Struct async_once_cell::future::Lazy

pub struct Lazy<T, F = Box<dyn Future<Output = T> + Send>> { /* fields omitted */ }

A value which is initialized on the first access.

Note: unlike OnceCell, dropping the Future that is running an unfinished initializer function will not discard the pending state.

Implementations

impl<T, F> Lazy<T, F>

pub const fn new(future: F) -> Self

Creates a new lazy value with the given initializing future.

pub fn try_get(&self) -> Option<&T>

Gets the value without blocking or starting the initialization.

pub fn try_get_mut(&mut self) -> Option<&mut T>

Gets the value without blocking or starting the initialization.

pub fn into_value(self) -> Option<T>

Gets the value if it was set.

impl<T, F> Lazy<T, F> where
    F: Future<Output = T> + Send + 'static, 

pub async fn get(&self) -> &T

Forces the evaluation of this lazy value and returns a reference to the result. This is equivalent to the Future impl on &Lazy, but is explicit and may be simpler to call.

Trait Implementations

impl<'a, T, F> Future for &'a Lazy<T, F> where
    F: Future<Output = T> + Send + 'static, 

type Output = &'a T

The type of value produced on completion.

fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<&'a T>

Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available.

impl<T: Send, F: Send> Send for Lazy<T, F>

impl<T: Sync + Send, F: Send> Sync for Lazy<T, F>