DIP19: Remove comma operator from D and provision better syntactic support for tuples

[Nick Sabalausky]

On Mon, 24 Sep 2012 10:47:38 +0200
"foobar" <foo at bar.com> wrote:
> 
> Nope.
> One of the ways in math to "build" the positive numbers based on 
> set theory is via singletons:
> n := |tuple of empty tuples|
> so "1" is defined as { {} } whereas "0" is simply {}. That does 
> not work with the above suggestion. Now, I realize this is an 
> arguably convoluted math example but it does show that the 
> treating { {} } as {} is limiting the expressive power of tuples.
> 

And int's are limiting compared to mathematical integers. So what?
So ok, maybe this is limiting from a theoretical standpoint. But
practically speaking? I dunno. We're not making tuples to emulate
set theory here, we're just looking for ad-hoc anonymous structs.

Besides, I only said they were logically the same thing, not
mechanically. I'm only suggesting that a one-element tuple be implicitly
convertible to/from the type of its element. So there would likely
still be the different types, it just makes sense that you should be
able to use one as the other.