Class iterator

include/stringzilla/stringzilla.hpp:671–721

    range_rmatches(string_type haystack, matcher_type needle) : matcher_(needle), haystack_(haystack) {}

    class iterator {
        matcher_type matcher_;
        string_view_type remaining_;

      public:
        using iterator_category = std::forward_iterator_tag;
        using difference_type = std::ptrdiff_t;
        using value_type = string_view_type;
        using pointer = string_view_type;   // Needed for compatibility with STL container constructors.
        using reference = string_view_type; // Needed for compatibility with STL container constructors.

        iterator(string_view_type haystack, matcher_type matcher) noexcept : matcher_(matcher), remaining_(haystack) {
            auto position = matcher_(remaining_);
            remaining_.remove_suffix(         //
                position != string_type::npos //
                    ? remaining_.size() - position - matcher_.needle_length()
                    : remaining_.size());
        }

        pointer operator->() const noexcept = delete;
        value_type operator*() const noexcept {
            return remaining_.substr(remaining_.size() - matcher_.needle_length());
        }

        iterator &operator++() noexcept {
            remaining_.remove_suffix(matcher_.skip_length());
            auto position = matcher_(remaining_);
            remaining_.remove_suffix(         //
                position != string_type::npos //
                    ? remaining_.size() - position - matcher_.needle_length()
                    : remaining_.size());
            return *this;
        }

        iterator operator++(int) noexcept {
            iterator temp = *this;
            ++(*this);
            return temp;
        }

        // Assumes both iterators point to the same underlying string.
        // This has to be `.data() + .size()`, to be compatible with `std::string_view` on MSVC.
        bool operator!=(iterator const &other) const noexcept {
            return remaining_.data() + remaining_.size() != other.remaining_.data() + other.remaining_.size();
        }
        bool operator==(iterator const &other) const noexcept {
            return remaining_.data() + remaining_.size() == other.remaining_.data() + other.remaining_.size();
        }
        bool operator!=(end_sentinel_type) const noexcept { return !remaining_.empty(); }
        bool operator==(end_sentinel_type) const noexcept { return remaining_.empty(); }
    };

    iterator begin() const noexcept { return {string_view_type(haystack_), matcher_}; }
    iterator end() const noexcept { return {string_view_type(haystack_.data(), 0ull), matcher_}; }