StructLayout (Java SE 25 & JDK 25)
Description: declaration: module: java.base, package: java.lang.foreign, interface: StructLayout
Keywords: java.lang.foreign.StructLayout interface

# Interface StructLayout

All Superinterfaces:
  `GroupLayout, MemoryLayout`

public sealed interface StructLayout extends GroupLayout
A group layout whose member layouts are laid out one after the other.

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
  `StructLayout`
  `withByteAlignment(long byteAlignment)`
  Returns a memory layout with the same characteristics as this layout, but with the given alignment constraint (in bytes).
  `StructLayout`
  `withName(String name)`
  Returns a memory layout with the same characteristics as this layout, but with the given name.
  `StructLayout`
  `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

    StructLayout 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:
      - `MemoryLayout.name()`

  - ### withoutName

    StructLayout 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:
      - `MemoryLayout.name()`

  - ### withByteAlignment

    StructLayout 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