<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Type Traits that Describe the Properties of a Type</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="Chapter 1. Boost.TypeTraits"> <link rel="up" href="../category.html" title="Type Traits by Category"> <link rel="prev" href="../category.html" title="Type Traits by Category"> <link rel="next" href="value_traits/primary.html" title="Categorizing a Type"> </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="../category.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../category.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="value_traits/primary.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section" lang="en"> <div class="titlepage"><div><div><h3 class="title"> <a name="boost_typetraits.category.value_traits"></a><a class="link" href="value_traits.html" title="Type Traits that Describe the Properties of a Type"> Type Traits that Describe the Properties of a Type</a> </h3></div></div></div> <div class="toc"><dl> <dt><span class="section"><a href="value_traits/primary.html"> Categorizing a Type</a></span></dt> <dt><span class="section"><a href="value_traits/properties.html"> General Type Properties</a></span></dt> <dt><span class="section"><a href="value_traits/relate.html"> Relationships Between Two Types</a></span></dt> </dl></div> <p> These traits are all <span class="emphasis"><em>value traits</em></span>, which is to say the traits classes all inherit from <a class="link" href="../reference/integral_constant.html" title="integral_constant">integral_constant</a>, and are used to access some numerical property of a type. Often this is a simple true or false Boolean value, but in a few cases may be some other integer value (for example when dealing with type alignments, or array bounds: see <code class="computeroutput"><a class="link" href="../reference/alignment_of.html" title="alignment_of">alignment_of</a></code>, <code class="computeroutput"><a class="link" href="../reference/rank.html" title="rank">rank</a></code> and <code class="computeroutput"><a class="link" href="../reference/extent.html" title="extent">extent</a></code>). </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 © 2000, 2006 Adobe Systems Inc, David Abrahams, Steve Cleary, Beman Dawes, Aleksey Gurtovoy, Howard Hinnant, Jesse Jones, Mat Marcus, Itay Maman, John Maddock, Alexander Nasonov, Thorsten Ottosen, Robert Ramey and Jeremy Siek<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="../category.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../category.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="value_traits/primary.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>