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 <H2>ostream_iterator</H2>
 <P><B>Library:</B>&nbsp;&nbsp;<A HREF="2-8.html">Iterators</A></P>

 <PRE><HR><B><I>ostream_iterator</I></B> <IMG SRC="images/inherits.gif"> <B><I><A HREF="iterator.html">iterator</A></I></B> <HR></PRE>

 <UL>
 <LI><A HREF="#sec1">Local Index</A></LI>
 <LI><A HREF="#sec2">Summary</A></LI>
 <LI><A HREF="#sec3">Synopsis</A></LI>
 <LI><A HREF="#sec4">Description</A></LI>
 <LI><A HREF="#sec5">Interface</A></LI>
 <LI><A HREF="#sec6">Member Types</A></LI>
 <LI><A HREF="#sec7">Constructors</A></LI>
 <LI><A HREF="#sec8">Operators</A></LI>
 <LI><A HREF="#sec9">Example</A></LI>
 <LI><A HREF="#sec10">See Also</A></LI>
 <LI><A HREF="#sec11">Standards Conformance</A></LI>
 </UL>
 <A NAME="sec1"><H3>Local Index</H3></A>
 <H4>Members</H4>
 <UL><TABLE CELLPADDING=3>
 <TR><TD VALIGN=top>
 <A HREF="#idx1060">char_type</A><BR>
 <A HREF="#idx1067">operator*()</A><BR>
 </TD>
 <TD VALIGN=top><A HREF="#idx1067">operator++()</A><BR>
 <A HREF="#idx1066">operator=()</A><BR>
 </TD>
 <TD VALIGN=top><A HREF="#idx1063">ostream_iterator()</A><BR>
 <A HREF="#idx1062">ostream_type</A><BR>
 </TD>
 <TD VALIGN=top><A HREF="#idx1061">traits_type</A><BR>
 </TD></TR>
 </TABLE></UL>

 <A NAME="sec2"><H3>Summary</H3></A>
 <P>Stream iterators allow for use of iterators with ostreams and istreams. They allow generic algorithms to be used directly on streams.</P>
 <A NAME="sec3"><H3>Synopsis</H3></A>

 <PRE>#include &lt;ostream&gt;

 namespace std {
   template &lt;class T, class charT,
             class traits = char_traits&lt;charT&gt; &gt;
   class ostream_iterator;
 }
 </PRE>
 <A NAME="sec4"><H3>Description</H3></A>
 <P>Stream iterators use the standard iterator interface for input and output streams.</P>
 <P>The class template <B><I>ostream_iterator</I></B> writes elements to an output stream. If you use the constructor that has a second argument, then that string is written after every element (the string must be null-terminated). Since an ostream iterator is an output iterator, it is not possible to dereference values through the iterator. You can only assign to it.</P>
 <A NAME="sec5"><H3>Interface</H3></A>

 <UL><PRE>namespace std {

   template &lt;class T, class charT = char,
             class traits = char_traits&lt;charT&gt; &gt;
   class ostream_iterator:
     public iterator&lt;output_iterator_tag,void,void,void,void&gt;
   {
     public:
     typedef T value_type;
     typedef charT char_type;
     typedef traits traits_type;
     typedef basic_ostream&lt;charT,traits&gt; ostream_type;

     ostream_iterator(ostream_type&amp;);
     ostream_iterator(ostream_type&amp;, const char_type*);
     ostream_iterator(const ostream_iterator&amp;);

     ostream_iterator&amp; operator=(const T&amp;);
     ostream_iterator&amp; operator*() const;
     ostream_iterator&amp; operator++();
     ostream_iterator  operator++(int);
   };
 }
 </PRE></UL>
 <A NAME="sec6"><H3>Member Types</H3></A>

 <A NAME="idx1060"></A><PRE><B>char_type</B>; </PRE>
 <UL>
 <P>Type of character the stream is built on.</P>
 </UL>


 <A NAME="idx1061"></A><PRE><B>traits_type</B>; </PRE>
 <UL>
 <P>Traits used to build the stream.</P>
 </UL>


 <A NAME="idx1062"></A><PRE><B>ostream_type</B>; </PRE>
 <UL>
 <P>Type of stream this iterator is constructed on.</P>
 </UL>

 <A NAME="sec7"><H3>Constructors</H3></A>

 <A NAME="idx1063"></A><PRE><B>ostream_iterator</B> (ostream_type&amp; s);</PRE>
 <UL>
 <P>Constructs an <B><I>ostream_iterator</I></B> on the given stream.</P>
 </UL>


 <A NAME="idx1064"></A><PRE><B>ostream_iterator</B> (ostream_type&amp; s,
                   const char_type* delimiter);</PRE>
 <UL>
 <P>Constructs an <B><I>ostream_iterator</I></B> on the given stream. The null terminated string <SAMP>delimiter</SAMP> is written to the stream after every element.</P>
 </UL>


