Update examples to use `default()` instead of `new()` which no longer exists

[boxbeam]

Also worth noting: finalize() does not appear to exist

[newpavlov]

The methods are part of the Digest trait, which is implemented through the blanket impl for most of hashes in this repository. Also, the doctests are tested as part of our CI, so we know they are valid.

[boxbeam]

Might be good to mention that in the examples. I couldn't figure out why new() wasn't working and LSP didn't recommend the trait.

[tarcieri]

Which example are you looking at?

The one here says: https://github.com/RustCrypto/hashes#usage

sha2 and the other hash implementation crates re-export the digest crate and the Digest trait for convenience, so you don't have to include it in your Cargo.toml it as an explicit dependency.

Now you can write the following code:

use sha2::{Sha256, Digest};
[...]

[boxbeam]

I guess to me it was unclear that new comes from Digest.

[youginil]

Maybe other trait imported caused your problem, if so, the code below should be helpful.

use sha2::{Digest, Sha256};
let mut hasher: Sha256 = Digest::new();
Digest::update(&mut hasher, b"hello");
let h = Digest::finalize(hasher);

https://doc.rust-lang.org/book/ch19-03-advanced-traits.html#fully-qualified-syntax-for-disambiguation-calling-methods-with-the-same-name