[xsd-users] error: cannot convert to ?int? in assignment

[shubhgd at cs.vt.edu]

Hi,

I am trying to use the XSD generated C++ classes for mapping an XML  
schema union type data. The XSD definition looks like:

<xs:element name="scalar">
	<xs:complexType>
	<xs:complexContent>
		<xs:extension base="nd">
		<xs:sequence>
			<xs:element name="sval" type="scalartype" minOccurs="1"/>
		</xs:sequence>
		</xs:extension>
	</xs:complexContent>
	</xs:complexType>
</xs:element>
<xs:simpleType name="scalartype">
       <xs:union memberTypes="xs:int xs:double xs:string xs:boolean"/>
</xs:simpleType>


and in the driver.cxx I want to use the value of a scalar variable  
from the corresponding XML. I tried to achieve this with the following  
piece of code:
auto_ptr<aircraft_t> a (aircraft (xml_file_path));
for (data::scalar_const_iterator s (d->scalar().begin ()); s !=  
d->scalar ().end ();++s)
  {
   string nm = s->name().get();
   if(nm == "npts_top")
   {
       int npts_top = s->sval();
   }
}

Here, aircraft is the root element. And the hierarchy is  
aircraft->data->scalar.

However, with this piece of code, I get the following error:
error: cannot convert ?const scalartype? to ?int? in assignment

which sounds right because sval is of type scalartype and not int. But  
scalartype can be a type of int (as it's a union of int, string, and  
so on). So, I am not able to convert sval to an int type which I was  
guessing would be taken care of by the underlying scalartype, but  
apparently not. Could any one let me know how to handle this? Thank  
you very much.


Thanks and Regards,
Shubhangi