CPLErr						T_IV
GDALAccess					T_IV
GDALColorEntry					T_OPAQUE_STRUCT
GDALColorEntry *				T_PTROBJ
GDALColorInterp					T_IV
GDALColorTableH					T_PTROBJ_SPECIAL
GDALDataType					T_IV
GDALDatasetH					T_PTROBJ_SPECIAL
GDALDatasetH ***				T_PTROBJ
GDALDriverH					T_PTROBJ_SPECIAL
GDALMajorObjectH				T_PTROBJ
GDALOptionDefinition				T_OPAQUE_STRUCT
GDALOptionDefinition *				T_PTROBJ
GDALPaletteInterp				T_IV
GDALProgressFunc				T_PTROBJ
GDALRPCInfo					T_OPAQUE_STRUCT
GDALRPCInfo *					T_PTROBJ
GDALRWFlag					T_IV
GDALRasterBandH					T_PTROBJ_SPECIAL
GDALRasterBandH *				T_PTROBJ
GDAL_GCP					T_OPAQUE_STRUCT
GDAL_GCP *					T_PTROBJ
GDAL_GCP **					T_PTROBJ
const GDALColorEntry *				T_PTROBJ
const GDAL_GCP *				T_PTROBJ
double *					T_GEOTRANSFORM
GDALAffine					T_GEOTRANSFORM
float *						T_PTROBJ
int *		  				T_PTROBJ
char **						T_CHARPTRPTR
#############################################################################
INPUT
T_OPAQUE_STRUCT
	if (sv_derived_from($arg, \"${ntype}\")) {
	    STRLEN len;
	    char  *s = SvPV((SV*)SvRV($arg), len);

	    if (len != sizeof($var))
		croak(\"Size %d of packed data != expected %d\",
			len, sizeof($var));
	    $var = *($type *)s;
	}
	else
	    croak(\"$var is not of type ${ntype}\")
T_PTROBJ_SPECIAL
   if (sv_derived_from($arg, \"${(my $ntt=$ntype)=~s/^GDAL_?/Geo::GDAL::/g;$ntt=~s/H$//;\$ntt}\")) {
       IV tmp = SvIV((SV*)SvRV($arg));
       $var = ($type) tmp;
   }
   else
       croak(\"$var is not of type ${(my $ntt=$ntype)=~s/^GDAL_?/Geo::GDAL::/;$ntt=~s/H$//;\$ntt}\");
T_GEOTRANSFORM
    if (sv_derived_from($arg, \"ARRAY\")) {
	$var = (double *) SvPVX(sv_2mortal(newSV(sizeof(double) * 6)));
	I32 tmp_i;
	for (tmp_i = 0; tmp_i < 6; tmp_i++) {
	    SV **tmp_sv = av_fetch((AV *)SvRV($arg), tmp_i, 0);
	    $var\[tmp_i] = SvNV(*tmp_sv);
	}
    } 
    else
	croak(\"$var is not an array ref\");
T_CHARPTRPTR
    if (sv_derived_from($arg, \"ARRAY\")) {
	AV *tmp = (AV *)SvRV($arg);
	I32 tmp_i, tmp_n = av_len(tmp) + 1;
	$var = (char **) SvPVX(sv_2mortal(newSV(sizeof(char *) * tmp_n)));
	for (tmp_i = 0; tmp_i < tmp_n - 1; tmp_i++) {
	    SV **tmp_sv = av_fetch((AV *)SvRV($arg), tmp_i, 0);
	    $var\[tmp_i] = SvPVX(*tmp_sv);
	}
	$var\[tmp_i] = NULL;
    } else
	croak(\"$var is not an array ref\");

#############################################################################
OUTPUT
T_OPAQUE_STRUCT
	sv_setref_pvn($arg, \"${ntype}\", (char *)&$var, sizeof($var));
T_PTROBJ_SPECIAL
       sv_setref_pv($arg, 
	\"${(my $ntt=$ntype)=~s/^GDAL_?/Geo::GDAL::/;$ntt=~s/H$//;\$ntt}\",
       (void*)$var);
T_GEOTRANSFORM
    {
	I32 tmp_i;
	AV *tmp_list = (AV *)sv_2mortal((SV *)newAV());
	for (tmp_i = 0; tmp_i < 6; tmp_i++)
	    av_push(tmp_list, newSVnv($var\[tmp_i]));
	$arg = newRV((SV *) tmp_list);
    }
T_CHARPTRPTR
    if ($var) {
	I32 tmp_i;
	AV *tmp_list = (AV *)sv_2mortal((SV *)newAV());
	for (tmp_i = 0; $var\[tmp_i] != NULL; tmp_i++)
	    av_push(tmp_list, newSVpv($var\[tmp_i], 0));
	$arg = newRV((SV *) tmp_list);
    }
    else {
	$arg = &PL_sv_undef;
    }