code: func (z *Dec) QuoRound(x, y *Dec, s Scale, r Rounder) *Dec {
  	return z.quo(x, y, sclr{s}, r)
  }
docs: // QuoRound sets z to the quotient x/y, rounded using the given Rounder to the
  // specified scale.
  //
  // If the rounder is RoundExact but the result can not be expressed exactly at
  // the specified scale, QuoRound returns nil, and the value of z is undefined.
  //
  // There is no corresponding Div method; the equivalent can be achieved through
  // the choice of Rounder used.
  //