std::inserter - cppreference.com

##### cppreference.com

##### Search

Create account

##### Namespaces

- Page
- Discussion

##### Variants

##### Views

- View
- Edit
- History

##### Actions

# std::inserter

From cppreference.com
< cpp‎ | iterator

Defined in header `<iterator>` |  |
template< class Container > std::insert_iterator<Container> inserter( Container& c, typename Container::iterator i ); |  |

`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.

### [edit] Parameters

c | - | container that supports a `insert` operation
i | - | iterator in `c` indicating the insertion position

### [edit] Return value

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

### [edit] Possible implementation

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

### [edit] Example

Run this code

    #include <algorithm>
    #include <iostream>
    #include <iterator>
    #include <vector>
    #include <set>

    int main()
    {

        std::multiset<int> s {1, 2, 3};

        // std::inserter is commonly used with 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> l {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(l, std::next(l.begin())));

        for (int n : l)
            std::cout << n << ' ';
        std::cout << '\n';
    }

Output:

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

### [edit] See also

insert_iterator | iterator adaptor for insertion into a container (class template) [edit]
back_inserter | creates a std::back_insert_iterator of type inferred from the argument (function template) [edit]
front_inserter | creates a std::front_insert_iterator of type inferred from the argument (function template) [edit]

Retrieved from "http://en.cppreference.com/mwiki/index.php?title=cpp/iterator/inserter&oldid=85731"