Variadic grouping

[Robert Clipsham]

On Monday, 29 July 2013 at 14:46:02 UTC, Robert Clipsham wrote:
> You can achieve this like so:
> ----
> template Outer(T...) {
>     template Inner(U...) {
>         // Do something with T and U
>     }
> }
> Outer!(a, b, c).Inner!(d, e, f);
> ----
>
> You can see an example of it in action here (type tuple 
> intersection):
> https://github.com/mrmonday/misc/blob/master/misc/misc.d#L5
>
> Robert

What would be more interesting would be to have the ability to
have variadic variadics, so you could use something like:
----
template Outer(T...) {
      template Inner(U... ...) {
          // Do something with T, U[0], U[1], U[2..$]
      }
}
Outer!(a, b, c).Inner!(d, e, f).Inner!(g, h, i); // Etc
----
Of course that raises the question of variadic variadic variadics
and variadic variadic variadic variadics and so on, and my
proposed syntax is already silly............