1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html> 3<head> 4<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 5<title>Utilities</title> 6<link rel="stylesheet" href="../../../doc/src/boostbook.css" type="text/css"> 7<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 8<link rel="home" href="../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> 9<link rel="up" href="../boost_units.html" title="Chapter 43. Boost.Units 1.1.0"> 10<link rel="prev" href="Examples.html" title="Examples"> 11<link rel="next" href="Reference.html" title="Reference"> 12</head> 13<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 14<table cellpadding="2" width="100%"><tr> 15<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../boost.png"></td> 16<td align="center"><a href="../../../index.html">Home</a></td> 17<td align="center"><a href="../../../libs/libraries.htm">Libraries</a></td> 18<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 19<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 20<td align="center"><a href="../../../more/index.htm">More</a></td> 21</tr></table> 22<hr> 23<div class="spirit-nav"> 24<a accesskey="p" href="Examples.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost_units.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="Reference.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="section"> 27<div class="titlepage"><div><div><h2 class="title" style="clear: both"> 28<a name="boost_units.Utilities"></a><a class="link" href="Utilities.html" title="Utilities">Utilities</a> 29</h2></div></div></div> 30<div class="toc"><dl class="toc"> 31<dt><span class="section"><a href="Utilities.html#boost_units.Utilities.Metaprogramming_Classes">Metaprogramming 32 Classes</a></span></dt> 33<dt><span class="section"><a href="Utilities.html#boost_units.Utilities.Metaprogramming_Predicates">Metaprogramming 34 Predicates</a></span></dt> 35</dl></div> 36<p> 37 Relatively complete SI and CGS unit systems are provided in <code class="computeroutput"><a class="link" href="Reference.html#header.boost.units.systems.si_hpp" title="Header <boost/units/systems/si.hpp>">boost/units/systems/si.hpp</a></code> 38 and <code class="computeroutput"><a class="link" href="Reference.html#header.boost.units.systems.cgs_hpp" title="Header <boost/units/systems/cgs.hpp>">boost/units/systems/cgs.hpp</a></code>, 39 respectively. 40 </p> 41<div class="section"> 42<div class="titlepage"><div><div><h3 class="title"> 43<a name="boost_units.Utilities.Metaprogramming_Classes"></a><a class="link" href="Utilities.html#boost_units.Utilities.Metaprogramming_Classes" title="Metaprogramming Classes">Metaprogramming 44 Classes</a> 45</h3></div></div></div> 46<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">long</span> <span class="identifier">N</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">ordinal</span><span class="special"><</span><span class="identifier">N</span><span class="special">>;</span> 47 48<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">,</span><span class="keyword">typename</span> <span class="identifier">V</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">get_tag</span><span class="special"><</span> <span class="identifier">dim</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span><span class="identifier">V</span><span class="special">></span> <span class="special">>;</span> 49<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">,</span><span class="keyword">typename</span> <span class="identifier">V</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">get_value</span><span class="special"><</span> <span class="identifier">dim</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span><span class="identifier">V</span><span class="special">></span> <span class="special">>;</span> 50<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">S</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">DT</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">get_system_tag_of_dim</span><span class="special"><</span><span class="identifier">S</span><span class="special">,</span><span class="identifier">DT</span><span class="special">>;</span> 51<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Seq</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">make_dimension_list</span><span class="special"><</span><span class="identifier">Seq</span><span class="special">>;</span> 52<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">DT</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">fundamental_dimension</span><span class="special"><</span><span class="identifier">DT</span><span class="special">>;</span> 53<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">DT1</span><span class="special">,</span><span class="keyword">int</span> <span class="identifier">E1</span><span class="special">,...></span> <span class="keyword">struct</span> <span class="identifier">composite_dimension</span><span class="special"><</span><span class="identifier">DT1</span><span class="special">,</span><span class="identifier">E1</span><span class="special">,...