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Boxy 024d98457c yeet unsound lifetime annotations on Query methods (#4243) 
# Objective
Continuation of #2964 (I really should have checked other methods when I made that PR)

yeet unsound lifetime annotations on `Query` methods.
Example unsoundness:
```rust
use bevy::prelude::*;

fn main() {
    App::new().add_startup_system(bar).add_system(foo).run();
}

pub fn bar(mut cmds: Commands) {
    let e = cmds.spawn().insert(Foo { a: 10 }).id();
    cmds.insert_resource(e);
}

#[derive(Component, Debug, PartialEq, Eq)]
pub struct Foo {
    a: u32,
}
pub fn foo(mut query: Query<&mut Foo>, e: Res<Entity>) {
    dbg!("hi");
    {
        let data: &Foo = query.get(*e).unwrap();
        let data2: Mut<Foo> = query.get_mut(*e).unwrap();
        assert_eq!(data, &*data2); // oops UB
    }

    {
        let data: &Foo = query.single();
        let data2: Mut<Foo> = query.single_mut();
        assert_eq!(data, &*data2); // oops UB
    }

    {
        let data: &Foo = query.get_single().unwrap();
        let data2: Mut<Foo> = query.get_single_mut().unwrap();
        assert_eq!(data, &*data2); // oops UB
    }

    {
        let data: &Foo = query.iter().next().unwrap();
        let data2: Mut<Foo> = query.iter_mut().next().unwrap();
        assert_eq!(data, &*data2); // oops UB
    }

    {
        let mut opt_data: Option<&Foo> = None;
        let mut opt_data_2: Option<Mut<Foo>> = None;
        query.for_each(|data| opt_data = Some(data));
        query.for_each_mut(|data| opt_data_2 = Some(data));
        assert_eq!(opt_data.unwrap(), &*opt_data_2.unwrap()); // oops UB
    }
    dbg!("bye");
}

```

## Solution
yeet unsound lifetime annotations on `Query` methods

Co-authored-by: Carter Anderson <mcanders1@gmail.com>
2022-03-22 02:49:41 +00:00
..
src Assert compiler errors for compile_fail tests (#3067) 2021-11-13 22:43:19 +00:00
tests yeet unsound lifetime annotations on Query methods (#4243) 2022-03-22 02:49:41 +00:00
Cargo.toml Bump Bevy to 0.7.0-dev (#4230) 2022-03-19 03:54:15 +00:00
README.md Assert compiler errors for compile_fail tests (#3067) 2021-11-13 22:43:19 +00:00

README.md

Compile fail tests for bevy_ecs

This crate is separate from bevy_ecs and not part of the Bevy workspace in order to not fail crater tests for Bevy. The tests assert on the exact compiler errors and can easily fail for new Rust versions due to updated compiler errors (e.g. changes in spans).

The CI workflow executes these tests on the stable rust toolchain (see tools/ci).