# Uses of Interface
java.lang.foreign.FunctionDescriptor

Packages that use FunctionDescriptorPREVIEW
Package
Description
java.lang.foreign
Provides low-level access to memory and functions outside the Java runtime.

## Uses of FunctionDescriptorPREVIEW in java.lang.foreign

Methods in java.lang.foreign that return FunctionDescriptorPREVIEW
Modifier and Type
Method
Description
`FunctionDescriptorPREVIEW`
FunctionDescriptor.`appendArgumentLayouts(MemoryLayoutPREVIEW... addedLayouts)`
Returns a function descriptor with the given argument layouts appended to the argument layouts of this function descriptor.
`FunctionDescriptorPREVIEW`
FunctionDescriptor.`changeReturnLayout(MemoryLayoutPREVIEW newReturn)`
Returns a function descriptor with the provided return layout.
`FunctionDescriptorPREVIEW`
FunctionDescriptor.`dropReturnLayout()`
Returns a new function descriptor, with no return layout.
`FunctionDescriptorPREVIEW`
FunctionDescriptor.`insertArgumentLayouts(int index, MemoryLayoutPREVIEW... addedLayouts)`
Returns a function descriptor with the given argument layouts inserted at the given index, into the argument layout array of this function descriptor.
`static FunctionDescriptorPREVIEW`
FunctionDescriptor.`of(MemoryLayoutPREVIEW resLayout, MemoryLayoutPREVIEW... argLayouts)`
Creates a function descriptor with the given return and argument layouts.
`static FunctionDescriptorPREVIEW`
FunctionDescriptor.`ofVoid(MemoryLayoutPREVIEW... argLayouts)`
Creates a function descriptor with the given argument layouts and no return layout.
Methods in java.lang.foreign with parameters of type FunctionDescriptorPREVIEW
Modifier and Type
Method
Description
`MethodHandle`
Linker.`downcallHandle(FunctionDescriptorPREVIEW function, Linker.OptionPREVIEW... options)`
Creates a method handle which is used to call a foreign function with the given signature.
`MethodHandle`
Linker.`downcallHandle(MemorySegmentPREVIEW address, FunctionDescriptorPREVIEW function, Linker.OptionPREVIEW... options)`
Creates a method handle which is used to call a foreign function with the given signature and address.
`MemorySegmentPREVIEW`
Linker.`upcallStub(MethodHandle target, FunctionDescriptorPREVIEW function, ArenaPREVIEW arena, Linker.OptionPREVIEW... options)`
Creates an upcall stub which can be passed to other foreign functions as a function pointer, associated with the given arena.