Trouble with protocols

[NickNoble-Slalom]

I have a protocol called Routable and a class implementation called Router. I would like to register this in my Container, then overwrite it for unit testing. This is what I have so far:

extension Container {
    var myRouter: Factory<some Routable> { self { Router() }.singleton }
}

And in my unit tests:

class MockRouter: Routable {
...
}

Container.shared.myRouter.register { MockRouter() }

with this error:
Cannot convert value of type 'MockRouter' to closure result type 'some Routable'

What am I doing wrong here?

[hmlongco]

If it's just a protocol then just do Factory<Routable>. If Routable has some sort of associated type (some?) then you can't do that as there's no way for Swift to determine the concrete type behind the closure.

[NickNoble-Slalom]

What do you mean by "just do Factory"?

[hmlongco]

HTML ate the braces, sorry.