You can use the switch_* attributes to specify the characteristic of a union in a remote procedure call. Use the ignore attribute to designate certain structure or union members as local to the client application.
| Attribute | Usage |
|---|---|
| switch | Selects the discriminant for an encapsulated union. |
| switch_is | Identifies the discriminant for a non-encapsulated union. |
| switch_type | Identifies the type of the discriminant for a non-encapsulated union. |
| ignore | Designates that a pointer contained in a structure or union and the object indicated by the pointer is not to be transmitted. |
You can also use the array and sized pointer attributes to specify characteristics of structure or union members.