| <html> |
| <head> |
| <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> |
| <title>Unicode and Boost.Regex</title> |
| <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> |
| <meta name="generator" content="DocBook XSL Stylesheets V1.74.0"> |
| <link rel="home" href="../index.html" title="Boost.Regex"> |
| <link rel="up" href="../index.html" title="Boost.Regex"> |
| <link rel="prev" href="introduction_and_overview.html" title="Introduction and Overview"> |
| <link rel="next" href="captures.html" title="Understanding Marked Sub-Expressions and Captures"> |
| </head> |
| <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> |
| <table cellpadding="2" width="100%"><tr> |
| <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../boost.png"></td> |
| <td align="center"><a href="../../../../../index.html">Home</a></td> |
| <td align="center"><a href="../../../../../libs/libraries.htm">Libraries</a></td> |
| <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> |
| <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> |
| <td align="center"><a href="../../../../../more/index.htm">More</a></td> |
| </tr></table> |
| <hr> |
| <div class="spirit-nav"> |
| <a accesskey="p" href="introduction_and_overview.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><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="captures.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> |
| </div> |
| <div class="section" lang="en"> |
| <div class="titlepage"><div><div><h2 class="title" style="clear: both"> |
| <a name="boost_regex.unicode"></a><a class="link" href="unicode.html" title="Unicode and Boost.Regex"> Unicode and Boost.Regex</a> |
| </h2></div></div></div> |
| <p> |
| There are two ways to use Boost.Regex with Unicode strings: |
| </p> |
| <a name="boost_regex.unicode.rely_on_wchar_t"></a><h5> |
| <a name="id905477"></a> |
| <a class="link" href="unicode.html#boost_regex.unicode.rely_on_wchar_t">Rely on wchar_t</a> |
| </h5> |
| <p> |
| If your platform's <code class="computeroutput"><span class="keyword">wchar_t</span></code> type |
| can hold Unicode strings, and your platform's C/C++ runtime correctly handles |
| wide character constants (when passed to <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">iswspace</span></code> |
| <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">iswlower</span></code> etc), then you can use <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">wregex</span></code> |
| to process Unicode. However, there are several disadvantages to this approach: |
| </p> |
| <div class="itemizedlist"><ul type="disc"> |
| <li> |
| It's not portable: there's no guarantee on the width of <code class="computeroutput"><span class="keyword">wchar_t</span></code>, |
| or even whether the runtime treats wide characters as Unicode at all, most |
| Windows compilers do so, but many Unix systems do not. |
| </li> |
| <li> |
| There's no support for Unicode-specific character classes: <code class="computeroutput"><span class="special">[[:</span><span class="identifier">Nd</span><span class="special">:]]</span></code>, <code class="computeroutput"><span class="special">[[:</span><span class="identifier">Po</span><span class="special">:]]</span></code> |
| etc. |
| </li> |
| <li> |
| You can only search strings that are encoded as sequences of wide characters, |
| it is not possible to search UTF-8, or even UTF-16 on many platforms. |
| </li> |
| </ul></div> |
| <a name="boost_regex.unicode.use_a_unicode_aware_regular_expression_type_"></a><h5> |
| <a name="id905605"></a> |
| <a class="link" href="unicode.html#boost_regex.unicode.use_a_unicode_aware_regular_expression_type_">Use |
| a Unicode Aware Regular Expression Type.</a> |
| </h5> |
| <p> |
| If you have the <a href="http://www.ibm.com/software/globalization/icu/" target="_top">ICU |
| library</a>, then Boost.Regex can be <a class="link" href="install.html#boost_regex.install.building_with_unicode_and_icu_support">configured |
| to make use of it</a>, and provide a distinct regular expression type (boost::u32regex), |
| that supports both Unicode specific character properties, and the searching |
| of text that is encoded in either UTF-8, UTF-16, or UTF-32. See: <a class="link" href="ref/non_std_strings/icu.html" title="Working With Unicode and ICU String Types">ICU |
| string class support</a>. |
| </p> |
| </div> |
| <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> |
| <td align="left"></td> |
| <td align="right"><div class="copyright-footer">Copyright © 1998 -2010 John Maddock<p> |
| Distributed under the Boost Software License, Version 1.0. (See accompanying |
| 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>) |
| </p> |
| </div></td> |
| </tr></table> |
| <hr> |
| <div class="spirit-nav"> |
| <a accesskey="p" href="introduction_and_overview.html"><img src="../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../index.html"><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="captures.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> |
| </div> |
| </body> |
| </html> |
