Context-Free Grammars? What about arrays?

[%u]

Sorry, please ignore the very last line:
   Temp!(2) b;      //Why does this break?

I totally wasn't thinking about the fact that T is a tuple in "int[T] arr;". (I
would intuitively think that it should still work, given that a tuple is just a
bunch of types, but I can see why it wouldn't.)

However, why the previous statement breaks:
    Temp!() a;
is still puzzling me, since giving nothing to the tuple should be equivalent to
nothing being in the array.

Thanks.