the trait `LowerHex` and `UpperHex` is not implemented for `Array`

[Its-Just-Nans]

Example for LowerHex

In 0.10.9 this works but not in 0.11.0

use sha2::{Sha512, Digest}; // 0.10.9

fn main() {
    let sha512 = format!("{:x}", Sha512::digest(&[1, 2, 3, 4, 5]));
    println!("{}", sha512);
}

use sha2::{Sha512, Digest}; // 0.11.0

fn main() {
    let sha512 = format!("{:x}", Sha512::digest(&[1, 2, 3, 4, 5])); /// ERROR
    println!("{}", sha512);
}

Is that normal ?

Thanks

[Its-Just-Nans]

From a bisect it seems that it's
caused by RustCrypto/hashes@7febf02
caused by RustCrypto/traits@102d328
caused by RustCrypto/traits@766c138

[tarcieri]

That's the commit that switched from generic-array to hybrid-array.

I'll go ahead and move this issue over to the hybrid-array repo.

[Its-Just-Nans]

Correct, my bisect is ending at the change here RustCrypto/traits@766c138

(i've edited my comment but you are faster)

[tarcieri]

We could potentially implement it (specifically for Array<u8, U> I suppose), though we have been trying to align the semantics of Array with core arrays as much as possible, which don't provide these impls.

That said, I imagine we might get quite a few requests for this if generic-array provides it, in which case it might be better to just add the impls for compatibility to ease the transition for now. We can always remove them in the next breaking release if we want to more tightly align with core arrays.

[Its-Just-Nans]

Note that it's also UpperHex

[tarcieri]

I confirmed that GenericArray has special case impls for arrays of u8: https://docs.rs/generic-array/latest/generic_array/struct.GenericArray.html#impl-LowerHex-for-GenericArray%3Cu8,+N%3E

[newpavlov]

Note that we have base16ct::HexDisplay, which is the recommended way of hex formatting for now.