No, that's wrong either. If the comment contains a dash ('-') your regex won't remove it.

use YAPE::Regex::Explain;
print  YAPE::Regex::Explain->new(qr(<!--[^-]+-->) )->explain();
__END__
The regular expression:

(?-imsx:<!--[^-]+-->)

matches as follows:

NODE         EXPLANATION
----------------------------------------------------------
(?-imsx:     group, but do not capture (case-sensitive)
             (with ^ and $ matching normally) (with . not
             matching \n) (matching whitespace and #
             normally):
----------------------------------------------------------
  <!--         '<!--'
----------------------------------------------------------
  [^-]+        any character except: '-' (1 or more times
               (matching the most amount possible))
----------------------------------------------------------
  -->          '-->'
----------------------------------------------------------
)            end of grouping
----------------------------------------------------------
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Example:

$ perl -le '$_="<!--rm me--><p>good</p><!--rm-too-->";s/<!--[^-]+-->//
+g;print'
<p>good</p><!--rm-too-->
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