Struct alloc::alloc::Global

pub struct Global;

🔬 This is a nightly-only experimental API. (allocator_api #32838)

This is supported on non-crate feature miri-test-libstd or test or doctest only.

The global memory allocator.

This type implements the Allocator trait by forwarding calls to the allocator registered with the #[global_allocator] attribute if there is one, or the std crate’s default.

Note: while this type is unstable, the functionality it provides can be accessed through the free functions in alloc.

Trait Implementations

impl Allocator for Global

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

🔬 This is a nightly-only experimental API. (allocator_api #32838)

Attempts to allocate a block of memory.

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

🔬 This is a nightly-only experimental API. (allocator_api #32838)

Behaves like allocate, but also ensures that the returned memory is zero-initialized.

unsafe fn deallocate(&self, ptr: NonNull<u8>, layout: Layout)

🔬 This is a nightly-only experimental API. (allocator_api #32838)

Deallocates the memory referenced by ptr.

unsafe fn grow(
    &self,
    ptr: NonNull<u8>,
    old_layout: Layout,
    new_layout: Layout
) -> Result<NonNull<[u8]>, AllocError>

🔬 This is a nightly-only experimental API. (allocator_api #32838)

Attempts to extend the memory block.

unsafe fn grow_zeroed(
    &self,
    ptr: NonNull<u8>,
    old_layout: Layout,
    new_layout: Layout
) -> Result<NonNull<[u8]>, AllocError>

🔬 This is a nightly-only experimental API. (allocator_api #32838)

Behaves like grow, but also ensures that the new contents are set to zero before being returned.

unsafe fn shrink(
    &self,
    ptr: NonNull<u8>,
    old_layout: Layout,
    new_layout: Layout
) -> Result<NonNull<[u8]>, AllocError>

🔬 This is a nightly-only experimental API. (allocator_api #32838)

Attempts to shrink the memory block.

fn by_ref(&self) -> &Self

🔬 This is a nightly-only experimental API. (allocator_api #32838)

Creates a “by reference” adapter for this instance of Allocator.

impl Clone for Global

fn clone(&self) -> Global

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Global

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Global

fn default() -> Global

Returns the “default value” for a type.

impl Copy for Global