This required multiple changes:
- Make hashes non-copiable because they contain a heap allocated pointer
- Reference classes via `NonnullOwnPtr` only (they are non-copiable)
- Drop all existing hashes implementations
- Use the `OpenSSLHashFunction` base class to implement the same hashes
I was not able to come up with a way to divide this commit into multiple
without increasing the amount of changes.
Nothing breaks with this commit!
Problem:
- `constexpr` functions are decorated with the `inline` specifier
keyword. This is redundant because `constexpr` functions are
implicitly `inline`.
- [dcl.constexpr], §7.1.5/2 in the C++11 standard): "constexpr
functions and constexpr constructors are implicitly inline (7.1.2)".
Solution:
- Remove the redundant `inline` keyword.
