{ var ref : T } vs new ref type

[crusso]

The impure collections wrap the pure collections in a single field object with a mutable field. That actually has more overhead than one would like in the current compiler (a boxed record with a named, boxed field). Perhaps it would be worth introducing a new stable ref type that just requires one indirection (not two) an always has constant time access rather than requiring a field lookup.

e  :  T
------------
ref e :  ref T

e : ref T
------------
! e : T

e1 : ref T   e2 : T
------------
e1 := e2 : ()

Unfortunately, doing this means adding a new representation to motoko values (i,e, a new tag similar to MutBox unless we just use MutBox for both fields and ref types).

[rvanasa]

Would it be feasible to optimize this as a special case (record with one var field) as an alternative to new language syntax?