Hi,

In message "[ruby-talk:6550] Note on docs for Array#reverse!"
    on 00/11/23, Robert Feldt <feldt / ce.chalmers.se> writes:
|
|"..., returning nil if arr is unchanged."
|
|does not fully describe the behavior

For reverse! behavior, `unchanged' means array size is either 0 or 1,
and that's all.  Neither I nor Ruby check for array contents.  It
costs a lot.

							matz.