Struct pinned_init::static_uninit::StaticUninit

#[repr(transparent)]
pub struct StaticUninit<T, const INIT: bool> { /* private fields */ }

This type is similar to MaybeUninit, but it provides a safe interface for initialization which can then be used statically. It represents a Value which is

• uninitialized iff INIT == false
• initialized iff INIT == true

StaticUninit<T, true> behaves like T, as it implements [DerefMut<Target = T>], BorrowMut<T> and more, you can also take the value directly with StaticUninit::into_inner.

It also gives access to an unsafe interface allowing arbitrary modifications of the underlying MaybeUninit if there are more complex initialization requirements.

Safety

If at any point you use one of the unsafe methods to access and modify the inner MaybeUninit<T>, you need to keep track of the initialization state of that particular StaticUninit until you pass it to some other part of the code. It is unsound to release a StaticUninit in

• a partially initialized state
• an unknown state of initialization to other code, StaticUninit always is either fully initialized, or fully uninitialized. To achive partial initialization, use smaller components that can be fully initialized seperatly and then create a wrapper struct using multiple wrapping StaticUninits (this is achieved by the #[pinned_init] proc macro attribute).

Implementations

impl<T> StaticUninit<T, true>

pub fn new(data: T) -> Self

Creates an already initialized T with its init status statically tracked.

pub fn into_inner(self) -> T

Retrieve the inner value of this StaticUninit.

pub unsafe fn raw_get(this: *mut Self) -> *mut T

Gets a mutable pointer to the initialized value. This avoids creating a reference, allowing mutable aliasing using *mut. This function is inspired by raw_get from UnsafeCell.

Safety

The supplied pointer must be valid.

When casting the returned pointer to

• &mut T the caller needs to ensure that no other references exist.
• &T the caller needs to ensure that no mutable references exist.

impl<T> StaticUninit<T, false>

pub fn uninit() -> Self

Creates a new uninitialized T with its init status statically tracked.

pub unsafe fn as_uninit_ref(&self) -> &MaybeUninit<T>

Gives access to the inner MaybeUninit immutably.

Safety

You need to keep track of the initialization state of self, it is unsound to leave a StaticUninit in

• a partially initialized state
• an unknown state of initialization and allow code to observe it unknowingly.

pub unsafe fn as_uninit_mut(&mut self) -> &mut MaybeUninit<T>

Gives access to the inner MaybeUninit mutably.

Safety

You need to keep track of the initialization state of self, it is unsound to leave a StaticUninit in

• a partially initialized state
• an unknown state of initialization and allow code to observe it unknowingly.

pub fn write(self, data: T) -> StaticUninit<T, true>

Initializes self using data and tracks that status statically.

Trait Implementations

impl<T> AsMut<T> for StaticUninit<T, true>

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

Converts this type into a mutable reference of the (usually inferred) input type.

impl<T> AsRef<T> for StaticUninit<T, true>

fn as_ref(&self) -> &T

Converts this type into a shared reference of the (usually inferred) input type.

impl<T> Borrow<T> for StaticUninit<T, true>

fn borrow(&self) -> &T

Immutably borrows from an owned value.

impl<T> BorrowMut<T> for StaticUninit<T, true>

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

Mutably borrows from an owned value.

impl<T: Clone> Clone for StaticUninit<T, true>

fn clone(&self) -> Self

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> Deref for StaticUninit<T, true>

type Target = T

The resulting type after dereferencing.

fn deref(&self) -> &Self::Target

Dereferences the value.

impl<T> DerefMut for StaticUninit<T, true>

fn deref_mut(&mut self) -> &mut Self::Target

Mutably dereferences the value.

impl<T, const INIT: bool> Drop for StaticUninit<T, INIT>

fn drop(&mut self)

Executes the destructor for this type.

impl<T> From<T> for StaticUninit<T, true>

fn from(data: T) -> Self

Converts to this type from the input type.

impl<T: Hash> Hash for StaticUninit<T, true>

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H) where
    H: Hasher, 

Feeds a slice of this type into the given Hasher.

impl<T: PartialEq<U>, U> PartialEq<StaticUninit<U, true>> for StaticUninit<T, true>

fn eq(&self, other: &StaticUninit<U, true>) -> bool

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

fn ne(&self, other: &StaticUninit<U, true>) -> bool

This method tests for !=.

impl<T: PartialOrd<U>, U> PartialOrd<StaticUninit<U, true>> for StaticUninit<T, true>

fn partial_cmp(&self, other: &StaticUninit<U, true>) -> Option<Ordering>

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

fn lt(&self, other: &StaticUninit<U, true>) -> bool

This method tests less than (for self and other) and is used by the < operator.

fn gt(&self, other: &StaticUninit<U, true>) -> bool

This method tests greater than (for self and other) and is used by the > operator.

fn le(&self, other: &StaticUninit<U, true>) -> bool

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

fn ge(&self, other: &StaticUninit<U, true>) -> bool

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

impl<T: Eq> Eq for StaticUninit<T, true>