Well, the K&R book talk about the complicated declarations, and recommend the use of the typedef command. Also, it contains a simple program called "dcl", analogous to what you linked.

If that's what you consider "slightly nontrivial", I never want to see what you would consider a difficult type declaration.

I'd volunteer some Haskell, but I am afraid that while complex, it doesn't have enough line noise in the type declarations.