Use pointers to make generic functions work

commonAttributes.go

@@ -19,13 +19,13 @@ func newCommonAttributes() *CommonAttributes {
 
 // AddAttribute adds the attribute to the CommonAttributes.
 func (c *CommonAttributes) AddAttribute(name, value string) {
-	addToSlice(c.UndefinedAttributes, &xml.Attr{Name: xml.Name{Local: name}, Value: value})
+	addToSlice(&c.UndefinedAttributes, &xml.Attr{Name: xml.Name{Local: name}, Value: value})
 }
 
 // DeleteAttribute deletes the attribute from the CommonAttributes. It return an
 // error.
 func (c *CommonAttributes) DeleteAttribute(id int) error {
-	if err := deleteFromSlice(c.UndefinedAttributes, id); err != nil {
+	if err := deleteFromSlice(&c.UndefinedAttributes, id); err != nil {
 		return fmt.Errorf("error deleting undefined attribute %v from common attributes %v: %v", id, c, err)
 	}
 	return nil