From Jason Turner

[range.chunk.by.iter]

C++20 → C++23 3.2 KB 121 lines
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Archived: C++20 | C++23
Markdown: C++20 | C++23
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  1. tmp/tmp5jiaadry/{from.md → to.md} +118 -0
tmp/tmp5jiaadry/{from.md → to.md} RENAMED
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+ #### Class `chunk_by_view::iterator` <a id="range.chunk.by.iter">[[range.chunk.by.iter]]</a>
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+
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+ ``` cpp
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+ namespace std::ranges {
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+ template<forward_range V, indirect_binary_predicate<iterator_t<V>, iterator_t<V>> Pred>
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+ requires view<V> && is_object_v<Pred>
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+ class chunk_by_view<V, Pred>::iterator {
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+ chunk_by_view* parent_ = nullptr; // exposition only
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+ iterator_t<V> current_ = iterator_t<V>(); // exposition only
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+ iterator_t<V> next_ = iterator_t<V>(); // exposition only
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+
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+ constexpr iterator(chunk_by_view& parent, iterator_t<V> current, // exposition only
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+ iterator_t<V> next);
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+
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+ public:
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+ using value_type = subrange<iterator_t<V>>;
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+ using difference_type = range_difference_t<V>;
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+ using iterator_category = input_iterator_tag;
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+ using iterator_concept = see below;
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+
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+ iterator() = default;
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+
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+ constexpr value_type operator*() const;
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+ constexpr iterator& operator++();
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+ constexpr iterator operator++(int);
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+
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+ constexpr iterator& operator--() requires bidirectional_range<V>;
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+ constexpr iterator operator--(int) requires bidirectional_range<V>;
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+
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+ friend constexpr bool operator==(const iterator& x, const iterator& y);
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+ friend constexpr bool operator==(const iterator& x, default_sentinel_t);
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+ };
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+ }
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+ ```
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+
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+ `iterator::iterator_concept` is defined as follows:
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+
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+ - If `V` models `bidirectional_range`, then `iterator_concept` denotes
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+ `bidirectional_iterator_tag`.
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+ - Otherwise, `iterator_concept` denotes `forward_iterator_tag`.
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+
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+ ``` cpp
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+ constexpr iterator(chunk_by_view& parent, iterator_t<V> current, iterator_t<V> next);
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+ ```
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+
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+ *Effects:* Initializes *parent\_* with `addressof(parent)`, *current\_*
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+ with `current`, and *next\_* with `next`.
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+
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+ ``` cpp
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+ constexpr value_type operator*() const;
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+ ```
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+
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+ *Preconditions:* *current\_* is not equal to *next\_*.
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+
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+ *Returns:* `subrange(`*`current_`*`, `*`next_`*`)`.
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+
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+ ``` cpp
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+ constexpr iterator& operator++();
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+ ```
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+
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+ *Preconditions:* *current\_* is not equal to *next\_*.
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+
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+ *Effects:* Equivalent to:
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+
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+ ``` cpp
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+ current_ = next_;
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+ next_ = parent_->find-next(current_);
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+ return *this;
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+ ```
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+
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+ ``` cpp
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+ constexpr iterator operator++(int);
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+ ```
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+
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+ *Effects:* Equivalent to:
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+
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+ ``` cpp
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+ auto tmp = *this;
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+ ++*this;
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+ return tmp;
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+ ```
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+
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+ ``` cpp
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+ constexpr iterator& operator--() requires bidirectional_range<V>;
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+ ```
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+
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+ *Effects:* Equivalent to:
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+
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+ ``` cpp
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+ next_ = current_;
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+ current_ = parent_->find-prev(next_);
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+ return *this;
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+ ```
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+
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+ ``` cpp
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+ constexpr iterator operator--(int) requires bidirectional_range<V>;
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+ ```
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+
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+ *Effects:* Equivalent to:
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+
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+ ``` cpp
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+ auto tmp = *this;
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+ --*this;
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+ return tmp;
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+ ```
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+
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+ ``` cpp
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+ friend constexpr bool operator==(const iterator& x, const iterator& y);
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+ ```
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+
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+ *Returns:* `x.`*`current_`*` == y.`*`current_`*.
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+
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+ ``` cpp
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+ friend constexpr bool operator==(const iterator& x, default_sentinel_t);
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+ ```
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+
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+ *Returns:* `x.`*`current_`*` == x.`*`next_`*.
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+