Diagnostics:
    # clangd does parse .clang-tidy, but some checks are too slow to run in
    # clang-tidy build, so let's enable them explicitly for clangd at least.
    ClangTidy:
        # The following checks had been disabled due to slowliness with C++23,
        # for more details see [1].
        #
        #   [1]: https://github.com/llvm/llvm-project/issues/61418
        #
        # But the code base had been written in a style that had been checked
        # by this check, so at least, let's enable it for clangd.
        Add: [
            # configured in .clang-tidy
            readability-identifier-naming,
            bugprone-reserved-identifier,
        ]