std::ranges::cartesian_product_view<First, Vs...>::end

 

C++

编译器支持

自立实现与有宿主实现

语言

标准库

标准库标头

具名要求

功能特性测试宏 (C++20)

语言支持库

概念库 (C++20)

元编程库 (C++11)

诊断库

通用工具库

字符串库

容器库

迭代器库

范围库 (C++20)

算法库

数值库

本地化库

输入/输出库

文件系统库 (C++17)

正则表达式库 (C++11)

并发支持库 (C++11)

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 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    sized_range	common_range view viewable_range	input_range output_range forward_range	bidirectional_range    random_access_range contiguous_range	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 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 concat_viewviews::concat (C++26)(C++26)	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)

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 (C++23 前)  (C++23)	simple-view non-propagating-cache

 

std::ranges::cartesian_product_view

成员函数

cartesian_product_view::cartesian_product_view

cartesian_product_view::begin

cartesian_product_view::end

cartesian_product_view::size

推导指引

迭代器

成员函数

cartesian_product_view::iterator::iterator

cartesian_product_view::iterator::operator*

cartesian_product_view::iterator::operator[]

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

cartesian_product_view::iterator::next

cartesian_product_view::iterator::prev

cartesian_product_view::iterator::distance_from

非成员函数

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

operator+(cartesian_product_view::iterator) operator-(cartesian_product_view::iterator)

iter_move(cartesian_product_view::iterator)

iter_swap(cartesian_product_view::iterator)

 

constexpr iterator<false> end()     requires ((!/*simple-view*/<First> || ... || !/*simple-view*/<Vs>) &&         /*cartesian-product-is-common*/<First, Vs...>);	(1)	(C++23 起)
constexpr iterator<true> end() const     requires /*cartesian-product-is-common*/<const First, const Vs...>;	(2)	(C++23 起)
constexpr std::default_sentinel_t end() const noexcept;	(3)	(C++23 起)

返回表示 cartesian_product_view 结尾的迭代器或者哨位。

令 bases_ 为底层的视图元组。

1,2) 等价于：

auto check = [](auto& rng) { return __begin_or_first_end(rng); };
return iterator<__is_const>(/*tuple-transform*/(check, bases_));，

其中：

• __is_const 对于 const-限定 的重载为 true，否则为 false。
• 若表达式 ranges::empty(rng) 对除第一个范围之外的任何底层范围 rng 中都为 true，则 __is_empty 为 true，否则为 false。
• 若 rng 为第一个底层的范围，则 __begin_or_first_end(rng) 表达式等价于 __is_empty ? ranges::begin(rng) : /*cartesian-common-arg-end*/(rng)，否则表达式等价于 ranges::begin(rng)。

3) 等价于 return std::default_sentinel;。

参数

（无）

返回值

指向最后元素之后的元素的迭代器，或指向和尾迭代器比较相等的哨位。

示例

运行此代码

#include <array>
#include <format>
#include <iostream>
#include <ranges>
#include <string_view>
#include <tuple>
using namespace std::literals;
 
int main()
{
    constexpr auto a = std::array{ "bool"sv, "goto"sv, "extern"sv, "long"sv }; /*
                                       ^         ^           ^         ^        */
    constexpr auto v = std::ranges::cartesian_product_view(a[0], a[1], a[2], a[3]);
 
    constexpr std::tuple<char const&,
                         char const&,
                         char const&,
                         char const&> last{*(v.end() - 1)};
 
    std::cout << std::format("{}{}{}{}{}",
                             std::get<0>(last),
                             std::get<1>(last),
                             std::get<2>(last),
                             std::get<3>(last), '\n');
}

输出：

long

参阅

begin	返回指向起始的迭代器 (公开成员函数)
ranges::end (C++20)	返回指示范围结尾的哨位 (定制点对象)