# Objective
Fixes#16776
## Solution
- reflect `&'static Location` as an opaque type
- I've added this to `impls/std.rs` because other core types are there
too. Maybe they should be split out into a `core.rs` in another PR.
- add source location to `EventId` (behind the
`tracking_change_detection` feature flag)
## Testing
---
## Showcase
```rust
fn apply_damage_to_health(
mut dmg_events: EventReader<DealDamage>,
) {
for (event, event_id) in dmg_events.read_with_id() {
info!(
"Applying {} damage, triggered by {}",
event.amount, event_id.caller
);
…
```
```
2024-12-12T01:21:50.126827Z INFO event: Applying 9 damage, triggered by examples/ecs/event.rs:47:16
```
## Migration Guide
- If you manually construct a `SendEvent`, use `SendEvent::new()`
---------
Co-authored-by: Alice Cecile <alice.i.cecile@gmail.com>
b2d3371814