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27 <a name="boost.proto.as_child_idp704447440"></a><div class="titlepage"></div>
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29 <h2><span class="refentrytitle">Function as_child</span></h2>
30 <p>boost::proto::as_child — A function that wraps non-Proto objects in Proto terminals (by reference) and leaves
31 Proto expression types alone.</p>
33 <h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2>
34 <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.traits_hpp" title="Header <boost/proto/traits.hpp>">boost/proto/traits.hpp</a>>
37 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span>
38 <span class="keyword">typename</span> <a class="link" href="result_of/as_child.html" title="Struct template as_child">proto::result_of::as_child</a><span class="special"><</span> <span class="identifier">T</span> <span class="special">></span><span class="special">::</span><span class="identifier">type</span> <span class="identifier">as_child</span><span class="special">(</span><span class="identifier">T</span> <span class="special">&</span> t<span class="special">)</span><span class="special">;</span>
39 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> T<span class="special">></span>
40 <span class="keyword">typename</span> <a class="link" href="result_of/as_child.html" title="Struct template as_child">proto::result_of::as_child</a><span class="special"><</span> <span class="identifier">T</span> <span class="keyword">const</span> <span class="special">></span><span class="special">::</span><span class="identifier">type</span> <span class="identifier">as_child</span><span class="special">(</span><span class="identifier">T</span> <span class="keyword">const</span> <span class="special">&</span> t<span class="special">)</span><span class="special">;</span>
41 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../../Domain.html" title="Concept Domain">Domain</a><span class="special">,</span> <span class="keyword">typename</span> T<span class="special">></span>
42 <span class="keyword">typename</span> <a class="link" href="result_of/as_child.html" title="Struct template as_child">proto::result_of::as_child</a><span class="special"><</span> <span class="identifier">T</span><span class="special">,</span> <span class="identifier">Domain</span> <span class="special">></span><span class="special">::</span><span class="identifier">type</span> <span class="identifier">as_child</span><span class="special">(</span><span class="identifier">T</span> <span class="special">&</span> t<span class="special">)</span><span class="special">;</span>
43 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <a class="link" href="../../Domain.html" title="Concept Domain">Domain</a><span class="special">,</span> <span class="keyword">typename</span> T<span class="special">></span>
44 <span class="keyword">typename</span> <a class="link" href="result_of/as_child.html" title="Struct template as_child">proto::result_of::as_child</a><span class="special"><</span> <span class="identifier">T</span> <span class="keyword">const</span><span class="special">,</span> <span class="identifier">Domain</span> <span class="special">></span><span class="special">::</span><span class="identifier">type</span>
45 <span class="identifier">as_child</span><span class="special">(</span><span class="identifier">T</span> <span class="keyword">const</span> <span class="special">&</span> t<span class="special">)</span><span class="special">;</span></pre></div>
46 <div class="refsect1">
47 <a name="idp478528000"></a><h2>Description</h2>
49 The <code class="computeroutput">proto::as_child()</code> function returns Proto expression
50 objects that are suitable for storage as child nodes in an expression tree. It turns
51 non-Proto objects into Proto terminals. Its behavior is domain-specific. By default,
52 non-Proto types are held wrapped by reference in a new Proto terminal expression, and
53 objects that are already Proto expressions are simply returned by reference.
56 If <code class="computeroutput">Domain</code> is not explicitly specified, it is assumed to
57 be <code class="computeroutput"><code class="computeroutput"><a class="link" href="default_domain.html" title="Struct default_domain">proto::default_domain</a></code></code>.
60 See <code class="computeroutput"><code class="computeroutput"><a class="link" href="domain/as_child.html" title="Struct template as_child">proto::domain::as_child</a></code><></code>
61 for a complete description of this function's default behavior.
63 <div class="variablelist"><table border="0" class="variablelist compact">
65 <col align="left" valign="top">
69 <td><p><span class="term">Returns:</span></p></td>
70 <td><code class="computeroutput">typename Domain::template as_child< T >()(t)</code></td>
75 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
76 <td align="left"></td>
77 <td align="right"><div class="copyright-footer">Copyright © 2008 Eric Niebler<p>
78 Distributed under the Boost Software License, Version 1.0. (See accompanying
79 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>)
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