doc/html/boost/proto/_byref.html


1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132

<!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 _byref</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.arg_hpp" title="Header &lt;boost/proto/transform/arg.hpp&gt;">
<link rel="prev" href="_void/impl.html" title="Struct template impl">
<link rel="next" href="_byref/result_T_idm46563224224928.html" title="Struct template result&lt;This(T &amp;)&gt;">
</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="_void/impl.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../proto/reference.html#header.boost.proto.transform.arg_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="_byref/result_T_idm46563224224928.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a>
</div>
<div class="refentry">
<a name="boost.proto._byref"></a><div class="titlepage"></div>
<div class="refnamediv">
<h2><span class="refentrytitle">Struct _byref</span></h2>
<p>boost::proto::_byref &#8212; A unary callable <a class="link" href="../../PolymorphicFunctionObject.html" title="Concept PolymorphicFunctionObject">PolymorphicFunctionObject</a> that wraps its argument
          in a <code class="computeroutput">boost::reference_wrapper&lt;&gt;</code>.</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: &lt;<a class="link" href="../../proto/reference.html#header.boost.proto.transform.arg_hpp" title="Header &lt;boost/proto/transform/arg.hpp&gt;">boost/proto/transform/arg.hpp</a>&gt;

</span>
<span class="keyword">struct</span> <a class="link" href="_byref.html" title="Struct _byref">_byref</a> <span class="special">:</span> <span class="keyword"></span> <a class="link" href="callable.html" title="Struct callable">proto::callable</a> <span class="special">{</span>
  <span class="comment">// member classes/structs/unions</span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> This<span class="special">,</span> <span class="keyword">typename</span> T<span class="special">&gt;</span> 
  <span class="keyword">struct</span> <a class="link" href="_byref/result_T_idm46563224224928.html" title="Struct template result&lt;This(T &amp;)&gt;">result</a><span class="special">&lt;</span><span class="identifier">This</span><span class="special">(</span><span class="identifier">T</span> <span class="special">&amp;</span><span class="special">)</span><span class="special">&gt;</span> <span class="special">{</span>
    <span class="comment">// types</span>
    <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">reference_wrapper</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="special">&gt;</span> <span class="keyword">const</span> <a class="link" href="_byref/result_T_idm46563224224928.html#boost.proto._byref.result_T_idm46563224224928.type"><span class="identifier">type</span></a><span class="special">;</span>
  <span class="special">}</span><span class="special">;</span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> This<span class="special">,</span> <span class="keyword">typename</span> T<span class="special">&gt;</span> 
  <span class="keyword">struct</span> <a class="link" href="_byref/result_T_idm46563224220560.html" title="Struct template result&lt;This(T)&gt;">result</a><span class="special">&lt;</span><span class="identifier">This</span><span class="special">(</span><span class="identifier">T</span><span class="special">)</span><span class="special">&gt;</span> <span class="special">{</span>
    <span class="comment">// types</span>
    <span class="keyword">typedef</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">reference_wrapper</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="keyword">const</span>  <span class="special">&gt;</span> <span class="keyword">const</span> <a class="link" href="_byref/result_T_idm46563224220560.html#boost.proto._byref.result_T_idm46563224220560.type"><span class="identifier">type</span></a><span class="special">;</span>
  <span class="special">}</span><span class="special">;</span>

