operator+(std::reverse_iterator)

template< class Iter >
reverse_iterator<Iter> operator+
    ( typename reverse_iterator<Iter>::difference_type n,
      const reverse_iterator<Iter>& it );

template< class Iter >
constexpr reverse_iterator<Iter> operator+
    ( std::iter_difference_t<Iter> n, const reverse_iterator<Iter>& it );

返回迭代器 it 增加 n 后的结果。实际上，底层迭代器被减少了 n。

参数

返回值

reverse_iterator < Iter > ( it. base ( ) - n )

示例

#include <iostream>
#include <iterator>
#include <list>
#include <vector>
int main()
{
    {
        std::vector v{0, 1, 2, 3};
        std::reverse_iterator<std::vector<int>::iterator>
            ri1{std::reverse_iterator{v.rbegin()}};
        std::cout << *ri1 << ' '; // 3
        std::reverse_iterator<std::vector<int>::iterator> ri2{2 + ri1};
        std::cout << *ri2 << ' '; // 1
    }
    {
        std::list l{5, 6, 7, 8};
        std::reverse_iterator<std::list<int>::iterator>
            ri1{std::reverse_iterator{l.rbegin()}};
        std::cout << *ri1 << '\n'; // 8
    //  auto ri2{2 + ri1}; // 错误：底层迭代器不满足随机访问迭代器要求
                           //        model random access iterator
    }
}

3 1 8

参见