TypeSwitchGuard = [ identifier ":=" ] PrimaryExpr "." "(" "type" ")" .
TypeCaseClause  = TypeSwitchCase ":" StatementList .
TypeSwitchCase  = "case" TypeList | "default" .
</pre>

<p>
The TypeSwitchGuard may include a
<a href="#Short_variable_declarations">short variable declaration</a>.
When that form is used, the variable is declared at the end of the
TypeSwitchCase in the <a href="#Blocks">implicit block</a> of each clause.