test/langtools/tools/javac/generics/wildcards/AssignmentSameType.java

/*
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 * 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
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 *
 * 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.
 *
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/*
 * @test
 * @summary Test subtyping for wildcards with the same type bound.
 *
 * @compile/fail/ref=AssignmentSameType.out -XDrawDiagnostics AssignmentSameType.java
 */

public class AssignmentSameType {

    public static void main(String[] args) {
        Ref<B> exact = null;
        Ref<? extends B> ebound = null;
        Ref<? super B> sbound = null;
        Ref<?> unbound = null;

;       exact = exact;          // <<pass>> <A> = <A>

        ebound = exact;         // <<pass>> <? extends A> = <A>
        ebound = ebound;        // <<pass>> <? extends A> = <? extends A>

        sbound = exact;         // <<pass>> <? super A> = <A>
        sbound = sbound;        // <<pass>> <? super A> = <? super A>

        unbound = exact;        // <<pass>> <?> = <A>
        unbound = ebound;       // <<pass>> <?> = <? extends A>
        unbound = sbound;       // <<pass>> <?> = <? super A>
        unbound = unbound;      // <<pass>> <?> = <?>

        exact = ebound;         // <<fail>> <A> = <? extends A>
        exact = sbound;         // <<fail>> <A> = <? super A>
        exact = unbound;        // <<fail>> <A> = <?>
        ebound = sbound;        // <<fail>> <? extends A> = <? super A>
        ebound = unbound;       // <<fail>> <? extends A> = <?>
        sbound = ebound;        // <<fail>> <? super A> = <? extends A>
        sbound = unbound;       // <<fail>> <? super A> = <?>
    }
}

class Ref<A> {}
class B {}