pub struct DroplessArena {
    pub(crate) start: Cell<*mut u8>,
    pub(crate) end: Cell<*mut u8>,
    pub(crate) chunks: RefCell<Vec<ArenaChunk>>,
}
Expand description

An arena that can hold objects of multiple different types that impl Copy and/or satisfy !mem::needs_drop.

Fields§

§start: Cell<*mut u8>

A pointer to the start of the free space.

§end: Cell<*mut u8>

A pointer to the end of free space.

The allocation proceeds downwards from the end of the chunk towards the start. (This is slightly simpler and faster than allocating upwards, see https://fitzgeraldnick.com/2019/11/01/always-bump-downwards.html.) When this pointer crosses the start pointer, a new chunk is allocated.

This is kept aligned to DROPLESS_ALIGNMENT.

§chunks: RefCell<Vec<ArenaChunk>>

A vector of arena chunks.

Implementations§

source§

impl DroplessArena

source

pub(crate) fn grow(&self, layout: Layout)

source

pub fn alloc_raw(&self, layout: Layout) -> *mut u8

source

pub fn alloc<T>(&self, object: T) -> &mut T

source

pub fn alloc_slice<T>(&self, slice: &[T]) -> &mut [T]where T: Copy,

Allocates a slice of objects that are copied into the DroplessArena, returning a mutable reference to it. Will panic if passed a zero-sized type.

Panics:

  • Zero-sized types
  • Zero-length slices
source

pub(crate) unsafe fn write_from_iter<T, I: Iterator<Item = T>>( &self, iter: I, len: usize, mem: *mut T ) -> &mut [T]

Safety

The caller must ensure that mem is valid for writes up to size_of::<T>() * len.

source

pub fn alloc_from_iter<T, I: IntoIterator<Item = T>>(&self, iter: I) -> &mut [T]

Trait Implementations§

source§

impl Default for DroplessArena

source§

fn default() -> DroplessArena

Returns the “default value” for a type. Read more
source§

impl Send for DroplessArena

Auto Trait Implementations§

Blanket Implementations§

source§

impl<T> Any for Twhere T: 'static + ?Sized,

source§

fn type_id(&self) -> TypeId

Gets the TypeId of self. Read more
source§

impl<T> Borrow<T> for Twhere T: ?Sized,

source§

fn borrow(&self) -> &T

Immutably borrows from an owned value. Read more
source§

impl<T> BorrowMut<T> for Twhere T: ?Sized,

source§

fn borrow_mut(&mut self) -> &mut T

Mutably borrows from an owned value. Read more
source§

impl<T> From<T> for T

source§

fn from(t: T) -> T

Returns the argument unchanged.

source§

impl<T, U> Into<U> for Twhere U: From<T>,

source§

fn into(self) -> U

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

source§

impl<T, U> TryFrom<U> for Twhere U: Into<T>,

§

type Error = Infallible

The type returned in the event of a conversion error.
source§

fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>

Performs the conversion.
source§

impl<T, U> TryInto<U> for Twhere U: TryFrom<T>,

§

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

The type returned in the event of a conversion error.
source§

fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>

Performs the conversion.

Layout§

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 48 bytes