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std::ranges::adjacent_view<V,N>:: begin

From cppreference.net
C++
Ranges library
Range adaptors
std::ranges::adjacent_view
Member functions
adjacent_view::begin
(C++26)
Iterator
Member functions
Non-member functions
Sentinel
Member functions
Non-member functions
constexpr auto begin ( ) requires ( ! __SimpleView < V > ) ;
(1) (自 C++23 起)
constexpr auto begin ( ) const requires ranges:: range < const V > ;
(2) (自 C++23 起)

返回指向 adjacent_view 首元素的 迭代器 。

令 base_ 为底层视图。

1) 等价于 return /*iterator*/ < false > ( ranges:: begin ( base_ ) , ranges:: end ( base_ ) ) ; 。
2) 等价于 return /*iterator*/ < true > ( ranges:: begin ( base_ ) , ranges:: end ( base_ ) ) ; 。

目录

参数

(无)

返回值

指向第一个元素的迭代器。

示例

运行此代码 
#include <ranges>
#include <tuple>
#include <type_traits>
int main()
{
    constexpr static auto v = {'A', 'B', 'C', 'D', 'E'};
    constexpr auto view = std::views::adjacent<3>(v);
    constexpr auto tuple = *view.begin();
    static_assert
    (
        std::is_same_v
        <
            decltype(tuple),
            const std::tuple<char const&, char const&, char const&>
        >
    );
    static_assert
    (
        std::get<0>(tuple) == 'A' &&
        std::get<1>(tuple) == 'B' &&
        std::get<2>(tuple) == 'C'
    );
}

参见

返回指向末尾的迭代器或哨兵
(公开成员函数)
(C++20)
返回指向范围起始位置的迭代器
(定制点对象)