test/langtools/tools/javac/ImplicitToString.java

/*
 * Copyright (c) 1999, 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.
 *
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 */

/**
 * @test
 * @bug 4244408
 * @summary toString() should be called implicitly when += is used.
 *
 * @run main ImplicitToString
 */


// The failure for this test is a ClassCastException when the code is run.

import java.util.ArrayList;

public class ImplicitToString {
    public static void main(String[] args) {
        String s = "";
        ArrayList al = new ArrayList();
        al.add(new Object());

        // In the following line, toString() should be implicitly called.
        s += al.get(0);
    }
}