1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>rational_adaptor</title> 5<link rel="stylesheet" href="../../../multiprecision.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../index.html" title="Chapter 1. Boost.Multiprecision"> 8<link rel="up" href="../rational.html" title="Rational Number Types"> 9<link rel="prev" href="br.html" title="Use With Boost.Rational"> 10<link rel="next" href="../misc.html" title="Miscellaneous Number Types."> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="br.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../rational.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="../misc.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h4 class="title"> 27<a name="boost_multiprecision.tut.rational.rational_adaptor"></a><a class="link" href="rational_adaptor.html" title="rational_adaptor">rational_adaptor</a> 28</h4></div></div></div> 29<pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">multiprecision</span><span class="special">{</span> 30 31<span class="keyword">template</span> <span class="special"><</span><span class="keyword">class</span> <span class="identifier">IntBackend</span><span class="special">></span> 32<span class="keyword">class</span> <span class="identifier">rational_adpater</span><span class="special">;</span> 33 34<span class="special">}}</span> 35</pre> 36<p> 37 The class template <code class="computeroutput"><span class="identifier">rational_adaptor</span></code> 38 is a back-end for <code class="computeroutput"><span class="identifier">number</span></code> 39 which converts any existing integer back-end into a rational-number back-end. 40 </p> 41<p> 42 So for example, given an integer back-end type <code class="computeroutput"><span class="identifier">MyIntegerBackend</span></code>, 43 the use would be something like: 44 </p> 45<pre class="programlisting"><span class="keyword">typedef</span> <span class="identifier">number</span><span class="special"><</span><span class="identifier">MyIntegerBackend</span><span class="special">></span> <span class="identifier">MyInt</span><span class="special">;</span> 46<span class="keyword">typedef</span> <span class="identifier">number</span><span class="special"><</span><span class="identifier">rational_adaptor</span><span class="special"><</span><span class="identifier">MyIntegerBackend</span><span class="special">></span> <span class="special">></span> <span class="identifier">MyRational</span><span class="special">;</span> 47 48<span class="identifier">MyRational</span> <span class="identifier">r</span> <span class="special">=</span> <span class="number">2</span><span class="special">;</span> 49<span class="identifier">r</span> <span class="special">/=</span> <span class="number">3</span><span class="special">;</span> 50<span class="identifier">MyInt</span> <span class="identifier">i</span> <span class="special">=</span> <span class="identifier">numerator</span><span class="special">(</span><span class="identifier">r</span><span class="special">);</span> 51<span class="identifier">assert</span><span class="special">(</span><span class="identifier">i</span> <span class="special">==</span> <span class="number">2</span><span class="special">);</span> 52</pre> 53</div> 54<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 55<td align="left"></td> 56<td align="right"><div class="copyright-footer">Copyright © 2002-2020 John 57 Maddock and Christopher Kormanyos<p> 58 Distributed under the Boost Software License, Version 1.0. (See accompanying 59 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>) 60 </p> 61</div></td> 62</tr></table> 63<hr> 64<div class="spirit-nav"> 65<a accesskey="p" href="br.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../rational.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="../misc.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 66</div> 67</body> 68</html> 69
