Struct option_lock::OnceCell[−][src]

#[repr(transparent)]
pub struct OnceCell<T>(_);
Expand description

An Option value which can be safely written once.

Implementations

impl<T> OnceCell<T>[src]

pub const fn empty() -> Self[src]

Create a new, empty OnceCell.

pub const fn new(value: T) -> Self[src]

Create a OnceCell from an owned value.

pub fn get(&self) -> Option<&T>[src]

Get a shared reference to the contained value, if any.

pub fn get_mut(&mut self) -> Option<&mut T>[src]

Get a mutable reference to the contained value, if any.

pub fn get_or_init(&self, init: impl FnOnce() -> T) -> &T[src]

Get a reference to the contained value, initializing it if necessary. The initializer will only be run by one thread if multiple are in competition.

pub fn get_or_try_init<E>(
    &self,
    init: impl FnOnce() -> Result<T, E>
) -> Result<&T, E>[src]

Get a reference to the contained value, initializing it if necessary. The initializer will only be run by one thread if multiple are in competition.

pub fn set(&self, value: T) -> Result<(), T>[src]

Assign the value of the OnceCell, returning Some(value) if the cell is already locked or populated.

pub fn into_inner(self) -> Option<T>[src]

Extract the inner value.

pub fn is_locked(&self) -> bool[src]

Check if the lock is currently acquired.

Trait Implementations

impl<T: Clone> Clone for OnceCell<T>[src]

fn clone(&self) -> Self[src]

Returns a copy of the value. Read more

fn clone_from(&mut self, source: &Self)1.0.0[src]

Performs copy-assignment from source. Read more

impl<T: Debug> Debug for OnceCell<T>[src]

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

Formats the value using the given formatter. Read more

impl<T> Default for OnceCell<T>[src]

fn default() -> Self[src]

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

impl<T: Display> Display for OnceCell<T>[src]

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

Formats the value using the given formatter. Read more

impl<T> From<Option<T>> for OnceCell<T>[src]

fn from(data: Option<T>) -> Self[src]

Performs the conversion.

impl<T> From<OptionLock<T>> for OnceCell<T>[src]

fn from(lock: OptionLock<T>) -> Self[src]

Performs the conversion.

impl<T> From<T> for OnceCell<T>[src]

fn from(data: T) -> Self[src]

Performs the conversion.

Auto Trait Implementations

impl<T> !RefUnwindSafe for OnceCell<T>

impl<T> Send for OnceCell<T> where
    T: Send, 

impl<T> Sync for OnceCell<T> where
    T: Send, 

impl<T> Unpin for OnceCell<T> where
    T: Unpin, 

impl<T> UnwindSafe for OnceCell<T> where
    T: UnwindSafe, 

Blanket Implementations

impl<T> Any for T where
    T: 'static + ?Sized, [src]

pub fn type_id(&self) -> TypeId[src]

Gets the TypeId of self. Read more

impl<T> Borrow<T> for T where
    T: ?Sized, [src]

pub fn borrow(&self) -> &T[src]

Immutably borrows from an owned value. Read more

impl<T> BorrowMut<T> for T where
    T: ?Sized, [src]

pub fn borrow_mut(&mut self) -> &mut T[src]

Mutably borrows from an owned value. Read more

impl<T> From<!> for T[src]

pub fn from(t: !) -> T[src]

Performs the conversion.

impl<T> From<T> for T[src]

pub fn from(t: T) -> T[src]

Performs the conversion.

impl<T, U> Into<U> for T where
    U: From<T>, [src]

pub fn into(self) -> U[src]

Performs the conversion.

impl<T> ToOwned for T where
    T: Clone, [src]

type Owned = T

The resulting type after obtaining ownership.

pub fn to_owned(&self) -> T[src]

Creates owned data from borrowed data, usually by cloning. Read more

pub fn clone_into(&self, target: &mut T)[src]

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

recently added

Uses borrowed data to replace owned data, usually by cloning. Read more

impl<T> ToString for T where
    T: Display + ?Sized, [src]

pub default fn to_string(&self) -> String[src]

Converts the given value to a String. Read more

impl<T, U> TryFrom<U> for T where
    U: Into<T>, [src]

type Error = Infallible

The type returned in the event of a conversion error.

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

Performs the conversion.

impl<T, U> TryInto<U> for T where
    U: TryFrom<T>, [src]

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

The type returned in the event of a conversion error.

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

Performs the conversion.