// Hypot sets z to Sqrt(p*p + q*q) and returns z.
func Hypot(z, p, q *decimal.Big) *decimal.Big {
p0 := new(decimal.Big).Set(p)
q0 := new(decimal.Big).Set(q)
if p0.Sign() <= 0 {
p0.Neg(p0)
}
if q0.Sign() <= 0 {
q0.Neg(q0)
}
if p0.Sign() == 0 {
return z.SetMantScale(0, 0)
}
p0.Mul(p0, p0)
q0.Mul(q0, q0)
return Sqrt(z, p0.Add(p0, q0))
}
