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| 25 | <div class="section" lang="en"> |
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| 26 | <div class="titlepage"><div><div><h3 class="title"> |
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| 27 | <a name="string_algo.rationale"></a>Rationale</h3></div></div></div> |
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| 28 | <div class="toc"><dl> |
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| 29 | <dt><span class="section"><a href="rationale.html#id2774637">Locales</a></span></dt> |
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| 30 | <dt><span class="section"><a href="rationale.html#string_algo.regex">Regular Expressions</a></span></dt> |
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| 31 | </dl></div> |
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| 32 | <div class="section" lang="en"> |
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| 33 | <div class="titlepage"><div><div><h4 class="title"> |
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| 34 | <a name="id2774637"></a>Locales</h4></div></div></div> |
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| 35 | <p> |
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| 36 | Locales have a very close relation to string processing. They contain information about |
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| 37 | the character sets and are used, for example, to change the case of characters and |
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| 38 | to classify the characters. |
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| 39 | </p> |
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| 40 | <p> |
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| 41 | C++ allows to work with multiple different instances of locales at once. If an algorithm |
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| 42 | manipulates some data in a way that requires the usage of locales, there must be a way |
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| 43 | to specify them. However, one instance of locales is sufficient for most of the applications, |
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| 44 | and for a user it could be very tedious to specify which locales to use at every place |
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| 45 | where it is needed. |
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| 46 | </p> |
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| 47 | <p> |
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| 48 | Fortunately, the C++ standard allows to specify the <span class="emphasis"><em>global</em></span> locales (using static member |
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| 49 | function <code class="computeroutput">std:locale::global()</code>). When instantiating an |
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| 50 | <code class="computeroutput">std::locale</code> class without explicit information, the instance will |
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| 51 | be initialized with the <span class="emphasis"><em>global</em></span> locale. This implies, that if an algorithm needs a locale, |
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| 52 | it should have an <code class="computeroutput">std::locale</code> parameter defaulting to <code class="computeroutput">std::locale()</code>. |
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| 53 | If a user needs to specify locales explicitly, she can do so. Otherwise the <span class="emphasis"><em>global</em></span> |
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| 54 | locales are used. |
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| 55 | </p> |
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| 56 | </div> |
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| 57 | <div class="section" lang="en"> |
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| 58 | <div class="titlepage"><div><div><h4 class="title"> |
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| 59 | <a name="string_algo.regex"></a>Regular Expressions</h4></div></div></div> |
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| 60 | <p> |
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| 61 | Regular expressions are an essential part of text processing. For this reason, the library |
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| 62 | also provides regex variants of some algorithms. The library does not attempt to replace |
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| 63 | Boost.Regex; it merely wraps its functionality in a new interface. |
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| 64 | As a part of this library, regex algorithms integrate smoothly with other components, which |
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| 65 | brings additional value. |
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| 66 | </p> |
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| 67 | </div> |
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| 68 | </div> |
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| 69 | <table width="100%"><tr> |
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| 70 | <td align="left"><small><p>Last revised: July 16, 2004 at 09:06:39 GMT</p></small></td> |
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| 71 | <td align="right"><small>Copyright © 2002-2004 Pavol Droba</small></td> |
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| 72 | </tr></table> |
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