1 /* 2 * Copyright 2003-2004 Sun Microsystems, Inc. All Rights Reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 20 * CA 95054 USA or visit www.sun.com if you need additional information or 21 * have any questions. 22 */ 23 24 /* 25 * @test 26 * @bug 4916607 27 * @summary Test casts (legal, warning, and errors) 28 * @author gafter 29 * 30 * @compile -Werror CastTest.java 31 */ 32 33 import java.util.*; 34 35 class CastTest { 36 37 // --- Directly transferring parameters --- 38 39 private class AA<T> { } 40 41 private class AB<T> extends AA<T> { } 42 private class AC<T> extends AA<Vector<T>> { } 43 private class AD<T> extends AA<Vector<? extends T>> { } 44 private class AE<T> extends AA<Vector<? super T>> { } 45 private class AF<T> extends AA<T[]> { } 46 private class AG<T> extends AA<String> { } 47 48 private void parameterTransfer() { 49 Object o; 50 51 o = (AB<String>) (AA<String>) null; // <<pass>> 52 o = (AC<String>) (AA<Vector<String>>) null; // <<pass>> 53 54 o = (AD<Number>) (AA<Vector<? extends Number>>) null; // <<pass>> 55 o = (AD<?>) (AA<Vector<? extends Object>>) null; // <<pass>> 56 o = (AD<Object>) (AA<Vector<?>>) null; // <<pass>> 57 58 o = (AE<String>) (AA<Vector<? super String>>) null; // <<pass>> 59 60 o = (AF<String>) (AA<String[]>) null; // <<pass>> 61 62 o = (AG<?>) (AA<String>) null; // <<pass>> 63 } 64 65 // --- Inconsistent matches --- 66 67 private class BA<T> { } 68 private class BB<T, S> { } 69 70 private class BC<T> extends BA<Integer> { } 71 private class BD<T> extends BB<T, T> { } 72 73 private void inconsistentMatches() { 74 Object o; 75 76 o = (BC<?>) (BA<Integer>) null; // <<pass>> 77 o = (BD<String>) (BB<String, String>) null; // <<pass>> 78 } 79 80 private void whyMustEverythingBeSo_______Complicated() { 81 // This has to work... 82 BD<Number> bd = new BD<Number>(); 83 BB<? extends Number, ? super Integer> bb = bd; 84 85 // 4916620: wildcards: legal cast is rejected 86 // bd = (BD<Number>) bb; // <<warn>> <<todo: cast-infer>> 87 } 88 89 // --- Transferring parameters via supertypes --- 90 91 private interface CA<T> { } 92 private interface CB<T> extends CA<T> { } 93 private interface CC<T> extends CA<T> { } 94 95 private class CD<T> implements CB<T> { } 96 private interface CE<T> extends CC<T> { } 97 98 private interface CF<S> { } 99 private interface CG<T> { } 100 private class CH<S, T> implements CF<S>, CG<T> { } 101 private interface CI<S> extends CF<S> { } 102 private interface CJ<T> extends CG<T> { } 103 private interface CK<S, T> extends CI<S>, CJ<T> { } 104 105 private void supertypeParameterTransfer() { 106 Object o; 107 o = (CE<String>) (CD<String>) null; // <<pass>> 108 109 // 4916622: unnecessary warning with cast 110 // o = (CH<String, Integer>) (CK<String, Integer>) null; // <<pass>> <<todo: cast-infer>> 111 } 112 113 // --- Disjoint --- 114 115 private interface DA<T> { } 116 private interface DB<T> extends DA<T> { } 117 private interface DC<T> extends DA<Integer> { } 118 119 private <N extends Number, I extends Integer, R extends Runnable, S extends String> void disjointness() { 120 Object o; 121 122 // Classes 123 o = (DA<? extends Number>) (DA<Integer>) null; // <<pass>> 124 o = (DA<? super Integer>) (DA<Number>) null; // <<pass>> 125 o = (DA<?>) (DA<Integer>) null; // <<pass>> 126 127 o = (DA<?>) (DA<? extends Integer>) null; // <<pass>> 128 129 o = (DA<?>) (DA<? super String>) null; // <<pass>> 130 131 o = (DA<?>) (DA<?>) null; // <<pass>> 132 133 // Typevars 134 o = (DA<? extends Number>) (DA<I>) null; // <<pass>> 135 136 // Raw (asymmetrical!) 137 o = (DA) (DB<Number>) null; // <<pass>> 138 o = (DA<?>) (DB) null; // <<pass>> 139 o = (DA<? extends Object>) (DB) null; // <<pass>> 140 141 o = (DB) (DA<Number>) null; // <<pass>> 142 o = (DB<?>) (DA) null; // <<pass>> 143 o = (DB<? extends Object>) (DA) null; // <<pass>> 144 145 // reported broken (5034609) 146 // o = (DC<?>) (DA<?>) null; // <<pass>> 147 } 148 149 }