class Gen1<T> {}


class Gen2<T> {}


class Gen3<T, U> {}


class NonGen {}


class Base {
    typealias Generic<T> = Gen1<T>
}


class A : Base {
    typealias Generic<T> = Gen2<T>
    
    // Cannot specialize a non-generic definition
    let g = Generic<Int>()
}


class B : Base {
    typealias Generic<T, U> = Gen3<T, U>
    
    // Cannot specialize a non-generic definition
    let g = Generic<Int, String>()
}


class C : Base {
    class Generic<T> {}
    
    // Cannot specialize a non-generic definition
    let g = Generic<Int>()
}


class D : Base {
    typealias Generic = NonGen
    
    // Works
    let g = Generic()
}


class E : Base {
    class Generic {}
    
    // Works
    let g = Generic()
}