The demise of T[new]

[dsimcha]

== Quote from Andrei Alexandrescu (SeeWebsiteForEmail at erdani.org)'s article
> Jason House wrote:
> > Andrei Alexandrescu Wrote:
> >
> >> grauzone wrote:
> >>> Walter Bright wrote:
> >>>> We both feel that this would simplify D, make it more flexible,
> >>>> and remove some awkward corner cases like the inability to say
> >>>> a.length++.
> >>> How would this remove this corner case?
> >> Can't increment length if it's read-only.
> >>
> >> Andrei
> >
> > removing syntactic sugar doesn't really remove corner cases. T[new]
> > is being replaced with an array builder. What usage semantics are
> > given up with an array builder? How will implicit conversions be
> > handled? (alias this, etc...). How will the Phobos array buiilder
> > support user specified lengths (for efficiency)?
> I think ArrayBuilder could a logic similar to Appender for "~=" and
> otherwise offer regular array primitives. I don't think implicit
> conversion to T[] is an essential feature, but it can be done.
> Andrei

So basically, ArrayBuilder would be like T[new], except:

1.  It would be a plain old library type, and the core language would know nothing
about it.
2.  T[].dup, T[] ~ T[], new T[3], etc. would return T[], not ArrayBuilder/T[new].

Is this basically correct?