Struct Once

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

A synchronization primitive which initializes a value lazily, once. Since this also includes a value, it is a bit more like Once from parking_lot or spin.

Implementations

impl<T> Once<T>

pub const fn new() -> Self

pub const fn uninitialized() -> Self

pub const fn initialized(value: T) -> Self

pub fn initialize(&self, value: T) -> Result<(), T>

pub fn try_call_once<'a, F>(&'a self, init: F) -> Result<&'a T, F>

where F: FnOnce() -> T,

pub fn call_once<'a, F>(&'a self, init: F) -> &'a T

where F: FnOnce() -> T,

pub fn wait<'a>(&'a self) -> &'a T

pub fn try_get<'a>(&'a self) -> Option<&'a T>

pub fn state(&self) -> OnceState

Trait Implementations

impl<T: Debug> Debug for Once<T>

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

Formats the value using the given formatter.

impl<T> Drop for Once<T>

fn drop(&mut self)

Executes the destructor for this type.

impl<T: RefUnwindSafe> RefUnwindSafe for Once<T>

impl<T: Send + Sync> Send for Once<T>

impl<T: Send + Sync> Sync for Once<T>

impl<T: UnwindSafe> UnwindSafe for Once<T>