std::ranges::concat_view<Views...>::begin

 

C++

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特性測試宏 (C++20)

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範圍庫 (C++20)

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檔案系統庫 (C++17)

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執行控制庫 (C++26)

技術規範

符號索引

外部庫

 

範圍庫 (Ranges library)

範圍訪問 begin cbegin   end cend rbegin crbegin   rend crend size ssize   data cdata reserve_hint (C++26)   empty

範圍轉換 (Range conversions) std::from_range_t std::from_range (C++23)(C++23)     to (C++23)

懸空迭代器處理 (Dangling iterator handling) dangling borrowed_iterator_t borrowed_subrange_t

範圍原語 (Range primitives)
range_size_trange_difference_trange_value_t elements_of (C++23)	iterator_tconst_iterator_tsentinel_tconst_sentinel_t (C++23)(C++23)	range_reference_trange_const_reference_trange_rvalue_reference_trange_common_reference_t (C++23)

範圍概念 (Range concepts)
range borrowed_range    common_range	sized_range viewable_range    view	input_range output_range forward_range	bidirectional_range    random_access_range contiguous_range	approximately_sized_range (C++26) constant_range (C++23)

檢視
view_interface	subrange

範圍工廠 (Range factories)
empty_viewviews::empty	single_viewviews::single	basic_istream_viewviews::istream	iota_viewviews::iota	repeat_viewviews::repeat (C++23)(C++23)

範圍介面卡 (Range adaptors)
views::all_tviews::all as_rvalue_viewviews::as_rvalue (C++23)(C++23)   filter_viewviews::filter transform_viewviews::transform take_viewviews::take take_while_viewviews::take_while common_viewviews::common views::counted to_input_viewviews::to_input (C++26)(C++26)	ref_view drop_viewviews::drop drop_while_viewviews::drop_while lazy_split_viewviews::lazy_split split_viewviews::split join_viewviews::join join_with_viewviews::join_with (C++23)(C++23)   concat_viewviews::concat (C++26)(C++26) cache_latest_viewviews::cache_latest (C++26)(C++26)	owning_view reverse_viewviews::reverse as_const_viewviews::as_const (C++23)(C++23) elements_viewviews::elements keys_viewviews::keys values_viewviews::values enumerate_viewviews::enumerate (C++23)(C++23) zip_viewviews::zip (C++23)(C++23) zip_transform_viewviews::zip_transform (C++23)(C++23)	adjacent_viewviews::adjacent (C++23)(C++23) views::pairwise (C++23) adjacent_transform_viewviews::adjacent_transform (C++23)(C++23) views::pairwise_transform (C++23) chunk_viewviews::chunk (C++23)(C++23) slide_viewviews::slide (C++23)(C++23) chunk_by_viewviews::chunk_by (C++23)(C++23) stride_viewviews::stride (C++23)(C++23) cartesian_product_viewviews::cartesian_product (C++23)(C++23)

範圍生成器 (Range generators) std::generator (C++23)

範圍介面卡閉包物件 (Range adaptor closure objects) range_adaptor_closure (C++23)

範圍介面卡物件 (Range adaptor objects)

輔助項 (Helper items)
copyable-box movable-box (直到 C++23)  (C++23)	simple-view non-propagating-cache

 

std::ranges::concat_view

成員函式

concat_view::concat_view

concat_view::begin

concat_view::end

concat_view::size

推導指引

迭代器 (Iterator)

成員函式

concat_view::iterator::iterator

concat_view::iterator::operator*

concat_view::iterator::operator[]

concat_view::iterator::operator++ concat_view::iterator::operator++(int) concat_view::iterator::operator-- concat_view::iterator::operator--(int) concat_view::iterator::operator+= concat_view::iterator::operator-=

concat_view::iterator::satisfy concat_view::iterator::prev concat_view::iterator::advance-fwd concat_view::iterator::advance-bwd

非成員函式

operator==(concat_view::iterator) operator<(concat_view::iterator) operator>(concat_view::iterator) operator<=(concat_view::iterator) operator>=(concat_view::iterator) operator<=>(concat_view::iterator)

operator+(concat_view::iterator) operator-(concat_view::iterator)

iter_move(concat_view::iterator)

iter_swap(concat_view::iterator)

 

constexpr /*iterator*/<false> begin()     requires (!(/*simple-view*/<Views> && ...));	(1)	(C++26 起)
constexpr /*iterator*/<true> begin() const     requires (ranges::range<const Views> && ...) &&                  /*concatable*/<const Views...>;	(2)	(C++26 起)

返回 concat_view 開頭的 迭代器。

1) 等價於 iterator <false> it(this, std::in_place_index<0>,
                   ranges::begin(std::get<0>(views_ )));
it.template satisfy <0>();
return it;。

2) 等價於 iterator <true> it(this, std::in_place_index<0>,
                  ranges::begin(std::get<0>(views_ )));
it.template satisfy <0>();
return it;。

返回值

如上所述。

示例

初步版本可以在 Compiler Explorer 上檢視。

執行此程式碼

#include <ranges>
#include <string_view>
using namespace std::literals;
 
int main()
{
    static constexpr auto c = {"🐱", "🐶"};
    static constexpr auto a = {"🤡"sv};
    static constexpr auto t = {"💚"sv};
    static constexpr auto cat{std::views::concat(c, a, t)};
    static_assert(*cat.begin() == "\U0001F431" and
                  cat.begin()[1] == "🐶" and
                  *(cat.begin() + 2) == "\N{CLOWN FACE}");
}

參閱

end	返回一個迭代器或一個哨兵到末尾 (public member function)
ranges::begin (C++20)	返回指向範圍開頭的迭代器 (定製點物件)