[swift-evolution] generic typealias inside generic type

[Vladimir.S]

Please consider this code:

struct Foo<T> {
     typealias Group<Key,Value> = (key:Key, group:[Value])

     func bar<U,V>(u: U, v: V) -> Foo<Group<U,V>> {
         return Foo<Group<U,V>>()
     }
}

It will not compile:
cannot specialize non-generic type '(key: Key, group: [Value])'

But this will work as expected:

typealias Group<Key,Value> = (key:Key, group:[Value])

struct Foo<T> {
     func bar<U,V>(u: U, v: V) -> Foo<Group<U,V>> {
         return Foo<Group<U,V>>()
     }
}

Shouldn't we be able to work with Group typealias inside Foo<T> without 
problems as it has no any relationship to generic type T ? Or I'm missing 
something?