maybe we could add a naive topN based on sort + slice last N elements, so clients can start using that, and then they'd benefit when a proper topN is in stdlib
## example implementations * [https://dlang.org/library/std/algorithm/sorting/top_n.html](https://dlang.org/library/std/algorithm/sorting/top_n.html) * [https://en.cppreference.com/w/cpp/algorithm/partial_sort](https://en.cppreference.com/w/cpp/algorithm/partial_sort)
