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| <div class="titlepage"><div><div><h2 class="title" style="clear: both"> |
| <a name="string_algo.rationale"></a>Rationale</h2></div></div></div> |
| <div class="toc"><dl> |
| <dt><span class="section"><a href="rationale.html#id2644159">Locales</a></span></dt> |
| <dt><span class="section"><a href="rationale.html#string_algo.regex">Regular Expressions</a></span></dt> |
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| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="id2644159"></a>Locales</h3></div></div></div> |
| <p> |
| Locales have a very close relation to string processing. They contain information about |
| the character sets and are used, for example, to change the case of characters and |
| to classify the characters. |
| </p> |
| <p> |
| C++ allows to work with multiple different instances of locales at once. If an algorithm |
| manipulates some data in a way that requires the usage of locales, there must be a way |
| to specify them. However, one instance of locales is sufficient for most of the applications, |
| and for a user it could be very tedious to specify which locales to use at every place |
| where it is needed. |
| </p> |
| <p> |
| Fortunately, the C++ standard allows to specify the <span class="emphasis"><em>global</em></span> locales (using static member |
| function <code class="computeroutput">std:locale::global()</code>). When instantiating an |
| <code class="computeroutput">std::locale</code> class without explicit information, the instance will |
| be initialized with the <span class="emphasis"><em>global</em></span> locale. This implies, that if an algorithm needs a locale, |
| it should have an <code class="computeroutput">std::locale</code> parameter defaulting to <code class="computeroutput">std::locale()</code>. |
| If a user needs to specify locales explicitly, she can do so. Otherwise the <span class="emphasis"><em>global</em></span> |
| locales are used. |
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| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="string_algo.regex"></a>Regular Expressions</h3></div></div></div> |
| <p> |
| Regular expressions are an essential part of text processing. For this reason, the library |
| also provides regex variants of some algorithms. The library does not attempt to replace |
| Boost.Regex; it merely wraps its functionality in a new interface. |
| As a part of this library, regex algorithms integrate smoothly with other components, which |
| brings additional value. |
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| <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> |
| <td align="left"><p><small>Last revised: February 27, 2008 at 20:00:24 +0000</small></p></td> |
| <td align="right"><div class="copyright-footer">Copyright © 2002-2004 Pavol Droba<p>Use, modification and distribution is subject to the Boost |
| Software License, Version 1.0. (See accompanying file |
| <code class="filename">LICENSE_1_0.txt</code> or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) |
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