 <A NAME="idx1065"></A><PRE><B>ostream_iterator</B> (const ostream_iterator&amp; x);</PRE>
 <UL>
 <P> Copy constructor.</P>
 </UL>

 <A NAME="sec8"><H3>Operators</H3></A>

 <A NAME="idx1066"></A><PRE>const T&amp; <br><B>operator= </B>(const T&amp; value);</PRE>
 <UL>
 <P> Insert <SAMP>value</SAMP> into the associated output stream <SAMP>x</SAMP> by calling <SAMP>x &lt;&lt; value</SAMP>.</P>
 </UL>


 <A NAME="idx1067"></A><PRE>const T&amp; ostream_iterator&amp;
 <B>operator*</B> ();
 ostream_iterator&amp;
 <B>operator++</B>();
 ostream_iterator
 <B>operator++ </B>(int);</PRE>
 <UL>
 <P>These operators do nothing. They simply allow the iterator to be used in common constructs.</P>
 </UL>

 <A NAME="sec9"><H3>Example</H3></A>

 <UL><PRE> #include &lt;iterator&gt;
  #include &lt;numeric&gt;
  #include &lt;deque&gt;
  #include &lt;iostream&gt;
  using namespace std;

  int main ()
  {
    //
    // Initialize a vector using an array.
    //
    int arr[4] = { 3,4,7,8 };
    int total=0;
    deque&lt;int&gt; d(arr+0, arr+4);
    //
    // stream the whole vector and a sum to cout
    //
    copy(d.begin(),d.end()-1,
         <B>ostream_iterator</B>&lt;int,char&gt;(cout," + "));
    cout &lt;&lt; *(d.end()-1) &lt;&lt; " = " &lt;&lt;
         accumulate(d.begin(),d.end(),total) &lt;&lt; endl;
    return 0;
  }
 </PRE></UL>
 <A NAME="sec10"><H3>See Also</H3></A>
 <P><B><I><A HREF="istream-iterator.html">istream_iterator</A></I></B>, <A HREF="iterators.html">Iterators</A></P>
 <A NAME="sec11"><H3>Standards Conformance</H3></A>
 <P><I>ISO/IEC 14882:1998 -- International Standard for Information Systems -- Programming Language C++, Section 24.5.2</I></P>

 <BR>
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	<TITLE>ostream_iterator</TITLE>
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	<A HREF="ostream-h.html"><IMG SRC="images/bprev.gif" WIDTH=20 HEIGHT=21 ALT="Previous file" BORDER=O></A><A HREF="noframes.html"><IMG SRC="images/btop.gif" WIDTH=56 HEIGHT=21 ALT="Top of Document" BORDER=O></A><A HREF="booktoc.html"><IMG SRC="images/btoc.gif" WIDTH=56 HEIGHT=21 ALT="Contents" BORDER=O></A><A HREF="tindex.html"><IMG SRC="images/bindex.gif" WIDTH=56 HEIGHT=21 ALT="Index page" BORDER=O></A><A HREF="ostreambuf-iterator.html"><IMG SRC="images/bnext.gif" WIDTH=25 HEIGHT=21 ALT="Next file" BORDER=O></A><DIV CLASS="DOCUMENTNAME"><B>Apache C++ Standard Library Reference Guide</B></DIV>
	<H2>ostream_iterator</H2>
	<P><B>Library:</B>  <A HREF="2-8.html">Iterators</A></P>

	<PRE><HR><B><I>ostream_iterator</I></B> <IMG SRC="images/inherits.gif"> <B><I><A HREF="iterator.html">iterator</A></I></B> <HR></PRE>

	<UL>
	<LI><A HREF="#sec1">Local Index</A></LI>
	<LI><A HREF="#sec2">Summary</A></LI>
	<LI><A HREF="#sec3">Synopsis</A></LI>
	<LI><A HREF="#sec4">Description</A></LI>
	<LI><A HREF="#sec5">Interface</A></LI>
	<LI><A HREF="#sec6">Member Types</A></LI>
	<LI><A HREF="#sec7">Constructors</A></LI>
	<LI><A HREF="#sec8">Operators</A></LI>
	<LI><A HREF="#sec9">Example</A></LI>
	<LI><A HREF="#sec10">See Also</A></LI>
	<LI><A HREF="#sec11">Standards Conformance</A></LI>
	</UL>
	<A NAME="sec1"><H3>Local Index</H3></A>
	<H4>Members</H4>
	<UL><TABLE CELLPADDING=3>
	<TR><TD VALIGN=top>
	<A HREF="#idx1060">char_type</A><BR>
	<A HREF="#idx1067">operator*()</A><BR>
	</TD>
	<TD VALIGN=top><A HREF="#idx1067">operator++()</A><BR>
	<A HREF="#idx1066">operator=()</A><BR>
	</TD>
	<TD VALIGN=top><A HREF="#idx1063">ostream_iterator()</A><BR>
	<A HREF="#idx1062">ostream_type</A><BR>
	</TD>
	<TD VALIGN=top><A HREF="#idx1061">traits_type</A><BR>
	</TD></TR>
	</TABLE></UL>

