> That's fair but it's trivial to convert a BinaryTree to a LinkedList (doubly or singly)

If there's a way of doing it that's trivial, and another way that's complex, I will do it the trivial way unless there's a very good reason to do it the complex way.

> The practical use case for in-place algorithms is operating on large data sets that are directly on a disk. Think some kind of database organizing data directly on a hard drive.

I just hope the system doesn't crash while it's in the middle of doing it!