tuple slicing operator

[Vlad Levenfeld via Digitalmars-d-learn]

I may be misunderstanding the intended semantics of the [] 
operator but I've come to interpret x[] to mean "give me x as a 
range" and this is the meaning I intend when I overload it in my 
own structs.

But -

auto z = tuple (1,1,1);
pragma (msg, typeof(z)); // Tuple!(int, int, int)
pragma (msg, typeof(z[])); // (int, int, int)

I'm surprised by what the last line outputs.

In generic code I tend to use [] to make sure a variable is a 
range before I use it (like static arrays, or structs following 
my interpretation of []). So now whenever tuples might come into 
the mix I have to pass the argument through an overloaded 
convenience function that can tell a range or tuple type from 
one-element variadic argument.

I've got a lot of difficulty with that last part so I am 
wondering, is there a better way to do this?