Struct NoOpAllocator 

pub struct NoOpAllocator;

An allocator that does not perform any actual allocation or deallocation.

This is useful when constructing Box and other dynamically allocated collections from raw pointers to pre-existing memory that is owned and managed elsewhere (e.g., by C++ code), to ensure that dropping the collection does not deallocate the underlying memory.

Trait Implementations

impl Allocator for NoOpAllocator

fn allocate(&self, _layout: Layout) -> Result<NonNull<[u8]>, AllocError>

Allocates memory as described by the given layout.

unsafe fn deallocate(&self, _ptr: NonNull<u8>, _layout: Layout)

Safety

unsafe fn grow( &self, _ptr: NonNull<u8>, _old_layout: Layout, _new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

Safety

unsafe fn shrink( &self, _ptr: NonNull<u8>, _old_layout: Layout, _new_layout: Layout, ) -> Result<NonNull<[u8]>, AllocError>

Safety

fn allocate_zeroed(&self, _layout: Layout) -> Result<NonNull<[u8]>, AllocError>

Allocates zeroed memory as described by the given layout.

impl Clone for NoOpAllocator

fn clone(&self) -> NoOpAllocator

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Default for NoOpAllocator

fn default() -> NoOpAllocator

Returns the “default value” for a type.