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diff --git a/doc/html/boost/proto/when_Grammar__idp714285760.html b/doc/html/boost/proto/when_Grammar__idp714285760.html new file mode 100644 index 0000000000..b2c5487039 --- /dev/null +++ b/doc/html/boost/proto/when_Grammar__idp714285760.html @@ -0,0 +1,93 @@ +<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> +<html> +<head> +<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> +<title>Struct template when<Grammar, proto::external_transform></title> +<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> +<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> +<link rel="home" href="../../index.html" title="The Boost C++ Libraries BoostBook Documentation Subset"> +<link rel="up" href="../../proto/reference.html#header.boost.proto.transform.when_hpp" title="Header <boost/proto/transform/when.hpp>"> +<link rel="prev" href="when_Grammar__idp714242928/impl.html" title="Struct 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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="when_Grammar__idp714285760/impl.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> +</div> +<div class="refentry"> +<a name="boost.proto.when_Grammar,_idp714285760"></a><div class="titlepage"></div> +<div class="refnamediv"> +<h2><span class="refentrytitle">Struct template when<Grammar, proto::external_transform></span></h2> +<p>boost::proto::when<Grammar, > — A grammar element that associates an externally-specified transform with the grammar. + The transform is looked up in the Data parameter using the Grammar as a key.</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.transform.when_hpp" title="Header <boost/proto/transform/when.hpp>">boost/proto/transform/when.hpp</a>> + +</span><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Grammar<span class="special">></span> +<span class="keyword">struct</span> <a class="link" href="when_Grammar__idp714285760.html" title="Struct template when<Grammar, proto::external_transform>">when</a><span class="special"><</span><span class="identifier">Grammar</span><span class="special">,</span> <a class="link" href="external_transform.html" title="Struct external_transform">proto::external_transform</a><span class="special">></span> <span class="special">:</span> + <span class="keyword"></span> + <a class="link" href="transform.html" title="Struct template transform">proto::transform</a>< when<Grammar, <a class="link" href="external_transform.html" title="Struct external_transform">proto::external_transform</a>> > +<span class="special">{</span> + <span class="comment">// types</span> + <span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">Grammar</span><span class="special">::</span><span class="identifier">proto_grammar</span> <a name="boost.proto.when_Grammar,_idp714285760.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="when_Grammar__idp714285760/impl.html" title="Struct template impl">impl</a> <span class="special">:</span> <span class="keyword"></span> + <span class="identifier">boost</span><span class="special">::</span><span class="identifier">remove_reference</span><span class="special"><</span> + <span class="keyword">typename</span> <span class="identifier">mpl</span><span class="special">::</span><span class="identifier">eval_if_c</span><span class="special"><</span> + <a class="link" href="result_of/has_env_var.html" title="Struct template has_env_var">proto::result_of::has_env_var</a><span class="special"><</span><span class="identifier">Data</span><span class="special">,</span> <a class="link" href="transforms_type.html" title="Struct transforms_type">proto::transforms_type</a><span class="special">></span><span class="special">::</span><span class="identifier">value</span><span class="special">,</span> + <a class="link" href="result_of/env_var.html" title="Struct template env_var">proto::result_of::env_var</a><span class="special"><</span><span class="identifier">Data</span><span class="special">,</span> <a class="link" href="transforms_type.html" title="Struct transforms_type">proto::transforms_type</a><span class="special">></span><span class="special">,</span> + <a class="link" href="result_of/env_var.html" title="Struct template env_var">proto::result_of::env_var</a><span class="special"><</span><span class="identifier">Data</span><span class="special">,</span> <a class="link" href="data_type.html" title="Struct data_type">proto::data_type</a><span class="special">></span> + <span class="special">></span><span class="special">::</span><span class="identifier">type</span> + <span class="special">></span><span class="special">::</span><span class="identifier">type</span> + <span class="special">::</span><span class="keyword">template</span> <span class="identifier">when</span><span class="special"><</span> <span class="identifier">Grammar</span> <span class="special">></span> + <span class="special">::</span><span class="keyword">template</span> <span class="identifier">impl</span><span class="special"><</span> <span class="identifier">Expr</span><span class="special">,</span> <span class="identifier">State</span><span class="special">,</span> <span class="identifier">Data</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></div> +<div class="refsect1"> +<a name="idp487814864"></a><h2>Description</h2> +<p> + Use <code class="computeroutput">proto::when<></code> to override a grammar's default + transform with a custom transform. It is for use when composing larger transforms by associating + smaller transforms with individual rules in your grammar. + </p> +<p> + The <code class="computeroutput">when<G, <a class="link" href="external_transform.html" title="Struct external_transform">proto::external_transform</a>></code> + indicates that the associated transform is not yet known. It should be looked up when the transform + is about to be applied. It is found by looking it up in the passed-in Data parameter, which + behaves like a compile-time map from grammar types to transform types. The map is indexed using + <code class="computeroutput">Grammar</code> as a key. The associated value type is used as the transform + to apply. In this way, the same grammar can be used to define multiple evaluating strategies that + can be added post-hoc. + </p> +<p> + See <code class="computeroutput"><a class="link" href="external_transforms.html" title="Struct template external_transforms">proto::external_transforms</a></code> for an example. + </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="when_Grammar__idp714242928/impl.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../proto/reference.html#header.boost.proto.transform.when_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="when_Grammar__idp714285760/impl.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> +</div> +</body> +</html> |