Short list with things to finish for D2

[bearophile]

Andrei Alexandrescu:

> * Encode operators by compile-time strings. For example, instead of the 
> plethora of opAdd, opMul, ..., we'd have this:
> 
> T opBinary(string op)(T rhs) { ... }
> 
> The string is "+", "*", etc.

Can you show an example of defining an operator, like a minus, with that?

In my set data structure I'd like to define "<=" among two sets as "is subset". Can that design allow me to overload just <= and >= ? (opCmp is not enough here).

Bye,
bearophile