Struct Subscription 

pub struct Subscription { /* private fields */ }

RAII handle for event subscriptions.

When a Subscription is dropped, the associated handler is automatically removed from the event bus. This ensures proper cleanup even when code panics or returns early.

Thread Safety

Subscription is Send + Sync, allowing it to be moved between threads and shared (though sharing is unusual since drop triggers unsubscription).

Example

// Subscription automatically unsubscribes when dropped
{
    let sub = bus.subscribe::<MyEvent, _>(100, handler);
    // Handler is active here
} // Handler is removed here

Implementations

impl Subscription

pub const fn id(&self) -> SubscriptionId

Get the subscription ID.

pub const fn type_id(&self) -> TypeId

Get the TypeId of the subscribed event type.

pub const fn type_name(&self) -> &'static str

Get the type name of the subscribed event type.

pub fn is_active(&self) -> bool

Check if the subscription is still active.

Returns false after cancel() has been called.

pub fn cancel(&self)

Explicitly cancel the subscription.

This is equivalent to dropping the subscription, but allows for explicit control over when unsubscription occurs.

Calling cancel() multiple times is safe and idempotent.

pub fn detach(&self)

Detach the subscription from RAII lifecycle management.

After calling this, dropping the Subscription will NOT unsubscribe the handler. The handler remains active until the EventBus is dropped.

This is necessary when the owner of the Subscription has a shorter lifetime than the desired handler lifetime (e.g., modules that are dropped after initialization while their event handlers should persist for the session).

Example

let sub = bus.subscribe::<MyEvent, _>(100, handler);
sub.detach(); // Handler stays active even after `sub` is dropped

Trait Implementations

impl Debug for Subscription

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

Formats the value using the given formatter.

impl Drop for Subscription

fn drop(&mut self)

Executes the destructor for this type.