<?xml version="1.0" encoding="UTF-8" standalone="no"?><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /><title>Chapter 26. Memory Based Streams</title><meta name="generator" content="DocBook XSL Stylesheets V1.74.0" /><meta name="keywords" content=" ISO C++ , library " /><link rel="home" href="../spine.html" title="The GNU C++ Library Documentation" /><link rel="up" href="io.html" title="Part XI. Input and Output" /><link rel="prev" href="bk01pt11ch25s02.html" title="Buffering" /><link rel="next" href="fstreams.html" title="Chapter 27. File Based Streams" /></head><body><div class="navheader"><table width="100%" summary="Navigation header"><tr><th colspan="3" align="center">Chapter 26. Memory Based Streams</th></tr><tr><td width="20%" align="left"><a accesskey="p" href="bk01pt11ch25s02.html">Prev</a> </td><th width="60%" align="center">Part XI.Input and Output</th><td width="20%" align="right"> <a accesskey="n" href="fstreams.html">Next</a></td></tr></table><hr /></div><div class="chapter" lang="en" xml:lang="en"><div class="titlepage"><div><div><h2 class="title"><a id="manual.io.memstreams"></a>Chapter 26. Memory Based Streams</h2></div></div></div><div class="toc"><p><b>Table of Contents</b></p><dl><dt><span class="sect1"><a href="stringstreams.html#manual.io.memstreams.compat">Compatibility With strstream</a></span></dt></dl></div><div class="sect1" lang="en" xml:lang="en"><div class="titlepage"><div><div><h2 class="title" style="clear: both"><a id="manual.io.memstreams.compat"></a>Compatibility With strstream</h2></div></div></div><p></p><p>Stringstreams (defined in the header <code class="code"><sstream></code>)are in this author's opinion one of the coolest things sincesliced time. An example of their use is in the Received Wisdomsection for Chapter 21 (Strings),<a class="ulink" href="../21_strings/howto.html#1.1internal" target="_top"> describing how toformat strings</a>.</p><p>The quick definition is: they are siblings of ifstream and ofstream,and they do for <code class="code">std::string</code> what their siblings do forfiles. All that work you put into writing <code class="code"><<</code> and<code class="code">>></code> functions for your classes now pays off<span class="emphasis"><em>again!</em></span> Need to format a string before passing the stringto a function? Send your stuff via <code class="code"><<</code> to anostringstream. You've read a string as input and need to parse it?Initialize an istringstream with that string, and then pull piecesout of it with <code class="code">>></code>. Have a stringstream and need toget a copy of the string inside? Just call the <code class="code">str()</code>member function.</p><p>This only works if you've written your<code class="code"><<</code>/<code class="code">>></code> functions correctly, though,and correctly means that they take istreams and ostreams asparameters, not i<span class="emphasis"><em>f</em></span>streams and o<span class="emphasis"><em>f</em></span>streams. If theytake the latter, then your I/O operators will work fine withfile streams, but with nothing else -- including stringstreams.</p><p>If you are a user of the strstream classes, you need to updateyour code. You don't have to explicitly append <code class="code">ends</code> toterminate the C-style character array, you don't have to mess with"freezing" functions, and you don't have to manage thememory yourself. The strstreams have been officially deprecated,which means that 1) future revisions of the C++ Standard won'tsupport them, and 2) if you use them, people will laugh at you.</p></div></div><div class="navfooter"><hr /><table width="100%" summary="Navigation footer"><tr><td width="40%" align="left"><a accesskey="p" href="bk01pt11ch25s02.html">Prev</a> </td><td width="20%" align="center"><a accesskey="u" href="io.html">Up</a></td><td width="40%" align="right"> <a accesskey="n" href="fstreams.html">Next</a></td></tr><tr><td width="40%" align="left" valign="top">Buffering </td><td width="20%" align="center"><a accesskey="h" href="../spine.html">Home</a></td><td width="40%" align="right" valign="top"> Chapter 27. File Based Streams</td></tr></table></div></body></html>