<?xml version="1.0" encoding="utf-8" ?> <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> <meta name="generator" content="Docutils 0.7: http://docutils.sourceforge.net/" /> <title>The MPL Reference Manual: Integral Constant</title> <link rel="stylesheet" href="../style.css" type="text/css" /> </head> <body class="docframe refmanual"> <table class="header"><tr class="header"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./data-types-concepts.html" class="navigation-link">Prev</a> <a href="./numeric.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group">Back Along</span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./data-types-concepts.html" class="navigation-link">Up</a> <a href="../refmanual.html" class="navigation-link">Home</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./refmanual_toc.html" class="navigation-link">Full TOC</a></span></td> <td class="header-group page-location"><a href="../refmanual.html" class="navigation-link">Front Page</a> / <a href="./data-types.html" class="navigation-link">Data Types</a> / <a href="./data-types-concepts.html" class="navigation-link">Concepts</a> / <a href="./integral-constant.html" class="navigation-link">Integral Constant</a></td> </tr></table><div class="header-separator"></div> <div class="section" id="integral-constant"> <h1><a class="toc-backref" href="./data-types-concepts.html#id1574">Integral Constant</a></h1> <div class="section" id="id1217"> <h3><a class="subsection-title" href="#description" name="description">Description</a></h3> <p>An <a class="reference internal" href="./integral-constant.html">Integral Constant</a> is a holder class for a compile-time value of an integral type. Every <a class="reference internal" href="./integral-constant.html">Integral Constant</a> is also a nullary <a class="reference internal" href="./metafunction.html">Metafunction</a>, returning itself. An integral constant <em>object</em> is implicitly convertible to the corresponding run-time value of the wrapped integral type.</p> </div> <div class="section" id="id1218"> <h3><a class="subsection-title" href="#expression-requirements" name="expression-requirements">Expression requirements</a></h3> <p>In the following table and subsequent specifications, <tt class="literal"><span class="pre">n</span></tt> is a model of <a class="reference internal" href="./integral-constant.html">Integral Constant</a>.</p> <table border="1" class="docutils table"> <colgroup> <col width="35%" /> <col width="39%" /> <col width="27%" /> </colgroup> <thead valign="bottom"> <tr><th class="head">Expression</th> <th class="head">Type</th> <th class="head">Complexity</th> </tr> </thead> <tbody valign="top"> <tr><td><tt class="literal"><span class="pre">n::tag</span></tt></td> <td><tt class="literal"><span class="pre">integral_c_tag</span></tt></td> <td>Constant time.</td> </tr> <tr><td><tt class="literal"><span class="pre">n::<a href="./value-type.html" class="identifier">value_type</a></span></tt></td> <td>An integral type</td> <td>Constant time.</td> </tr> <tr><td><tt class="literal"><span class="pre">n::value</span></tt></td> <td>An integral constant expression</td> <td>Constant time.</td> </tr> <tr><td><tt class="literal"><span class="pre">n::type</span></tt></td> <td><a class="reference internal" href="./integral-constant.html">Integral Constant</a></td> <td>Constant time.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./next.html" class="identifier">next</a><n>::type</span></tt></td> <td><a class="reference internal" href="./integral-constant.html">Integral Constant</a></td> <td>Constant time.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./prior.html" class="identifier">prior</a><n>::type</span></tt></td> <td><a class="reference internal" href="./integral-constant.html">Integral Constant</a></td> <td>Constant time.</td> </tr> <tr><td><tt class="literal"><span class="pre">n::<a href="./value-type.html" class="identifier">value_type</a></span> <span class="pre">const</span> <span class="pre">c</span> <span class="pre">=</span> <span class="pre">n()</span></tt></td> <td> </td> <td>Constant time.