This is a bit of a readability improvement IMHO; I often find myself
confused when dealing when dimension pairs, as there's no easy way to
jump to the implementation of a dimension for tuples to remind myself
for the n-th time how exactly that impl works. Now it should be possible
to jump directly to that impl.
Another bonus is that Dimension supports 3-ary tuples as well - by using
a () as a default value of a 3rd dimension.
Release Notes:
- N/A
07e3d53d58