From Jason Turner

[range.repeat.view]

C++20 → C++23 3.7 KB 108 lines
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Archived: C++20 | C++23
Markdown: C++20 | C++23
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  1. tmp/tmp75i0oxvv/{from.md → to.md} +105 -0
tmp/tmp75i0oxvv/{from.md → to.md} RENAMED
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+ #### Class template `repeat_view` <a id="range.repeat.view">[[range.repeat.view]]</a>
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+
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+ ``` cpp
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+ namespace std::ranges {
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+ template<class T>
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+ concept integer-like-with-usable-difference-type = // exposition only
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+ is-signed-integer-like<T> || (is-integer-like<T> && weakly_incrementable<T>);
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+
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+ template<move_constructible T, semiregular Bound = unreachable_sentinel_t>
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+ requires (is_object_v<T> && same_as<T, remove_cv_t<T>> &&
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+ (integer-like-with-usable-difference-type<Bound> ||
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+ same_as<Bound, unreachable_sentinel_t>))
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+ class repeat_view : public view_interface<repeat_view<T, Bound>> {
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+ private:
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+ // [range.repeat.iterator], class repeat_view::iterator
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+ struct iterator; // exposition only
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+
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+ movable-box<T> value_; // exposition only, see [range.move.wrap]
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+ Bound bound_ = Bound(); // exposition only
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+
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+ public:
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+ repeat_view() requires default_initializable<T> = default;
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+
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+ constexpr explicit repeat_view(const T& value, Bound bound = Bound())
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+ requires copy_constructible<T>;
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+ constexpr explicit repeat_view(T&& value, Bound bound = Bound());
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+ template<class... TArgs, class... BoundArgs>
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+ requires constructible_from<T, TArgs...> &&
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+ constructible_from<Bound, BoundArgs...>
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+ constexpr explicit repeat_view(piecewise_construct_t,
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+ tuple<TArgs...> value_args, tuple<BoundArgs...> bound_args = tuple<>{});
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+
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+ constexpr iterator begin() const;
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+ constexpr iterator end() const requires (!same_as<Bound, unreachable_sentinel_t>);
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+ constexpr unreachable_sentinel_t end() const noexcept;
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+
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+ constexpr auto size() const requires (!same_as<Bound, unreachable_sentinel_t>);
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+ };
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+
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+ template<class T, class Bound>
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+ repeat_view(T, Bound) -> repeat_view<T, Bound>;
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+ }
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+ ```
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+
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+ ``` cpp
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+ constexpr explicit repeat_view(const T& value, Bound bound = Bound())
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+ requires copy_constructible<T>;
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+ ```
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+
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+ *Preconditions:* If `Bound` is not `unreachable_sentinel_t`,
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+ `bound` ≥ 0.
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+
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+ *Effects:* Initializes *value\_* with `value` and *bound\_* with
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+ `bound`.
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+
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+ ``` cpp
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+ constexpr explicit repeat_view(T&& value, Bound bound = Bound());
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+ ```
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+
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+ *Preconditions:* If `Bound` is not `unreachable_sentinel_t`,
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+ `bound` ≥ 0.
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+
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+ *Effects:* Initializes *value\_* with `std::move(value)` and *bound\_*
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+ with `bound`.
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+
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+ ``` cpp
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+ template<class... TArgs, class... BoundArgs>
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+ requires constructible_from<T, TArgs...> &&
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+ constructible_from<Bound, BoundArgs...>
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+ constexpr explicit repeat_view(piecewise_construct_t,
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+ tuple<TArgs...> value_args, tuple<BoundArgs...> bound_args = tuple<>{});
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+ ```
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+
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+ *Effects:* Initializes *value\_* with
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+ `make_from_tuple<T>(std::move(value_args))` and initializes *bound\_*
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+ with `make_from_tuple<Bound>(std::move(bound_args))`. The behavior is
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+ undefined if `Bound` is not `unreachable_sentinel_t` and *bound\_* is
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+ negative.
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+
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+ ``` cpp
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+ constexpr iterator begin() const;
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+ ```
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+
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+ *Effects:* Equivalent to:
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+ `return `*`iterator`*`(addressof(*`*`value_`*`));`
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+
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+ ``` cpp
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+ constexpr iterator end() const requires (!same_as<Bound, unreachable_sentinel_t>);
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+ ```
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+
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+ *Effects:* Equivalent to:
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+ `return `*`iterator`*`(addressof(*`*`value_`*`), `*`bound_`*`);`
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+
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+ ``` cpp
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+ constexpr unreachable_sentinel_t end() const noexcept;
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+ ```
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+
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+ *Effects:* Equivalent to: `return unreachable_sentinel;`
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+
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+ ``` cpp
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+ constexpr auto size() const requires (!same_as<Bound, unreachable_sentinel_t>);
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+ ```
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+
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+ *Effects:* Equivalent to: `return `*`to-unsigned-like`*`(`*`bound_`*`);`
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+