[llvm] [libc++] Add assertions for potential OOB reads in std::nth_element (PR #67023)

[via llvm-commits]

philnik777 wrote:

You can use `// NOLINT(check-name)` or `// NOLINTNEXTLINE(check-name)` to disable clang-tidy warnings. I would probably put a `// NOLINTNEXTLINE(readability-function-cognitive-complexity)` above the function.

https://github.com/llvm/llvm-project/pull/67023