This macro only handles XDR Unions of the form
union pre_op_attr switch (bool attributes_follow) {
case TRUE:
wcc_attr attributes;
case FALSE:
void;
};
This is translated to
enum pre_op_attr {
Void,
attributes(wcc_attr)
}
The serde methods can be generated with XDRBoolUnion(pre_op_attr, attributes, wcc_attr)
The “true” type must have the Default trait