More tricky range semantics

[Joseph Rushton Wakeling via Digitalmars-d]

On 16/01/15 00:24, Andrei Alexandrescu via Digitalmars-d wrote:
> That's right. To simplify the problem space we might decree that forward (or
> better) ranges with reference semantics are not allowed. -- Andrei

That would seem to place significant restrictions on the ability to define 
effective random number generators and related functionality ... ?