Function circular_distance

src/svgfill/src/arrange_polygons.cpp:2598–2605

template <typename Vec>
std::size_t circular_distance(typename Vec::const_iterator first,
                              typename Vec::const_iterator last,
                              const Vec& vec) {
    if (first <= last) {
        return static_cast<std::size_t>(last - first);
    }
    return static_cast<std::size_t>(vec.end() - first) + static_cast<std::size_t>(last - vec.begin());
}

template <typename Vec, typename Pred>
std::pair<typename Vec::const_iterator,