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