Struct wnf::Subscription

pub struct Subscription<'a, F> { /* private fields */ }

Available on crate feature subscribe only.

A subscription of a listener to updates of a state

This is returned from OwnedState::subscribe and BorrowedState::subscribe.

Note that the listener is automatically unsubscribed when the Subscription<'_, F> is dropped. In this case, errors while unsubscribing are silently ignored. If you want to handle them explicitly, use the Subscription::unsubscribe method, which returns an io::Result<()>. Note that the listener will not be called anymore after unsubscribing, even when there is an error.

If you want to keep the subscription for as long as the process is running and the state exists, use the Subscription::forget method.

Implementations

impl<F> Subscription<'_, F>

pub const fn forget(self)

Forgets this Subscription<'_, F>, effectively keeping it forever

When a Subscription<'_, F> is dropped, the listener is unsubscribed. You can avoid this behavior by calling this method. It consumes the Subscription<'_, F> without dropping it, effectively keeping the subscription for as long as the process is running and the state exists.

pub fn unsubscribe(self) -> Result<()>

Unsubscribes the listener for this Subscription<'_, F>

This happens automatically when the Subscription<'_, F> is dropped (unless you call Subscription::forget), so there is usually no need to call this method. Its only purpose is to enable you to handle errors while unsubscribing. Note that the listener will not be called anymore after unsubscribing, even when there is an error.

Errors

Returns an error if unsubscribing fails

Trait Implementations

impl<F> Debug for Subscription<'_, F>

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

Formats the value using the given formatter.

impl<F> Drop for Subscription<'_, F>

fn drop(&mut self)

Executes the destructor for this type.

impl<F> Hash for Subscription<'_, F>

fn hash<H: Hasher>(&self, state: &mut H)

Feeds this value into the given Hasher.

fn hash_slice<H>(data: &[Self], state: &mut H)where
    H: Hasher,
    Self: Sized,

Feeds a slice of this type into the given Hasher.

impl<F> PartialEq<Subscription<'_, F>> for Subscription<'_, F>

fn eq(&self, other: &Self) -> bool

This method tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

This method tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl<F> Eq for Subscription<'_, F>