>;</span> 54 55<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Dim</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">System</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">get_dimension</span><span class="special"><</span> <span class="identifier">unit</span><span class="special"><</span><span class="identifier">Dim</span><span class="special">,</span><span class="identifier">System</span><span class="special">></span> <span class="special">>;</span> 56<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Unit</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">Y</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">get_dimension</span><span class="special"><</span> <span class="identifier">quantity</span><span class="special"><</span><span class="identifier">Unit</span><span class="special">,</span><span class="identifier">Y</span><span class="special">></span> <span class="special">>;</span> 57<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Dim</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">System</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">get_system</span><span class="special"><</span> <span class="identifier">unit</span><span class="special"><</span><span class="identifier">Dim</span><span class="special">,</span><span class="identifier">System</span><span class="special">></span> <span class="special">>;</span> 58<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Unit</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">Y</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">get_system</span> <span class="identifier">quantity</span><span class="special"><</span><span class="identifier">Unit</span><span class="special">,</span><span class="identifier">Y</span><span class="special">></span> <span class="special">>;</span> 59 60<span class="keyword">struct</span> <span class="identifier">dimensionless_type</span><span class="special">;</span> 61<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">System</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">dimensionless_unit</span><span class="special"><</span><span class="identifier">System</span><span class="special">>;</span> 62<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">System</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">Y</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">dimensionless_quantity</span><span class="special"><</span><span class="identifier">System</span><span class="special">,</span><span class="identifier">Y</span><span class="special">>;</span> 63 64<span class="keyword">struct</span> <span class="identifier">implicitly_convertible</span><span class="special">;</span> 65<span class="keyword">struct</span> <span class="identifier">trivial_conversion</span><span class="special">;</span> 66<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">T</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">S1</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">S2</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">base_unit_converter</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span><span class="identifier">S1</span><span class="special">,</span><span class="identifier">S2</span><span class="special">>;</span> 67 68<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Q1</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">Q2</span><span class="special">></span> <span class="keyword">class</span> <span class="identifier">conversion_helper</span><span class="special"><</span><span class="identifier">Q1</span><span class="special">,</span><span class="identifier">Q2</span><span class="special">>;</span> 69</pre> 70</div> 71<div class="section"> 72<div class="titlepage"><div><div><h3 class="title"> 73<a name="boost_units.Utilities.Metaprogramming_Predicates"></a><a class="link" href="Utilities.html#boost_units.Utilities.Metaprogramming_Predicates" title="Metaprogramming Predicates">Metaprogramming 74 Predicates</a> 75</h3></div></div></div> 76<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">,</span><span class="keyword">typename</span> <span class="identifier">V</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_dim</span><span class="special"><</span> <span class="identifier">dim</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span><span class="identifier">V</span><span class="special">></span> <span class="special">>;</span> 77<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">,</span><span class="keyword">typename</span> <span class="identifier">V</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_empty_dim</span><span class="special"><</span> <span class="identifier">dim</span><span class="special"><</span><span class="identifier">T</span><span class="special">,</span><span class="identifier">V</span><span class="special">></span> <span class="special">>;</span> 78 79<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Seq</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_dimension_list</span><span class="special"><</span><span class="identifier">Seq</span><span class="special">>;</span> 80 81<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">S</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_system</span><span class="special"><</span> <span class="identifier">homogeneous_system</span><span class="special"><</span><span class="identifier">S</span><span class="special">></span> <span class="special">>;</span> 82<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">S</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_system</span><span class="special"><</span> <span class="identifier">heterogeneous_system</span><span class="special"><</span><span class="identifier">S</span><span class="special">></span> <span class="special">>;</span> 83<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">S</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_homogeneous_system</span><span class="special"><</span> <span class="identifier">homogeneous_system</span><span class="special"><</span><span class="identifier">S</span><span class="special">></span> <span class="special">>;</span> 84<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">S</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_heterogeneous_system</span><span class="special"><</span> <span class="identifier">heterogeneous_system</span><span class="special"><</span><span class="identifier">S</span><span class="special">></span> <span class="special">>;</span> 85 86<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Dim</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">System</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_unit</span><span class="special"><</span> <span class="identifier">unit</span><span class="special"><</span><span