Support for Clang-Tidy

[JacksonAllan]

In parallel with #10, it might be nice for Verstable to “support” Clang-Tidy by raising as few diagnostic warnings as possible.

Currently, Clang-Tidy is detecting many false positive NULL-dereferences regarding the buckets array pointer. This might be because it is not following the logic of the metadata “placeholder” mechanism and implicit guarantees it provides ensuring that buckets, when accessed, is not NULL.

These and other warnings could be silenced via liberal use of // NOLINT, although I am unsure about adding to the library any comments (or other content) whose purpose isn’t obvious. Such comments could perhaps be qualified with further comments explaining why they are necessary.

I’m opening this issue to keep a record and remind myself to investigate the matter further.

Relevant issues and pull requests:
#8
#9