1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html> 3<head> 4<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 5<title>Global s1</title> 6<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> 7<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 8<link rel="home" href="../../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> 9<link rel="up" href="../../xpressive/reference.html#header.boost.xpressive.regex_primitives_hpp" title="Header <boost/xpressive/regex_primitives.hpp>"> 10<link rel="prev" href="s0.html" title="Global s0"> 11<link rel="next" href="s2.html" title="Global s2"> 12</head> 13<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 14<table cellpadding="2" width="100%"><tr> 15<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td> 16<td align="center"><a href="../../../../index.html">Home</a></td> 17<td align="center"><a href="../../../../libs/libraries.htm">Libraries</a></td> 18<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 19<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 20<td align="center"><a href="../../../../more/index.htm">More</a></td> 21</tr></table> 22<hr> 23<div class="spirit-nav"> 24<a accesskey="p" href="s0.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../xpressive/reference.html#header.boost.xpressive.regex_primitives_hpp"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="s2.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.xpressive.s1"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Global s1</span></h2> 30<p>boost::xpressive::s1 — Sub-match placeholder, like $1 in perl. </p> 31</div> 32<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 33<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../xpressive/reference.html#header.boost.xpressive.regex_primitives_hpp" title="Header <boost/xpressive/regex_primitives.hpp>">boost/xpressive/regex_primitives.hpp</a>> 34 35</span><a class="link" href="mark_tag.html" title="Struct mark_tag">mark_tag</a> <span class="keyword">const</span> s1<span class="special">;</span></pre></div> 36<div class="refsect1"> 37<a name="id-1.3.47.5.10.35.4"></a><h2>Description</h2> 38<p>To create a sub-match, assign a sub-expression to the sub-match placeholder. For instance, (s1= _) will match any one character and remember which character was matched in the 1st sub-match. Later in the pattern, you can refer back to the sub-match. For instance, (s1= _) >> s1 will match any character, and then match the same character again.</p> 39<p>After a successful regex_match() or regex_search(), the sub-match placeholders can be used to index into the <a class="link" href="match_results.html" title="Struct template match_results">match_results</a><> object to retrieve the Nth sub-match. </p> 40</div> 41</div> 42<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 43<td align="left"></td> 44<td align="right"><div class="copyright-footer">Copyright © 2007 Eric Niebler<p> 45 Distributed under the Boost Software License, Version 1.0. (See accompanying 46 file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 47 </p> 48</div></td> 49</tr></table> 50<hr> 51<div class="spirit-nav"> 52<a accesskey="p" href="s0.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../xpressive/reference.html#header.boost.xpressive.regex_primitives_hpp"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="s2.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 53</div> 54</body> 55</html> 56
