151 lines
9.4 KiB
HTML
151 lines
9.4 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">
|
|
<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: numeric_cast</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="./inherit-linearly.html" class="navigation-link">Prev</a> <a href="./min.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./inherit-linearly.html" class="navigation-link">Back</a> <a href="./min.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./miscellaneous.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="./metafunctions.html" class="navigation-link">Metafunctions</a> / <a href="./miscellaneous.html" class="navigation-link">Miscellaneous</a> / <a href="./numeric-cast.html" class="navigation-link">numeric_cast</a></td>
|
|
</tr></table><div class="header-separator"></div>
|
|
<div class="section" id="numeric-cast">
|
|
<h1><a class="toc-backref" href="./miscellaneous.html#id1568">numeric_cast</a></h1>
|
|
<div class="section" id="id1181">
|
|
<h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3>
|
|
<pre class="literal-block">
|
|
template<
|
|
typename SourceTag
|
|
, typename TargetTag
|
|
>
|
|
struct <a href="./numeric-cast.html" class="identifier">numeric_cast</a>;
|
|
</pre>
|
|
</div>
|
|
<div class="section" id="id1182">
|
|
<h3><a class="subsection-title" href="#description" name="description">Description</a></h3>
|
|
<p>Each <tt class="literal"><span class="pre"><a href="./numeric-cast.html" class="identifier">numeric_cast</a></span></tt> specialization is a user-specialized unary <a class="reference internal" href="./metafunction-class.html">Metafunction Class</a>
|
|
providing a conversion between two numeric types.</p>
|
|
</div>
|
|
<div class="section" id="id1183">
|
|
<h3><a class="subsection-title" href="#header" name="header">Header</a></h3>
|
|
<pre class="literal-block">
|
|
#include <<a href="../../../../boost/mpl/numeric_cast.hpp" class="header">boost/mpl/numeric_cast.hpp</a>>
|
|
</pre>
|
|
</div>
|
|
<div class="section" id="id1184">
|
|
<h3><a class="subsection-title" href="#parameters" name="parameters">Parameters</a></h3>
|
|
<table border="1" class="docutils table">
|
|
<colgroup>
|
|
<col width="17%" />
|
|
<col width="30%" />
|
|
<col width="53%" />
|
|
</colgroup>
|
|
<thead valign="bottom">
|
|
<tr><th class="head">Parameter</th>
|
|
<th class="head">Requirement</th>
|
|
<th class="head">Description</th>
|
|
</tr>
|
|
</thead>
|
|
<tbody valign="top">
|
|
<tr><td><tt class="literal"><span class="pre">SourceTag</span></tt></td>
|
|
<td><a class="reference internal" href="./integral-constant.html">Integral Constant</a></td>
|
|
<td>A tag for the conversion's source type.</td>
|
|
</tr>
|
|
<tr><td><tt class="literal"><span class="pre">TargetTag</span></tt></td>
|
|
<td><a class="reference internal" href="./integral-constant.html">Integral Constant</a></td>
|
|
<td>A tag for the conversion's destination type.</td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
</div>
|
|
<div class="section" id="id1185">
|
|
<h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3>
|
|
<p>If <tt class="literal"><span class="pre">x</span></tt> and <tt class="literal"><span class="pre">y</span></tt> are two numeric types, <tt class="literal"><span class="pre">x</span></tt> is convertible to <tt class="literal"><span class="pre">y</span></tt>, and
|
|
<tt class="literal"><span class="pre">x_tag</span></tt> and <tt class="literal"><span class="pre">y_tag</span></tt> are the types' corresponding <a class="reference internal" href="./integral-constant.html">Integral Constant</a> tags:</p>
|
|
<pre class="literal-block">
|
|
typedef <a href="./apply-wrap.html" class="identifier">apply_wrap</a><tt class="literal"><span class="pre">2</span></tt>< <a href="./numeric-cast.html" class="identifier">numeric_cast</a><x_tag,y_tag>,x >::type r;
|
|
</pre>
|
|
<table class="docutils field-list" frame="void" rules="none">
