| 60 | class sentinel {}; |
| 61 | |
| 62 | class iterator { |
| 63 | private: |
| 64 | const char** ptr_; |
| 65 | scan_buffer* buf_; // This could be merged with ptr_. |
| 66 | char value_; |
| 67 | |
| 68 | static auto get_sentinel() -> const char** { |
| 69 | static const char* ptr = nullptr; |
| 70 | return &ptr; |
| 71 | } |
| 72 | |
| 73 | friend class scan_buffer; |
| 74 | |
| 75 | friend auto operator==(iterator lhs, sentinel) -> bool { |
| 76 | return *lhs.ptr_ == nullptr; |
| 77 | } |
| 78 | friend auto operator!=(iterator lhs, sentinel) -> bool { |
| 79 | return *lhs.ptr_ != nullptr; |
| 80 | } |
| 81 | |
| 82 | iterator(scan_buffer* buf) : buf_(buf) { |
| 83 | if (buf->ptr_ == buf->end_) { |
| 84 | ptr_ = get_sentinel(); |
| 85 | return; |
| 86 | } |
| 87 | ptr_ = &buf->ptr_; |
| 88 | value_ = *buf->ptr_; |
| 89 | } |
| 90 | |
| 91 | friend scan_buffer& get_buffer(iterator it) { return *it.buf_; } |
| 92 | |
| 93 | public: |
| 94 | iterator() : ptr_(get_sentinel()), buf_(nullptr) {} |
| 95 | |
| 96 | auto operator++() -> iterator& { |
| 97 | if (!buf_->try_consume()) ptr_ = get_sentinel(); |
| 98 | value_ = *buf_->ptr_; |
| 99 | return *this; |
| 100 | } |
| 101 | auto operator++(int) -> iterator { |
| 102 | iterator copy = *this; |
| 103 | ++*this; |
| 104 | return copy; |
| 105 | } |
| 106 | auto operator*() const -> char { return value_; } |
| 107 | |
| 108 | auto base() const -> const char* { return buf_->ptr_; } |
| 109 | |
| 110 | friend auto to_contiguous(iterator it) -> maybe_contiguous_range; |
| 111 | friend auto advance(iterator it, size_t n) -> iterator; |
| 112 | }; |
| 113 | |
| 114 | friend auto to_contiguous(iterator it) -> maybe_contiguous_range { |
| 115 | if (it.buf_->is_contiguous()) return {it.buf_->ptr_, it.buf_->end_}; |