diff options
Diffstat (limited to 'doc/html/boost/proto/_.html')
| -rwxr-xr-x | doc/html/boost/proto/_.html | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/doc/html/boost/proto/_.html b/doc/html/boost/proto/_.html new file mode 100755 index 0000000000..df261a266e --- /dev/null +++ b/doc/html/boost/proto/_.html @@ -0,0 +1,106 @@ +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Struct _</title> +<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.76.1"> +<link rel="home" href="../../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../../proto/reference.html#header.boost.proto.matches_hpp" title="Header <boost/proto/matches.hpp>"> +<link rel="prev" href="unpack_expr_id1504094.html" title="Function unpack_expr"> +<link rel="next" href="_/impl.html" title="Struct template impl"> +</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="unpack_expr_id1504094.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../proto/reference.html#header.boost.proto.matches_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="_/impl.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="refentry"> +<a name="boost.proto._"></a><div class="titlepage"></div> +<div class="refnamediv"> +<h2><span class="refentrytitle">Struct _</span></h2> +<p>boost::proto::_ — A wildcard grammar element that matches any expression, and a transform that returns + the current expression unchanged.</p> +</div> +<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> +<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.matches_hpp" title="Header <boost/proto/matches.hpp>">boost/proto/matches.hpp</a>> + +</span> +<span class="keyword">struct</span> <a class="link" href="_.html" title="Struct _">_</a> <span class="special">:</span> <span class="keyword"></span> <a class="link" href="transform.html" title="Struct template transform">proto::transform</a><_> <span class="special">{</span> + <span class="comment">// types</span> + <span class="keyword">typedef</span> <span class="identifier">_</span> <a name="boost.proto._.proto_grammar"></a><span class="identifier">proto_grammar</span><span class="special">;</span> + + <span class="comment">// member classes/structs/unions</span> + <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../../Expr.html" title="Concept Expr">Expr</a><span class="special">,</span> <span class="keyword">typename</span> State<span class="special">,</span> <span class="keyword">typename</span> Data<span class="special">></span> + <span class="keyword">struct</span> <a class="link" href="_/impl.html" title="Struct template impl">impl</a> <span class="special">:</span> <span class="keyword"></span> <a class="link" href="transform_impl.html" title="Struct template transform_impl">proto::transform_impl</a><Expr, State, Data> <span class="special">{</span> + <span class="comment">// types</span> + <span class="keyword">typedef</span> <span class="identifier">Expr</span> <a class="link" href="_/impl.html#boost.proto._.impl.result_type"><span class="identifier">result_type</span></a><span class="special">;</span> + + <span class="comment">// <a class="link" href="_/impl.html#id1504602-bb">public member functions</a></span> + <span class="identifier">Expr</span> <a class="link" href="_/impl.html#id1504607-bb"><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span></a><span class="special">(</span><span class="keyword">typename</span> <span class="identifier">impl</span><span class="special">::</span><span class="identifier">expr_param</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">impl</span><span class="special">::</span><span class="identifier">state_param</span><span class="special">,</span> + <span class="keyword">typename</span> <span class="identifier">impl</span><span class="special">::</span><span class="identifier">data_param</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span> + <span class="special">}</span><span class="special">;</span> +<span class="special">}</span><span class="special">;</span></pre></div> +<div class="refsect1"> +<a name="id2757708"></a><h2>Description</h2> +<p> + The wildcard type, <code class="computeroutput">proto::_</code>, is a grammar element such + that <code class="computeroutput"><a class="link" href="matches.html" title="Struct template matches">proto::matches</a><E, proto::_>::value</code> + is <code class="computeroutput">true</code> for any expression type <code class="computeroutput">E</code>. + </p> +<p> + The wildcard can also be used as a stand-in for a template argument when matching terminals. + For instance, the following is a grammar that will match any + <code class="computeroutput">std::complex<></code> terminal:</p> +<pre class="programlisting"><span class="identifier">BOOST_MPL_ASSERT</span><span class="special">(</span><span class="special">(</span> + <a class="link" href="matches.html" title="Struct template matches">proto::matches</a><span class="special"><</span> + <a class="link" href="terminal.html" title="Struct template terminal">proto::terminal</a><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">complex</span><span class="special"><</span><span class="keyword">double</span><span class="special">></span> <span class="special">></span><span class="special">::</span><span class="identifier">type</span><span class="special">,</span> + <span class="bold"><strong><a class="link" href="terminal.html" title="Struct template terminal">proto::terminal</a><span class="special"><</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">complex</span><span class="special"><</span> <span class="identifier">proto</span><span class="special">::</span><span class="identifier">_</span> <span class="special">></span> <span class="special">></span></strong></span> + <span class="special">></span> +<span class="special">)</span><span class="special">)</span><span class="special">;</span></pre> +<p> + </p> +<p> + When used as a transform, <code class="computeroutput">proto::_</code> returns the current expression + unchanged. For instance, in the following, <code class="computeroutput">proto::_</code> is used with + the <code class="computeroutput"><a class="link" href="fold.html" title="Struct template fold">proto::fold<></a></code> + transform to fold the children of a node:</p> +<pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">CountChildren</span> <span class="special">:</span> + <a class="link" href="or_.html" title="Struct template or_">proto::or_</a><span class="special"><</span> + <span class="comment">// Terminals have no children</span> + <a class="link" href="when.html" title="Struct template when">proto::when</a><span class="special"><</span><a class="link" href="terminal.html" title="Struct template terminal">proto::terminal</a><span class="special"><</span><span class="identifier">proto</span><span class="special">::</span><span class="identifier">_</span><span class="special">></span><span class="special">,</span> <span class="identifier">mpl</span><span class="special">::</span><span class="identifier">int_</span><span class="special"><</span><span class="number">0</span><span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">></span><span class="special">,</span> + <span class="comment">// Use proto::fold<> to count the children of non-terminals</span> + <a class="link" href="otherwise.html" title="Struct template otherwise">proto::otherwise</a><span class="special"><</span> + <a class="link" href="fold.html" title="Struct template fold">proto::fold</a><span class="special"><</span> + <span class="identifier">proto</span><span class="special">::</span><span class="identifier">_</span><span class="special">,</span> <span class="comment">// <-- fold the current expression</span> + <span class="identifier">mpl</span><span class="special">::</span><span class="identifier">int_</span><span class="special"><</span><span class="number">0</span><span class="special">></span><span class="special">(</span><span class="special">)</span><span class="special">,</span> + <span class="identifier">mpl</span><span class="special">::</span><span class="identifier">plus</span><span class="special"><</span><a class="link" href="_state.html" title="Struct _state">proto::_state</a><span class="special">,</span> <span class="identifier">mpl</span><span class="special">::</span><span class="identifier">int_</span><span class="special"><</span><span class="number">1</span><span class="special">></span> <span class="special">></span><span class="special">(</span><span class="special">)</span> + <span class="special">></span> + <span class="special">></span> + <span class="special">></span> +<span class="special">{</span><span class="special">}</span><span class="special">;</span></pre> +<p> + </p> +</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="unpack_expr_id1504094.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../proto/reference.html#header.boost.proto.matches_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="_/impl.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> |