# [−][src]Struct std::alloc::Global

    pub struct Global;

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

The global memory allocator.

This type implements the `AllocRef` 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 AllocRef for Global`[src]

#### `fn alloc(&mut self, layout: Layout) -> Result<(NonNull<u8>, usize), AllocErr>`[src]

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

On success, returns a pointer meeting the size and alignment guarantees of `layout` and the actual size of the allocated block, which must be greater than or equal to `layout.size()`. Read more

#### `unsafe fn dealloc(&mut self, ptr: NonNull<u8>, layout: Layout)`[src]

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

Deallocate the memory referenced by `ptr`. Read more

#### `unsafe fn realloc(
&mut self,
ptr: NonNull<u8>,
layout: Layout,
new_size: usize
) -> Result<(NonNull<u8>, usize), AllocErr>`[src]

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

Returns a pointer suitable for holding data described by a new layout with `layout`’s alignment and a size given by `new_size` and the actual size of the allocated block. The latter is greater than or equal to `layout.size()`. To accomplish this, the allocator may extend or shrink the allocation referenced by `ptr` to fit the new layout. Read more

#### `fn alloc_zeroed(
&mut self,
layout: Layout
) -> Result<(NonNull<u8>, usize), AllocErr>`[src]

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

Behaves like `alloc`, but also ensures that the contents are set to zero before being returned. Read more

#### `unsafe fn realloc_zeroed(
&mut self,
ptr: NonNull<u8>,
layout: Layout,
new_size: usize
) -> Result<(NonNull<u8>, usize), AllocErr>`[src]

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

Behaves like `realloc`, but also ensures that the new contents are set to zero before being returned. Read more

#### `unsafe fn grow_in_place(
&mut self,
ptr: NonNull<u8>,
layout: Layout,
new_size: usize
) -> Result<usize, CannotReallocInPlace>`[src]

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

Attempts to extend the allocation referenced by `ptr` to fit `new_size`. Read more

#### `unsafe fn grow_in_place_zeroed(
&mut self,
ptr: NonNull<u8>,
layout: Layout,
new_size: usize
) -> Result<usize, CannotReallocInPlace>`[src]

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

Behaves like `grow_in_place`, but also ensures that the new contents are set to zero before being returned. Read more

#### `unsafe fn shrink_in_place(
&mut self,
ptr: NonNull<u8>,
layout: Layout,
new_size: usize
) -> Result<usize, CannotReallocInPlace>`[src]

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

Attempts to shrink the allocation referenced by `ptr` to fit `new_size`. Read more

### `impl Clone for Global`[src]

#### `fn clone(&self) -> Global`[src]

Returns a copy of the value. Read more

#### `fn clone_from(&mut self, source: &Self)`1.0.0[src]

Performs copy-assignment from `source`. Read more

### `impl Copy for Global`[src]

### `impl Debug for Global`[src]

#### `fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`[src]

Formats the value using the given formatter. Read more

### `impl Default for Global`[src]

#### `fn default() -> Global`[src]

Returns the "default value" for a type. Read more

## Auto Trait Implementations

### `impl RefUnwindSafe for Global`

### `impl Send for Global`

### `impl Sync for Global`

### `impl Unpin for Global`

### `impl UnwindSafe for Global`

## Blanket Implementations

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `fn type_id(&self) -> TypeId`[src]

Gets the `TypeId` of `self`. Read more

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

#### `fn borrow(&self) -> &T`[src]

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

#### `fn borrow_mut(&mut self) -> &mut T`[src]

Mutably borrows from an owned value. Read more

### `impl<T> From<T> for T`[src]

#### `fn from(t: T) -> T`[src]

Performs the conversion.

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `fn into(self) -> U`[src]

Performs the conversion.

### `impl<T> ToOwned for T where
T: Clone,` [src]

#### `type Owned = T`

The resulting type after obtaining ownership.

#### `fn to_owned(&self) -> T`[src]

Creates owned data from borrowed data, usually by cloning. Read more

#### `fn clone_into(&self, target: &mut T)`[src]

🔬 This is a nightly-only experimental API. (`toowned_clone_into` #41263)

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

#### `fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>`[src]

Performs the conversion.

### `impl<T, U> TryInto<U> for T where
U: TryFrom<T>,` [src]

#### `type Error = <U as TryFrom<T>>::Error`

The type returned in the event of a conversion error.

#### `fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>`[src]

Performs the conversion.