<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>transform</title> <link rel="stylesheet" href="../../../../../../../../doc/html/boostbook.css" type="text/css"> <meta name="generator" content="DocBook XSL Stylesheets V1.75.1"> <link rel="home" href="../../../../index.html" title="Chapter 1. Fusion 2.0"> <link rel="up" href="../functions.html" title="Functions"> <link rel="prev" href="filter_if.html" title="filter_if"> <link rel="next" href="replace.html" title="replace"> </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="../../../../../../../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="filter_if.html"><img src="../../../../../../../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="../functions.html"><img src="../../../../../../../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="replace.html"><img src="../../../../../../../../doc/html/images/next.png" alt="Next"></a> </div> <div class="section" title="transform"> <div class="titlepage"><div><div><h5 class="title"> <a name="fusion.algorithm.transformation.functions.transform"></a><a class="link" href="transform.html" title="transform">transform</a> </h5></div></div></div> <a name="fusion.algorithm.transformation.functions.transform.description"></a><h6> <a name="id768323"></a> <a class="link" href="transform.html#fusion.algorithm.transformation.functions.transform.description">Description</a> </h6> <p> For a sequence <code class="computeroutput"><span class="identifier">seq</span></code> and function object or function pointer <code class="computeroutput"><span class="identifier">f</span></code>, <code class="computeroutput"><span class="identifier">transform</span></code> returns a new sequence with elements created by applying <code class="computeroutput"><span class="identifier">f</span><span class="special">(</span><span class="identifier">e</span><span class="special">)</span></code> to each element of <code class="computeroutput"><span class="identifier">e</span></code> of <code class="computeroutput"><span class="identifier">seq</span></code>. </p> <a name="fusion.algorithm.transformation.functions.transform.unary_version_synopsis"></a><h6> <a name="id768396"></a> <a class="link" href="transform.html#fusion.algorithm.transformation.functions.transform.unary_version_synopsis">Unary version synopsis</a> </h6> <pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> <span class="keyword">typename</span> <span class="identifier">Sequence</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">F</span> <span class="special">></span> <span class="keyword">typename</span> <a class="link" href="../metafunctions/transform.html" title="transform"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">transform</span></code></a><span class="special"><</span><span class="identifier">Sequence</span> <span class="keyword">const</span><span class="special">,</span> <span class="identifier">F</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">transform</span><span class="special">(</span> <span class="identifier">Sequence</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">seq</span><span class="special">,</span> <span class="identifier">F</span> <span class="identifier">f</span><span class="special">);</span> </pre> <div class="table"> <a name="id768538"></a><p class="title"><b>Table 1.59. 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="../../../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward Sequence</a> </p> </td> <td> <p> Operation's argument </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">f</span></code> </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">f</span><span class="special">(</span><span class="identifier">e</span><span class="special">)</span></code> is a valid expression for each element <code class="computeroutput"><span class="identifier">e</span></code> of <code class="computeroutput"><span class="identifier">seq</span></code>. <code class="computeroutput"><a href="http://www.boost.org/libs/utility/utility.htm#result_of" target="_top"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">result_of</span></code></a><span class="special"><</span><span class="identifier">F</span><span class="special">(</span><span class="identifier">E</span><span class="special">)>::</span><span class="identifier">type</span></code> is the return type of <code class="computeroutput"><span class="identifier">f</span></code> when called with a value of each element type <code class="computeroutput"><span class="identifier">E</span></code>. </p> </td> <td> <p> Transformation function </p> </td> </tr> </tbody> </table></div> </div> <br class="table-break"><a name="fusion.algorithm.transformation.functions.transform.expression_semantics"></a><h6> <a name="id768741"></a> <a class="link" href="transform.html#fusion.algorithm.transformation.functions.transform.expression_semantics">Expression Semantics</a> </h6> <pre class="programlisting"><a class="link" href="transform.html" title="transform"><code class="computeroutput"><span class="identifier">transform</span></code></a><span class="special">(</span><span class="identifier">seq</span><span class="special">,</span> <span class="identifier">f</span><span class="special">);</span> </pre> <p> <span class="bold"><strong>Return type</strong></span>: A model of <a class="link" href="../../../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward Sequence</a> </p> <p> <span class="bold"><strong>Semantics</strong></span>: Returns a new sequence, containing the return values of <code class="computeroutput"><span