</pre>

<p>
A <a href="#Type_parameter_declarations">type parameter</a> or a <a href="#Type_declarations">generic type</a>
may be used as a type in a case. If upon <a href="#Instantiations">instantiation</a> that type turns
out to duplicate another entry in the switch, the first matching case is chosen.
</p>

<pre>
func f[P any](x any) int {
	switch x.(type) {
	case P:
		return 0
	case string:
		return 1