[core] Use of illegal wildcard types

[bagipro]

CC from #913

Class io.reactivex.internal.operators.observable.ObservableAny

    public void subscribeActual(io.reactivex.Observer<? super java.lang.Boolean> observer) {

But java.lang.Boolean is a final class, and ? super java.lang.Boolean is illegal type

APK: https://drive.google.com/file/d/1qC3tlWs9AtPBpyS6iU9kcSphLryfJOxi/view

[skylot]

@sergey-wowwow I don't see error here. Next code is correct and compiles:

    public static void test(List<? super Boolean> list) {
        list.add(Boolean.TRUE);
    }

Sure you can't insert in this list anything else instead Boolean.
Maybe you mistake ? super Boolean with ? extends Boolean ?
Anyway, these bounds include bound type, so it does not matter is class final or not, a definition will always compile. And usage in your sample is correct (check original code).

Here sample code to show differents between these bounds (JLS docs can be found here):

	class A { }
	class B extends A { }
	class C extends B { }

	public void check() {
		List<? super B> s = new ArrayList<A>(); // ok
		s.add(new A()); // error
		s.add(new B()); // ok
		s.add(new C()); // ok

		Object s0 = s.get(0); // ok
		A s1 = s.get(0); // error
		B s2 = s.get(0); // error
		C s3 = s.get(0); // error

		List<? extends B> e = new ArrayList<C>(); // ok
		e.add(new A()); // error
		e.add(new B()); // error
		e.add(new C()); // error

		Object e0 = e.get(0); // ok
		A e1 = e.get(0); // ok
		B e2 = e.get(0); // ok
		C e3 = e.get(0); // error
	}

Yeah, wildcard bounds are weird ;)