#capability #safety #trait #implement-only

hazmat

A collection of helpers for working with hazardous materials in Rust crates

2 unstable releases

Uses new Rust 2021

0.1.0 Jun 16, 2022
0.0.0 Jun 15, 2022

#515 in Rust patterns

MIT/Apache

9KB

hazmat Rust library

A collection of helpers for working with hazardous materials in Rust crates.

#[hazmat::suit]

Ever needed to expose an internal trait for downstream users to implement, that shouldn't be usable outside of your crate? Add the #[hazmat::suit] attribute to the trait and it becomes "implement-only":

#[hazmat::suit]
pub trait LowLevel {
    fn low_level(self) -> bool;
}

struct DownstreamType;

#[hazmat::suit]
impl LowLevel for DownstreamType {
    fn low_level(self, other: Self) -> bool {
        true
    }
}

fn use_low_level() {
    let a = DownstreamType;
    let b = DownstreamType;

    // This won't compile outside of the crate in which the trait is defined.
    assert!(a.low_level(b, LowLevelCap));
}

License

Licensed under either of

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.

Dependencies

~220–630KB
~15K SLoC