+
+ //
+ template <class VisitorType>
+ bool
+ apply_visitor(const XMLElement& element, VisitorType& visitor)
+ {
+ const ElementList& l = element.GetChildren();
+ ElementList::const_iterator i;
+
+ for ( i = l.begin(); i != l.end(); ++i )
+ {
+ if ( ! visitor.Element(**i) )
+ {
+ return false;
+ }
+
+ if ( ! apply_visitor(**i, visitor) )
+ {
+ return false;
+ }
+ }
+
+ return true;
+ }
+
+ //
+ class AttributeVisitor
+ {
+ std::string attr_name;
+
+ public:
+ AttributeVisitor(const std::string& n) : attr_name(n) {}
+ std::set<std::string> value_list;
+
+ bool Element(const XMLElement& e)
+ {
+ const AttributeList& l = e.GetAttributes();
+ AttributeList::const_iterator i;
+
+ for ( i = l.begin(); i != l.end(); ++i )
+ {
+ if ( i->name == attr_name )
+ {
+ value_list.insert(i->value);
+ }
+ }
+
+ return true;
+ }
+ };
+
+ //
+ class ElementVisitor
+ {
+ std::string element_name;
+
+ public:
+ ElementVisitor(const std::string& n) : element_name(n) {}
+ std::set<std::string> value_list;
+
+ bool Element(const XMLElement& e)
+ {
+ if ( e.GetBody() == element_name )
+ {
+ value_list.insert(e.GetBody());
+ }
+
+ return true;
+ }
+ };
+