TYPEMAP
int * T_INTP
double * T_DOUBLEP
double2D * T_DOUBLEPP

INPUT
T_INTP
        $var = ($type)pack1D($arg,'i')
T_DOUBLEP
        $var = ($type)pack1D($arg,'d')
T_DOUBLEPP
        $var = ($type)pack2D($arg,'d')

OUTPUT
T_INTP
        unpack1D((SV*)$arg, (void *)$var, 'i', 0);
T_DOUBLEP
        unpack1D((SV*)$arg, (void *)$var, 'd', 0);