ehlo. > | 2. How should I change the following code to get my object back from > | Hash? > > You should define "hash" and "eql?" to use objects as hash keys. Yes, it works, thanks. But why the procedure is so complex? Why not just use 'operator <=>'? What I mean is that writing a good hash function may be not a simple task, but most keys can be ordered by <=>. dozen