const debacle

[Janice Caron]

On 26/03/2008, Steven Schveighoffer <schveiguy at yahoo.com> wrote:
> "Janice Caron" wrote
>
> >I think I've got it.
>
>  Janice, if you look closely, this follows EXACTLY my proposition in
>  "Proposal for scoped const contracts", just substitute foo for inout :)  But
>  I'm glad we came to the same conclusion...

You're right!

I guess, as with all these things, it's not so much the syntax itself
that matters, as grokking what it all means. Sorry it took me so long.


>  Other than that, this is exactly what I proposed and what I think should be
>  implemented.

The question is, is our scheme simple enough. It won't fly if it
complicates the const system too much.

That said, there's not a great deal of difference in appearance,
between our scheme, and Walter's. For example, by omitting the
brackets, compare:

    inout(T) f(inout T x);

with

    T f(return T x);

They don't look that dissimilar. I think it might fly. Walter's scheme
isn't sufficiently expressive, and the declared return type is
counterintuitive. I think our scheme is better (though if Walter
wanted to call it return(T) instead of inout(T), I guess I could live
with that - as long as we get to keep everything else).

Another advantage of our scheme is, we get to use temporary values!

    alias inout(char)[] iostring;

    iostring f(iostring s)
    {
        iostring tmp = s[1..$];
        return tmp;
    }



So, what problem would you like to tackle next? :-)
(Joking)