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>Concept Domain</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="proto/reference.html" title="Reference"> 10<link rel="prev" href="CallableTransform.html" title="Concept CallableTransform"> 11<link rel="next" href="Expr.html" title="Concept Expr"> 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="CallableTransform.html"><img src="../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="proto/reference.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="Expr.html"><img src="../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="Domain"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Concept Domain</span></h2> 30<p>Domain</p> 31</div> 32<div class="refsect1"> 33<a name="id-1.3.33.5.60.3"></a><h2>Description</h2> 34<p> 35 A Domain creates an association between expressions and a so-called 36 generator, which is a function that maps an expression in the default 37 domain to an equivalent expression in this Domain. It also associates 38 an expression with a grammar, to which all expressions within this 39 Domain must conform. 40 </p> 41</div> 42<div class="refsect1"> 43<a name="id-1.3.33.5.60.4"></a><h2>Associated types</h2> 44<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 45<li class="listitem"> 46<p><span class="bold"><strong>proto_grammar</strong></span></p> 47<pre class="literallayout">Domain::proto_grammar</pre> 48<p> 49 </p> 50<p>The grammar to which every expression in this Domain 51 must conform.</p> 52<p> 53 </p> 54</li> 55<li class="listitem"> 56<p><span class="bold"><strong>proto_generator</strong></span></p> 57<pre class="literallayout">Domain::proto_generator</pre> 58<p> 59 </p> 60<p> 61 A Unary Polymorphic Function that accepts expressions in the 62 default domain and emits expressions in this Domain. 63 </p> 64<p> 65 </p> 66</li> 67<li class="listitem"> 68<p><span class="bold"><strong>proto_super_domain</strong></span></p> 69<pre class="literallayout">Domain::proto_super_domain</pre> 70<p> 71 </p> 72<p> 73 The Domain that is a super-domain of this domain, if 74 any such domain exists. If not, it is some unspecified 75 type. 76 </p> 77<p> 78 </p> 79</li> 80<li class="listitem"> 81<p><span class="bold"><strong>result_type</strong></span></p> 82<pre class="literallayout">boost::result_of<Domain(Expr)>::type</pre> 83<p> 84 </p> 85<p> 86 The type of the result of applying 87 <code class="computeroutput">proto_generator</code> to 88 the specified expression type. The result is required to 89 model <a class="link" href="Expr.html" title="Concept Expr">Expr</a>. The domain type 90 associated with <code class="computeroutput">result_type</code> 91 (<code class="computeroutput">result_type::proto_domain</code>) 92 is required to be the same type as this Domain. 93 </p> 94<p> 95 </p> 96</li> 97<li class="listitem"> 98<p><span class="bold"><strong>as_expr_result_type</strong></span></p> 99<pre class="literallayout">Domain::as_expr<Object>::result_type</pre> 100<p> 101 </p> 102<p> 103 The result of converting some type to a Proto expression 104 type in this domain. This is used, for instance, when 105 calculating the type of a variable to hold a Proto 106 expression. 107 <code class="computeroutput">as_expr_result_type</code> 108 models 109 <code class="computeroutput"><a class="link" href="Expr.html" title="Concept Expr">Expr</a></code>. 110 </p> 111<p> 112 </p> 113</li> 114<li class="listitem"> 115<p><span class="bold"><strong>as_child_result_type</strong></span></p> 116<pre class="literallayout">Domain::as_child<Object>::result_type</pre> 117<p> 118 </p> 119<p> 120 The result of converting some type to a Proto expression 121 type in this domain. This is used, for instance, to 122 compute the type of an object suitable for storage 123 as a child in an expression tree. 124 <code class="computeroutput">as_child_result_type</code> 125 models 126 <code class="computeroutput"><a class="link" href="Expr.html" title="Concept Expr">Expr</a></code>. 127 </p> 128<p> 129 </p> 130</li> 131</ul></div> 132</div> 133<div class="refsect1"> 134<a name="id-1.3.33.5.60.5"></a><h2>Notation</h2> 135<div class="variablelist"><dl class="variablelist"> 136<dt><span class="term">Domain</span></dt> 137<dd>A type playing the role of domain-type in the <a class="link" href="Domain.html" title="Concept Domain">Domain</a> concept.</dd> 138<dt><span class="term">Expr</span></dt> 139<dd>A type playing the role of expression-type in the <a class="link" href="Domain.html" title="Concept Domain">Domain</a> concept.</dd> 140<dt><span class="term">Object</span></dt> 141<dd>A type playing the role of object-type in the <a class="link" href="Domain.html" title="Concept Domain">Domain</a> concept.</dd> 142<dt><span class="term"><code class="varname">d</code></span></dt> 143<dd>Object of type Domain</dd> 144<dt><span class="term"><code class="varname">e</code></span></dt> 145<dd>Object of type Expr</dd> 146<dt><span class="term"><code class="varname">o</code></span></dt> 147<dd>Object of type Object</dd> 148</dl></div> 149</div> 150<div class="refsect1"> 151<a name="id-1.3.33.5.60.6"></a><h2>Valid expressions</h2> 152<div class="informaltable"><table class="table"> 153<colgroup> 154<col> 155<col> 156<col> 157<col> 158</colgroup> 159<thead><tr> 160<th>Name</th> 161<th>Expression</th> 162<th>Type</th> 163<th>Semantics</th> 164</tr></thead> 165<tbody> 166<tr> 167<td><p>Apply Generator</p></td> 168<td><p>d(e)</p></td> 169<td><p><span class="type">result_type</span></p></td> 170<td><p> 171 The result of applying <code class="computeroutput">proto_generator</code> 172 to the specified expression. 173 </p></td> 174</tr> 175<tr> 176<td><p>As Expression</p></td> 177<td><p>Domain::as_expr< Object >()(o)</p></td> 178<td><p><span class="type">as_expr_result_type</span></p></td> 179<td><p> 180 The result of converting some object to a Proto expression 181 in this domain. It returns a Proto expression object that 182 is suitable for storage in a variable. It should return a 183 new object, which may be a copy of the object passed in. 184 </p></td> 185</tr> 186<tr> 187<td><p>As Child</p></td> 188<td><p>Domain::as_child< Object >()(o)</p></td> 189<td><p><span class="type">as_child_result_type</span></p></td> 190<td><p> 191 The result of converting some object to a Proto expression 192 in this domain. It returns an object suitable for storage 193 as a child in an expression tree, which may simply be a 194 reference to the object passed in. 195 </p></td> 196</tr> 197</tbody> 198</table></div> 199</div> 200<div class="refsect1"> 201<a name="id-1.3.33.5.60.7"></a><h2>Models</h2> 202<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "><li class="listitem"><span class="simplelist"><span class="type">boost::proto::default_domain</span></span></li></ul></div> 203</div> 204</div> 205<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 206<td align="left"></td> 207<td align="right"><div class="copyright-footer">Copyright © 2008 Eric Niebler<p> 208 Distributed under the Boost Software License, Version 1.0. (See accompanying 209 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>) 210 </p> 211</div></td> 212</tr></table> 213<hr> 214<div class="spirit-nav"> 215<a accesskey="p" href="CallableTransform.html"><img src="../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="proto/reference.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="Expr.html"><img src="../../doc/src/images/next.png" alt="Next"></a> 216</div> 217</body> 218</html> 219
