std::front_inserter

Defined in header <iterator> 
template< class Container >
std::front_insert_iterator<Container> front_inserter( Container& c );
 (constexpr since C++20)

front_inserter is a convenience function template that constructs a std::front_insert_iterator for the container c with the type deduced from the type of the argument.

Parameters

c - container that supports a push_front operation

Return value

A std::front_insert_iterator which can be used to add elements to the beginning of the container c.

Possible implementation

template<class Container>
std::front_insert_iterator<Container> front_inserter( Container& c )
{
    return std::front_insert_iterator<Container>(c);
}

Example

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

Output:

5 4 3 2 1

See also

iterator adaptor for insertion at the front of a container
(class template)
creates a std::back_insert_iterator of type inferred from the argument
(function template)
creates a std::insert_iterator of type inferred from the argument
(function template)

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