in reply to
An optimization of last resort: eliminate capturing from your regexps
So, is it really the case that using @- and @+ like you do here does not cause the runtime penalty that is imposed by using the "match" variables ( $`, $&, $' ) ? If so, that's good to know...
perlvar (in my current 5.8.6) still has the warning about the impact of using any of those three match variables in a script, but that impact is not mentioned at all in the sections about @+ and @- (however the latter does indicate how to use these arrays to get the same values as what the match variables would give you).