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    cpp/iterator/back insert iterator: Difference between revisions

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    {{dcl list template | cpp/iterator/inserter/dcl list operator{{=}} | back_insert_iterator}}
    {{dcl list template | cpp/iterator/inserter/dcl list operator{{=}} | back_insert_iterator}}
    {{dcl list template | cpp/iterator/inserter/dcl list operator* | back_insert_iterator}}
    {{dcl list template | cpp/iterator/inserter/dcl list operator* | back_insert_iterator}}
    {{dcl list template | cpp/iterator/inserter/dcl list operator++ | back_insert_iterator}}
    {{dcl list template | cpp/iterator/inserter/dcl list | back_insert_iterator}}
    {{dcl list end}}
    {{dcl list end}}


    Revision as of 16:02, 29 May 2013

     
    C++
     
    Iterator library
    Iterator concepts
    Iterator primitives
    Algorithm concepts and utilities
    Indirect callable concepts
    Common algorithm requirements
    (C++20)
    (C++20)
    (C++20)
    Utilities
    (C++20)
    Iterator adaptors
    Range access
    (C++11)(C++14)
    (C++14)(C++14)  
    (C++11)(C++14)
    (C++14)(C++14)  
    (C++17)(C++20)
    (C++17)
    (C++17)
     
    std::back_insert_iterator
     

    Template:ddcl list begin

    Defined in header <iterator> 
    template< class Container >
class back_insert_iterator : public std::iterator< std::output_iterator_tag,
                                                   void, void, void, void >

    Template:ddcl list end std::back_insert_iterator is an Template:concept that appends to a container for which it was constructed, using the container's push_back() member function whenever the iterator (whether dereferenced or not) is assigned to. Incrementing the std::back_insert_iterator is a no-op.

    Member types

    Member type Definition
    container_type Container

    Member functions

    Template:cpp/iterator/inserter/dcl list constructorTemplate:cpp/iterator/inserter/dcl list operator=Template:cpp/iterator/inserter/dcl list operator*Template:cpp/iterator/inserter/dcl list operator arith

    Member objects

    Member name Definition
    container (protected) a pointer of type Container*

    Member types

    Member type Definition
    iterator_category std::output_iterator_tag
    value_type void
    difference_type

    void

    		(until C++20)

    std::ptrdiff_t

    		(since C++20)
    pointer void
    reference void

    Member types iterator_category, value_type, difference_type, pointer and reference are required to be obtained by inheriting from std::iterator<std::output_iterator_tag, void, void, void, void>.

    		(until C++17)

    Example

    Run this code
    #include <iostream>
#include <iterator>
#include <algorithm>
#include <cstdlib>
int main()
{
    std::vector<int> v;
    std::generate_n(std::back_insert_iterator<std::vector<int>>(v), // can be simplified
                    10, [](){ return std::rand() % 10; });        // with std::back_inserter
    for (int n : v)
        std::cout << n << ' ';
    std::cout << '\n';
}

    Output: 

    3 6 7 5 3 5 6 2 9 1

    See also

    Template:cpp/iterator/dcl list back inserterTemplate:cpp/iterator/dcl list front insert iteratorTemplate:cpp/iterator/dcl list insert iterator