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

[dsimcha]

== Quote from Jarrett Billingsley (jarrett.billingsley at gmail.com)'s article
> 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.

But you can alias this a function, not just a member.  Example:

import std.conv;

struct Foo {
   string num;

    uint numToString() {
       return to!uint(num);
    }

    alias numToString this;
}