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| <div class="titlepage"><div><div><h3 class="title"> |
| <a name="range.reference.utilities"></a><a class="link" href="utilities.html" title="Utilities"> Utilities</a> |
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| <div class="toc"><dl> |
| <dt><span class="section"><a href="utilities/iterator_range.html"> Class <code class="computeroutput"><span class="identifier">iterator_range</span></code></a></span></dt> |
| <dt><span class="section"><a href="utilities/sub_range.html"> Class <code class="computeroutput"><span class="identifier">sub_range</span></code></a></span></dt> |
| <dt><span class="section"><a href="utilities/join.html"> Function join</a></span></dt> |
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| <p> |
| Having an abstraction that encapsulates a pair of iterators is very useful. |
| The standard library uses <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span></code> |
| in some circumstances, but that class is cumbersome to use because we need |
| to specify two template arguments, and for all range algorithm purposes we |
| must enforce the two template arguments to be the same. Moreover, <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special"><</span><span class="identifier">iterator</span><span class="special">,</span><span class="identifier">iterator</span><span class="special">></span></code> is hardly self-documenting whereas more |
| domain specific class names are. Therefore these two classes are provided: |
| </p> |
| <div class="itemizedlist"><ul class="itemizedlist" type="disc"> |
| <li class="listitem"> |
| Class <code class="computeroutput"><span class="identifier">iterator_range</span></code> |
| </li> |
| <li class="listitem"> |
| Class <code class="computeroutput"><span class="identifier">sub_range</span></code> |
| </li> |
| <li class="listitem"> |
| Function <code class="computeroutput"><span class="identifier">join</span></code> |
| </li> |
| </ul></div> |
| <p> |
| The <code class="computeroutput"><span class="identifier">iterator_range</span></code> class |
| is templated on an <a href="../../../../../../libs/iterator/doc/new-iter-concepts.html#forward-traversal-iterators-lib-forward-traversal-iterators" target="_top">Forward |
| Traversal Iterator</a> and should be used whenever fairly general code |
| is needed. The <code class="computeroutput"><span class="identifier">sub_range</span></code> |
| class is templated on an <a class="link" href="../concepts/forward_range.html" title="Forward Range">Forward |
| Range</a> and it is less general, but a bit easier to use since its template |
| argument is easier to specify. The biggest difference is, however, that a |
| <code class="computeroutput"><span class="identifier">sub_range</span></code> can propagate constness |
| because it knows what a corresponding <code class="computeroutput"><span class="identifier">const_iterator</span></code> |
| is. |
| </p> |
| <p> |
| Both classes can be used as ranges since they implement the <a class="link" href="extending.html" title="Extending the library">minimal |
| interface</a> required for this to work automatically. |
| </p> |
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| <td align="right"><div class="copyright-footer">Copyright © 2003 -2010 Thorsten Ottosen, Neil Groves<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>) |
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