- When a bitcase includes multiple <enumref> clauses, the contents of the
- bitcase are only present once regardless of the number of bitcase expressions
- that match.
+ <bitcase>:
+ if ( switch expression & bitcase expression ) is non-zero,
+ bitcase fields are included in structure.
+
+ <case>:
+ if ( switch expression == case expression ) is true,
+ then case fields are included in structure.
+
+ It can be used only as the last field of a structure.
+
+ When a bitcase or case includes multiple <enumref> clauses, the contents
+ of the bitcase or case are only present once regardless of the number of
+ bitcase or case expressions that match.
+
+ <enumref> inside <bitcase> can only refer to an enum's <bit> members.
+ <enumref> inside <case> can only refer to an enum's <value> members.
+
+ A switch may contain multiple <bitcase> or <case> elements.
+ Usually it will only contain <bitcase> elements
+ or only contain <case> elements.
+ That is, mixing of <case> and <bitcase> usually doesn't make any sense.
+
+ The same value may appear in multiple <case> or <bitcase> elements.
+
+ New protocol definitions should prefer to use this instead of <valueparam>
+ and instead of <union>.