class="identifier">Dim</span><span class="special">,</span><span class="identifier">System</span><span class="special">></span> <span class="special">>;</span> 87<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Dim</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">System</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_unit_of_system</span><span class="special"><</span> <span class="identifier">unit</span><span class="special"><</span><span class="identifier">Dim</span><span class="special">,</span><span class="identifier">System</span><span class="special">>,</span><span class="identifier">System</span> <span class="special">>;</span> 88<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Dim</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">System</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_unit_of_dimension</span><span class="special"><</span> <span class="identifier">unit</span><span class="special"><</span><span class="identifier">Dim</span><span class="special">,</span><span class="identifier">System</span><span class="special">>,</span><span class="identifier">Dim</span> <span class="special">>;</span> 89 90<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Unit</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">Y</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_quantity</span><span class="special"><</span> <span class="identifier">quantity</span><span class="special"><</span><span class="identifier">Unit</span><span class="special">,</span><span class="identifier">Y</span><span class="special">></span> <span class="special">>;</span> 91<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Dim</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">System</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">Y</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_quantity_of_system</span><span class="special"><</span> <span class="identifier">quantity</span><span class="special"><</span><span class="identifier">unit</span><span class="special"><</span><span class="identifier">Dim</span><span class="special">,</span><span class="identifier">System</span><span class="special">>,</span><span class="identifier">Y</span><span class="special">>,</span><span class="identifier">System</span> <span class="special">>;</span> 92<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">Dim</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">System</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">Y</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_quantity_of_dimension</span><span class="special"><</span> <span class="identifier">quantity</span><span class="special"><</span><span class="identifier">unit</span><span class="special"><</span><span class="identifier">Dim</span><span class="special">,</span><span class="identifier">System</span><span class="special">>,</span><span class="identifier">Y</span><span class="special">>,</span><span class="identifier">Dim</span> <span class="special">>;</span> 93 94<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">System</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_dimensionless</span><span class="special"><</span> <span class="identifier">unit</span><span class="special"><</span><span class="identifier">dimensionless_type</span><span class="special">,</span><span class="identifier">System</span><span class="special">></span> <span class="special">>;</span> 95<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">System</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_dimensionless_unit</span><span class="special"><</span> <span class="identifier">unit</span><span class="special"><</span><span class="identifier">dimensionless_type</span><span class="special">,</span><span class="identifier">System</span><span class="special">></span> <span class="special">>;</span> 96<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">System</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">Y</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_dimensionless</span><span class="special"><</span> <span class="identifier">quantity</span><span class="special"><</span><span class="identifier">unit</span><span class="special"><</span><span class="identifier">dimensionless_type</span><span class="special">,</span><span class="identifier">System</span><span class="special">>,</span><span class="identifier">Y</span><span class="special">></span> <span class="special">>;</span> 97<span class="keyword">template</span><span class="special"><</span><span class="keyword">class</span> <span class="identifier">System</span><span class="special">,</span><span class="keyword">class</span> <span class="identifier">Y</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">is_dimensionless_quantity</span><span class="special"><</span> <span class="identifier">quantity</span><span class="special"><</span><span class="identifier">unit</span><span class="special"><</span><span class="identifier">dimensionless_type</span><span class="special">,</span><span class="identifier">System</span><span class="special">>,</span><span class="identifier">Y</span><span class="special">></span> <span class="special">>;</span> 98</pre> 99</div> 100</div> 101<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 102<td align="left"></td> 103<td align="right"><div class="copyright-footer">Copyright © 2003-2008 Matthias Christian Schabel<br>Copyright © 2007-2010 Steven 104 Watanabe<p> 105 Distributed under the Boost Software License, Version 1.0. (See accompanying 106 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>) 107 </p> 108</div></td> 109</tr></table> 110<hr> 111<div class="spirit-nav"> 112<a accesskey="p" href="Examples.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../boost_units.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="Reference.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> 113</div> 114</body> 115</html> 116
