Function ArgSort

src/encoder/ordinal.h:208–218

namespace cpu_impl {
template <typename InIt, typename OutIt, typename Comp>
void ArgSort(InIt in_first, InIt in_last, OutIt out_first, Comp comp = std::less{}) {
  auto n = std::distance(in_first, in_last);
  using Idx = typename std::iterator_traits<OutIt>::value_type;

  auto out_last = out_first + n;
  std::iota(out_first, out_last, 0);
  auto op = [&](Idx const &l, Idx const &r) {
    return comp(in_first[l], in_first[r]);
  };
  std::stable_sort(out_first, out_last, op);
}

[[nodiscard]] inline std::int32_t SearchSorted(CatStrArrayView haystack,
                                               Span<std::int32_t const> ref_sorted_idx,