libdeng2: Added NoneId utility

Id that is initialized to None, unlike the regular Id which is given a unique identifier in its constructor.
skyjake · May 1, 2014 · c6e1029 · c6e1029
1 parent cf5cc6a
commit c6e1029
Showing 1 changed file with 10 additions and 0 deletions.
diff --git a/doomsday/libdeng2/include/de/core/id.h b/doomsday/libdeng2/include/de/core/id.h
@@ -103,6 +103,16 @@ DENG2_PUBLIC QTextStream &operator << (QTextStream &os, Id const &id);
 
 inline uint qHash(Id const &id) { return id; }
 
+/**
+ * Utility for declaring identifiers that are initially uninitialized.
+ */
+class DENG2_PUBLIC NoneId : public Id
+{
+public:
+    NoneId() : Id(None) {}
+    NoneId(Id const &other) : Id(other) {}
+};
+
 } // namespace de
 
 #endif // LIBDENG2_ID_H