Struct LazyPinned

pub struct LazyPinned<T>(pub Option<T>);

Pinned data which can be lazily initialized.

LazyPinned<T> vs. Option<T>

LazyPinned<T> act like Option<T>. In fact, LazyPinned<T> is implemented by just wrapping Option<T>. However, they have different behaviors in pinning projection.

Pin<P<Option<T>>> guarantees the Option<T> is not moved, where P<_> is a pointer type which deref to _. Thus, when the data is None, it cannot be set to Some(T) unless T: Unpin.

Pin<P<LazyPinned<T>>> only guarantees the inner T is pinned. Thus, Pin<&mut LazyPinned<T>> optionally projects to Pin<&mut T> instead of Pin<P<Option<T>>>. When Pin<P<LazyPinned<T>>> is None, it can be initialized with a value of T.

Tuple Fields

0: Option<T>

Implementations

impl<T> LazyPinned<T>

pub fn as_pin_ref(self: Pin<&Self>) -> Option<Pin<&T>>

pub fn as_pin_mut(self: Pin<&mut Self>) -> Option<Pin<&mut T>>

pub fn pin_project_or_insert(self: Pin<&mut Self>, v: T) -> Pin<&mut T>

pub fn pin_project_or_insert_with( self: Pin<&mut Self>, f: impl FnOnce() -> T, ) -> Pin<&mut T>

pub fn use_pin_or_insert( self: Pin<&mut Self>, use_pin: impl FnOnce(Pin<&mut T>), v: T, ) -> Pin<&mut T>

pub fn use_pin_or_insert_with( self: Pin<&mut Self>, use_pin: impl FnOnce(Pin<&mut T>), insert: impl FnOnce() -> T, ) -> Pin<&mut T>

pub fn use_pin_or_insert_with_data<Data>( self: Pin<&mut Self>, data: Data, use_pin: impl FnOnce(Data, Pin<&mut T>), insert: impl FnOnce(Data) -> T, ) -> Pin<&mut T>

Trait Implementations

impl<T: Clone> Clone for LazyPinned<T>

fn clone(&self) -> LazyPinned<T>

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl<T: Debug> Debug for LazyPinned<T>

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

Formats the value using the given formatter.

impl<T> Default for LazyPinned<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T: Hash> Hash for LazyPinned<T>

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, Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<T: Ord> Ord for LazyPinned<T>

fn cmp(&self, other: &LazyPinned<T>) -> 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.

impl<T: PartialEq> PartialEq for LazyPinned<T>

fn eq(&self, other: &LazyPinned<T>) -> bool

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<T: PartialOrd> PartialOrd for LazyPinned<T>

fn partial_cmp(&self, other: &LazyPinned<T>) -> 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<T: Copy> Copy for LazyPinned<T>

impl<T: Eq> Eq for LazyPinned<T>

impl<T> StructuralPartialEq for LazyPinned<T>