+/* --- @SOD_CONVERT@ --- *
+ *
+ * Arguments: @cls@ = a class type name
+ * @const void *obj@ = a pointer to an instance
+ *
+ * Returns: Pointer to appropriate instance ichain, or null if the
+ * instance isn't of the specified class.
+ *
+ * Use: This is a simple wrapper around the @sod_convert@, which
+ * you should see for full details. It accepts a class type
+ * name rather than a pointer to a class object, and arranges to
+ * return a pointer of the correct type.
+ */