std::front_inserter

 

C++

Language

Standard Library Headers

Freestanding and hosted implementations

Named requirements

Language support library

Concepts library (C++20)

Diagnostics library

Utilities library

Strings library

Containers library

Iterators library

Ranges library (C++20)

Algorithms 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 concepts
indirectly_readable (C++20) indirectly_writable (C++20) weakly_incrementable (C++20) incrementable (C++20) input_or_output_iterator (C++20) sentinel_for (C++20) sized_sentinel_for (C++20)	input_iterator (C++20) output_iterator (C++20) forward_iterator (C++20) bidirectional_iterator (C++20) random_access_iterator (C++20) contiguous_iterator (C++20)
Iterator primitives
iterator_traits input_iterator_tagoutput_iterator_tagforward_iterator_tagbidirectional_iterator_tagrandom_access_iterator_tagcontiguous_iterator_tag (C++20) iterator (deprecated in C++17)	incrementable_traits (C++20) indirectly_readable_traits (C++20) iter_value_titer_difference_titer_reference_titer_rvalue_reference_titer_common_reference_t (C++20)(C++20)(C++20)(C++20)(C++20)
Iterator adaptors
reverse_iterator move_iterator (C++11) move_sentinel (C++20) common_iterator (C++20) counted_iterator (C++20) back_insert_iterator front_insert_iterator insert_iterator	make_reverse_iterator (C++14) make_move_iterator (C++11) default_sentinel_tdefault_sentinel (C++20)(C++20) unreachable_sentinel_tunreachable_sentinel (C++20)(C++20) back_inserter front_inserter inserter
Stream iterators
istream_iterator ostream_iterator	istreambuf_iterator ostreambuf_iterator
Iterator customization points
ranges::iter_move (C++20)
ranges::iter_swap (C++20)
Iterator operations
advance distance prev (C++11) next (C++11)	ranges::advance (C++20) ranges::distance (C++20) ranges::prev (C++20) ranges::next (C++20)
Range access
begincbegin (C++11)(C++14) endcend (C++11)(C++14) sizessize (C++17)(C++20)	rbegincrbegin (C++14)(C++14) rendcrend (C++14)(C++14) empty (C++17) data (C++17)

 

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

front_inserter is a convenience function template that constructs a std::front_insert_iterator for the container c with the type deduced from the type of the argument.

Parameters

c

-

container that supports a push_front operation

Return value

A std::front_insert_iterator which can be used to add elements to the beginning of the container c

Possible implementation

template< class Container > std::front_insert_iterator<Container> front_inserter( Container& c ) { return std::front_insert_iterator<Container>(c); }

Example

Run this code

#include <vector>
#include <deque>
#include <iostream>
#include <iterator>
#include <algorithm>
int main()
{
    std::vector<int> v{1,2,3,4,5};
    std::deque<int> d;
    std::copy(v.begin(), v.end(), std::front_inserter(d));
    for(int n : d)
        std::cout << n << ' ';
}

Output:

5 4 3 2 1

See also

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