accepts_invalid_concrete_same_type.swift

protocol Fooable {
  associatedtype Foo
}

protocol Barrable {
  associatedtype Bar: Fooable
}

struct X {}
struct Y: Fooable {
  typealias Foo = X
}
struct Z: Barrable {
  typealias Bar = Y
}

struct X2 { }

func test8<T: Barrable, U: Barrable>(_ t: T, u: U)
  where T.Bar == Y, U.Bar.Foo == X2, T.Bar == U.Bar {
}