std::ranges::adjacent_view<V,N>::iterator<Const>::operator[]

 

C++

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独立和宿主

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特性测试宏 (C++20)

语言支持库

概念库 (C++20)

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内存管理库

元编程库 (C++11)

通用工具库

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范围库 (C++20)

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文件系统库 (C++17)

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技术规范

符号索引

外部库

 

范围库

范围访问 begin cbegin   end cend rbegin crbegin   rend crend size ssize   data cdata reserve_hint (C++26)   empty

范围转换 std::from_range_t std::from_range (C++23)(C++23)     to (C++23)

悬垂迭代器处理 dangling borrowed_iterator_t borrowed_subrange_t

范围原语
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)

范围概念
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)

视图
view_interface	subrange

范围工厂
empty_viewviews::empty	single_viewviews::single	basic_istream_viewviews::istream	iota_viewviews::iota	repeat_viewviews::repeat (C++23)(C++23)

范围适配器
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)

范围生成器 std::generator (C++23)

范围适配器闭包对象 range_adaptor_closure (C++23)

范围适配器对象

辅助项
copyable-box movable-box (until C++23)  (C++23)	simple-view non-propagating-cache

 

std::ranges::adjacent_view

成员函数

adjacent_view::adjacent_view

adjacent_view::begin

adjacent_view::end

adjacent_view::size

迭代器

成员函数

adjacent_view::iterator::iterator

adjacent_view::iterator::operator*

adjacent_view::iterator::operator[]

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

非成员函数

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

operator+(adjacent_view::iterator) operator-(adjacent_view::iterator)

iter_move(adjacent_view::iterator)

iter_swap(adjacent_view::iterator)

哨位

成员函数

adjacent_view::sentinel::sentinel

非成员函数

operator==(adjacent_view::iterator,adjacent_view::sentinel)

operator-(adjacent_view::iterator,adjacent_view::sentinel)

 

constexpr auto operator[]( difference_type n ) const     requires ranges::random_access_range<Base>;		(C++23 起)

返回指定相对位置的元素。

设 current_ 为底层迭代器数组。

等价于

return /*tuple-transform*/([&](auto& i) -> decltype(auto) { return i[n]; }, current_);

参数

n

-

相对于当前位置的位置偏移

返回值

相对于当前位置偏移 n 处的元素。

示例

运行此代码

#include <ranges>
#include <tuple>
 
int main()
{
    constexpr static auto v = {0, 1, 2, 3, 4, 5};
    //                               └──┬──┘  
    //                                  └─────────────────┐
    constexpr auto view = v | std::views::adjacent<3>; // │
    //                 ┌───────────────────┬──────────────┘ 
    //                 │                ┌──┴──┐
    static_assert(view[2] == std::tuple{2, 3, 4});
}