Add upcasts for circuitmux_policy_data_t and circuitmux_policy_circ_data_t to circuitmux.h

src/or/circuitmux.h

@@ -76,6 +76,23 @@ struct circuitmux_policy_circ_data_s {
   uint32_t magic;
 };
 
+/*
+ * Upcast #defines for the above types
+ */
+
+/**
+ * Convert a circuitmux_policy_data_t subtype to a circuitmux_policy_data_t.
+ */
+
+#define TO_CMUX_POL_DATA(x)  (&((x)->_base))
+
+/**
+ * Convert a circuitmux_policy_circ_data_t subtype to a
+ * circuitmux_policy_circ_data_t.
+ */
+
+#define TO_CMUX_POL_CIRC_DATA(x)  (&((x)->_base))
+
 /* Consistency check */
 void circuitmux_assert_okay(circuitmux_t *cmux);