<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Terminology and style guidelines</title> <link rel="stylesheet" href="../../../../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> <link rel="home" href="../index.html" title="Chapter 1. Range 2.0"> <link rel="up" href="../index.html" title="Chapter 1. Range 2.0"> <link rel="prev" href="reference/extending/method_3/method_3_2.html" title="Method 3.2: Implement a Range Adaptor with arguments"> <link rel="next" href="library_headers.html" title="Library Headers"> </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="reference/extending/method_3/method_3_2.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="library_headers.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h2 class="title" style="clear: both"> <a name="range.style_guide"></a><a class="link" href="style_guide.html" title="Terminology and style guidelines"> Terminology and style guidelines</a> </h2></div></div></div> <p> The use of a consistent terminology is as important for <a class="link" href="concepts.html" title="Range Concepts">Ranges</a> and range-based algorithms as it is for iterators and iterator-based algorithms. If a conventional set of names are adopted, we can avoid misunderstandings and write generic function prototypes that are <span class="bold"><strong><span class="emphasis"><em>self-documenting</em></span></strong></span>. </p> <p> Since ranges are characterized by a specific underlying iterator type, we get a type of range for each type of iterator. Hence we can speak of the following types of ranges: </p> <div class="itemizedlist"><ul class="itemizedlist" type="disc"> <li class="listitem"> <span class="bold"><strong><span class="emphasis"><em>Value access</em></span></strong></span> category: <div class="itemizedlist"><ul class="itemizedlist" type="circle"> <li class="listitem"> Readable Range </li> <li class="listitem"> Writeable Range </li> <li class="listitem"> Swappable Range </li> <li class="listitem"> Lvalue Range </li> </ul></div> </li> <li class="listitem"> <span class="bold"><strong><span class="emphasis"><em>Traversal</em></span></strong></span> category: <div class="itemizedlist"><ul class="itemizedlist" type="circle"> <li class="listitem"> <a class="link" href="concepts/single_pass_range.html" title="Single Pass Range">Single Pass Range</a> </li> <li class="listitem"> <a class="link" href="concepts/forward_range.html" title="Forward Range">Forward Range</a> </li> <li class="listitem"> <a class="link" href="concepts/bidirectional_range.html" title="Bidirectional Range">Bidirectional Range</a> </li> <li class="listitem"> <a class="link" href="concepts/random_access_range.html" title="Random Access Range">Random Access Range</a> </li> </ul></div> </li> </ul></div> <p> Notice how we have used the categories from the <a href="../../../../../libs/iterator/doc/new-iter-concepts.html" target="_top">new style iterators</a>. </p> <p> Notice that an iterator (and therefore an range) has one <span class="bold"><strong><span class="emphasis"><em>traversal</em></span></strong></span> property and one or more properties from the <span class="bold"><strong><span class="emphasis"><em>value access</em></span></strong></span> category. So in reality we will mostly talk about mixtures such as </p> <div class="itemizedlist"><ul class="itemizedlist" type="disc"> <li class="listitem"> Random Access Readable Writeable Range </li> <li class="listitem"> Forward Lvalue Range </li> </ul></div> <p> By convention, we should always specify the <span class="bold"><strong><span class="emphasis"><em>traversal</em></span></strong></span> property first as done above. This seems reasonable since there will only be one <span class="bold"><strong><span class="emphasis"><em>traversal</em></span></strong></span> property, but perhaps many <span class="bold"><strong><span class="emphasis"><em>value access</em></span></strong></span> properties. </p> <p> It might, however, be reasonable to specify only one category if the other category does not matter. For example, the <a class="link" href="reference/utilities/iterator_range.html" title="Class iterator_range"><code class="computeroutput"><span class="identifier">iterator_range</span></code></a> can be constructed from a Forward Range. This means that we do not care about what <span class="bold"><strong><span class="emphasis"><em>value access</em></span></strong></span> properties the Range has. Similarly, a Readable Range will be one that has the lowest possible <span class="bold"><strong><span class="emphasis"><em>traversal</em></span></strong></span> property (Single Pass). </p> <p> As another example, consider how we specify the interface of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">sort</span><span class="special">()</span></code>. Algorithms are usually more cumbersome to specify the interface of since both <span class="bold"><strong><span class="emphasis"><em>traversal</em></span></strong></span> and <span class="bold"><strong><span class="emphasis"><em>value access</em></span></strong></span> properties must be exactly defined. The iterator-based version looks like this: </p> <p> </p> <pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> <span class="keyword">class</span> <span class="identifier">RandomAccessTraversalReadableWritableIterator</span> <span class="special">></span> <span class="keyword">void</span> <span class="identifier">sort</span><span class="special">(</span> <span class="identifier">RandomAccessTraversalReadableWritableIterator</span> <span class="identifier">first</span><span class="special">,</span> <span class="identifier">RandomAccessTraversalReadableWritableIterator</span> <span class="identifier">last</span> <span class="special">);</span> </pre> <p> </p> <p> For ranges the interface becomes </p> <p> </p> <pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> <span class="keyword">class</span> <span class="identifier">RandomAccessReadableWritableRange</span> <span class="special">></span> <span class="keyword">void</span> <span class="identifier">sort</span><span class="special">(</span> <span class="identifier">RandomAccessReadableWritableRange</span><span class="special">&</span> <span class="identifier">r</span> <span class="special">);</span> </pre> <p> </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 © 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>) </p> </div></td> </tr></table> <hr> <div class="spirit-nav"> <a accesskey="p" href="reference/extending/method_3/method_3_2.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="library_headers.html"><img src="../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>