std::reverse_iterator<Iter>:: base

返回底层迭代器。

返回值

current

注释

基础迭代器指向的是 reverse_iterator 当前所指元素（从 iterator_type 视角看）的下一个元素。即 & * ( this - > base ( ) - 1 ) == & * ( * this ) 。

示例

#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';
}

*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

参见