std::ranges::cartesian_product_view<First, Vs...>::begin
來自 cppreference.com
< cpp | ranges | cartesian product view
constexpr iterator<false> begin() requires (!/*simple-view*/<First> || ... || !/*simple-view*/<Vs>); |
(1) | (C++23 起) |
constexpr iterator<true> begin() const requires (ranges::range<const First> && ... && ranges::range<const Vs>); |
(2) | (C++23 起) |
返回指向 cartesian_product_view
首元素的迭代器。
令 bases_
為底層檢視的元組。
1) 等價於 return /*iterator*/<false>(
tuple-transform
(ranges::begin, bases_));。2) 等價於 return /*iterator*/<true>(
tuple-transform
(ranges::begin, bases_));。目錄 |
[編輯] 引數
(無)
[編輯] 返回值
指向首元素的迭代器。
[編輯] 示例
執行此程式碼
#include <array> #include <format> #include <iostream> #include <ranges> #include <string_view> #include <tuple> using namespace std::literals; int main() { constexpr auto a = std::array{"Curiously"sv, "Recurring"sv, "Template"sv, "Pattern"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&> first{*v.begin()}; std::cout << std::format("{}{}{}{}{}", std::get<0>(first), std::get<1>(first), std::get<2>(first), std::get<3>(first), '\n'); }
輸出
CRTP
[編輯] 參閱
返回一個迭代器或一個哨兵到末尾 (公開成員函式) | |
(C++20) |
返回指向範圍開頭的迭代器 (自定義點物件) |