75 lines
4.9 KiB
HTML
75 lines
4.9 KiB
HTML
<?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">
|
|
<!-- Copyright Aleksey Gurtovoy 2006. Distributed under the Boost -->
|
|
<!-- Software License, Version 1.0. (See accompanying -->
|
|
<!-- file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) -->
|
|
<head>
|
|
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
|
|
<meta name="generator" content="Docutils 0.3.6: http://docutils.sourceforge.net/" />
|
|
<title>THE BOOST MPL LIBRARY: Numeric Metafunction Protocol/Infrastructure</title>
|
|
<link rel="stylesheet" href="../style.css" type="text/css" />
|
|
</head>
|
|
<body class="docframe">
|
|
<table class="header"><tr class="header"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./tag-dispatching-protocol.html" class="navigation-link">Prev</a> <a href="./renaming-cleanup.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./tag-dispatching-protocol.html" class="navigation-link">Back</a> <a href="./renaming-cleanup.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./changes-in-boost-1-32-0.html" class="navigation-link">Up</a> <a href="../index.html" class="navigation-link">Home</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./tutorial_toc.html" class="navigation-link">Full TOC</a></span></td>
|
|
<td class="header-group page-location"><a href="../index.html" class="navigation-link">Front Page</a> / <a href="./changelog-history.html" class="navigation-link">Changelog & History</a> / <a href="./changes-in-boost-1-32-0.html" class="navigation-link">Changes in Boost 1.32.0 Release</a> / <a href="./numeric-metafunction.html" class="navigation-link">Numeric Metafunction Protocol/Infrastructure</a></td>
|
|
</tr></table><div class="header-separator"></div>
|
|
<div class="section" id="numeric-metafunction">
|
|
<h1><a class="toc-backref" href="./changes-in-boost-1-32-0.html#id67" name="numeric-metafunction">Numeric Metafunction Protocol/Infrastructure</a></h1>
|
|
<p>The arithmetic, comparison and bitwise metafunctions are now
|
|
<cite>polymorphic</cite>, and can operate on a variety of numeric types,
|
|
including rational, fixed-point and complex numbers. They allow
|
|
<cite>mixed arithmetic</cite>, meaning that you can perform an operation on
|
|
arguments of different types, and the result will yield the
|
|
largest/most general of the argument types. The infrastructure
|
|
allows user-defined numeric types to be freely intermixed with
|
|
predefined library types. See
|
|
<a class="reference" href="../../test/numeric_ops.cpp" target="_top">libs/mpl/test/numeric_ops.cpp</a>
|
|
for an illustrative example, and the <a class="reference" href="./reference-manual.html">reference manual</a> for
|
|
the formal infrastructure specification.</p>
|
|
<p>If you were using MPL numeric metafunctions on your own integral
|
|
wrapper class similar to <tt class="literal"><span class="pre">mpl::int_</span></tt>, you can plug your class
|
|
into the new infrastructure by extending it with the following
|
|
member:</p>
|
|
<pre class="literal-block">
|
|
typedef mpl::integral_c_tag tag;
|
|
</pre>
|
|
<p>For example:</p>
|
|
<table border="1" class="table">
|
|
<colgroup>
|
|
<col width="48%" />
|
|
<col width="52%" />
|
|
</colgroup>
|
|
<thead valign="bottom">
|
|
<tr><th>Before</th>
|
|
<th>Now</th>
|
|
</tr>
|
|
</thead>
|
|
<tbody valign="top">
|
|
<tr><td><pre class="first last literal-block">
|
|
template< int n > struct my_int
|
|
{
|
|
static int const value = n;
|
|
typedef my_int type;
|
|
};
|
|
</pre>
|
|
</td>
|
|
<td><pre class="first last literal-block">
|
|
template< int n > struct my_int
|
|
{
|
|
<strong>typedef mpl::integral_c_tag tag;</strong>
|
|
static int const value = n;
|
|
typedef my_int type;
|
|
};
|
|
</pre>
|
|
</td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
</div>
|
|
|
|
<div class="footer-separator"></div>
|
|
<table class="footer"><tr class="footer"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./tag-dispatching-protocol.html" class="navigation-link">Prev</a> <a href="./renaming-cleanup.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./tag-dispatching-protocol.html" class="navigation-link">Back</a> <a href="./renaming-cleanup.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./changes-in-boost-1-32-0.html" class="navigation-link">Up</a> <a href="../index.html" class="navigation-link">Home</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./tutorial_toc.html" class="navigation-link">Full TOC</a></span></td>
|
|
</tr></table></body>
|
|
</html>
|