/*
 * call-seq:
 *    res.num_tuples()
 *
 * Returns the number of tuples (rows) in the query result.
 *
 * Similar to <tt>res.result.length</tt> (but faster).
 */
static VALUE
pgresult_num_tuples(obj)
  VALUE obj;
{
  int n;

  n = PQntuples(get_pgresult(obj));
  return INT2NUM(n);
}