blob: 6b155584bcee76a0af06826f246347101a80241e [file] [log] [blame]
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>front</title>
<link rel="stylesheet" href="../../../../../../../../doc/src/boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.75.2">
<link rel="home" href="../../../../index.html" title="Chapter&#160;1.&#160;Fusion 2.0">
<link rel="up" href="../metafunctions.html" title="Metafunctions">
<link rel="prev" href="empty.html" title="empty">
<link rel="next" href="back.html" title="back">
</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="empty.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../metafunctions.html"><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="back.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h5 class="title">
<a name="fusion.sequence.intrinsic.metafunctions.front"></a><a class="link" href="front.html" title="front">front</a>
</h5></div></div></div>
<a name="fusion.sequence.intrinsic.metafunctions.front.description"></a><h6>
<a name="id890304"></a>
<a class="link" href="front.html#fusion.sequence.intrinsic.metafunctions.front.description">Description</a>
</h6>
<p>
Returns the result type of <a class="link" href="../functions/front.html" title="front"><code class="computeroutput"><span class="identifier">front</span></code></a>.
</p>
<a name="fusion.sequence.intrinsic.metafunctions.front.synopsis"></a><h6>
<a name="id890333"></a>
<a class="link" href="front.html#fusion.sequence.intrinsic.metafunctions.front.synopsis">Synopsis</a>
</h6>
<pre class="programlisting"><span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Seq</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">front</span>
<span class="special">{</span>
<span class="keyword">typedef</span> <span class="emphasis"><em>unspecified</em></span> <span class="identifier">type</span><span class="special">;</span>
<span class="special">};</span>
</pre>
<div class="table">
<a name="id890403"></a><p class="title"><b>Table&#160;1.26.&#160;Parameters</b></p>
<div class="table-contents"><table class="table" summary="Parameters">
<colgroup>
<col>
<col>
<col>
</colgroup>
<thead><tr>
<th>
<p>
Parameter
</p>
</th>
<th>
<p>
Requirement
</p>
</th>
<th>
<p>
Description
</p>
</th>
</tr></thead>
<tbody><tr>
<td>
<p>
<code class="computeroutput"><span class="identifier">Seq</span></code>
</p>
</td>
<td>
<p>
A model of <a class="link" href="../../concepts/forward_sequence.html" title="Forward Sequence">Forward
Sequence</a>
</p>
</td>
<td>
<p>
Argument sequence
</p>
</td>
</tr></tbody>
</table></div>
</div>
<br class="table-break"><a name="fusion.sequence.intrinsic.metafunctions.front.expression_semantics"></a><h6>
<a name="id890490"></a>
<a class="link" href="front.html#fusion.sequence.intrinsic.metafunctions.front.expression_semantics">Expression
Semantics</a>
</h6>
<pre class="programlisting"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">front</span><span class="special">&lt;</span><span class="identifier">Seq</span><span class="special">&gt;::</span><span class="identifier">type</span>
</pre>
<p>
<span class="bold"><strong>Return type</strong></span>: Any type
</p>
<p>
<span class="bold"><strong>Semantics</strong></span>: The type returned by dereferencing
an iterator to the first element in <code class="computeroutput"><span class="identifier">Seq</span></code>.
Equivalent to <code class="computeroutput"><a class="link" href="../../../iterator/metafunctions/deref.html" title="deref"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">deref</span></code></a><span class="special">&lt;</span><a class="link" href="begin.html" title="begin"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">begin</span></code></a><span class="special">&lt;</span><span class="identifier">Seq</span><span class="special">&gt;::</span><span class="identifier">type</span><span class="special">&gt;::</span><span class="identifier">type</span></code>.
</p>
<a name="fusion.sequence.intrinsic.metafunctions.front.header"></a><h6>
<a name="id890618"></a>
<a class="link" href="front.html#fusion.sequence.intrinsic.metafunctions.front.header">Header</a>
</h6>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">sequence</span><span class="special">/</span><span class="identifier">intrinsic</span><span class="special">/</span><span class="identifier">front</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
<span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">fusion</span><span class="special">/</span><span class="identifier">include</span><span class="special">/</span><span class="identifier">front</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
</pre>
<a name="fusion.sequence.intrinsic.metafunctions.front.example"></a><h6>
<a name="id890733"></a>
<a class="link" href="front.html#fusion.sequence.intrinsic.metafunctions.front.example">Example</a>
</h6>
<pre class="programlisting"><span class="keyword">typedef</span> <a class="link" href="../../../container/vector.html" title="vector"><code class="computeroutput"><span class="identifier">vector</span></code></a><span class="special">&lt;</span><span class="keyword">int</span><span class="special">,</span><span class="keyword">char</span><span class="special">&gt;</span> <span class="identifier">vec</span><span class="special">;</span>
<span class="identifier">BOOST_MPL_ASSERT</span><span class="special">((</span><span class="identifier">boost</span><span class="special">::</span><span class="identifier">is_same</span><span class="special">&lt;</span><a class="link" href="front.html" title="front"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">front</span></code></a><span class="special">&lt;</span><span class="identifier">vec</span><span class="special">&gt;::</span><span class="identifier">type</span><span class="special">,</span> <span class="keyword">int</span><span class="special">&amp;&gt;));</span>
</pre>
</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; 2001-2007 Joel de Guzman, Dan Marsden, Tobias
Schwinger<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="empty.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../metafunctions.html"><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="back.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>