mirror of
https://github.com/bevyengine/bevy
synced 2024-11-27 07:00:18 +00:00
637a149910
# Objective
make bevy ecs a lil bit less unsound
## Solution
make unsound API unsafe so that there is an unsafe block to blame:
```rust
use bevy_ecs::prelude::*;
#[derive(Debug, Component)]
struct Foo(u8);
fn main() {
let mut world = World::new();
let e1 = world.spawn().id();
let e2 = world.spawn().insert(Foo(2)).id();
world.entities_mut().meta[0] = world.entities_mut().meta[1].clone();
let foo = world.entity(e1).get::<Foo>().unwrap();
// whoo i love having components i dont have
dbg!(foo);
}
```
This is not _strictly_ speaking UB, however:
- `Query::get_multiple` cannot work if this is allowed
- bevy_ecs is a pile of unsafe code whose soundness generally depends on the world being in a "correct" state with "no funny business" so it seems best to disallow this
- it is trivial to get bevy to panic inside of functions with safety invariants that have been violated (the entity location is not valid)
- it seems to violate what the safety invariant on `Entities::flush` is trying to ensure
|
||
|---|---|---|
| .. | ||
| map_entities.rs | ||
| mod.rs | ||
| serde.rs | ||