Namespaces
Variants
Views
Actions

std::back_inserter

From cppreference.com
< cpp‎ | iterator
 
 
Iterator library
Iterator concepts
(C++20)
(C++20)
(C++20)
(C++20)
Iterator primitives
Iterator adaptors
Stream iterators
Iterator customization points
Iterator operations
(C++11)
(C++11)
Range access
(C++11)(C++14)
(C++11)(C++14)
(C++17)(C++20)
(C++14)(C++14)
(C++14)(C++14)
(C++17)
(C++17)
 
Defined in header <iterator>
template< class Container >
std::back_insert_iterator<Container> back_inserter( Container& c );
(until C++20)
template< class Container >
constexpr std::back_insert_iterator<Container> back_inserter( Container& c );
(since C++20)

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.

Contents

[edit] Parameters

c - container that supports a push_back operation

[edit] Return value

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

[edit] Possible implementation

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

[edit] Example

#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

[edit] See also

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