Template parameters that don't affect template type

[Engine Machine via Digitalmars-d-learn]

Also, what if we use a class instead of a struct?

in this case they are both references to the same thing.

I see a problem with reflection though, as one could get the 
template parameter value and it would wrong on conversion. D 
takes the easy way out of just preventing complex and potentially 
ill-defined behavior, I guess that is ultimately a good thing, 
even if it makes it a pain in some cases.