Creating a Sub-view of a non - RA (hasSlicing) range.

[monarch_dodra]

I've been enjoying my time with D's ranges, but something is 
nagging at me: If the range is not random access, then how does 
one create a sub-view of that range?

Say I have a forward range (for example, an SList[]). I would 
like to create a new range containing only the first 5 elements 
of that old range. How can I do that?

I see no logical reason that prevents me from doing it, since C++ 
iterators can do it quite fine. (the C++ algorithms that work 
only on RA ranges is mostly for efficiency reasons). Not being 
able to do this would severely limit the amount of containers 
that can seamlessly merge with algorithms.

For example, I can't call splitter on an SList. Not sure if this 
is just "not currently supported", or just not possible...

Any thoughts?