+ virtual Type minType() const
+ { return INVALID; }
+
+ virtual Type maxType() const
+ { return INVALID; }
+
+ /**
+ * Test if this filter has a non-empty type range
+ */
+ bool hasTypeRange() const;
+
+ /**
+ * Assuming hasTypeRange is true, test if a given type passes the range
+ */
+ bool passType(Type aTy) const;
+