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

Modifier and Type	Interface	Description
`static interface`	`MemoryLayout.PathElement`	An element in a layout path.

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

Modifier and Type	Method	Description
`List<MemoryLayout>`	`memberLayouts()`	Returns the member layouts of this group layout.

Methods declared in interface MemoryLayout

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

Modifier and Type	Method	Description
`VarHandle`	`arrayElementVarHandle(MemoryLayout.PathElement... elements)`	Creates a var handle that accesses adjacent elements in a memory segment at offsets selected by the given layout path, where the accessed elements have this layout, and where the initial layout in the path is this layout.
`long`	`byteAlignment()`	Returns the alignment constraint associated with this layout, expressed in bytes.
`long`	`byteOffset(MemoryLayout.PathElement... elements)`	Computes the offset, in bytes, of the layout selected by the given layout path, where the initial layout in the path is this layout.
`MethodHandle`	`byteOffsetHandle(MemoryLayout.PathElement... elements)`	Creates a method handle that computes the offset, in bytes, of the layout selected by the given layout path, where the initial layout in the path is this layout.
`long`	`byteSize()`	Returns the layout size, in bytes.
`boolean`	`equals(Object other)`	Compares the specified object with this layout for equality.
`int`	`hashCode()`	Returns the hash code value for this layout.
`Optional<String>`	`name()`	Returns the name (if any) associated with this layout.
`long`	`scale(long offset, long index)`	Returns `offset + (byteSize() * index)`.
`MethodHandle`	`scaleHandle()`	Returns a method handle that can be used to invoke `MemoryLayout.scale(long, long)` on this layout.
`MemoryLayout`	`select(MemoryLayout.PathElement... elements)`	Returns the layout selected from the provided path, where the initial layout in the path is this layout.
`MethodHandle`	`sliceHandle(MemoryLayout.PathElement... elements)`	Creates a method handle which, given a memory segment, returns a slice corresponding to the layout selected by the given layout path, where the initial layout in the path is this layout.
`String`	`toString()`	Returns the string representation of this layout.
`VarHandle`	`varHandle(MemoryLayout.PathElement... elements)`	Creates a var handle that accesses a memory segment at the offset selected by the given layout path, where the initial layout in the path is this layout.

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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