  <span class="comment">// <a class="link" href="_byref.html#idm46563224216176-bb">public member functions</a></span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> 
    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">reference_wrapper</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="special">&gt;</span> <span class="keyword">const</span> <a class="link" href="_byref.html#idm46563224215616-bb"><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span></a><span class="special">(</span><span class="identifier">T</span> <span class="special">&amp;</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
  <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> 
    <span class="identifier">boost</span><span class="special">::</span><span class="identifier">reference_wrapper</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="keyword">const</span> <span class="special">&gt;</span> <span class="keyword">const</span> <a class="link" href="_byref.html#idm46563224207024-bb"><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span></a><span class="special">(</span><span class="identifier">T</span> <span class="keyword">const</span> <span class="special">&amp;</span><span class="special">)</span> <span class="keyword">const</span><span class="special">;</span>
<span class="special">}</span><span class="special">;</span></pre></div>
<div class="refsect1">
<a name="idm45927826730864"></a><h2>Description</h2>
<p>
            Example:
            </p>
<pre class="programlisting"><a class="link" href="terminal.html" title="Struct template terminal">proto::terminal</a><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;</span><span class="special">::</span><span class="identifier">type</span> <span class="identifier">i</span> <span class="special">=</span> <span class="special">{</span><span class="number">42</span><span class="special">}</span><span class="special">;</span>
<span class="identifier">boost</span><span class="special">::</span><span class="identifier">reference_wrapper</span><span class="special">&lt;</span><a class="link" href="terminal.html" title="Struct template terminal">proto::terminal</a><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;</span><span class="special">::</span><span class="identifier">type</span><span class="special">&gt;</span> <span class="identifier">j</span>
  <span class="special">=</span> <a class="link" href="when.html" title="Struct template when">proto::when</a><span class="special">&lt;</span><a class="link" href="_.html" title="Struct _">proto::_</a><span class="special">,</span> <span class="identifier">proto</span><span class="special">::</span><span class="identifier">_byref</span><span class="special">(</span><span class="identifier">_</span><span class="special">)</span><span class="special">&gt;</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="identifier">i</span><span class="special">)</span><span class="special">;</span>
<span class="identifier">assert</span><span class="special">(</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">addressof</span><span class="special">(</span><span class="identifier">i</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">addressof</span><span class="special">(</span><span class="identifier">j</span><span class="special">.</span><span class="identifier">get</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 class="refsect2">
<a name="idm45927826693248"></a><h3>
<a name="idm46563224216176-bb"></a><code class="computeroutput">_byref</code> public member functions</h3>
<div class="orderedlist"><ol class="orderedlist" type="1">
<li class="listitem">
<pre class="literallayout"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> 
  <span class="identifier">boost</span><span class="special">::</span><span class="identifier">reference_wrapper</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="special">&gt;</span> <span class="keyword">const</span> <a name="idm46563224215616-bb"></a><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="identifier">T</span> <span class="special">&amp;</span> t<span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<p>
                Wrap the parameter <code class="computeroutput">t</code> in a
                <code class="computeroutput">boost::reference_wrapper&lt;&gt;</code>
              </p>
<div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody>
<tr>
<td><p><span class="term">Parameters:</span></p></td>
<td><div class="variablelist"><table border="0" class="variablelist compact">
<colgroup>
<col align="left" valign="top">
<col>
</colgroup>
<tbody><tr>
<td><p><span class="term"><code class="computeroutput">t</code></span></p></td>
<td><p>The object to wrap </p></td>
</tr></tbody>
</table></div></td>
</tr>
<tr>
<td><p><span class="term">Returns:</span></p></td>
<td><p>
                <code class="computeroutput">boost::ref(t)</code>
              </p></td>
</tr>
<tr>
<td><p><span class="term">Throws:</span></p></td>
<td>Will not throw.</td>
</tr>
</tbody>
</table></div>
</li>
<li class="listitem">
<pre class="literallayout"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> T<span class="special">&gt;</span> 
  <span class="identifier">boost</span><span class="special">::</span><span class="identifier">reference_wrapper</span><span class="special">&lt;</span> <span class="identifier">T</span> <span class="keyword">const</span> <span class="special">&gt;</span> <span class="keyword">const</span> <a name="idm46563224207024-bb"></a><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="identifier">T</span> <span class="keyword">const</span> <span class="special">&amp;</span> t<span class="special">)</span> <span class="keyword">const</span><span class="special">;</span></pre>
<p>This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. </p>
</li>
</ol></div>
</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 &#169; 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="_void/impl.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../proto/reference.html#header.boost.proto.transform.arg_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="_byref/result_T_idm46563224224928.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>