Developing a plan for D2.0: Getting everything on the table

[Jarrett Billingsley]

On Tue, Jul 14, 2009 at 12:42 PM, Andrei
Alexandrescu<SeeWebsiteForEmail at erdani.org> wrote:

>> - opImplicitCast
>
> I think alias this should render that unnecesary.

'alias this' might cover a lot of cases, but this is the pretty big
one that I can think of: consider a Bigint or the like.  You might
want to use such a type transparently in place of any other integer
type, i.e. as an array index.  Something like "a[bi.toSizet()]" looks
pretty awful.  But 'alias this' couldn't work in this case, because
the underlying representation is *not* an integer.  It's probably an
array or somesuch.  opImplicitCast would allow you to transparently
use a Bigint in place of a normal int while still letting you
represent the data any way you want (and letting you check the
validity of the cast at runtime).  Basically any type which represents
its data as something other than what you want to implicitly cast to
would have the same problem.