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/OpenJDK 21

Interface UnionLayout

All Superinterfaces:
GroupLayoutPREVIEW, MemoryLayoutPREVIEW 
public sealed interface UnionLayout extends GroupLayoutPREVIEW
UnionLayout is a preview API of the Java platform.
Programs can only use UnionLayout when preview features are enabled.
Preview features may be removed in a future release, or upgraded to permanent features of the Java platform.
A group layout whose member layouts are laid out at the same starting offset.
Implementation Requirements:
Implementing classes are immutable, thread-safe and value-based.
Since:
20

Nested Class Summary

Nested classes/interfaces declared in interface java.lang.foreign.MemoryLayoutPREVIEW

MemoryLayout.PathElementPREVIEW

Method Summary

Modifier and Type Method Description
UnionLayoutPREVIEW withByteAlignment(long byteAlignment)
Returns a memory layout with the same characteristics as this layout, but with the given alignment constraint (in bytes).
UnionLayoutPREVIEW withName(String name)
Returns a memory layout with the same characteristics as this layout, but with the given name.
UnionLayoutPREVIEW withoutName()
Returns a memory layout with the same characteristics as this layout, but with no name.

Methods declared in interface java.lang.foreign.GroupLayoutPREVIEW

memberLayouts

Methods declared in interface java.lang.foreign.MemoryLayoutPREVIEW

byteAlignment, byteOffset, byteOffsetHandle, byteSize, equals, hashCode, name, select, sliceHandle, toString, varHandle

Method Details

withName

UnionLayoutPREVIEW withName(String name)
Returns a memory layout with the same characteristics as this layout, but with the given name.
Specified by:
withName in interface GroupLayoutPREVIEW
Specified by:
withName in interface MemoryLayoutPREVIEW
Parameters:
name - the layout name.
Returns:
a memory layout with the same characteristics as this layout, but with the given name
See Also:

withoutName

UnionLayoutPREVIEW withoutName()
Returns a memory layout with the same characteristics as this layout, but with no name.
Specified by:
withoutName in interface GroupLayoutPREVIEW
Specified by:
withoutName in interface MemoryLayoutPREVIEW
Returns:
a memory layout with the same characteristics as this layout, but with no name
See Also:

withByteAlignment

UnionLayoutPREVIEW withByteAlignment(long byteAlignment)
Returns a memory layout with the same characteristics as this layout, but with the given alignment constraint (in bytes).
Specified by:
withByteAlignment in interface GroupLayoutPREVIEW
Specified by:
withByteAlignment in interface MemoryLayoutPREVIEW
Parameters:
byteAlignment - the layout alignment constraint, expressed in bytes.
Returns:
a memory layout with the same characteristics as this layout, but with the given alignment constraint (in bytes)
Throws:
IllegalArgumentException - if byteAlignment is not a power of two.
IllegalArgumentException - if byteAlignment is less than M, where M is the maximum alignment constraint in any of the member layouts associated with this group layout.

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Documentation extracted from Debian's OpenJDK Development Kit package.
Licensed under the GNU General Public License, version 2, with the Classpath Exception.
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/java/lang/foreign/UnionLayout.html