Struct InitOnce

pub struct InitOnce<T> { /* private fields */ }

Lazily initialize a value of some arbitrary type T. Reading the value doesn’t block the caller, if it is being initialized concurrently.

Implementations

impl<T> InitOnce<T>

pub const fn new() -> Self

Create an uninitialized InitOnce.

pub fn state(&self) -> InitState<'_, T>

Query the state of an InitOnce instance.

If the current state is InitState::Polling, the caller is responsible for polling the init function to completion.

pub fn try_init<F>(&self, init: F) -> Option<&T>

where F: FnMut() -> T,

Attempt to initialize this InitOnce with the value returned by the closure init.

pub async fn try_init_async<F>(&self, init: F) -> Option<&T>

where F: Future<Output = T>,

Attempt to initialize this InitOnce with the value returned by the future init.

pub fn init<F>(&mut self, init: F) -> &mut T

where F: FnMut() -> T,

Initialize this InitOnce with the value returned by the closure init.

pub async fn init_async<F>(&mut self, init: F) -> &mut T

where F: Future<Output = T>,

Initialize this InitOnce with the value returned by the future init.

Trait Implementations

impl<T: Debug> Debug for InitOnce<T>

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

Formats the value using the given formatter.

impl<T> Default for InitOnce<T>

fn default() -> Self

Returns the “default value” for a type.

impl<T> Drop for InitOnce<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<T: Sync> Sync for InitOnce<T>