opDollar questions

[monarch_dodra]

1.
I saw a pull request that claimed to "fix" opDollar go through 
recently. Does this mean we can now use it correctly? In both
r[0..$];
and
r[$..$];
forms?

2.
Would it be OK if I asked for a little implementation tutorial on 
opDollar, and how to correctly write one when dimensions can get 
involved? I'm unsure how it is done (I've seen both 
"opDollar(size_t dim)()" and "opDollar(size_t dim)")

3.
One last question: The possibility of using opDollar to slice a 
range to its end (in particular, infinite ranges) has been 
brought up more than once. May I request we have a normalized 
type:
struct InfDollar{}

Or something inside range.d?

This way, infinite ranges would not have to invent a new token 
themselves just for this, and simply implement "auto 
opSlice(size_t i, InfDollar dol)?"

4. In the context of the above question, would it be possible to 
implement opDollar simply as an enum?
enum opDollar = InfDollar.init;
Or would that be a problem?