|
|
<col class="field-name" />
|
|
<col class="field-body" />
|
|
<tbody valign="top">
|
|
<tr class="field"><th class="field-name">Return type:</th><td class="field-body">A type.</td>
|
|
</tr>
|
|
<tr class="field"><th class="field-name">Semantics:</th><td class="field-body"><tt class="literal"><span class="pre">r</span></tt> is a value of <tt class="literal"><span class="pre">x</span></tt> converted to the type of <tt class="literal"><span class="pre">y</span></tt>.</td>
|
|
</tr>
|
|
</tbody>
|
|
</table>
|
|
</div>
|
|
<div class="section" id="id1186">
|
|
<h3><a class="subsection-title" href="#complexity" name="complexity">Complexity</a></h3>
|
|
<p>Unspecified.</p>
|
|
</div>
|
|
<div class="section" id="id1187">
|
|
<h3><a class="subsection-title" href="#example" name="example">Example</a></h3>
|
|
<pre class="literal-block">
|
|
struct complex_tag : <a href="./int.html" class="identifier">int_</a><10> {};
|
|
|
|
template< typename Re, typename Im > struct complex
|
|
{
|
|
typedef complex_tag tag;
|
|
typedef complex type;
|
|
typedef Re real;
|
|
typedef Im imag;
|
|
};
|
|
|
|
template< typename C > struct real : C::real {};
|
|
template< typename C > struct imag : C::imag {};
|
|
|
|
namespace boost { namespace mpl {
|
|
|
|
template<> struct <a href="./numeric-cast.html" class="identifier">numeric_cast</a>< integral_c_tag,complex_tag >
|
|
{
|
|
template< typename N > struct <a href="./apply.html" class="identifier">apply</a>
|
|
: complex< N, <a href="./integral-c.html" class="identifier">integral_c</a>< typename N::<a href="./value-type.html" class="identifier">value_type</a>, 0 > >
|
|
{
|
|
};
|
|
};
|
|
|
|
template<>
|
|
struct plus_impl< complex_tag,complex_tag >
|
|
{
|
|
template< typename N1, typename N2 > struct <a href="./apply.html" class="identifier">apply</a>
|
|
: complex<
|
|
<a href="./plus.html" class="identifier">plus</a>< typename N1::real, typename N2::real >
|
|
, <a href="./plus.html" class="identifier">plus</a>< typename N1::imag, typename N2::imag >
|
|
>
|
|
{
|
|
};
|
|
};
|
|
|
|
}}
|
|
|
|
typedef <a href="./int.html" class="identifier">int_</a><2> i;
|
|
typedef complex< <a href="./int.html" class="identifier">int_</a><5>, <a href="./int.html" class="identifier">int_</a><-1> > c1;
|
|
typedef complex< <a href="./int.html" class="identifier">int_</a><-5>, <a href="./int.html" class="identifier">int_</a><1> > c2;
|
|
|
|
typedef <a href="./plus.html" class="identifier">plus</a><c1,i> r4;
|
|
<a href="./assert-relation.html" class="identifier">BOOST_MPL_ASSERT_RELATION</a>( real<r4>::value, ==, 7 );
|
|
<a href="./assert-relation.html" class="identifier">BOOST_MPL_ASSERT_RELATION</a>( imag<r4>::value, ==, -1 );
|
|
|
|
typedef <a href="./plus.html" class="identifier">plus</a><i,c2> r5;
|
|
<a href="./assert-relation.html" class="identifier">BOOST_MPL_ASSERT_RELATION</a>( real<r5>::value, ==, -3 );
|
|
<a href="./assert-relation.html" class="identifier">BOOST_MPL_ASSERT_RELATION</a>( imag<r5>::value, ==, 1 );
|
|
</pre>
|
|
</div>
|
|
<div class="section" id="id1188">
|
|
<h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3>
|
|
<p><a class="reference internal" href="./metafunctions.html">Metafunctions</a>, <a class="reference internal" href="./numeric-metafunction.html">Numeric Metafunction</a>, <a class="reference internal" href="./plus.html">plus</a>, <a class="reference internal" href="./minus.html">minus</a>, <a class="reference internal" href="./times.html">times</a></p>
|
|
<!-- Metafunctions/Miscellaneous//min |80 -->
|
|
</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="./inherit-linearly.html" class="navigation-link">Prev</a> <a href="./min.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./inherit-linearly.html" class="navigation-link">Back</a> <a href="./min.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./miscellaneous.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>
|