Trait ExpectableState

pub trait ExpectableState: Clone {
    type State: 'static;

    // Required methods
    fn store_task(&mut self, cx: &mut Context<'_>) -> usize;
    fn remove_task(&mut self, key: usize);
    fn notify_state_changed(&self);
    fn read(&self) -> Self::State;
}

Trait for objects that allow futures to trigger based on state changes

This trait will commonly be used via the ExpectableStateExt extension trait which provides the convenient when_satisfied function.

You can implement this trait for your own types which implement their own state tracking and notification of futures, or you can use the ExpectationHarness struct in this module which provides a ready to use implementation.

Required Associated Types

type State: 'static

Type of current state we are tracking

Required Methods

fn store_task(&mut self, cx: &mut Context<'_>) -> usize

Register a task as needing waking when state changes

fn remove_task(&mut self, key: usize)

Remove a task from being tracked. Called by ExpectationFuture when polled.

fn notify_state_changed(&self)

Notify all pending tasks that state has changed

fn read(&self) -> Self::State

Read a snapshot of the current State

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementors

impl<S: Clone + 'static, A> ExpectableState for Expectable<S, A>

type State = S