std::front_inserter
Min standard notice:
Header: <iterator>
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.
# Declarations
template< class Container >
std::front_insert_iterator<Container> front_inserter( Container& c );
(constexpr since C++20)
# 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.
# 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';
}