Bump MSRV to 1.57 & improve the memory safety guarantees around open_readonly.
#432
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Rust 1.42 introduced extended slice patterns. Rust 1.46 introduced `if` in `const fn`. Rust 1.57 introduced `panic!` in `const fn`.
Do more complete NUL termination checking, at compile-time. Remove the `unsafe` from the function as it is now memory-safe.
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As I wrote in your other PR, I don't think it's worth to introduce the Ref type.
A better solution would be to use zero-terminated byte slices (i.e. const FILE_PATH: &[u8] = b"/dev/urandom\0";) for paths and add the following asserts to open_readonly:
assert_eq!(path[path.len() - 1], 0);
assert!(path[..path.len() - 1].iter().all(|&b| b != 0));Since we use static paths, compiler should be able to optimize them out.
I agree. This is a lot of complexity to just ensure that a byte slice passed to a function contains a zero byte (which is all we need for safety).
I think the assert just needs to be: assert!(path.iter().any(|&b| b == 0));for the function to be safe. If our slice has bytes after the null-terminator, that's weird but not unsafe. This implementation has the advantage of optimizing out at even |
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Closing in favor of #434. |
Do more complete NUL termination checking, at compile-time. Remove the
unsafefrom the function as it is now memory-safe.