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>Struct template expression</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="../../yap/reference.html#header.boost.yap.expression_hpp" title="Header <boost/yap/expression.hpp>"> 10<link rel="prev" href="../../BOOST_NO_CONSTEXPR_IF.html" title="Macro BOOST_NO_CONSTEXPR_IF"> 11<link rel="next" href="express_1_3_48_8_2_5_1_1_2.html" title="Struct template expression<expr_kind::terminal, hana::tuple< T >>"> 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 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alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.yap.expression"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Struct template expression</span></h2> 30<p>boost::yap::expression</p> 31</div> 32<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 33<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../yap/reference.html#header.boost.yap.expression_hpp" title="Header <boost/yap/expression.hpp>">boost/yap/expression.hpp</a>> 34 35</span><span class="keyword">template</span><span class="special"><</span><span class="identifier">expr_kind</span> Kind<span class="special">,</span> <span class="keyword">typename</span> Tuple<span class="special">></span> 36<span class="keyword">struct</span> <a class="link" href="expression.html" title="Struct template expression">expression</a> <span class="special">{</span> 37 <span class="comment">// types</span> 38 <span class="keyword">typedef</span> <span class="identifier">Tuple</span> <a name="boost.yap.expression.tuple_type"></a><span class="identifier">tuple_type</span><span class="special">;</span> 39 40 <span class="comment">// <a class="link" href="expression.html#boost.yap.expressionconstruct-copy-destruct">construct/copy/destruct</a></span> 41 <a class="link" href="expression.html#id-1_3_48_8_2_5_1_1_1_7-bb"><span class="identifier">expression</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 42 <a class="link" href="expression.html#id-1_3_48_8_2_5_1_1_1_8-bb"><span class="identifier">expression</span></a><span class="special">(</span><span class="identifier">tuple_type</span> <span class="special">&&</span><span class="special">)</span><span class="special">;</span> 43 44 <span class="comment">// <a class="link" href="expression.html#id-1_3_48_8_2_5_1_1_1_6-bb">public member functions</a></span> 45 <span class="keyword">decltype</span><span class="special">(</span><span class="keyword">auto</span><span class="special">)</span> <span class="keyword">constexpr</span> <a class="link" href="expression.html#id-1_3_48_8_2_5_1_1_1_6_1-bb"><span class="identifier">value</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 46 <span class="keyword">decltype</span><span class="special">(</span><span class="keyword">auto</span><span class="special">)</span> <span class="keyword">constexpr</span> <a class="link" href="expression.html#id-1_3_48_8_2_5_1_1_1_6_2-bb"><span class="identifier">left</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 47 <span class="keyword">decltype</span><span class="special">(</span><span class="keyword">auto</span><span class="special">)</span> <span class="keyword">constexpr</span> <a class="link" href="expression.html#id-1_3_48_8_2_5_1_1_1_6_3-bb"><span class="identifier">right</span></a><span class="special">(</span><span class="special">)</span><span class="special">;</span> 48 49 <span class="comment">// public data members</span> 50 <span class="keyword">static</span> <span class="keyword">const</span> <span class="identifier">expr_kind</span> <span class="identifier">kind</span><span class="special">;</span> 51 <span class="identifier">tuple_type</span> <span class="identifier">elements</span><span class="special">;</span> 52<span class="special">}</span><span class="special">;</span></pre></div> 53<div class="refsect1"> 54<a name="id-1.3.48.8.2.5.3.4"></a><h2>Description</h2> 55<p>Reference expression template that provides all operator overloads.