std::move_iterator

From cppreference.com
Defined in header <iterator>
template <class Iterator>
class move_iterator
(since C++11)

std::move_iterator is an iterator adaptor which behaves exactly like the underlying iterator (which must be at least an InputIterator), except that dereferencing converts the value returned by the underlying iterator into an rvalue. If this iterator is used as an input iterator, the effect is that the values are moved from, rather than copied from.

Contents

[edit] Member types

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&&

[edit] Member functions

constructs a new move_iterator
(public member function)
replaces a move_iterator
(public member function)
accesses the underlying iterator
(public member function)
accesses the pointed-to element
(public member function)
obtains rvalue reference to indexed element
(public member function)
advances the iterator
(public member function)
decrements the iterator
(public member function)

[edit] Non-member functions

compares two move_iterators
(function template)

[edit] Example

#include <iostream>
#include <algorithm>
#include <vector>
#include <iterator>
#include <numeric>
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';
}

Output:

Old contents of the vector: "this" "is" "an" "example"
Concatenated as string: thisisanexample
New contents of the vector: "" "" "" ""

[edit] See also

creates a std::move_iterator of type inferred from the argument
(function template)