[:] as empty associative array literal, plus warning for null

[bearophile]

Andrei Alexandrescu:

> Where does the whole "stronger typing" comes in? This is 
> poppycock. We need real arguments here.

Maybe it's a matter of definitions, for me having "null" as 
literal for empty array, null pointer, empty associative array, 
and more is more weakly typed compared to having a literal like 
[] usable only for empty dynamic arrays (and strings), a literal 
as [:] usable only for empty associative arrays, and null for 
pointers, class references (and little else like a Nullable).

Bye,
bearophile