In article <op.uhjn5zij9245dp / kool>,
  "Michael Selig" <michael.selig / fs.com.au> writes:

> To me it would be preferable if Regexp & String methods behaved the same  
> way in this regard - probably the best would be to raise errors in both.  
> That would prevent confusing behaviour like the above test.

Regexp is not usable for broken strings because oniguruma don't support them.
It is implementation restriction.  Not desired specification.

Note that, broken strings are required for Unix filenames, at least.
-- 
Tanaka Akira