	<A NAME="sec2"><H3>Summary</H3></A>
	<P>Stream iterators allow for use of iterators with ostreams and istreams. They allow generic algorithms to be used directly on streams.</P>
	<A NAME="sec3"><H3>Synopsis</H3></A>

	<PRE>#include <ostream>

	namespace std {
	template <class T, class charT,
	class traits = char_traits<charT> >
	class ostream_iterator;
	}
	</PRE>
	<A NAME="sec4"><H3>Description</H3></A>
	<P>Stream iterators use the standard iterator interface for input and output streams.</P>
	<P>The class template <B><I>ostream_iterator</I></B> writes elements to an output stream. If you use the constructor that has a second argument, then that string is written after every element (the string must be null-terminated). Since an ostream iterator is an output iterator, it is not possible to dereference values through the iterator. You can only assign to it.</P>
	<A NAME="sec5"><H3>Interface</H3></A>

	<UL><PRE>namespace std {

	template <class T, class charT = char,
	class traits = char_traits<charT> >
	class ostream_iterator:
	public iterator<output_iterator_tag,void,void,void,void>
	{
	public:
	typedef T value_type;
	typedef charT char_type;
	typedef traits traits_type;
	typedef basic_ostream<charT,traits> ostream_type;

	ostream_iterator(ostream_type&);
	ostream_iterator(ostream_type&, const char_type*);
	ostream_iterator(const ostream_iterator&);

	ostream_iterator& operator=(const T&);
	ostream_iterator& operator*() const;
	ostream_iterator& operator++();
	ostream_iterator operator++(int);
	};
	}
	</PRE></UL>
	<A NAME="sec6"><H3>Member Types</H3></A>

	<A NAME="idx1060"></A><PRE><B>char_type</B>; </PRE>
	<UL>
	<P>Type of character the stream is built on.</P>
	</UL>


	<A NAME="idx1061"></A><PRE><B>traits_type</B>; </PRE>
	<UL>
	<P>Traits used to build the stream.</P>
	</UL>


	<A NAME="idx1062"></A><PRE><B>ostream_type</B>; </PRE>
	<UL>
	<P>Type of stream this iterator is constructed on.</P>
	</UL>

	<A NAME="sec7"><H3>Constructors</H3></A>

	<A NAME="idx1063"></A><PRE><B>ostream_iterator</B> (ostream_type& s);</PRE>
	<UL>
	<P>Constructs an <B><I>ostream_iterator</I></B> on the given stream.</P>
	</UL>


	<A NAME="idx1064"></A><PRE><B>ostream_iterator</B> (ostream_type& s,
	const char_type* delimiter);</PRE>
	<UL>
	<P>Constructs an <B><I>ostream_iterator</I></B> on the given stream. The null terminated string <SAMP>delimiter</SAMP> is written to the stream after every element.</P>
	</UL>


	<A NAME="idx1065"></A><PRE><B>ostream_iterator</B> (const ostream_iterator& x);</PRE>
	<UL>
	<P> Copy constructor.</P>
	</UL>

	<A NAME="sec8"><H3>Operators</H3></A>

	<A NAME="idx1066"></A><PRE>const T& <br><B>operator= </B>(const T& value);</PRE>
	<UL>
	<P> Insert <SAMP>value</SAMP> into the associated output stream <SAMP>x</SAMP> by calling <SAMP>x << value</SAMP>.</P>
	</UL>


	<A NAME="idx1067"></A><PRE>const T& ostream_iterator&
	<B>operator*</B> ();
	ostream_iterator&
	<B>operator++</B>();
	ostream_iterator
	<B>operator++ </B>(int);</PRE>
	<UL>
	<P>These operators do nothing. They simply allow the iterator to be used in common constructs.</P>
	</UL>

	<A NAME="sec9"><H3>Example</H3></A>

	<UL><PRE> #include <iterator>
	#include <numeric>
	#include <deque>
	#include <iostream>
	using namespace std;

	int main ()
	{
	//
	// Initialize a vector using an array.
	//
	int arr[4] = { 3,4,7,8 };
	int total=0;
	deque<int> d(arr+0, arr+4);
	//
	// stream the whole vector and a sum to cout
	//
	copy(d.begin(),d.end()-1,
	<B>ostream_iterator</B><int,char>(cout," + "));
	cout << *(d.end()-1) << " = " <<
	accumulate(d.begin(),d.end(),total) << endl;
	return 0;
	}
	</PRE></UL>
	<A NAME="sec10"><H3>See Also</H3></A>
	<P><B><I><A HREF="istream-iterator.html">istream_iterator</A></I></B>, <A HREF="iterators.html">Iterators</A></P>
	<A NAME="sec11"><H3>Standards Conformance</H3></A>
	<P><I>ISO/IEC 14882:1998 -- International Standard for Information Systems -- Programming Language C++, Section 24.5.2</I></P>

	<BR>
	<HR>
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