std::ranges::adjacent_view<V,N>::iterator<Const>::operator++,--,+=,-=

 

C++

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功能特性测试宏 (C++20)

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范围访问
begin cbegin end cend	rbegin crbegin rend crend	size ssize data cdata	empty
范围转换器
to (C++23)
范围原语
range_size_trange_difference_t range_value_t	range_reference_trange_const_reference_trange_rvalue_reference_t (C++23)	iterator_tconst_iterator_tsentinel_t (C++23)
悬垂迭代器处理
dangling	borrowed_iterator_t	borrowed_subrange_t
范围概念
range borrowed_range    sized_range constant_range (C++23)	common_range view viewable_range	input_range output_range forward_range	bidirectional_range random_access_range contiguous_range
视图
view_interface	subrange
范围工厂
empty_viewviews::empty single_viewviews::single	iota_viewviews::iota repeat_viewviews::repeat (C++23)(C++23)	basic_istream_viewviews::istream cartesian_product_viewviews::cartesian_product_view (C++23)(C++23)
适配器
views::all_tviews::all ref_view owning_view as_rvalue_viewviews::as_rvalue (C++23)(C++23)   filter_viewviews::filter transform_viewviews::transform take_viewviews::take take_while_viewviews::take_while	drop_viewviews::drop drop_while_viewviews::drop_while join_viewviews::join join_with_viewviews::join_with (C++23)(C++23) lazy_split_viewviews::lazy_split split_viewviews::split views::counted common_viewviews::common	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)
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std::generator (C++23)
范围适配器对象
范围适配器闭包对象
range_adaptor_closure (C++23)
辅助项
copyable-box	simple-view

 

std::ranges::adjacent_view

成员函数

adjacent_view::adjacent_view (C++23)

adjacent_view::begin (C++23)

adjacent_view::end (C++23)

adjacent_view::size (C++23)

迭代器

成员函数

adjacent_view::iterator::iterator (C++23)

adjacent_view::iterator::operator* (C++23)

adjacent_view::iterator::operator[] (C++23)

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-= (C++23)(C++23)(C++23)(C++23)(C++23)(C++23)

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) (C++23)(C++23)(C++23)(C++23)(C++23)(C++23)

operator+(adjacent_view::iterator) operator-(adjacent_view::iterator) (C++23)(C++23)

iter_move(adjacent_view::iterator) (C++23)

iter_swap(adjacent_view::iterator) (C++23)

哨兵

成员函数

adjacent_view::sentinel::sentinel (C++23)

非成员函数

operator==(adjacent_view::iterator,adjacent_view::sentinel) (C++23)

operator-(adjacent_view::iterator,adjacent_view::sentinel) (C++23)

 

constexpr /*iterator*/& operator++();	(1)	(C++23 起)
constexpr /*iterator*/ operator++( int );	(2)	(C++23 起)
constexpr /*iterator*/& operator--()   requires ranges::bidirectional_range<Base>;	(3)	(C++23 起)
constexpr /*iterator*/ operator--( int )   requires ranges::bidirectional_range<Base>;	(4)	(C++23 起)
constexpr /*iterator*/& operator+=( difference_type n )   requires ranges::random_access_range<Base>;	(5)	(C++23 起)
constexpr /*iterator*/& operator-=( difference_type n )   requires ranges::random_access_range<Base>;	(6)	(C++23 起)

递增或递减迭代器。

令 current_ 为底层迭代器数组。

1) 等价于：

for (auto& i : current_)
    std::ranges::next(i);
return *this;

如果在调用之前，current_.back() 不可递增，则行为未定义。

2) 等价于：

auto tmp = *this;
++*this;
return tmp;

3) 等价于：

for (auto& i : current_)
    std::ranges::prev(i);
return *this;

如果调用之前，current_.front() 不可递增，则行为未定义。

4) 等价于：

auto tmp = *this;
--*this;
return tmp;

5) 等价于：

for (auto& i : current_)
    i += n;
return *this;

如果调用之前，current_.back() + n 无良定义，则行为未定义。

6) 等价于：

for (auto& i : current_)
    i -= n;
return *this;

如果调用之前，current_.front() - n 无良定义，则行为未定义。

参数

n

-

相对于当前位置的偏移量

返回值

1,3,5,6) *this

2,4) *this 被修改前的拷贝。

示例

运行此代码

#include <cassert>
#include <list>
#include <ranges>
#include <utility>
#include <vector>
 
[[nodiscard]]
bool operator== (std::pair<int&, int&> x, std::pair<int, int> y)
{
    return x.first == y.first and x.second == y.second;
}
 
int main()
{
    {
        auto v = std::vector{0, 1, 2, 3, 4, 5};
        auto i = (v | std::views::pairwise).begin();
        assert((*i == std::pair{0, 1}));
        ++i;                            // 重载 (1)
        assert((*i == std::pair{1, 2}));
        --i;                            // 重载 (3)
        assert((*i == std::pair{0, 1}));
        i += 2;                         // 重载 (5)
        assert((*i == std::pair{2, 3}));
        i -= 2;                         // 重载 (6)
        assert((*i == std::pair{0, 1}));
    }
    {
        auto v = std::list{0, 1, 2, 3, 4, 5};
        auto i = (v | std::views::pairwise).begin();
        assert((*i == std::pair{0, 1}));
        ++i;                            // 重载 (1)
        assert((*i == std::pair{1, 2}));
        --i;                            // 重载 (3)
        assert((*i == std::pair{0, 1}));
//      i += 2; // Error: v is not a random_access_range; 重载 (5)
//      i -= 2; // Error: v is not a random_access_range; 重载 (6)
    }
}

参阅

operator+operator- (C++23)

进行迭代器算数 (公开成员函数)