Enum JoinTrigger 

pub enum JoinTrigger {
    Input {
        index: usize,
        value: Box<dyn Any + Send>,
    },
}

Identifies which input produced a value in a multi-input join transform.

Passed to the event loop inside the closure registered with JoinBuilder::on_triggers. Use JoinTrigger::index to branch on the source input and JoinTrigger::as_input to downcast the value to the concrete type.

Why this carries Box<dyn Any>

This is the one deliberate exception to the data-plane de-erasure A join fans N differently-typed inputs into a single trigger channel, and the user’s on_triggers closure branches on them via JoinTrigger::as_input — the erasure is the public API here, not an implementation accident. Removing it would mean N channels or a generated input enum, i.e. a different feature. The cost (one box + downcast per join input value) is confined to this module and applies only to explicit user-built joins, never to the connector spine.

Variants

Input

Fields

index: usize

value: Box<dyn Any + Send>

Implementations

impl JoinTrigger

pub fn as_input<T: 'static>(&self) -> Option<&T>

pub fn index(&self) -> usize