Class Iterator

common/ast/navigable_ast_internal.h:47–102

 public:
  class Iterator {
   public:
    using difference_type = ptrdiff_t;
    using value_type = decltype(RangeTraits::Adapt(*PtrType()));
    using iterator_category = std::bidirectional_iterator_tag;

    Iterator() : ptr_(nullptr), span_() {}
    Iterator(SpanType span, size_t i) : ptr_(span.data() + i), span_(span) {}

    value_type operator*() const {
      ABSL_DCHECK(ptr_ != nullptr);
      ABSL_DCHECK(span_.data() != nullptr);
      ABSL_DCHECK_GE(ptr_, span_.data());
      ABSL_DCHECK_LT(ptr_, span_.data() + span_.size());
      return RangeTraits::Adapt(*ptr_);
    }

    template <int... Barrier, typename T = value_type>
    std::enable_if_t<std::is_lvalue_reference<T>::value,
                     std::add_pointer_t<std::remove_reference_t<T>>>
    operator->() const {
      return &operator*();
    }

    Iterator& operator++() {
      ++ptr_;
      return *this;
    }

    Iterator operator++(int) {
      Iterator tmp = *this;
      ++ptr_;
      return tmp;
    }

    Iterator& operator--() {
      --ptr_;
      return *this;
    }

    Iterator operator--(int) {
      Iterator tmp = *this;
      --ptr_;
      return tmp;
    }

    bool operator==(const Iterator& other) const {
      return ptr_ == other.ptr_ && span_ == other.span_;
    }

    bool operator!=(const Iterator& other) const { return !(*this == other); }

   private:
    PtrType ptr_;
    SpanType span_;
  };

  explicit NavigableAstRange(SpanType span) : span_(span) {}