jdk8-mips64-public/langtools: test/tools/javac/generics/wildcards/pos/CastTest.java@0b6cc4ea670f

     1 /*

     2  * Copyright (c) 2003, 2004, Oracle and/or its affiliates. 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 Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    24 /*

    25  * @test

    26  * @bug 4916607

    27  * @summary Test casts (legal, warning, and errors)

    28  * @author gafter

    29  *

    30  * @compile  -Werror CastTest.java

    31  */

    33 import java.util.*;

    35 class CastTest {

    37     // --- Directly transferring parameters ---

    39     private class AA<T> { }

    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> { }

    48     private void parameterTransfer() {

    49         Object o;

    51         o = (AB<String>) (AA<String>) null; // <<pass>>

    52         o = (AC<String>) (AA<Vector<String>>) null; // <<pass>>

    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>>

    58         o = (AE<String>) (AA<Vector<? super String>>) null; // <<pass>>

    60         o = (AF<String>) (AA<String[]>) null; // <<pass>>

    62         o = (AG<?>) (AA<String>) null; // <<pass>>

    63     }

    65     // --- Inconsistent matches ---

    67     private class BA<T> { }

    68     private class BB<T, S> { }

    70     private class BC<T> extends BA<Integer> { }

    71     private class BD<T> extends BB<T, T> { }

    73     private void inconsistentMatches() {

    74         Object o;

    76         o = (BC<?>) (BA<Integer>) null; // <<pass>>

    77         o = (BD<String>) (BB<String, String>) null; // <<pass>>

    78     }

    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;

    85         // 4916620: wildcards: legal cast is rejected

    86         // bd = (BD<Number>) bb; // <<warn>> <<todo: cast-infer>>

    87     }

    89     // --- Transferring parameters via supertypes ---

    91     private interface CA<T> { }

    92     private interface CB<T> extends CA<T> { }

    93     private interface CC<T> extends CA<T> { }

    95     private class CD<T> implements CB<T> { }

    96     private interface CE<T> extends CC<T> { }

    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> { }

   105     private void supertypeParameterTransfer() {

   106         Object o;

   107         o = (CE<String>) (CD<String>) null; // <<pass>>

   109         // 4916622: unnecessary warning with cast

   110         // o = (CH<String, Integer>) (CK<String, Integer>) null; // <<pass>> <<todo: cast-infer>>

   111     }

   113     // --- Disjoint ---

   115     private interface DA<T> { }

   116     private interface DB<T> extends DA<T> { }

   117     private interface DC<T> extends DA<Integer> { }

   119     private <N extends Number, I extends Integer, R extends Runnable, S extends String> void disjointness() {

   120         Object o;

   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>>

   127         o = (DA<?>) (DA<? extends Integer>) null; // <<pass>>

   129         o = (DA<?>) (DA<? super String>) null; // <<pass>>

   131         o = (DA<?>) (DA<?>) null; // <<pass>>

   133         // Typevars

   134         o = (DA<? extends Number>) (DA<I>) null; // <<pass>>

   136         // Raw (asymmetrical!)

   137         o = (DA) (DB<Number>) null; // <<pass>>

   138         o = (DA<?>) (DB) null; // <<pass>>

   139         o = (DA<? extends Object>) (DB) null; // <<pass>>

   141         o = (DB) (DA<Number>) null; // <<pass>>

   142         o = (DB<?>) (DA) null; // <<pass>>

   143         o = (DB<? extends Object>) (DA) null; // <<pass>>

   145         // reported broken (5034609)

   146         // o = (DC<?>) (DA<?>) null; // <<pass>>

   147     }

   149 }

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