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>Class template apply_visitor_delayed_t</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="../variant/reference.html#header.boost.variant.apply_visitor_hpp" title="Header <boost/variant/apply_visitor.hpp>"> 10<link rel="prev" href="unwrap_recursive_wrapper.html" title="Class template unwrap_recursive_wrapper"> 11<link rel="next" href="apply_visit_1_3_46_5_7_1_2.html" title="Class template apply_visitor_delayed_cpp14_t"> 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="unwrap_recursive_wrapper.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../variant/reference.html#header.boost.variant.apply_visitor_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="apply_visit_1_3_46_5_7_1_2.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> 25</div> 26<div class="refentry"> 27<a name="boost.apply_visitor_delayed_t"></a><div class="titlepage"></div> 28<div class="refnamediv"> 29<h2><span class="refentrytitle">Class template apply_visitor_delayed_t</span></h2> 30<p>boost::apply_visitor_delayed_t — Adapts a visitor for use as a function object.</p> 31</div> 32<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 33<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="../variant/reference.html#header.boost.variant.apply_visitor_hpp" title="Header <boost/variant/apply_visitor.hpp>">boost/variant/apply_visitor.hpp</a>> 34 35</span><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Visitor<span class="special">></span> 36<span class="keyword">class</span> <a class="link" href="apply_visitor_delayed_t.html" title="Class template apply_visitor_delayed_t">apply_visitor_delayed_t</a> <span class="special">{</span> 37<span class="keyword">public</span><span class="special">:</span> 38 <span class="comment">// types</span> 39 <span class="keyword">typedef</span> <span class="keyword">typename</span> <span class="identifier">Visitor</span><span class="special">::</span><span class="identifier">result_type</span> <a name="boost.apply_visitor_delayed_t.result_type"></a><span class="identifier">result_type</span><span class="special">;</span> 40 41 <span class="comment">// <a class="link" href="apply_visitor_delayed_t.html#boost.apply_visitor_delayed_tconstruct-copy-destruct">construct/copy/destruct</a></span> 42 <span class="keyword">explicit</span> <a class="link" href="apply_visitor_delayed_t.html#id-1_3_46_5_7_1_1_5-bb"><span class="identifier">apply_visitor_delayed_t</span></a><span class="special">(</span><span class="identifier">Visitor</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> 43 44 <span class="comment">// <a class="link" href="apply_visitor_delayed_t.html#id-1_3_46_5_7_1_1_6-bb">function object interface</a></span> 45 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> ... Variant<span class="special">></span> <span class="identifier">result_type</span> <a class="link" href="apply_visitor_delayed_t.html#id-1_3_46_5_7_1_1_6_1_1-bb"><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span></a><span class="special">(</span><span class="identifier">Variant</span><span class="special">&</span><span class="special">...</span><span class="special">)</span><span class="special">;</span> 46 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Variant<span class="special">></span> <span class="identifier">result_type</span> <a class="link" href="apply_visitor_delayed_t.html#id-1_3_46_5_7_1_1_6_1_2-bb"><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span></a><span class="special">(</span><span class="identifier">Variant</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> 47 <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Variant1<span class="special">,</span> <span class="keyword">typename</span> Variant2<span class="special">></span> 48 <span class="identifier">result_type</span> <a class="link" href="apply_visitor_delayed_t.html#id-1_3_46_5_7_1_1_6_1_3-bb"><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span></a><span class="special">(</span><span class="identifier">Variant1</span> <span class="special">&</span><span class="special">,</span> <span class="identifier">Variant2</span> <span class="special">&</span><span class="special">)</span><span class="special">;</span> 49<span class="special">}</span><span class="special">;</span></pre></div> 50<div class="refsect1"> 51<a name="id-1.3.46.5.8.3.4"></a><h2>Description</h2> 52<p>Adapts the function given at construction for use as a 53 function object. This is useful, for example, when one needs to 54 operate on each element of a sequence of variant objects using a 55 standard library algorithm such as 56 <code class="computeroutput">std::for_each</code>.</p> 57<p>See the "visitor-only" form of 58 <code class="computeroutput"><a class="link" href="apply_visitor.html" title="Function apply_visitor">apply_visitor</a></code> for a simple 59 way to create <code class="computeroutput">apply_visitor_delayed_t</code> objects.