feedc0de/boost_fusion
1
0
Fork 0
forked from boostorg/fusion
Code Pull Requests Activity
Files
4b061d27167d7253376fbb2da7629e1154a02141
boost_fusion/doc/html/fusion/algorithms/iteration/functions/accumulate.html
Joel de Guzman 6ca462baa0 doc updates 
[SVN r35784]
2006-10-30 01:20:23 +00:00

158 lines
13 KiB
HTML
Raw Blame History

This file contains invisible Unicode characters

This file contains invisible Unicode characters that are indistinguishable to humans but may be processed differently by a computer. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
<title>accumulate</title>
<link rel="stylesheet" href="../../../../boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.66.1">
<link rel="start" href="../../../../index.html" title="Chapter 1. Fusion 2.0">
<link rel="up" href="../functions.html" title="Functions">
<link rel="prev" href="fold.html" title="fold">
<link rel="next" href="for_each.html" title="for_each">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%">
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../../boost.png"></td>
<td align="center"><a href="../../../../../../../../index.htm">Home</a></td>
<td align="center"><a href="../../../../../../../libraries.htm">Libraries</a></td>
<td align="center"><a href="../../../../../../../../people/people.htm">People</a></td>
<td align="center"><a href="../../../../../../../../more/faq.htm">FAQ</a></td>
<td align="center"><a href="../../../../../../../../more/index.htm">More</a></td>
</table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="fold.html"><img src="../../../../images/prev.png" alt="Prev"></a><a accesskey="u" href="../functions.html"><img src="../../../../images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../images/home.png" alt="Home"></a><a accesskey="n" href="for_each.html"><img src="../../../../images/next.png" alt="Next"></a>
</div>
<div class="section" lang="en">
<div class="titlepage"><div><div><h5 class="title">
<a name="fusion.algorithms.iteration.functions.accumulate"></a><a href="accumulate.html" title="accumulate">accumulate</a></h5></div></div></div>
<a name="fusion.algorithms.iteration.functions.accumulate.description"></a><h6>
<a name="id551708"></a>
<a href="accumulate.html#fusion.algorithms.iteration.functions.accumulate.description">Description</a>
</h6>
<p>
Repeatedly applies binary <a href="../../concepts/polymorphic_function_object.html" title="Polymorphic
Function Object">Polymorphic
Function Object</a> <tt class="computeroutput"><span class="identifier">f</span></tt>
to each element of a sequence and the previous state. <a href="accumulate.html" title="accumulate"><tt class="computeroutput"><span class="identifier">accumulate</span></tt></a> is equivalent to
<a href="fold.html" title="fold"><tt class="computeroutput"><span class="identifier">fold</span></tt></a>.
</p>
<a name="fusion.algorithms.iteration.functions.accumulate.synopsis"></a><h6>
<a name="id551792"></a>
<a href="accumulate.html#fusion.algorithms.iteration.functions.accumulate.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">Sequence</span><span class="special">,</span>
<span class="keyword">typename</span> <span class="identifier">State</span><span class="special">,</span>
<span class="keyword">typename</span> <span class="identifier">F</span>
<span class="special">&gt;</span>
<span class="keyword">typename</span> <a href="../metafunctions/accumulate.html" title="accumulate"><tt class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">accumulate</span></tt></a><span class="special">&lt;</span><span class="identifier">Sequence</span><span class="special">,</span> <span class="identifier">State</span><span class="special">,</span> <span class="identifier">F</span><span class="special">&gt;::</span><span class="identifier">type</span> <span class="identifier">accumulate</span><span class="special">(</span>
<span class="identifier">Sequence</span><span class="special">&amp;</span> <span class="identifier">seq</span><span class="special">,</span> <span class="identifier">State</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">initial_state</span><span class="special">,</span> <span class="identifier">F</span> <span class="keyword">const</span><span class="special">&amp;</span> <span class="identifier">f</span><span class="special">);</span>
</pre>
<div class="table">
<a name="id552052"></a><p class="title"><b>Table 1.33. Parameters</b></p>
<table class="table" summary="Parameters">
<colgroup>
<col>
<col>
<col>
</colgroup>
<thead><tr>
<th>Parameter</th>
<th>Requirement</th>
<th>Description</th>
</tr></thead>
<tbody>
<tr>
<td><tt class="computeroutput"><span class="identifier">seq</span></tt></td>
<td>A
model of <a href="../../../sequences/concepts/forward_sequence.html" title="Forward
Sequence">Forward
Sequence</a>, <tt class="computeroutput"><span class="identifier">f</span><span class="special">(</span><span class="identifier">eN</span> <span class="special">....</span><span class="identifier">f</span><span class="special">(</span><span class="identifier">e2</span><span class="special">,</span><span class="identifier">f</span><span class="special">(</span><span class="identifier">e1</span><span class="special">,</span><span class="identifier">initial_state</span><span class="special">)))</span></tt> must be a valid expression for
each element <tt class="computeroutput"><span class="identifier">e1</span></tt> to
<tt class="computeroutput"><span class="identifier">eN</span></tt> in <tt class="computeroutput"><span class="identifier">seq</span></tt>
</td>
<td>Operation's argument</td>
</tr>
<tr>
<td><tt class="computeroutput"><span class="identifier">initial_state</span></tt></td>
<td>Any
type</td>
<td>Initial state</td>
</tr>
<tr>
<td><tt class="computeroutput"><span class="identifier">f</span></tt></td>
<td>A
model of binary <a href="../../concepts/polymorphic_function_object.html" title="Polymorphic
Function Object">Polymorphic
