template template parameter

[Caligo]

I should have been more clear, but my actual question is how do I
access the parameters of a template parameter.  My example works, but
I wanted to know if there is a different and perhaps a better of doing
it.

In your example it would look something like this:

struct SomeContainer(T, int x, int y){     }

struct Foo(alias ContainerType){

  // e.g.
  int my_x = ContainerType.x * 2;
  int my_y = ContainerType.y * 2;
}