TYPEMAP
GslSpline *     	T_PTROBJ
GslAccel *      	T_PTROBJ
gsl_spline *            T_PTR
gsl_interp_accel *      T_PTR
gsl_rng *		ANY_OBJ
gsl_ran_discrete_t *	T_PTROBJ

OUTPUT
ANY_OBJ
	sv_setref_pv($arg, CLASS, (void *) $var);

INPUT
ANY_OBJ
	$var = INT2PTR($type, SvIV((SV*)SvRV($arg)))