From Jason Turner

[range.cache.latest.iterator]

C++23 → Trunk 3.2 KB 118 lines
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Archived: C++23
Markdown: C++23 | Trunk
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  1. tmp/tmpvkg7m_xz/{from.md → to.md} +115 -0
tmp/tmpvkg7m_xz/{from.md → to.md} RENAMED
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+ #### Class `cache_latest_view::iterator` <a id="range.cache.latest.iterator">[[range.cache.latest.iterator]]</a>
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+
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+ ``` cpp
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+ namespace std::ranges {
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+ template<input_range V>
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+ requires view<V>
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+ class cache_latest_view<V>::iterator {
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+ cache_latest_view* parent_; // exposition only
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+ iterator_t<V> current_; // exposition only
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+
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+ constexpr explicit iterator(cache_latest_view& parent); // exposition only
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+
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+ public:
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+ using difference_type = range_difference_t<V>;
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+ using value_type = range_value_t<V>;
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+ using iterator_concept = input_iterator_tag;
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+
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+ iterator(iterator&&) = default;
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+ iterator& operator=(iterator&&) = default;
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+
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+ constexpr iterator_t<V> base() &&;
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+ constexpr const iterator_t<V>& base() const & noexcept;
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+
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+ constexpr range_reference_t<V>& operator*() const;
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+
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+ constexpr iterator& operator++();
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+ constexpr void operator++(int);
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+
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+ friend constexpr range_rvalue_reference_t<V> iter_move(const iterator& i)
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+ noexcept(noexcept(ranges::iter_move(i.current_)));
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+
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+ friend constexpr void iter_swap(const iterator& x, const iterator& y)
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+ noexcept(noexcept(ranges::iter_swap(x.current_, y.current_)))
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+ requires indirectly_swappable<iterator_t<V>>;
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+ };
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+ }
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+ ```
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+
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+ ``` cpp
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+ constexpr explicit iterator(cache_latest_view& parent);
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+ ```
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+
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+ *Effects:* Initializes *current\_* with
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+ `ranges::begin(parent.`*`base_`*`)` and *parent\_* with
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+ `addressof(parent)`.
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+
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+ ``` cpp
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+ constexpr iterator_t<V> base() &&;
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+ ```
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+
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+ *Returns:* `std::move(`*`current_`*`)`.
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+
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+ ``` cpp
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+ constexpr const iterator_t<V>& base() const & noexcept;
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+ ```
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+
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+ *Returns:* *current\_*.
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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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+ *Effects:* Equivalent to:
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+
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+ ``` cpp
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+ parent_->cache_.reset();
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+ ++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 void operator++(int);
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+ ```
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+
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+ *Effects:* Equivalent to: `++*this`.
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+
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+ ``` cpp
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+ constexpr range_reference_t<V>& operator*() const;
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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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+ if constexpr (is_reference_v<range_reference_t<V>>) {
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+ if (!parent_->cache_) {
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+ parent_->cache_ = addressof(as-lvalue(*current_));
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+ }
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+ return **parent_->cache_;
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+ } else {
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+ if (!parent_->cache_) {
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+ parent_->cache_.emplace-deref(current_);
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+ }
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+ return *parent_->cache_;
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+ }
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+ ```
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+
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+ [*Note 1*: Evaluations of `operator*` on the same iterator object can
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+ conflict [[intro.races]]. — *end note*]
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+
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+ ``` cpp
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+ friend constexpr range_rvalue_reference_t<V> iter_move(const iterator& i)
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+ noexcept(noexcept(ranges::iter_move(i.current_)));
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+ ```
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+
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+ *Effects:* Equivalent to: `return ranges::iter_move(i.`*`current_`*`);`
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+
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+ ``` cpp
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+ friend constexpr void iter_swap(const iterator& x, const iterator& y)
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+ noexcept(noexcept(ranges::iter_swap(x.current_, y.current_)))
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+ requires indirectly_swappable<iterator_t<V>>;
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+ ```
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+
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+ *Effects:* Equivalent to
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+ `ranges::iter_swap(x.`*`current_`*`, y.`*`current_`*`)`.
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+