[hash2] Hash Algorithm Requirements versus concepts

From: Andrzej Krzemienski (akrzemi1_at_[hidden])
Date: 2024-12-08 18:25:39

Hi Everyone,
It strikes me that the description of Hash Algorithm Requirements does not
use C++ concepts. Even though the library is C++11-compatible, it could use
a concept in the documentation.

The goal of the concepts was to serve a case like this, so I wonder if this
is just an omission from the authors, or if this is an indication that
concepts do not deliver their promise.

There is the optional `block_size` but this could be modeled by two
concepts HashAlgorithm and BlockHashAlgorithm. The type of `block_size`
looks like a candidate for another concept HashAlgorithmResult.

Regards,
&rzej;