I've set up a class template (so far untested) thus:

class    AARL (T, ndx = "ndx")
        if (isIntegral(T.init.ndx) )
If I'm correct, this should work for ndx an integer variable of T, but I'd really like T to be able to be anything which can be stored both in an array and in an associative array.  But I can't figure out how to specify ndx.  After all, T might be a float, so it wouldn't have any appropriate attributes.  And I'd also like ndx to be able to be a function either a member of the class/struct T or a stand alone function.

So how should I set up this template?

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