Struct FutureWriter

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

Available on crate features runtime and component-model and component-model-async only.

Represents the writable end of a Component Model future.

Note that FutureWriter instances must be disposed of using either write or close; otherwise the in-store representation will leak and the reader end will hang indefinitely. Consider using GuardedFutureWriter to ensure that disposal happens automatically.

Implementations

impl<T> FutureWriter<T>

pub async fn write(self, accessor: impl AsAccessor, value: T) -> bool

where T: Lower + Send + Sync + 'static,

Write the specified value to this future.

The returned Future will yield true if the read end accepted the value; otherwise it will return false, meaning the read end was dropped before the value could be delivered.

Panics

Panics if the store that the [Accessor] is derived from does not own this future.

pub async fn watch_reader(&mut self, accessor: impl AsAccessor)

Wait for the read end of this future is dropped.

The [Accessor] provided can be acquired from Instance::run_concurrent or from within a host function for example.

Panics

Panics if the store that the [Accessor] is derived from does not own this future.

pub fn close(&mut self, store: impl AsContextMut)

where T: Lower + Send + Sync + 'static,

Close this FutureWriter, writing the default value.

Panics

Panics if the store that the [Accessor] is derived from does not own this future. Usage of this future after calling close will also cause a panic.

pub fn close_with(&mut self, accessor: impl AsAccessor)

where T: Lower + Send + Sync + 'static,

Convenience method around Self::close.

pub fn guard<A>(self, accessor: A) -> GuardedFutureWriter<T, A>

where T: Lower + Send + Sync + 'static, A: AsAccessor,

Returns a GuardedFutureWriter which will auto-close this future on drop and clean it up from the store.

Note that the accessor provided must own this future and is additionally transferred to the GuardedFutureWriter return value.

Trait Implementations

impl<T, A> From<GuardedFutureWriter<T, A>> for FutureWriter<T>

where T: Lower + Send + Sync + 'static, A: AsAccessor,

fn from(guard: GuardedFutureWriter<T, A>) -> Self

Converts to this type from the input type.