Is rebase always destructive?

Hi,

When doing a rebase, I can find a number of reasons for which one might feel like to preserve the rebased branch (that is, perform an operation which copies the branch over a new base, not moves).

-  For example, a successful rebase doesn't necessarily mean that the
   code, as of the rebased branch, is consistent and compiles. That is,
   the rebase can be broken even if git can put things together diff-wise.
   In such a case I wouldn't be happy to lose the original instance of
   the branch.

-  Or I might want to build different versions of the program, and each
   version of it needs a given set of fixes (the same one). Then rebasing
   my bugfix branch is not a good idea, I'd much rather copy it over all
   those versions.

I can't see any option for rebase which would yield this cp-like behaviour. Am I missing something? Or people don't need such a feature? (Then give me some LART please, my mind is not yet gittified enough to see why is this not needed.) Or is it usually done by other means, not rebase?

Thanks Csaba