Struct FastAlloc

pub struct FastAlloc { /* private fields */ }

Fast allocator, effectively working as a cache.

This type implements Default and Copy. This type is intended to stored in a variable or a field in a struct before allocating code, and used as the seocnd argument in crate::boxed::Box::new_in and crate::vec::Vec::new_in.

crate::boxed::Box::new and crate::vec::Vec::new are slower than using this field because they use FastAlloc::default internally, which is slower than store FastAlloc in a variable.

Misc

It implements std::alloc::Allocator. So it can be used as the second argument for std::boxed::Box and std::vec::Vec. But you should prefer using crate::boxed::Box and crate::vec::Vec, which is a wrapper around the original types.

Implementations

impl FastAlloc

pub const fn global() -> Self

crate::boxed::Box or crate::vec::Vec created with this instance is managed by the global allocator and it can outlive the crate::Allocator instance used for [Allocator::scope].

Trait Implementations

impl Allocator for FastAlloc

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

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

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)

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)

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)

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)

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)

Attempts to shrink the memory block.

fn by_ref(&self) -> &Self

where Self: Sized,

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

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

impl Clone for FastAlloc

fn clone(&self) -> FastAlloc

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Default for FastAlloc

fn default() -> Self

Returns the “default value” for a type.

impl Copy for FastAlloc