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/OpenJDK 25

Interface UnionLayout

All Superinterfaces:
GroupLayout, MemoryLayout
public sealed interface UnionLayout extends GroupLayout
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:
22

Nested Class Summary

Nested classes/interfaces declared in interface MemoryLayout

MemoryLayout.PathElement

Method Summary

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

Methods declared in interface GroupLayout

memberLayouts

Methods declared in interface MemoryLayout

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

Method Details

withName

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

withoutName

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

withByteAlignment

UnionLayout 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 GroupLayout
Specified by:
withByteAlignment in interface MemoryLayout
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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https://docs.oracle.com/en/java/javase/25/docs/api/java.base/java/lang/foreign/UnionLayout.html