Struct Allocation 

pub struct Allocation<'a, T: ?Sized = u8> {
    pub ptr: NonNull<T>,
    pub lifetime: AllocTime<'a>,
    pub level: Level,
}

A successful allocation and current Level.

Design notes

The ptr field is, when returned by an allocator, always a valid pointer. However, we can not express this as a mutable reference to MaybeUninit for unsized types. Instead, a pointer is needed to provide address, provenance, and pointer metadata. The cost of this is that we discard the validity information which has to be unsafely re-applied by the user (of course, verifying that the point actually is valid since this type is fully public).

Fields

ptr: NonNull<T>

Pointer to the uninitialized region with specified layout.

lifetime: AllocTime<'a>

The lifetime of the allocation.

level: Level

The observed amount of consumed bytes after the allocation.

For Bump this is precise, i.e. the offset of the ptr in the arena data is the level’s byte offset minus the layout size.

Implementations

impl<T> Allocation<'_, T>

pub fn level_start(&self) -> Level

Get the Level at which the allocation starts.

This can be used as the level of Bump::get_unchecked with the arena it as allocated from. There is an equivalent method for some unsized types.

Usage

use static_alloc::Bump;

let arena = Bump::<[u32; 4]>::uninit();
let alloc = arena.get::<u32>().unwrap();

assert_eq!(alloc.level.byte_offset(), 4);
assert_eq!(alloc.level_start().byte_offset(), 0);

impl<T> Allocation<'_, [T]>

pub fn level_start(&self) -> Level

Get the Level at which the allocation starts.

This can be used as the level of Bump::get_unchecked with the arena it as allocated from. There is an equivalent method for some unsized types.

See the sized Allocation::level_start.

impl<'alloc, T> Allocation<'alloc, T>

pub unsafe fn leak(self, val: T) -> &'alloc mut T

Write a value into the allocation and leak it.

Safety

Must have been allocated for a layout that fits the layout of T previously. The pointer must not be aliased.

Usage

Consider the alternative Bump::leak to safely allocate and directly leak a value.

pub unsafe fn boxed(self, val: T) -> LeakBox<'alloc, T>

Write a value into the allocation and own it.

Safety

Must have been allocated for a layout that fits the layout of T previously. The pointer must not be aliased.

Usage

Consider the alternative Bump::leak to safely allocate and directly leak a value.

pub unsafe fn uninit(self) -> &'alloc mut MaybeUninit<T>

Convert this into a mutable reference to an uninitialized slot.

Safety

Must have been allocated for a layout that fits the layout of T previously.

Trait Implementations

impl<'a, T: Clone + ?Sized> Clone for Allocation<'a, T>

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<'a, T: Copy + ?Sized> Copy for Allocation<'a, T>

impl<'a, T: Debug + ?Sized> Debug for Allocation<'a, T>

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

Formats the value using the given formatter.

impl<'a, T: Eq + ?Sized> Eq for Allocation<'a, T>

impl<'a, T: Ord + ?Sized> Ord for Allocation<'a, T>

fn cmp(&self, other: &Self) -> Ordering

This method returns an Ordering between self and other.

fn max(self, other: Self) -> Self

where Self: Sized,

Compares and returns the maximum of two values.

fn min(self, other: Self) -> Self

where Self: Sized,

Compares and returns the minimum of two values.

fn clamp(self, min: Self, max: Self) -> Self

where Self: Sized,

Restrict a value to a certain interval.

fn clamp_to<R>(self, range: R) -> Self

where Self: Sized, R: ClampBounds<Self>,

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

Restrict a value to a certain range.

impl<'a, T: PartialEq + ?Sized> PartialEq for Allocation<'a, T>

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl<'a, T: PartialOrd + ?Sized> PartialOrd for Allocation<'a, T>

fn partial_cmp(&self, other: &Self) -> Option<Ordering>

This method returns an ordering between self and other values if one exists.

fn lt(&self, other: &Rhs) -> bool

Tests less than (for self and other) and is used by the < operator.

fn le(&self, other: &Rhs) -> bool

Tests less than or equal to (for self and other) and is used by the <= operator.

fn gt(&self, other: &Rhs) -> bool

Tests greater than (for self and other) and is used by the > operator.

fn ge(&self, other: &Rhs) -> bool

Tests greater than or equal to (for self and other) and is used by the >= operator.

impl<'a, T: PartialEq + ?Sized> StructuralPartialEq for Allocation<'a, T>