Function Object</a>
</td>
<td>Operation's argument</td>
</tr>
</tbody>
</table>
</div>
<a name="fusion.algorithms.iteration.functions.accumulate.expression_semantics"></a><h6>
<a name="id552284"></a>
<a href="accumulate.html#fusion.algorithms.iteration.functions.accumulate.expression_semantics">Expression
Semantics</a>
</h6>
<pre class="programlisting">
<span class="identifier">accumulate</span><span class="special">(</span><span class="identifier">seq</span><span class="special">,</span> <span class="identifier">initial_state</span><span class="special">,</span> <span class="identifier">f</span><span class="special">);</span>
</pre>
<p>
<span class="bold"><b>Return type</b></span>: Any type
</p>
<p>
<span class="bold"><b>Semantics</b></span>: Equivalent to <tt class="computeroutput"><span class="identifier">f</span><span class="special">(</span><span class="identifier">eN</span> <span class="special">....</span><span class="identifier">f</span><span class="special">(</span><span class="identifier">e2</span><span class="special">,</span><span class="identifier">f</span><span class="special">(</span><span class="identifier">e1</span><span class="special">,</span><span class="identifier">initial_state</span><span class="special">)))</span></tt>
where <tt class="computeroutput"><span class="identifier">e1</span> <span class="special">...</span><span class="identifier">eN</span></tt> are the elements of <tt class="computeroutput"><span class="identifier">seq</span></tt>.
</p>
<a name="fusion.algorithms.iteration.functions.accumulate.complexity"></a><h6>
<a name="id552490"></a>
<a href="accumulate.html#fusion.algorithms.iteration.functions.accumulate.complexity">Complexity</a>
</h6>
<p>
Linear, exactly <tt class="computeroutput"><a href="../../../sequences/intrinsics/metafunctions/size.html" title="size"><tt class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">size</span></tt></a><span class="special">&lt;</span><span class="identifier">Sequence</span><span class="special">&gt;::</span><span class="identifier">value</span></tt> applications of <tt class="computeroutput"><span class="identifier">f</span></tt>.
</p>
<a name="fusion.algorithms.iteration.functions.accumulate.header"></a><h6>
<a name="id552582"></a>
<a href="accumulate.html#fusion.algorithms.iteration.functions.accumulate.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">algorithm</span><span class="special">/</span><span class="identifier">iteration</span><span class="special">/</span><span class="identifier">accumulate</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span>
</pre>
<a name="fusion.algorithms.iteration.functions.accumulate.example"></a><h6>
<a name="id552688"></a>
<a href="accumulate.html#fusion.algorithms.iteration.functions.accumulate.example">Example</a>
</h6>
<pre class="programlisting">
<span class="keyword">struct</span> <span class="identifier">make_string</span>
<span class="special">{</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">State</span><span class="special">&gt;</span>
<span class="keyword">struct</span> <span class="identifier">apply</span>
<span class="special">{</span>
<span class="keyword">typedef</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="identifier">type</span><span class="special">;</span>
<span class="special">};</span>
<span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">&gt;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="keyword">operator</span><span class="special">()(</span><span class="keyword">const</span> <span class="identifier">T</span><span class="special">&amp;</span> <span class="identifier">t</span><span class="special">,</span> <span class="keyword">const</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&amp;</span> <span class="identifier">str</span><span class="special">)</span> <span class="keyword">const</span>
<span class="special">{</span>
<span class="keyword">return</span> <span class="identifier">str</span> <span class="special">+</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">lexical_cast</span><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&gt;(</span><span class="identifier">t</span><span class="special">);</span>
<span class="special">}</span>
<span class="special">};</span>
<span class="special">...</span>
<span class="keyword">const</span> <a href="../../../sequences/containers/vector.html" title="vector"><tt class="computeroutput"><span class="identifier">vector</span></tt></a><span class="special">&lt;</span><span class="keyword">int</span><span class="special">,</span><span class="keyword">int</span><span class="special">&gt;</span> <span class="identifier">vec</span><span class="special">(</span><span class="number">1</span><span class="special">,</span><span class="number">2</span><span class="special">);</span>
<span class="identifier">assert</span><span class="special">(</span><a href="accumulate.html" title="accumulate"><tt class="computeroutput"><span class="identifier">accumulate</span></tt></a><span class="special">(</span><span class="identifier">vec</span><span class="special">,</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">(</span><span class="string">""</span><span class="special">),</span> <span class="identifier">make_string</span><span class="special">())</span> <span class="special">==</span> <span class="string">"12"</span><span class="special">);</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"><small>Copyright © 2001-2005 Joel de Guzman, Dan Marsden</small></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="fold.html"><img src="../../../../images/prev.png" alt="Prev"></a><a accesskey="u" href="../functions.html"><img src="../../../../images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../images/home.png" alt="Home"></a><a accesskey="n" href="for_each.html"><img src="../../../../images/next.png" alt="Next"></a>
</div>
</body>
</html>
View Git Blame Copy Permalink