Insert Iterators

     Insert Iterator

Iterator adaptor that allows an iterator to insert into a container rather than overwrite elements in the container.

Contents

• Synopsis
• Description
• Interface
• See Also

#include <iterator>

template <class Container>
class insert_iterator : public output_iterator;
template <class Container>
class back_insert_iterator:public output_iterator;
template <class Container>
class front_insert_iterator : public output_iterator;

Insert iterators are iterator adaptors that let an iterator insert new elements into a collection rather than overwrite existing elements when copying to a container. There are several types of insert iterator classes.

• The class back_insert_iterator is used to insert items at the end of a collection. The function back_inserter can be used with an iterator inline, to create an instance of a back_insert_iterator for a particular collection type.

• The class front_insert_iterator is used to insert items at the start of a collection. The function front_inserter creates an instance of a front_insert_iterator for a particular collection type.

• An insert_iterator inserts new items into a collection at a location defined by an iterator supplied to the constructor. Like the other insert iterators, insert_iterator has a helper function called inserter, which takes a collection and an iterator into that collection, and creates an instance of the insert_iterator.

template <class Container>
 class insert_iterator : public output_iterator {

public:
   insert_iterator (Container&, typename Container::iterator);
   insert_iterator<Container>&
    operator= (const typename Container::value_type&);
   insert_iterator<Container>& operator* ();
   insert_iterator<Container>& operator++ ();
   insert_iterator<Container>& operator++ (int);
};
template <class Container>
 class back_insert_iterator : public output_iterator {
public:
   explicit back_insert_iterator (Container&);
   back_insert_iterator<Container>&
    operator= (const typename Container::value_type&);
   back_insert_iterator<Container>& operator* ();
   back_insert_iterator<Container>& operator++ ();
   back_insert_iterator<Container> operator++ (int);
};
template <class Container>
 class front_insert_iterator : public output_iterator {
public:
   explicit front_insert_iterator (Container&);
   front_insert_iterator<Container>&
    operator= (const typename Container::value_type&);
   front_insert_iterator<Container>& operator* ();
   front_insert_iterator<Container>& operator++ ();
   front_insert_iterator<Container> operator++ (int);
};
 template <class Container, class Iterator>
 insert_iterator<Container> inserter (Container&, Iterator);
 
 template <class Container>
 back_insert_iterator<Container> back_inserter (Container&);
 template <class Container>
 front_insert_iterator<Container> front_inserter (Container&);

back_insert_iterator, front_insert_iterator