Rust 1.57.0

# FFI

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> Sometimes, your Rust code may need to interact with code written in another language. To do this, Rust has a keyword, `extern`, that facilitates creating and using a Foreign Function Interface (FFI).

    extern "C" {
        fn abs(input: i32) -> i32;
    }

    fn main() {
        unsafe {
            println!("Absolute value of -3 according to C: {}", abs(-3));
        }
    }

Run

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