NAME

std::back_inserter - std::back_inserter

Synopsis

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

back_inserter is a convenient function template that constructs a
std::back_insert_iterator for the container c with the type deduced from the type of
the argument.

Parameters

c - container that supports a push_back operation

Return value

A std::back_insert_iterator which can be used to add elements to the end of the
container c

Possible implementation

template< class Container >
std::back_insert_iterator<Container> back_inserter( Container& c )
{
return std::back_insert_iterator<Container>(c);
}

Example

// Run this code

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

int main()
{
std::vector<int> v{1, 2, 3, 4, 5, 6, 7, 8, 9, 10};
std::fill_n(std::back_inserter(v), 3, -1);
for (int n : v)
std::cout << n << ' ';
}

Output:

1 2 3 4 5 6 7 8 9 10 -1 -1 -1

See also

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