1 /*
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 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
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 7  * published by the Free Software Foundation.  Oracle designates this
 8  * particular file as subject to the "Classpath" exception as provided
 9  * by Oracle in the LICENSE file that accompanied this code.
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12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14  * version 2 for more details (a copy is included in the LICENSE file that
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25 
26 package java.lang.foreign;
27 
28 import java.util.List;
29 
30 /**
31  * A compound layout that is an aggregation of multiple, heterogeneous <em>member layouts</em>. There are two ways in which member layouts
32  * can be combined: if member layouts are laid out one after the other, the resulting group layout is a
33  * {@linkplain StructLayout struct layout}; conversely, if all member layouts are laid out at the same starting offset,
34  * the resulting group layout is a {@linkplain UnionLayout union layout}.
35  *
36  * @implSpec
37  * This class is immutable, thread-safe and <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>.
38  *
39  * @sealedGraph
40  * @since 22
41  */
42 public sealed interface GroupLayout extends MemoryLayout permits StructLayout, UnionLayout {
43 
44     /**
45      * {@return the member layouts of this group layout}
46      *
47      * @apiNote the order in which member layouts are returned is the same order in which member layouts have
48      * been passed to one of the group layout factory methods (see {@link MemoryLayout#structLayout(MemoryLayout...)},
49      * {@link MemoryLayout#unionLayout(MemoryLayout...)}).
50      */
51     List<MemoryLayout> memberLayouts();
52 
53     /**
54      * {@inheritDoc}
55      */
56     @Override
57     GroupLayout withName(String name);
58 
59     /**
60      * {@inheritDoc}
61      */
62     @Override
63     GroupLayout withoutName();
64 
65     /**
66      * {@inheritDoc}
67      * @throws IllegalArgumentException {@inheritDoc}
68      * @throws IllegalArgumentException if {@code byteAlignment} is less than {@code M}, where {@code M} is the maximum alignment
69      * constraint in any of the member layouts associated with this group layout.
70      */
71     @Override
72     GroupLayout withByteAlignment(long byteAlignment);
73 }