Ranges

[dsimcha]

== Quote from bearophile (bearophileHUGS at lycos.com)'s article
> Yigal Chripun:
> > point in case, look how much
> > unnecessary confusion Ranges cause which would be eliminated had D
> > allowed for compile-time interfaces.
> What are interfaces from the point of view of the compiler?

Abstract classes with only pure virtual functions.  In other words, basically
under the hood, an interface is just the layout of a vtable.

This actually leads to a comment I want to make in the wider debate:  I personally
find explicit interfaces really, really annoying and I think that duck typing is
by far the most intuitive type system there is.  I used to program primarily in
duck typed languages and resort to every kludge imaginable for speed.  What
attracted me to D was that the templates and type inference are so powerful that I
almost feel like it's still a duck typed language, but much faster and with more
error checking.  I guess that's why I like ranges so much.

Also, while the fact that you need interfaces to specify a vtable layout is an
implementation detail, I would argue that, in close to the metal languages, it
does more harm than good to try too hard to prevent implementation details from
leaking into the language abstractions.  Otherwise, what would be the point of it
being a close to the metal language?  The fact that, for templates, one does not
need to specify vtable layouts and for OO you do justifies the asymmetry between
templates and OO.  Interfaces for templates would just add boilerplate and make
explicit something that is already implicitly knowable and checked at compile time
anyhow.