std::move_iterator
STD：移动[医]迭代器
| Defined in header | | |
|---|---|---|
| template< class Iterator > class move_iterator; | | (since C++11) |
std::move_iterator是迭代器适配器，它的行为与底层迭代器%28完全相同，至少必须是InputIterator%29，但反引用将基础迭代器返回的值转换为rvalue。如果将此迭代器用作输入迭代器，则其效果是将值移出，而不是从其复制。
成员类型
| Member type | Definition |
|---|---|
| iterator_type | Iterator |
| difference_type | std::iterator_traits<Iterator>::difference_type |
| pointer | Iterator |
| value_type | std::iterator_traits<Iterator>::value_type |
| iterator_category | std::iterator_traits<Iterator>::iterator_category |
| reference | value_type&& (until C++17) If std::iterator_traits<Iterator>::reference is a reference, this is the rvalue reference version of the same type. Otherwise (such as if the wrapped iterator returns by value), this is std::iterator_traits<Iterator>::reference unchanged. (since C++17) |
成员函数
| (constructor) | constructs a new iterator adaptor (public member function) |
|---|---|
| operator= | assigns another iterator (public member function) |
| base | accesses the underlying iterator (public member function) |
| operator*operator-> | accesses the pointed-to element (public member function) |
| operator[] | accesses an element by index (public member function) |
| operator++operator++(int)operator+=operator+operator--operator--(int)operator-=operator- | advances or decrements the iterator (public member function) |
成员对象
| Member name | Definition |
|---|---|
| current (private) | a copy of the base() iterator, the name is for exposition only |
非会员职能
| operator==operator!=operator | compares the underlying iterators (function template) |
|---|---|
| operator+ | advances the iterator (function template) |
| operator- | computes the distance between two iterator adaptors (function template) |
例
二次
#include <iostream>
#include <algorithm>
#include <vector>
#include <iterator>
#include <numeric>
#include <string>
int main()
{
std::vector<std::string> v{"this", "is", "an", "example"};
std::cout << "Old contents of the vector: ";
for (auto& s : v)
std::cout << '"' << s << "\" ";
typedef std::vector<std::string>::iterator iter_t;
std::string concat = std::accumulate(
std::move_iterator<iter_t>(v.begin()),
std::move_iterator<iter_t>(v.end()),
std::string() // Can be simplified with std::make_move_iterator
std::cout << "\nConcatenated as string: " << concat << '\n'
<< "New contents of the vector: ";
for (auto& s : v)
std::cout << '"' << s << "\" ";
std::cout << '\n';
}
二次
可能的产出：
二次
Old contents of the vector: "this" "is" "an" "example"
Concatenated as string: thisisanexample
New contents of the vector: "" "" "" ""
二次
另见
| make_move_iterator (C++11) | creates a std::move_iterator of type inferred from the argument (function template) |
|---|
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