aoqi@0: /*
aoqi@0:  * Copyright (c) 2003, 2004, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  */
aoqi@0: 
aoqi@0: /*
aoqi@0:  * @test
aoqi@0:  * @bug 4916607
aoqi@0:  * @summary Test casts (legal, warning, and errors)
aoqi@0:  * @author gafter
aoqi@0:  *
aoqi@0:  * @compile  -Werror CastTest.java
aoqi@0:  */
aoqi@0: 
aoqi@0: import java.util.*;
aoqi@0: 
aoqi@0: class CastTest {
aoqi@0: 
aoqi@0:     // --- Directly transferring parameters ---
aoqi@0: 
aoqi@0:     private class AA<T> { }
aoqi@0: 
aoqi@0:     private class AB<T> extends AA<T> { }
aoqi@0:     private class AC<T> extends AA<Vector<T>> { }
aoqi@0:     private class AD<T> extends AA<Vector<? extends T>> { }
aoqi@0:     private class AE<T> extends AA<Vector<? super T>> { }
aoqi@0:     private class AF<T> extends AA<T[]> { }
aoqi@0:     private class AG<T> extends AA<String> { }
aoqi@0: 
aoqi@0:     private void parameterTransfer() {
aoqi@0:         Object o;
aoqi@0: 
aoqi@0:         o = (AB<String>) (AA<String>) null; // <<pass>>
aoqi@0:         o = (AC<String>) (AA<Vector<String>>) null; // <<pass>>
aoqi@0: 
aoqi@0:         o = (AD<Number>) (AA<Vector<? extends Number>>) null; // <<pass>>
aoqi@0:         o = (AD<?>) (AA<Vector<? extends Object>>) null; // <<pass>>
aoqi@0:         o = (AD<Object>) (AA<Vector<?>>) null; // <<pass>>
aoqi@0: 
aoqi@0:         o = (AE<String>) (AA<Vector<? super String>>) null; // <<pass>>
aoqi@0: 
aoqi@0:         o = (AF<String>) (AA<String[]>) null; // <<pass>>
aoqi@0: 
aoqi@0:         o = (AG<?>) (AA<String>) null; // <<pass>>
aoqi@0:     }
aoqi@0: 
aoqi@0:     // --- Inconsistent matches ---
aoqi@0: 
aoqi@0:     private class BA<T> { }
aoqi@0:     private class BB<T, S> { }
aoqi@0: 
aoqi@0:     private class BC<T> extends BA<Integer> { }
aoqi@0:     private class BD<T> extends BB<T, T> { }
aoqi@0: 
aoqi@0:     private void inconsistentMatches() {
aoqi@0:         Object o;
aoqi@0: 
aoqi@0:         o = (BC<?>) (BA<Integer>) null; // <<pass>>
aoqi@0:         o = (BD<String>) (BB<String, String>) null; // <<pass>>
aoqi@0:     }
aoqi@0: 
aoqi@0:     private void whyMustEverythingBeSo_______Complicated() {
aoqi@0:         // This has to work...
aoqi@0:         BD<Number> bd = new BD<Number>();
aoqi@0:         BB<? extends Number, ? super Integer> bb = bd;
aoqi@0: 
aoqi@0:         // 4916620: wildcards: legal cast is rejected
aoqi@0:         // bd = (BD<Number>) bb; // <<warn>> <<todo: cast-infer>>
aoqi@0:     }
aoqi@0: 
aoqi@0:     // --- Transferring parameters via supertypes ---
aoqi@0: 
aoqi@0:     private interface CA<T> { }
aoqi@0:     private interface CB<T> extends CA<T> { }
aoqi@0:     private interface CC<T> extends CA<T> { }
aoqi@0: 
aoqi@0:     private class CD<T> implements CB<T> { }
aoqi@0:     private interface CE<T> extends CC<T> { }
aoqi@0: 
aoqi@0:     private interface CF<S> { }
aoqi@0:     private interface CG<T> { }
aoqi@0:     private class CH<S, T> implements CF<S>, CG<T> { }
aoqi@0:     private interface CI<S> extends CF<S> { }
aoqi@0:     private interface CJ<T> extends CG<T> { }
aoqi@0:     private interface CK<S, T> extends CI<S>, CJ<T> { }
aoqi@0: 
aoqi@0:     private void supertypeParameterTransfer() {
aoqi@0:         Object o;
aoqi@0:         o = (CE<String>) (CD<String>) null; // <<pass>>
aoqi@0: 
aoqi@0:         // 4916622: unnecessary warning with cast
aoqi@0:         // o = (CH<String, Integer>) (CK<String, Integer>) null; // <<pass>> <<todo: cast-infer>>
aoqi@0:     }
aoqi@0: 
aoqi@0:     // --- Disjoint ---
aoqi@0: 
aoqi@0:     private interface DA<T> { }
aoqi@0:     private interface DB<T> extends DA<T> { }
aoqi@0:     private interface DC<T> extends DA<Integer> { }
aoqi@0: 
aoqi@0:     private <N extends Number, I extends Integer, R extends Runnable, S extends String> void disjointness() {
aoqi@0:         Object o;
aoqi@0: 
aoqi@0:         // Classes
aoqi@0:         o = (DA<? extends Number>) (DA<Integer>) null; // <<pass>>
aoqi@0:         o = (DA<? super Integer>) (DA<Number>) null; // <<pass>>
aoqi@0:         o = (DA<?>) (DA<Integer>) null; // <<pass>>
aoqi@0: 
aoqi@0:         o = (DA<?>) (DA<? extends Integer>) null; // <<pass>>
aoqi@0: 
aoqi@0:         o = (DA<?>) (DA<? super String>) null; // <<pass>>
aoqi@0: 
aoqi@0:         o = (DA<?>) (DA<?>) null; // <<pass>>
aoqi@0: 
aoqi@0:         // Typevars
aoqi@0:         o = (DA<? extends Number>) (DA<I>) null; // <<pass>>
aoqi@0: 
aoqi@0:         // Raw (asymmetrical!)
aoqi@0:         o = (DA) (DB<Number>) null; // <<pass>>
aoqi@0:         o = (DA<?>) (DB) null; // <<pass>>
aoqi@0:         o = (DA<? extends Object>) (DB) null; // <<pass>>
aoqi@0: 
aoqi@0:         o = (DB) (DA<Number>) null; // <<pass>>
aoqi@0:         o = (DB<?>) (DA) null; // <<pass>>
aoqi@0:         o = (DB<? extends Object>) (DA) null; // <<pass>>
aoqi@0: 
aoqi@0:         // reported broken (5034609)
aoqi@0:         // o = (DC<?>) (DA<?>) null; // <<pass>>
aoqi@0:     }
aoqi@0: 
aoqi@0: }