<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>Concept Domain</title> <link rel="stylesheet" href="../../doc/src/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.2"> <link rel="home" href="index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> <link rel="up" href="proto/reference.html" title="Reference"> <link rel="prev" href="CallableTransform.html" title="Concept CallableTransform"> <link rel="next" href="Expr.html" title="Concept Expr"> </head> <body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> <table cellpadding="2" width="100%"><tr> <td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../boost.png"></td> <td align="center"><a href="../../index.html">Home</a></td> <td align="center"><a href="../../libs/libraries.htm">Libraries</a></td> <td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> <td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> <td align="center"><a href="../../more/index.htm">More</a></td> </tr></table> <hr> <div class="spirit-nav"> <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> </div> <div class="refentry"> <a name="Domain"></a><div class="titlepage"></div> <div class="refnamediv"> <h2><span class="refentrytitle">Concept Domain</span></h2> <p>Domain</p> </div> <div class="refsect1"> <a name="id2466573"></a><h2>Description</h2> <p> A Domain creates an association between expressions and a so-called generator, which is a function that maps an expression in the default domain to an equivalent expression in this Domain. It also associates an expression with a grammar, to which all expressions within this Domain must conform. </p> </div> <div class="refsect1"> <a name="id2466587"></a><h2>Associated types</h2> <div class="itemizedlist"><ul class="itemizedlist" type="disc"> <li class="listitem"> <p><span class="bold"><strong>proto_grammar</strong></span></p> <pre class="literallayout">Domain::proto_grammar</pre> <p> </p> <p>The grammar to which every expression in this Domain must conform.</p> <p> </p> </li> <li class="listitem"> <p><span class="bold"><strong>proto_generator</strong></span></p> <pre class="literallayout">Domain::proto_generator</pre> <p> </p> <p> A Unary Polymorphic Function that accepts expressions in the default domain and emits expressions in this Domain. </p> <p> </p> </li> <li class="listitem"> <p><span class="bold"><strong>proto_super_domain</strong></span></p> <pre class="literallayout">Domain::proto_super_domain</pre> <p> </p> <p> The Domain that is a super-domain of this domain, if any such domain exists. If not, it is some unspecified type. </p> <p> </p> </li> <li class="listitem"> <p><span class="bold"><strong>result_type</strong></span></p> <pre class="literallayout">boost::result_of<Domain(Expr)>::type</pre> <p> </p> <p> The type of the result of applying <code class="computeroutput">proto_generator</code> to the specified expression type. The result is required to model <a class="link" href="Expr.html" title="Concept Expr">Expr</a>. The domain type associated with <code class="computeroutput">result_type</code> (<code class="computeroutput">result_type::proto_domain</code>) is required to be the same type as this Domain. </p> <p> </p> </li> <li class="listitem"> <p><span class="bold"><strong>as_expr_result_type</strong></span></p> <pre class="literallayout">Domain::as_expr<Object>::result_type</pre> <p> </p> <p> The result of converting some type to a Proto expression type in this domain. This is used, for instance, when calculating the type of a variable to hold a Proto expression. <code class="computeroutput">as_expr_result_type</code> models <code class="computeroutput"><a class="link" href="Expr.html" title="Concept Expr">Expr</a></code>. </p> <p> </p> </li> <li class="listitem"> <p><span class="bold"><strong>as_child_result_type</strong></span></p> <pre class="literallayout">Domain::as_child<Object>::result_type</pre> <p> </p> <p> The result of converting some type to a Proto expression type in this domain. This is used, for instance, to compute the type of an object suitable for storage as a child in an expression tree. <code class="computeroutput">as_child_result_type</code> models <code class="computeroutput"><a class="link" href="Expr.html" title="Concept Expr">Expr</a></code>. </p> <p> </p> </li> </ul></div> </div> <div class="refsect1"> <a name="id2466779"></a><h2>Notation</h2> <div class="variablelist"><dl> <dt><span class="term">Domain</span></dt> <dd>A type playing the role of domain-type in the <a class="link" href="Domain.html" title="Concept Domain">Domain</a> concept.</dd> <dt><span class="term">Expr</span></dt> <dd>A type playing the role of expression-type in the <a class="link" href="Domain.html" title="Concept Domain">Domain</a> concept.</dd> <dt><span class="term">Object</span></dt> <dd>A type playing the role of object-type in the <a class="link" href="Domain.html" title="Concept Domain">Domain</a> concept.</dd> <dt><span class="term"><code class="varname">d</code></span></dt> <dd>Object of type Domain</dd> <dt><span class="term"><code class="varname">e</code></span></dt> <dd>Object of type Expr</dd> <dt><span class="term"><code class="varname">o</code></span></dt> <dd>Object of type Object</dd> </dl></div> </div> <div class="refsect1"> <a name="id2466852"></a><h2>Valid expressions</h2> <div class="informaltable"><table class="table"> <colgroup> <col> <col> <col> <col> </colgroup> <thead><tr> <th>Name</th> <th>Expression</th> <th>Type</th> <th>Semantics</th> </tr></thead> <tbody> <tr> <td><p>Apply Generator</p></td> <td><p>d(e)</p></td> <td><p><span class="type">result_type</span></p></td> <td><p> The result of applying <code class="computeroutput">proto_generator</code> to the specified expression. </p></td> </tr> <tr> <td><p>As Expression</p></td> <td><p>Domain::as_expr< Object >()(o)</p></td> <td><p><span class="type">as_expr_result_type</span></p></td> <td><p> The result of converting some object to a Proto expression in this domain. It returns a Proto expression object that is suitable for storage in a variable. It should return a new object, which may be a copy of the object passed in. </p></td> </tr> <tr> <td><p>As Child</p></td> <td><p>Domain::as_child< Object >()(o)</p></td> <td><p><span class="type">as_child_result_type</span></p></td> <td><p> The result of converting some object to a Proto expression in this domain. It returns an object suitable for storage as a child in an expression tree, which may simply be a reference to the object passed in. </p></td> </tr> </tbody> </table></div> </div> <div class="refsect1"> <a name="id2466936"></a><h2>Models</h2> <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"><span class="simplelist"><span class="type">boost::proto::default_domain</span></span></li></ul></div> </div> </div> <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> <td align="left"></td> <td align="right"><div class="copyright-footer">Copyright © 2008 Eric Niebler<p> Distributed under the Boost Software License, Version 1.0. (See accompanying 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>) </p> </div></td> </tr></table> <hr> <div class="spirit-nav"> <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> </div> </body> </html>