1<?xml version="1.0" encoding="utf-8" ?> 2<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> 3<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> 4<head> 5<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> 6<meta name="generator" content="Docutils 0.7: http://docutils.sourceforge.net/" /> 7<title>The MPL Reference Manual: unpack_args</title> 8<link rel="stylesheet" href="../style.css" type="text/css" /> 9</head> 10<body class="docframe refmanual"> 11<table class="header"><tr class="header"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./apply-wrap.html" class="navigation-link">Prev</a> <a href="./composition-and-argument-binding.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./apply-wrap.html" class="navigation-link">Back</a> Along</span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./invocation.html" class="navigation-link">Up</a> <a href="../refmanual.html" class="navigation-link">Home</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./refmanual_toc.html" class="navigation-link">Full TOC</a></span></td> 12<td class="header-group page-location"><a href="../refmanual.html" class="navigation-link">Front Page</a> / <a href="./metafunctions.html" class="navigation-link">Metafunctions</a> / <a href="./invocation.html" class="navigation-link">Invocation</a> / <a href="./unpack-args.html" class="navigation-link">unpack_args</a></td> 13</tr></table><div class="header-separator"></div> 14<div class="section" id="unpack-args"> 15<h1><a class="toc-backref" href="./invocation.html#id1527">unpack_args</a></h1> 16<div class="section" id="id901"> 17<h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3> 18<pre class="literal-block"> 19template< 20 typename F 21 > 22struct <a href="./unpack-args.html" class="identifier">unpack_args</a> 23{ 24 // <em>unspecified</em> 25 // <em>...</em> 26}; 27</pre> 28</div> 29<div class="section" id="id902"> 30<h3><a class="subsection-title" href="#description" name="description">Description</a></h3> 31<p>A higher-order primitive transforming an <em>n</em>-ary <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a> <tt class="literal"><span class="pre">F</span></tt> into 32an unary <a class="reference internal" href="./metafunction-class.html">Metafunction Class</a> <tt class="literal"><span class="pre">g</span></tt> accepting a single sequence of <em>n</em> arguments.</p> 33</div> 34<div class="section" id="id903"> 35<h3><a class="subsection-title" href="#header" name="header">Header</a></h3> 36<pre class="literal-block"> 37#include <<a href="../../../../boost/mpl/unpack_args.hpp" class="header">boost/mpl/unpack_args.hpp</a>> 38</pre> 39</div> 40<div class="section" id="id904"> 41<h3><a class="subsection-title" href="#model-of" name="model-of">Model of</a></h3> 42<p><a class="reference internal" href="./metafunction-class.html">Metafunction Class</a></p> 43</div> 44<div class="section" id="id905"> 45<h3><a class="subsection-title" href="#parameters" name="parameters">Parameters</a></h3> 46<table border="1" class="docutils table"> 47<colgroup> 48<col width="19%" /> 49<col width="28%" /> 50<col width="53%" /> 51</colgroup> 52<thead valign="bottom"> 53<tr><th class="head">Parameter</th> 54<th class="head">Requirement</th> 55<th class="head">Description</th> 56</tr> 57</thead> 58<tbody valign="top"> 59<tr><td><tt class="literal"><span class="pre">F</span></tt></td> 60<td><a class="reference internal" href="./lambda-expression.html">Lambda Expression</a></td> 61<td>A lambda expression to adopt.</td> 62</tr> 63</tbody> 64</table> 65</div> 66<div class="section" id="id906"> 67<h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3> 68<p>For an arbitrary <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a> <tt class="literal"><span class="pre">f</span></tt>, and arbitrary types <tt class="literal"><span class="pre">a1</span></tt>,... <tt class="literal"><span class="pre">an</span></tt>:</p> 69<pre class="literal-block"> 70typedef <a href="./unpack-args.html" class="identifier">unpack_args</a><f> g; 71</pre> 72<table class="docutils field-list" frame="void" rules="none"> 73<col class="field-name" /> 74<col class="field-body" /> 75<tbody valign="top"> 76<tr class="field"><th class="field-name">Return type:</th><td class="field-body"><p class="first"><a class="reference internal" href="./metafunction-class.html">Metafunction Class</a>.</p> 77</td> 78</tr> 79<tr class="field"><th class="field-name">Semantics:</th><td class="field-body"><p class="first"><tt class="literal"><span class="pre">g</span></tt> is a unary <a class="reference internal" href="./metafunction-class.html">Metafunction Class</a> such that</p> 80<pre class="literal-block"> 81<a href="./apply-wrap.html" class="identifier">apply_wrap</a><em>n</em>< g, <a href="./vector.html" class="identifier">vector</a><a1,<em>...</em>a<em>n</em>> >::type 82</pre> 83<p>is identical to</p> 84<pre class="last literal-block"> 85<a href="./apply.html" class="identifier">apply</a><F,a1,<em>...</em>a<em>n</em>>::type 86</pre> 87</td> 88</tr> 89</tbody> 90</table> 91</div> 92<div class="section" id="id907"> 93<h3><a class="subsection-title" href="#example" name="example">Example</a></h3> 94<pre class="literal-block"> 95<a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( <a href="./apply.html" class="identifier">apply</a>< 96 <a href="./unpack-args.html" class="identifier">unpack_args</a>< is_same<<a href="./placeholders.html" class="identifier">_1</a>,<a href="./placeholders.html" class="identifier">_2</a>> > 97 , <a href="./vector.html" class="identifier">vector</a><int,int> 98 > )); 99</pre> 100</div> 101<div class="section" id="id908"> 102<h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3> 103<p><a class="reference internal" href="./metafunctions.html">Metafunctions</a>, <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a>, <a class="reference internal" href="./metafunction-class.html">Metafunction Class</a>, <a class="reference internal" href="./apply.html">apply</a>, <a class="reference internal" href="./apply-wrap.html">apply_wrap</a>, <a class="reference internal" href="./bind.html">bind</a></p> 104</div> 105</div> 106 107<div class="footer-separator"></div> 108<table class="footer"><tr class="footer"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./apply-wrap.html" class="navigation-link">Prev</a> <a href="./composition-and-argument-binding.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./apply-wrap.html" class="navigation-link">Back</a> Along</span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./invocation.html" class="navigation-link">Up</a> <a href="../refmanual.html" class="navigation-link">Home</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./refmanual_toc.html" class="navigation-link">Full TOC</a></span></td> 109<td><div class="copyright-footer"><div class="copyright">Copyright © 2001-2009 Aleksey Gurtovoy and David Abrahams</div> 110Distributed under the Boost Software License, Version 1.0. (See accompanying 111file LICENSE_1_0.txt or copy at <a class="reference external" href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)</div></td></tr></table></body> 112</html> 113