# File lib/backports/1.8.7/string.rb, line 57
  def rpartition(pattern)
    pattern = Backports.coerce_to(pattern, String, :to_str) unless pattern.is_a? Regexp
    i = rindex(pattern)
    return ["", "", self] unless i

    if pattern.is_a? Regexp
      match = Regexp.last_match
      [match.pre_match, match[0], match.post_match]
    else
      last = i+pattern.length
      [self[0...i], self[i...last], self[last...length]]
    end
  end