// Denom returns the denominator of x; it is always > 0. The result is a
// reference to x's denominator; it may change if a new value is assigned to
// x, and vice versa.
func (q *Rat) Denom() *Int {
q.doinit()
n := new(Int)
n.init = true
n.ptr = C._mpq_denref(&q.i[0])
return n
}
// IsInt returns true if the denominator of z is 1.
func (z *Rat) IsInt() bool {
z.doinit()
return C.__mpz_cmp_ui(C._mpq_denref(&z.i[0]), C.ulong(1)) == 0
}