.

Um, I don't think that I've ever seen that work in _any_ language, and I'm not 
sure that it would be a good thing if it did. Array!D is a completely different 
type from Array!C or Array!(const C). I could see an argument that Array!D 
should work as Array!(const D), but that seems off to me. Converting Array!D to 
const (Array!D) should work though.

In any case, converting a collection of one type to a collection of another type 
is something that I've never seen done, and I'm not sure that it would be a 
desirable feature ultimately. I'm not sure that it should _not_ be possible, but 
it would certainly make me nervous. I'd really have to think about the 
implications before I agreed that it was a good idea.

- Jonathan M Davis