compound::iterator isn't far from a forward_iterator, and if we want
to use it with std::ranges, we have to upgrade it. This is because
std::ranges::subrange() only provides front() for forward ranges, and
we do use this front(). Boost apparently isn't as strict.
To make it a forward_range, we have to drop operator-> and make
operator* return a value (similar to std::views::tranform), since
forward iterators require that pointers and references be stable,
and this iterator returns a pointer to one of its members.
We also add an iterator_concept member to declare the compatibility
to std::ranges.
Note we're suppressing a UBSanitizer overflow error in UTs. That's
because our linter complains about a possible overflow, which never
happens, but tests are still failing because of it.
This is in order to prevent new incorrect uses of dht::shard_of() to
be accidentally added. Also, makes sure that all current uses are
caught by the compiler and require an explicit rename.
Contains methods to generate partition and clustering keys. In the case
of the former, one can specify the shard to generate keys for.
We currently have some methods to generate these but they are not
generic. Therefore the tests are littered by open-coded variants.
The methods introduced here are completely generic: they can generate
keys for any schema.
