std::reverse_iterator<Iter>::base
来自 cppreference.cn
iterator_type base() const; |
(自 C++17 起为 constexpr) | |
返回底层迭代器。
目录 |
[edit] 返回值
[edit] 注解
基础迭代器指向 `reverse_iterator` 当前所指向元素的下一个元素(从 `iterator_type` 的角度看)。也就是说 &*(this->base() - 1) == &*(*this)。
[edit] 示例
运行此代码
#include <iostream> #include <iterator> #include <vector> int main() { std::vector<int> v = {0, 1, 2, 3, 4, 5}; using RevIt = std::reverse_iterator<std::vector<int>::iterator>; const auto it = v.begin() + 3; RevIt r_it{it}; std::cout << "*it == " << *it << '\n' << "*r_it == " << *r_it << '\n' << "*r_it.base() == " << *r_it.base() << '\n' << "*(r_it.base() - 1) == " << *(r_it.base() - 1) << '\n'; RevIt r_end{v.begin()}; RevIt r_begin{v.end()}; for (auto it = r_end.base(); it != r_begin.base(); ++it) std::cout << *it << ' '; std::cout << '\n'; for (auto it = r_begin; it != r_end; ++it) std::cout << *it << ' '; std::cout << '\n'; }
输出
*it == 3 *r_it == 2 *r_it.base() == 3 *(r_it.base() - 1) == 2 0 1 2 3 4 5 5 4 3 2 1 0
[edit] 参阅
访问指向的元素 (public member function) |