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>Macro BOOST_PROTO_BASIC_EXTENDS</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#header.boost.proto.extends_hpp" title="Header <boost/proto/extends.hpp>"> 10<link rel="prev" href="BOOST_PROTO_EXTENDS.html" title="Macro BOOST_PROTO_EXTENDS"> 11<link rel="next" href="BOOST_PROTO_EXTENDS_ASSIGN.html" title="Macro BOOST_PROTO_EXTENDS_ASSIGN"> 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="BOOST_PROTO_EXTENDS.html"><img src="../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="proto/reference.html#header.boost.proto.extends_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="BOOST_PROTO_EXTENDS_ASSIGN.html"><img src="../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="BOOST_PROTO_BASIC_EXTENDS"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Macro BOOST_PROTO_BASIC_EXTENDS</span></h2> 30<p>BOOST_PROTO_BASIC_EXTENDS — For creating expression wrappers that add members to a Proto expression template, like 31 <code class="computeroutput"><a class="link" href="boost/proto/extends.html" title="Struct template extends">proto::extends<></a></code>, 32 but while retaining POD-ness of the expression wrapper.</p> 33</div> 34<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 35<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="proto/reference.html#header.boost.proto.extends_hpp" title="Header <boost/proto/extends.hpp>">boost/proto/extends.hpp</a>> 36 37</span>BOOST_PROTO_BASIC_EXTENDS(Expr, Derived, Domain)</pre></div> 38<div class="refsect1"> 39<a name="id-1.3.33.5.12.8.4"></a><h2>Description</h2> 40<p> 41 <code class="computeroutput">BOOST_PROTO_BASIC_EXTENDS()</code> adds the basic typedefs, member functions, and 42 data members necessary to make a struct a valid Proto expression extension. It does <span class="emphasis"><em>not</em></span> 43 add any constructors, virtual functions or access control blocks that would render the containing 44 struct non-POD. 45 </p> 46<p> 47 <code class="computeroutput">Expr</code> is the Proto expression that the enclosing struct extends. 48 <code class="computeroutput">Derived</code> is the type of the enclosing struct. 49 <code class="computeroutput">Domain</code> is the Proto domain to which this expression extension belongs. 50 (See <code class="computeroutput"><a class="link" href="boost/proto/domain.html" title="Struct template domain">proto::domain<></a></code>.) 51 Can be preceeded with "<code class="computeroutput">typename</code>" if the specified domain is a dependent type. 52 </p> 53<p><code class="computeroutput">BOOST_PROTO_BASIC_EXTENDS()</code> adds to its enclosing struct 54 exactly one data member of type <code class="computeroutput">Expr</code>. 55 </p> 56<p>If the <code class="computeroutput">Domain</code> parameter is dependent, you can specify it as 57 <code class="computeroutput">typename Domain</code>, as in 58 <code class="computeroutput">BOOST_PROTO_BASIC_EXTENDS(Expr, Derived, typename Domain)</code> 59 </p> 60<p> 61 <span class="bold"><strong>Example:</strong></span></p> 62<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> <span class="keyword">class</span> <span class="identifier">Expr</span> <span class="special">></span> 63<span class="keyword">struct</span> <span class="identifier">my_expr</span><span class="special">;</span> 64 65<span class="keyword">struct</span> <span class="identifier">my_domain</span> 66 <span class="special">:</span> <a class="link" href="boost/proto/domain.html" title="Struct template domain">proto::domain</a><span class="special"><</span> <a class="link" href="boost/proto/pod_generator.html" title="Struct template pod_generator">proto::pod_generator</a><span class="special"><</span> <span class="identifier">my_expr</span> <span class="special">></span> <span class="special">></span> 67<span class="special">{</span><span class="special">}</span><span class="special">;</span> 68 69<span class="keyword">template</span><span class="special"><</span> <span class="keyword">class</span> <span class="identifier">Expr</span> <span class="special">></span> 70<span class="keyword">struct</span> <span class="identifier">my_expr</span> 71<span class="special">{</span> 72 <span class="comment">// OK, this makes my_expr<> a valid Proto expression extension.</span> 73 <span class="comment">// my_expr<> does /not/ have overloaded assignment, subscript,</span> 74 <span class="comment">// and function call operators that build expression templates, however.</span> 75 <a class="link" href="BOOST_PROTO_BASIC_EXTENDS.html" title="Macro BOOST_PROTO_BASIC_EXTENDS">BOOST_PROTO_BASIC_EXTENDS</a><span class="special">(</span><span class="identifier">Expr</span><span class="special">,</span> <span class="identifier">my_expr</span><span class="special">,</span> <span class="identifier">my_domain</span><span class="special">)</span> 76<span class="special">}</span><span class="special">;</span> 77 78<span class="comment">// OK, my_expr<> is POD, so this is statically initialized:</span> 79<span class="identifier">my_expr</span><span class="special"><</span> <a class="link" href="boost/proto/terminal.html" title="Struct template terminal">proto::terminal</a><span class="special"><</span><span class="keyword">int</span><span class="special">></span><span class="special">::</span><span class="identifier">type</span> <span class="special">></span> <span class="keyword">const</span> <span class="identifier">_1</span> <span class="special">=</span> <span class="special">{</span><span class="special">{</span><span class="number">1</span><span class="special">}</span><span class="special">}</span><span class="special">;</span></pre> 80<p> 81 </p> 82<p> 83 See also: 84 </p> 85<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 86<li class="listitem"><code class="computeroutput"><a class="link" href="BOOST_PROTO_EXTENDS_ASSIGN.html" title="Macro BOOST_PROTO_EXTENDS_ASSIGN">BOOST_PROTO_EXTENDS_ASSIGN</a>()</code></li> 87<li class="listitem"><code class="computeroutput"><a class="link" href="BOOST_PROTO__1_3_33_5_10_7.html" title="Macro BOOST_PROTO_EXTENDS_SUBSCRIPT">BOOST_PROTO_EXTENDS_SUBSCRIPT</a>()</code></li> 88<li class="listitem"><code class="computeroutput"><a class="link" href="BOOST_PROTO__1_3_33_5_10_6.html" title="Macro BOOST_PROTO_EXTENDS_FUNCTION">BOOST_PROTO_EXTENDS_FUNCTION</a>()</code></li> 89<li class="listitem"><code class="computeroutput"><a class="link" href="BOOST_PROTO_EXTENDS.html" title="Macro BOOST_PROTO_EXTENDS">BOOST_PROTO_EXTENDS</a>()</code></li> 90</ul></div> 91<p> 92 </p> 93</div> 94</div> 95<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 96<td align="left"></td> 97<td align="right"><div class="copyright-footer">Copyright © 2008 Eric Niebler<p> 98 Distributed under the Boost Software License, Version 1.0. (See accompanying 99 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>) 100 </p> 101</div></td> 102</tr></table> 103<hr> 104<div class="spirit-nav"> 105<a accesskey="p" href="BOOST_PROTO_EXTENDS.html"><img src="../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="proto/reference.html#header.boost.proto.extends_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="BOOST_PROTO_EXTENDS_ASSIGN.html"><img src="../../doc/src/images/next.png" alt="Next"></a> 106</div> 107</body> 108</html> 109
