1/*
2 * @test /nodynamiccopyright/
3 * @bug 4916607 4931647
4 * @summary an extends-bound (covariant) wildcard is like readonly
5 * @author gafter
6 *
7 * @compile/fail/ref=Readonly.out -XDrawDiagnostics Readonly.java
8 */
9
10class Err<T> {
11    Err<T> get() { return null; }
12    void put(Err<T> t) {}
13
14    static void f(Err<? extends String> e) {
15        e.put(e.get());
16    }
17}
18