I don't want to waste my time if no one feels it will be useful.

In his preface to his book "Portrait of Dorian Gray", Oscar Wilde once wrote, "All Art is Quite Useless". I have always seen this as an argument for the concept of "Art for Art's Sake" (popularized by Charles Baudelaire and the impressionists (Monet, Renoir, etc)).

My point, if you would find enjoyment in creating Tie::Hash::Ranked, then create it. Don't worry if anyone finds it useful, code for code's sake is reason enough.