Rolf Magnus wrote:

> That's generally true for any type used as template argument. BTW:
> Can you have a type that is derived from a local or unnamed type, but isn't
> itself one?
>
Yep, but I wanted to head off the next question when he tries do do
something like:
int foo() {
struct x { int a; };
vector<x> v;
}

Derived, may be not, but the standard uses compounded from
rather than derived...and that you can do.