</p> 60<p>See <code class="computeroutput"><a class="link" href="apply_visit_1_3_46_5_7_1_2.html" title="Class template apply_visitor_delayed_cpp14_t">apply_visitor_delayed_cpp14_t</a></code> 61 which is used on C++14 compatible compilers when <code class="computeroutput">Visitor</code> has no 62 <code class="computeroutput">result_type</code> typedef.</p> 63<div class="refsect2"> 64<a name="id-1.3.46.5.8.3.4.5"></a><h3> 65<a name="boost.apply_visitor_delayed_tconstruct-copy-destruct"></a><code class="computeroutput">apply_visitor_delayed_t</code> 66 public 67 construct/copy/destruct</h3> 68<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"> 69<pre class="literallayout"><span class="keyword">explicit</span> <a name="id-1_3_46_5_7_1_1_5-bb"></a><span class="identifier">apply_visitor_delayed_t</span><span class="special">(</span><span class="identifier">Visitor</span> <span class="special">&</span> visitor<span class="special">)</span><span class="special">;</span></pre> 70<div class="variablelist"><table border="0" class="variablelist compact"> 71<colgroup> 72<col align="left" valign="top"> 73<col> 74</colgroup> 75<tbody><tr> 76<td><p><span class="term">Effects:</span></p></td> 77<td>Constructs the function object with the given 78 visitor.</td> 79</tr></tbody> 80</table></div> 81</li></ol></div> 82</div> 83<div class="refsect2"> 84<a name="id-1.3.46.5.8.3.4.6"></a><h3> 85<a name="id-1_3_46_5_7_1_1_6-bb"></a><code class="computeroutput">apply_visitor_delayed_t</code> function object interface</h3> 86<div class="orderedlist"><ol class="orderedlist" type="1"><li class="listitem"> 87<pre class="literallayout"><a name="id-1_3_46_5_7_1_1_6_1-bb"></a><span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> ... Variant<span class="special">></span> <span class="identifier">result_type</span> <a name="id-1_3_46_5_7_1_1_6_1_1-bb"></a><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="identifier">Variant</span><span class="special">&</span><span class="special">...</span> operand<span class="special">)</span><span class="special">;</span> 88<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Variant<span class="special">></span> <span class="identifier">result_type</span> <a name="id-1_3_46_5_7_1_1_6_1_2-bb"></a><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="identifier">Variant</span> <span class="special">&</span> operand<span class="special">)</span><span class="special">;</span> 89<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> Variant1<span class="special">,</span> <span class="keyword">typename</span> Variant2<span class="special">></span> 90 <span class="identifier">result_type</span> <a name="id-1_3_46_5_7_1_1_6_1_3-bb"></a><span class="keyword">operator</span><span class="special">(</span><span class="special">)</span><span class="special">(</span><span class="identifier">Variant1</span> <span class="special">&</span> operand1<span class="special">,</span> <span class="identifier">Variant2</span> <span class="special">&</span> operand2<span class="special">)</span><span class="special">;</span></pre>Function call operator.<p class="simpara">Invokes 91 <code class="computeroutput"><a class="link" href="apply_visitor.html" title="Function apply_visitor">apply_visitor</a></code> on the 92 stored visitor using the given operands.</p> 93<div class="variablelist"><table border="0" class="variablelist compact"> 94<colgroup> 95<col align="left" valign="top"> 96<col> 97</colgroup> 98<tbody><tr> 99<td><p><span class="term">Notes:</span></p></td> 100<td>Version with variadic templates is used by default if 101 <a class="link" href="../BOOST_VARIANT_1_3_46_5_3_4.html" title="Macro BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES">BOOST_VARIANT_DO_NOT_USE_VARIADIC_TEMPLATES</a> is not defined.</td> 102</tr></tbody> 103</table></div> 104</li></ol></div> 105</div> 106</div> 107</div> 108<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 109<td align="left"></td> 110<td align="right"><div class="copyright-footer">Copyright © 2002, 2003 Eric Friedman, Itay Maman<br>Copyright © 2014-2020 Antony Polukhin<p>Distributed under the Boost Software License, Version 1.0. 111 (See accompanying file <code class="filename">LICENSE_1_0.txt</code> or copy at 112 <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 113 </p> 114</div></td> 115</tr></table> 116<hr> 117<div class="spirit-nav"> 118<a accesskey="p" href="unwrap_recursive_wrapper.html"><img src="../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../variant/reference.html#header.boost.variant.apply_visitor_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="apply_visit_1_3_46_5_7_1_2.html"><img src="../../../doc/src/images/next.png" alt="Next"></a> 119</div> 120</body> 121</html> 122
