Struct safina::Promise

pub struct Promise<T> where
    T: 'static + Send,  { /* private fields */ }

A Future that resolves when you call set on its clone.

Uses Arc internally. All clones of this struct use the same inner struct on the heap.

You can call set on any clone of this struct.

You can call set once and await once, obtaining the value.

Subsequent or concurrent awaits of the struct will wait forever.

Implementations

impl<T> Promise<T> where
    T: 'static + Send, 

pub fn new() -> Promise<T>

pub fn is_set(&self) -> bool

Returns true if set has been called.

Panics

Panics if the inner mutex is poisoned.

pub fn set(self, value: T)

Sets the value of the struct and wakes up any awaiting task.

Consumes the struct.

Panics

Panics if the value was already set.

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

Sets the value of the struct and wakes up any awaiting task.

Errors

Returns Err(value) if the value was already set. This returns the value just passed in.

Trait Implementations

impl<T> Clone for Promise<T> where
    T: 'static + Send, 

pub fn clone(&self) -> Promise<T>

Returns a copy of the value.

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

Performs copy-assignment from source.

impl<T> Default for Promise<T> where
    T: 'static + Send, 

pub fn default() -> Promise<T>

Returns the “default value” for a type.

impl<T> Future for Promise<T> where
    T: 'static + Send, 

type Output = T

The type of value produced on completion.

pub fn poll(
    self: Pin<&mut Promise<T>>,
    cx: &mut Context<'_>
) -> Poll<<Promise<T> as Future>::Output>

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