std::back_inserter

C++

Language

Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

Filesystem library (C++17)

Technical Specifications

Iterator library

Iterator primitives
iterator_traits
input_iterator_tagoutput_iterator_tagforward_iterator_tagbidirectional_iterator_tagrandom_access_iterator_tag
iterator
Iterator adaptors
reverse_iterator move_iterator (C++11) back_insert_iterator front_insert_iterator insert_iterator	make_reverse_iterator (C++14) make_move_iterator (C++11) back_inserter front_inserter inserter
Stream iterators
istream_iterator
ostream_iterator
istreambuf_iterator
ostreambuf_iterator
Iterator operations
advance
distance
prev (C++11)
next (C++11)
Range access
begincbegin (C++11)(C++14)
endcend (C++11)(C++14)
rbegincrbegin (C++14)(C++14)
rendcrend (C++14)(C++14)
Container access
size (C++17)
empty (C++17)
data (C++17)

Defined in header <iterator>
template< class Container > std::back_insert_iterator<Container> back_inserter( Container& c );

back_inserter is a convenience 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)
front_inserter	creates a std::front_insert_iterator of type inferred from the argument (function template)
inserter	creates a std::insert_iterator of type inferred from the argument (function template)