Defined in header <iterator>
template< class Container >
class front_insert_iterator : public std::iterator< std::output_iterator_tag,
                                                   void,void,void,void >
(until C++17)
template< class Container >
class front_insert_iterator;
(since C++17)

std::front_insert_iterator is an LegacyOutputIterator that prepends elements to a container for which it was constructed. The container's push_front() member function is called whenever the iterator (whether dereferenced or not) is assigned to. Incrementing the std::front_insert_iterator is a no-op.

Member types

Member type Definition
iterator_category std::output_iterator_tag
value_type void


(until C++20)


(since C++20)
pointer void
reference void
container_type Container

Member types iterator_category, value_type, difference_type, pointer and reference are required to be obtained by inheriting from std::iterator<std::output_iterator_tag, void, void, void, void>.

(until C++17)

Member functions

constructs a new front_insert_iterator
(public member function)
inserts an object into the associated container
(public member function)
(public member function)
(public member function)

Member objects

Member name Definition
container (protected) a pointer of type Container*


#include <vector>
#include <deque>
#include <iostream>
#include <iterator>
#include <algorithm>
int main()
    std::vector<int> v{1,2,3,4,5};
    std::deque<int> d;
    std::copy(v.begin(), v.end(),
              std::front_insert_iterator<std::deque<int>>(d)); // or std::front_inserter(d)
    for(int n : d)
        std::cout << n << ' ';
    std::cout << '\n';


5 4 3 2 1

See also

creates a std::front_insert_iterator of type inferred from the argument
(function template)
iterator adaptor for insertion at the end of a container
(class template)
iterator adaptor for insertion into a container
(class template)

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