std:: inserter

inserter is a convenience function template that constructs a std::insert_iterator for the container c and its iterator i with the type deduced from the type of the argument.

Parameters

Return value

A std::insert_iterator which can be used to insert elements into the container c at the position indicated by i .

Possible implementation

template<class Container>
std::insert_iterator<Container> inserter(Container& c, typename Container::iterator i)
{
    return std::insert_iterator<Container>(c, i);
}

Example

#include <algorithm>
#include <iostream>
#include <iterator>
#include <set>
#include <vector>
 
int main()
{
    std::multiset<int> s{1, 2, 3};
 
    // std::inserter is commonly used with multi-sets
    std::fill_n(std::inserter(s, s.end()), 5, 2);
 
    for (int n : s)
        std::cout << n << ' ';
    std::cout << '\n';
 
    std::vector<int> d{100, 200, 300};
    std::vector<int> v{1, 2, 3, 4, 5};
 
    // when inserting in a sequence container, insertion point advances
    // because each std::insert_iterator::operator= updates the target iterator
    std::copy(d.begin(), d.end(), std::inserter(v, std::next(v.begin())));
 
    for (int n : v)
        std::cout << n << ' ';
    std::cout << '\n';
}

1 2 2 2 2 2 2 3 
1 100 200 300 2 3 4 5

Defect reports

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

See also