std::reverse_iterator<Iter>::base
来自cppreference.com
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iterator_type base() const; |
(C++17 起为 constexpr) |
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返回底层迭代器。
返回值
注解
底层迭代器指代(相对于 iterator_type 的)reverse_iterator 当前所指元素的下一个元素。即 &*(*this.base() - 1) == &*(*this)。
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
参阅
| 访问被指向的元素 (公开成员函数) |