</p> 56<div class="note"><table border="0" summary="Note"> 57<tr> 58<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../doc/src/images/note.png"></td> 59<th align="left">Note</th> 60</tr> 61<tr><td align="left" valign="top"> 62<p>Due to a limitation of Doxygen, each of the <code class="computeroutput">value()</code>, <code class="computeroutput">left()</code>, <code class="computeroutput">right()</code>, and operator overloads listed here is a stand-in for three member functions. For each function <code class="computeroutput">f</code>, the listing here is: </p> 63<pre class="programlisting"><span class="identifier">return_type</span> <span class="identifier">f</span> <span class="special">(</span><span class="special">)</span><span class="special">;</span> 64</pre> 65<p> However, there are actually three functions: </p> 66<pre class="programlisting"><span class="identifier">return_type</span> <span class="identifier">f</span> <span class="special">(</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">&</span><span class="special">;</span> 67<span class="identifier">return_type</span> <span class="identifier">f</span> <span class="special">(</span><span class="special">)</span> <span class="special">&</span><span class="special">;</span> 68<span class="identifier">return_type</span> <span class="identifier">f</span> <span class="special">(</span><span class="special">)</span> <span class="special">&&</span><span class="special">;</span> 69</pre> 70<p> </p> 71</td></tr> 72</table></div> 73<p> 74</p> 75<div class="refsect2"> 76<a name="id-1.3.48.8.2.5.3.4.4"></a><h3> 77<a name="boost.yap.expressionconstruct-copy-destruct"></a><code class="computeroutput">expression</code> 78 public 79 construct/copy/destruct</h3> 80<div class="orderedlist"><ol class="orderedlist" type="1"> 81<li class="listitem"> 82<pre class="literallayout"><a name="id-1_3_48_8_2_5_1_1_1_7-bb"></a><span class="identifier">expression</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 83<p>Default constructor. Does nothing. </p> 84</li> 85<li class="listitem"> 86<pre class="literallayout"><a name="id-1_3_48_8_2_5_1_1_1_8-bb"></a><span class="identifier">expression</span><span class="special">(</span><span class="identifier">tuple_type</span> <span class="special">&&</span> rhs<span class="special">)</span><span class="special">;</span></pre> 87<p>Moves <span class="emphasis"><em>rhs</em></span> into the only data mamber, <code class="computeroutput">elements</code>. </p> 88</li> 89</ol></div> 90</div> 91<div class="refsect2"> 92<a name="id-1.3.48.8.2.5.3.4.5"></a><h3> 93<a name="id-1_3_48_8_2_5_1_1_1_6-bb"></a><code class="computeroutput">expression</code> public member functions</h3> 94<div class="orderedlist"><ol class="orderedlist" type="1"> 95<li class="listitem"> 96<pre class="literallayout"><span class="keyword">decltype</span><span class="special">(</span><span class="keyword">auto</span><span class="special">)</span> <span class="keyword">constexpr</span> <a name="id-1_3_48_8_2_5_1_1_1_6_1-bb"></a><span class="identifier">value</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 97<p>A convenience member function that dispatches to the free function <code class="computeroutput">value()</code>. </p> 98</li> 99<li class="listitem"> 100<pre class="literallayout"><span class="keyword">decltype</span><span class="special">(</span><span class="keyword">auto</span><span class="special">)</span> <span class="keyword">constexpr</span> <a name="id-1_3_48_8_2_5_1_1_1_6_2-bb"></a><span class="identifier">left</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 101<p>A convenience member function that dispatches to the free function <code class="computeroutput">left()</code>. </p> 102</li> 103<li class="listitem"> 104<pre class="literallayout"><span class="keyword">decltype</span><span class="special">(</span><span class="keyword">auto</span><span class="special">)</span> <span class="keyword">constexpr</span> <a name="id-1_3_48_8_2_5_1_1_1_6_3-bb"></a><span class="identifier">right</span><span class="special">(</span><span class="special">)</span><span class="special">;</span></pre> 105<p>A convenience member function that dispatches to the free function <code class="computeroutput">right()</code>. </p> 106</li> 107</ol></div> 108</div> 109</div> 110</div> 111<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 112<td align="left"></td> 113<td align="right"><div class="copyright-footer">Copyright © 2018 T. Zachary Laine<p> 114 Distributed under the Boost Software License, Version 1.0. (See accompanying 115 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>) 116 </p> 117</div></td> 118</tr></table> 119<hr> 120<div class="spirit-nav"> 121<a accesskey="p" href="../../BOOST_NO_CONSTEXPR_IF.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../yap/reference.html#header.boost.yap.expression_hpp"><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="express_1_3_48_8_2_5_1_1_2.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 122</div> 123</body> 124</html> 125
