📄 ost_2238.htm

📁 ARM编辑、编译软件
💻 HTM
字号:
<HTML><TITLE>ostream_iterator</TITLE><BODY>
<A HREF="ref.htm"><IMG SRC="images/banner.gif"></A>
<P><STRONG>Click on the banner to return to the Class Reference home page.</STRONG></P>
<P>&copy;Copyright 1996 Rogue Wave Software</P>
<H2>ostream_iterator</H2>
<HR><PRE>     Iterator</PRE><HR>
<A NAME="Summary"><H3>Summary</H3></A>
<P>Stream iterators  provide  iterator capabilities for ostreams and istreams.  They allow generic algorithms to be used directly on streams.</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="#Constructors"><LI>Constructors</LI></A>
<A HREF="#Destructor"><LI>Destructor</LI></A>
<A HREF="#Operators"><LI>Operators</LI></A>
<A HREF="#Example"><LI>Example</LI></A>
<A HREF="#Warning"><LI>Warning</LI></A>
<A HREF="#See Also"><LI>See Also</LI></A>
</UL>
<A NAME="Synopsis"><H3>Synopsis</H3></A>
<PRE>#include &#60;iterator></PRE>
<PRE>
template &#60;class T>
class <B>ostream_iterator</B> : public output_iterator;</PRE>
<A NAME="Description"><H3>Description</H3></A>
<P>Stream iterators provide the standard iterator interface for input and output streams.</P>
<P>The class <B><I>ostream_iterator</B></I>  writes elements to an output stream.  If  you use the constructor that has a second, <SAMP>char *</SAMP> argument, then that string will  be  written  after  every element .  (The string must be null-terminated.) Since an ostream iterator is an output iterator, it is not possible to get an element out of the iterator.  You can only assign to it.</P>
<A NAME="Interface"><H3>Interface</H3></A>
<PRE>template &#60;class T>
 class ostream_iterator  :  public  output_iterator 
{

 public:
    ostream_iterator(ostream&#38;);
    ostream_iterator (ostream&#38;, const char*); 
    ostream_iterator (const ostream_iterator&#60;T>&#38;);
    ~ostream_itertor ();
    ostream_iterator&#60;T>&#38; operator=(const T&#38;);
    ostream_iterator&#60;T>&#38; operator* () const;
    ostream_iterator&#60;T>&#38; operator++ ();
    ostream_iterator&#60;T>  operator++ (int);
 };
</PRE>
<A NAME="Constructors"><H3>Constructors</H3></A>
<PRE><B>ostream_iterator</B> (ostream&#38; s);</PRE>
<UL><P>Construct an<B><I> ostream_iterator</B></I> on the given stream.</P>
</UL>
<PRE><B>ostream_iterator</B> (ostream&#38; s, const char* delimiter);</PRE>
<UL><P>Construct an<B><I> ostream_iterator</B></I> on the given stream.  The null terminated string delimitor is written to the stream after every element.</P>
</UL>
<PRE><B>ostream_iterator</B> (const ostream_iterator&#60;T>&#38; x);</PRE>
<UL><P> Copy constructor.</P>
</UL>
<A NAME="Destructor"><H3>Destructor</H3></A>
<PRE><B>~ostream_iterator</B> ();</PRE>
<UL><P> Destructor</P>
</UL>
<A NAME="Operators"><H3>Operators</H3></A>
<PRE>const T&#38; 
<B>operator= </B>(const T&#38; value);</PRE>
<UL><P> Shift the value <SAMP>T</SAMP> onto the output stream.</P>
</UL>
<PRE>const T&#38; ostream_iterator&#60;T>&#38; 
<B>operator*</B> ();
ostream_iterator&#60;T>&#38;  
<B>operator++</B>();
ostream_iterator&#60;T>
<B>operator++ </B>(int);</PRE>
<UL><P>These operators all do nothing.  They simply allow  the iterator to be used in common constructs.</P>
</UL>
<A NAME="Example"><H3>Example</H3></A>
<PRE> #include &#60;iterator></PRE>
<PRE> #include &#60;numeric>
 #include &#60;deque>
 #include &#60;iostream.h>
 int main ()
 {
   //
   // Initialize a vector using an array.
   //
   int arr[4] = { 3,4,7,8 };
   int total=0;
   deque&#60;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>&#60;int>(cout," + "));
   cout &#60;&#60; *(d.end()-1) &#60;&#60; " = " &#60;&#60;
          accumulate(d.begin(),d.end(),total) &#60;&#60; endl;
   return 0;
 }
</PRE>
<A NAME="Warning"><H3>Warning</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 will need to write :</P>
<P><SAMP>deque&#60;int, allocator></SAMP></P>
<P>instead of :</P>
<P><SAMP>deque&#60;int></SAMP></P>
<A NAME="See Also"><H3>See Also</H3></A>
<P><A HREF="ist_4337.htm"><B><I>istream_iterator</B></I></A>, <A HREF="Ite_5295.htm"><B><I>Iterators</B></I></A></P>
<HR>
<A HREF="ope_9743.htm"><IMG SRC="images/prev.gif"></A> <A HREF="ref.htm#contents"><IMG SRC="images/toc.gif"></A> <A HREF="Out_3702.htm"><IMG SRC="images/next.gif"></A></BODY></HTML>
⌨️ 快捷键说明

复制代码 Ctrl + C
搜索代码 Ctrl + F
全屏模式 F11
切换主题 Ctrl + Shift + D
显示快捷键 ?
增大字号 Ctrl + =
减小字号 Ctrl + -