Struct alloc_wg::alloc::NonZeroLayout

pub struct NonZeroLayout(_);

Non-zero Layout of a block of memory.

An instance of NonZeroLayout describes a particular layout of memory. You build a NonZeroLayout up as an input to give to an allocator.

All layouts have an associated non-negative size and a power-of-two alignment.

Methods

impl NonZeroLayout

pub fn from_size_align(size: usize, align: usize) -> Result<Self, LayoutErr>

Constructs a Layout from a given size and align, or returns LayoutErr if either of the following conditions are not met:

• align must not be zero,
• align must be a power of two,
• size must not be zero,
• size, when rounded up to the nearest multiple of align, must not overflow (i.e., the rounded value must be less than usize::MAX).

pub const unsafe fn from_size_align_unchecked(size: usize, align: usize) -> Self

Creates a layout, bypassing all checks.

Safety

This function is unsafe as it does not verify the preconditions from NonZeroLayout::from_size_align.

pub fn size(&self) -> usize

The minimum size in bytes for a memory block of this layout.

pub fn align(&self) -> usize

The minimum byte alignment for a memory block of this layout.

pub fn new<T>() -> Result<Self, LayoutErr>

Constructs a NonZeroLayout suitable for holding a value of type T.

Returns Err if T is a ZST.

pub const unsafe fn new_unchecked<T>() -> Self

Constructs a NonZeroLayout suitable for holding a value of type T.

Safety

This function is unsafe as it does not verify the preconditions from NonZeroLayout::new.

pub fn for_value<T: ?Sized>(t: &T) -> Result<Self, LayoutErr>

Produces layout describing a record that could be used to allocate backing structure for T (which could be a trait or other unsized type like a slice).

Returns Err if T is a ZST.

pub unsafe fn for_value_unchecked<T: ?Sized>(t: &T) -> Self

Produces layout describing a record that could be used to allocate backing structure for T (which could be a trait or other unsized type like a slice).

Safety

This function is unsafe as it does not verify the preconditions from NonZeroLayout::for_value.

Trait Implementations

impl Into<Layout> for NonZeroLayout

fn into(self) -> Layout

Performs the conversion.

impl Clone for NonZeroLayout

fn clone(&self) -> NonZeroLayout

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Copy for NonZeroLayout

impl Eq for NonZeroLayout

impl PartialEq<NonZeroLayout> for NonZeroLayout

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

This method tests for self and other values to be equal, and is used by ==.

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

This method tests for !=.

impl Debug for NonZeroLayout

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

Formats the value using the given formatter.

impl TryFrom<Layout> for NonZeroLayout

type Error = LayoutErr

The type returned in the event of a conversion error.

fn try_from(layout: Layout) -> Result<Self, Self::Error>

Performs the conversion.