or of a type containing <code>T</code> as a component, directly or indirectly,
if those containing types are only array or struct types.
</p>

<pre>
// invalid array types
type (
	T1 [10]T1                 // element type of T1 is T1
	T2 [10]struct{ f T2 }     // T2 contains T2 as component of a struct
	T3 [10]T4                 // T3 contains T3 as component of a struct in T4