std:: move_iterator

std::move_iterator is an iterator adaptor which behaves exactly like the underlying iterator (which must be at least a LegacyInputIterator or model input_iterator (since C++20) , or stronger iterator concept (since C++23) ), 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.

Nested types

Data members

Member functions

Non-member functions

Helper templates

This partial specialization of std::disable_sized_sentinel_for prevents specializations of move_iterator from satisfying sized_sentinel_for if their underlying iterators do not satisfy the concept.

Notes

Example

#include <algorithm>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <ranges>
#include <string>
#include <string_view>
#include <vector>
 
void print(const std::string_view rem, const auto& v)
{
    std::cout << rem;
    for (const auto& s : v)
        std::cout << std::quoted(s) << ' ';
    std::cout << '\n';
};
 
int main()
{
    std::vector<std::string> v{"this", "_", "is", "_", "an", "_", "example"};
    print("Old contents of the vector: ", v);
    std::string concat;
    for (auto begin = std::make_move_iterator(v.begin()),
              end = std::make_move_iterator(v.end());
         begin != end; ++begin)
    {
        std::string temp{*begin}; // moves the contents of *begin to temp
        concat += temp;
    }
 
    // Starting from C++17, which introduced class template argument deduction,
    // the constructor of std::move_iterator can be used directly:
    // std::string concat = std::accumulate(std::move_iterator(v.begin()),
    //                                      std::move_iterator(v.end()),
    //                                      std::string());
 
    print("New contents of the vector: ", v);
    print("Concatenated as string: ", std::ranges::single_view(concat));
}

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

Defect reports

The following behavior-changing defect reports were applied retroactively to previously published C++ standards.

See also