README.md

safe_attr

safe_attr provides a #[safe] attribute to mark functions with

What?

Take this example:

union Num {
    float: f32,
    long: u32,
}

fn use_both() {
    let mut num = Num { long: 132 };
    let the_float = unsafe { num.float };
    // do things with the float...
    let the_long = unsafe { num.long };
    // do things with the long...

    // maybe use some more unsafes later...
}

Now, you know this is perfectly safe. Both of the types are of the same size, converting it shouldn't require such verbosity. With safe_attr, you can now do:

use safe_attr::safe;

#[safe]
fn use_both() {
    let mut num = Num { long: 132 };
    let the_float = num.float;
    let the_long = num.long;
}

This attribute allows you to avoid spamming unsafes everywhere in code that doesn't require it.

This does not mean this attribute should be abused. It could easily lead to making unsafe code's bugs harder to track down in larger functions, and also simply makes it harder to find problem spots. As such, you are encouraged to still mark the function with a // Safety: comment, and furthermore only use this attribute for use cases similar to the above example.

How?

This attribute simply wraps the function's body in an unsafe. That's it.