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<H2>insert_iterator, inserter</H2>
<HR><PRE> Insert Iterator</PRE><HR>
<A NAME="Summary"><H3>Summary</H3></A>
<P>An insert iterator used to insert items into a collection rather than overwrite the collection.</P>
<H3>Contents</H3>
<UL>
<A HREF="#Synopsis"><LI>Synopsis</LI></A>
<A HREF="#Description"><LI>Description</LI></A>
<A HREF="#Interface"><LI>Interface</LI></A>
<A HREF="#Constructor"><LI>Constructor</LI></A>
<A HREF="#Operators"><LI>Operators</LI></A>
<A HREF="#Non-member Function"><LI>Non-member Function</LI></A>
<A HREF="#Example"><LI>Example</LI></A>
<A HREF="#Warnings"><LI>Warnings</LI></A>
<A HREF="#See Also"><LI>See Also</LI></A>
</UL>
<A NAME="Synopsis"><H3>Synopsis</H3></A>
<PRE>#include <iterator></PRE>
<PRE>
template <class Container>
class <B>insert_iterator : </B>public output_iterator;
</PRE>
<A NAME="Description"><H3>Description</H3></A>
<P>Insert iterators let you <I>insert</I> new elements into a collection rather than copy a new element's value over the value of an existing element. The class<B><I> insert_iterator</B></I> is used to insert items into a specified location of a collection. The function <SAMP>inserter</SAMP> creates an instance of an<B><I> insert_iterator</B></I> given a particular collection type and iterator. An <B><I>insert_iterator</B></I> can be used with <A HREF="vec_0251.htm"><B><I>vector</B></I></A>s, <A HREF="deq_4164.htm"><B><I>deque</B></I></A>s, <A HREF="lis_3222.htm"><B><I>list</B></I></A>s, <A HREF="map_8018.htm"><B><I>map</B></I></A>s and <A HREF="set_1649.htm"><B><I>set</B></I></A>s.</P>
<A NAME="Interface"><H3>Interface</H3></A>
<PRE>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 Iterator>
insert_iterator<Container> inserter (Container&, Iterator)
</PRE>
<A NAME="Constructor"><H3>Constructor</H3></A>
<PRE><B>insert_iterator </B>(Container& x, typename Container::iterator i);</PRE>
<UL><P>Constructor. Creates an instance of an <B><I>insert_iterator</B></I> associated with container <SAMP>x</SAMP> and iterator <SAMP>i.</SAMP></P>
</UL>
<A NAME="Operators"><H3>Operators</H3></A>
<PRE>insert_iterator<Container>&
<B>operator=</B> (const typename Container::value_type& value);</PRE>
<UL><P>Assignment operator. Inserts a copy of <SAMP>value</SAMP> into the container at the location specified by the <SAMP>insert_iterator</SAMP>, increments the iterator, and returns <SAMP>*this</SAMP>.</P>
</UL>
<PRE>insert_iterator<Container>&
<B>operator*</B> ();</PRE>
<UL><P>Returns <SAMP>*this</SAMP> (the input iterator itself).</P>
</UL>
<PRE>insert_iterator<Container>&
<B>operator++</B> ();
insert_iterator<Container>&
<B>operator++</B> (int);</PRE>
<UL><P>Increments the insert iterator and returns <SAMP>*this</SAMP>.</P>
</UL>
<A NAME="Non-member Function"><H3>Non-member Function</H3></A>
<PRE>template <class Container, class Iterator>
insert_iterator<Container>
<B>inserter</B> (Container& x, Iterator i);</PRE>
<UL><P>Returns an <B><I>insert_iterator</B></I> that will insert elements into container <SAMP>x</SAMP> at location <SAMP>i</SAMP>. This function allows you to create insert iterators inline.</P>
</UL>
<A NAME="Example"><H3>Example</H3></A>
<PRE> #include <iterator>
#include <vector>
#include <iostream.h></PRE>
<PRE> int main()
{
//Initialize a vector using an array
int arr[4] = {3,4,7,8};
vector<int> v(arr,arr+4);</PRE>
<PRE> //Output the original vector
cout << "Start with a vector: " << endl << " ";
copy(v.begin(),v.end(),ostream_iterator<int>(cout," "));</PRE>
<PRE> //Insert into the middle
<B>insert_iterator</B><vector<int> > ins(v, v.begin()+2);
*ins = 5;
*ins = 6;</PRE>
<PRE> //Output the new vector
cout << endl << endl;
cout << "Use an insert_iterator: " << endl << " ";
copy(v.begin(),v.end(),ostream_iterator<int>(cout," "));</PRE>
<PRE> return 0;
}
</PRE>
<A NAME="Warnings"><H3>Warnings</H3></A>
<P>If your compiler does not support default template parameters, then you need to always supply the <SAMP>Allocator</SAMP> template argument. For instance, you'll have to write:</P>
<P><SAMP>vector<int, allocator></SAMP></P>
<P>instead of:</P>
<P><SAMP>vector<int></SAMP></P>
<A NAME="See Also"><H3>See Also</H3></A>
<P><A HREF="bac_0189.htm"><B><I>back_insert_iterator</B></I></A>, <A HREF="fro_0713.htm"><B><I>front_insert_iterator</B></I></A>, <A HREF="Ins_1844.htm"><B><I>Insert Iterators</B></I></A></P>
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