Trait Event

pub trait Event: Encode {
    type RemainingTopics: EventTopicsAmount;

    const SIGNATURE_TOPIC: Option<[u8; 32]>;

    // Required method
    fn topics<E, B>(
        &self,
        builder: TopicsBuilder<Uninit, E, B>,
    ) -> <B as TopicsBuilderBackend<E>>::Output
       where E: Environment,
             B: TopicsBuilderBackend<E>;
}

Implemented by event types to guide the event topic serialization using the topics builder.

Normally this trait should be implemented automatically via #[derive(ink::Event).

Required Associated Constants

const SIGNATURE_TOPIC: Option<[u8; 32]>

The unique signature topic of the event. None for anonymous events.

It can be automatically calculated or manually specified.

Usually this is calculated using the #[derive(ink::Event)] derive, which by default calculates this as blake2b("Event(field1_type,field2_type)"

Required Associated Types

type RemainingTopics: EventTopicsAmount

Type state indicating how many event topics are to be expected by the topics builder.

Required Methods

fn topics<E, B>( &self, builder: TopicsBuilder<Uninit, E, B>, ) -> <B as TopicsBuilderBackend<E>>::Output

where E: Environment, B: TopicsBuilderBackend<E>,

Guides event topic serialization using the given topics builder.

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