auto ref function parameters in a free function

[Vlad Levenfeld via Digitalmars-d-learn]

On Sunday, 3 August 2014 at 21:24:03 UTC, Vlad Levenfeld wrote:
> certain data structures I use are not intended to be copied, 
> .....

although these cases are probably better off being compared by 
some kind of key rather than directly... so, auto ref isn't 
necessary here, it was just something I had tried and was 
surprised at the error message I got.