cppdraft_translate/cppdraft/range/take/view.md

[range.take.view]

25 Ranges library [ranges]

25.7 Range adaptors [range.adaptors]

25.7.10 Take view [range.take]

25.7.10.2 Class template take_view [range.take.view]

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namespace std::ranges {template<view V>class take_view : public view_interface<take_view> {private: V base_ = V(); // exposition only range_difference_t count_ = 0; // exposition only// [range.take.sentinel], class template take_view​::​sentineltemplate class sentinel; // exposition onlypublic: take_view() requires default_initializable = default; constexpr explicit take_view(V base, range_difference_t count); constexpr V base() const & requires copy_constructible { return base_; }constexpr V base() && { return std::move(base_); }constexpr auto begin() requires () {if constexpr (sized_range) {if constexpr (random_access_range) {return ranges::begin(base_); } else {auto sz = range_difference_t(size()); return counted_iterator(ranges::begin(base_), sz); }} else if constexpr (sized_sentinel_for<sentinel_t, iterator_t>) {auto it = ranges::begin(base_); auto sz = std::min(count_, ranges::end(base_) - it); return counted_iterator(std::move(it), sz); } else {return counted_iterator(ranges::begin(base_), count_); }}constexpr auto begin() const requires range {if constexpr (sized_range) {if constexpr (random_access_range) {return ranges::begin(base_); } else {auto sz = range_difference_t(size()); return counted_iterator(ranges::begin(base_), sz); }} else if constexpr (sized_sentinel_for<sentinel_t, iterator_t>) {auto it = ranges::begin(base_); auto sz = std::min(count_, ranges::end(base_) - it); return counted_iterator(std::move(it), sz); } else {return counted_iterator(ranges::begin(base_), count_); }}constexpr auto end() requires () {if constexpr (sized_range) {if constexpr (random_access_range)return ranges::begin(base_) + range_difference_t(size()); elsereturn default_sentinel; } else if constexpr (sized_sentinel_for<sentinel_t, iterator_t>) {return default_sentinel; } else {return sentinel{ranges::end(base_)}; }}constexpr auto end() const requires range {if constexpr (sized_range) {if constexpr (random_access_range)return ranges::begin(base_) + range_difference_t(size()); elsereturn default_sentinel; } else if constexpr (sized_sentinel_for<sentinel_t, iterator_t>) {return default_sentinel; } else {return sentinel{ranges::end(base_)}; }}constexpr auto size() requires sized_range {auto n = ranges::size(base_); return ranges::min(n, static_cast<decltype(n)>(count_)); }constexpr auto size() const requires sized_range {auto n = ranges::size(base_); return ranges::min(n, static_cast<decltype(n)>(count_)); }constexpr auto reserve_hint() {if constexpr (approximately_sized_range) {auto n = static_cast<range_difference_t>(ranges::reserve_hint(base_)); return to-unsigned-like(ranges::min(n, count_)); }return to-unsigned-like(count_); }constexpr auto reserve_hint() const {if constexpr (approximately_sized_range) {auto n = static_cast<range_difference_t>(ranges::reserve_hint(base_)); return to-unsigned-like(ranges::min(n, count_)); }return to-unsigned-like(count_); }}; template take_view(R&&, range_difference_t)-> take_view<views::all_t>;}

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constexpr explicit take_view(V base, range_difference_t<V> count);

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Preconditions: count >= 0 is true.

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Effects: Initializes base_ with std​::​move(base) andcount_ with count.