Class iterator

include/stringzilla/stringzilla.hpp:580–617

    range_matches(string_type haystack, matcher_type needle) noexcept : 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_prefix(position != string_type::npos ? position : remaining_.size());
        }

        pointer operator->() const noexcept = delete;
        value_type operator*() const noexcept { return remaining_.substr(0, matcher_.needle_length()); }

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

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

        // Assumes both iterators point to the same underlying string.
        bool operator!=(iterator const &other) const noexcept { return remaining_.data() != other.remaining_.data(); }
        bool operator==(iterator const &other) const noexcept { return remaining_.data() == other.remaining_.data(); }
        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() + haystack_.size(), 0ull), matcher_}; }