</td> </tr> </tbody> </table> </div> <div class="section" id="id1219"> <h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3> <table border="1" class="docutils table"> <colgroup> <col width="40%" /> <col width="60%" /> </colgroup> <thead valign="bottom"> <tr><th class="head">Expression</th> <th class="head">Semantics</th> </tr> </thead> <tbody valign="top"> <tr><td><tt class="literal"><span class="pre">n::tag</span></tt></td> <td><tt class="literal"><span class="pre">n</span></tt>'s tag type; <tt class="literal"><span class="pre">n::tag::value</span></tt> is <tt class="literal"><span class="pre">n</span></tt>'s <em>conversion rank</em>.</td> </tr> <tr><td><tt class="literal"><span class="pre">n::<a href="./value-type.html" class="identifier">value_type</a></span></tt></td> <td>A cv-unqualified type of <tt class="literal"><span class="pre">n::value</span></tt>.</td> </tr> <tr><td><tt class="literal"><span class="pre">n::value</span></tt></td> <td>The value of the wrapped integral constant.</td> </tr> <tr><td><tt class="literal"><span class="pre">n::type</span></tt></td> <td><tt class="literal"><span class="pre">is_same<n::type,n>::value</span> <span class="pre">==</span> <span class="pre">true</span></tt>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./next.html" class="identifier">next</a><n>::type</span></tt></td> <td>An <a class="reference internal" href="./integral-constant.html">Integral Constant</a> <tt class="literal"><span class="pre">c</span></tt> of type <tt class="literal"><span class="pre">n::<a href="./value-type.html" class="identifier">value_type</a></span></tt> such that <tt class="literal"><span class="pre">c::value</span> <span class="pre">==</span> <span class="pre">n::value</span> <span class="pre">+</span> <span class="pre">1</span></tt>.</td> </tr> <tr><td><tt class="literal"><span class="pre"><a href="./prior.html" class="identifier">prior</a><n>::type</span></tt></td> <td>An <a class="reference internal" href="./integral-constant.html">Integral Constant</a> <tt class="literal"><span class="pre">c</span></tt> of type <tt class="literal"><span class="pre">n::<a href="./value-type.html" class="identifier">value_type</a></span></tt> such that <tt class="literal"><span class="pre">c::value</span> <span class="pre">==</span> <span class="pre">n::value</span> <span class="pre">-</span> <span class="pre">1</span></tt>.</td> </tr> <tr><td><tt class="literal"><span class="pre">n::<a href="./value-type.html" class="identifier">value_type</a></span> <span class="pre">const</span> <span class="pre">c</span> <span class="pre">=</span> <span class="pre">n()</span></tt></td> <td><tt class="literal"><span class="pre">c</span> <span class="pre">==</span> <span class="pre">n::value</span></tt>.</td> </tr> </tbody> </table> </div> <div class="section" id="id1220"> <h3><a class="subsection-title" href="#models" name="models">Models</a></h3> <ul class="simple"> <li><a class="reference internal" href="./bool.html">bool_</a></li> <li><a class="reference internal" href="./int.html">int_</a></li> <li><a class="reference internal" href="./long.html">long_</a></li> <li><a class="reference internal" href="./char.html">char_</a></li> <li><a class="reference internal" href="./integral-c.html">integral_c</a></li> </ul> </div> <div class="section" id="id1221"> <h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3> <p><a class="reference internal" href="./data-types.html">Data Types</a>, <a class="reference internal" href="./integral-sequence-wrapper.html">Integral Sequence Wrapper</a>, <a class="reference internal" href="./integral-c.html">integral_c</a></p> </div> </div> <div class="footer-separator"></div> <table class="footer"><tr class="footer"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./data-types-concepts.html" class="navigation-link">Prev</a> <a href="./numeric.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group">Back Along</span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./data-types-concepts.html" class="navigation-link">Up</a> <a href="../refmanual.html" class="navigation-link">Home</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./refmanual_toc.html" class="navigation-link">Full TOC</a></span></td> <td><div class="copyright-footer"><div class="copyright">Copyright © 2001-2009 Aleksey Gurtovoy and David Abrahams</div> Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at <a class="reference external" href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)</div></td></tr></table></body> </html>