class Float

def round_with_digits(ndigits=0)
  ndigits = Backports::coerce_to_int(ndigits)
  case
  when ndigits == 0
    round_without_digits
  when ndigits < 0
    p = 10 ** -ndigits
    p > abs ? 0 : (self / p).round * p
  else
    p = 10 ** ndigits
    prod = self * p
    prod.infinite? || prod.nan? ? self : prod.round.to_f / p
  end
end