class="identifier">f</span><span class="special">(</span><span class="identifier">e</span><span class="special">)</span></code> for each element <code class="computeroutput"><span class="identifier">e</span></code> within <code class="computeroutput"><span class="identifier">seq</span></code>. </p> <a name="fusion.algorithm.transformation.functions.transform.binary_version_synopsis"></a><h6> <a name="id768841"></a> <a class="link" href="transform.html#fusion.algorithm.transformation.functions.transform.binary_version_synopsis">Binary version synopsis</a> </h6> <pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> <span class="keyword">typename</span> <span class="identifier">Sequence1</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Sequence2</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">F</span> <span class="special">></span> <span class="keyword">typename</span> <a class="link" href="../metafunctions/transform.html" title="transform"><code class="computeroutput"><span class="identifier">result_of</span><span class="special">::</span><span class="identifier">transform</span></code></a><span class="special"><</span><span class="identifier">Sequence1</span> <span class="keyword">const</span><span class="special">,</span> <span class="identifier">Sequence2</span> <span class="keyword">const</span><span class="special">,</span> <span class="identifier">F</span><span class="special">>::</span><span class="identifier">type</span> <span class="identifier">transform</span><span class="special">(</span> <span class="identifier">Sequence1</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">seq1</span><span class="special">,</span> <span class="identifier">Sequence2</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">seq2</span><span class="special">,</span> <span class="identifier">F</span> <span class="identifier">f</span><span class="special">);</span> </pre> <div class="table"> <a name="id769030"></a><p class="title"><b>Table 1.60. 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">seq1</span></code> </p> </td> <td> <p> A model of <a class="link" href="../../../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward Sequence</a> </p> </td> <td> <p> Operation's argument </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">seq2</span></code> </p> </td> <td> <p> A model of <a class="link" href="../../../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward Sequence</a> </p> </td> <td> <p> Operation's argument </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">f</span></code> </p> </td> <td> <p> <code class="computeroutput"><span class="identifier">f</span><span class="special">(</span><span class="identifier">e1</span><span class="special">,</span><span class="identifier">e2</span><span class="special">)</span></code> is a valid expression for each pair of elements <code class="computeroutput"><span class="identifier">e1</span></code> of <code class="computeroutput"><span class="identifier">seq1</span></code> and <code class="computeroutput"><span class="identifier">e2</span></code> of <code class="computeroutput"><span class="identifier">seq2</span></code>. <code class="computeroutput"><a href="http://www.boost.org/libs/utility/utility.htm#result_of" target="_top"><code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">result_of</span></code></a><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">E2</span><span class="special">)>::</span><span class="identifier">type</span></code> is the return type of <code class="computeroutput"><span class="identifier">f</span></code> when called with elements of type <code class="computeroutput"><span class="identifier">E1</span></code> and <code class="computeroutput"><span class="identifier">E2</span></code> </p> </td> <td> <p> Transformation function </p> </td> </tr> </tbody> </table></div> </div> <br class="table-break"><p> <span class="bold"><strong>Return type</strong></span>: A model of <a class="link" href="../../../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward Sequence</a>. </p> <p> <span class="bold"><strong>Semantics</strong></span>: Returns a new sequence, containing the return values of <code class="computeroutput"><span class="identifier">f</span><span class="special">(</span><span class="identifier">e1</span><span class="special">,</span> <span class="identifier">e2</span><span class="special">)</span></code> for each pair of elements <code class="computeroutput"><span class="identifier">e1</span></code> and <code class="computeroutput"><span class="identifier">e2</span></code> within <code class="computeroutput"><span class="identifier">seq1</span></code> and <code class="computeroutput"><span class="identifier">seq2</span></code> respectively. </p> <a name="fusion.algorithm.transformation.functions.transform.complexity"></a><h6> <a name="id769383"></a> <a class="link" href="transform.html#fusion.algorithm.transformation.functions.transform.complexity">Complexity</a> </h6> <p> Constant. Returns a view which is lazily evaluated. </p> <a name="fusion.algorithm.transformation.functions.transform.header"></a><h6> <a name="id769405"></a> <a class="link" href="transform.html#fusion.algorithm.transformation.functions.transform.header">Header</a> </h6> <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</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">transformation</span><span class="special">/</span><span class="identifier">transform</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> <span class="preprocessor">#include</span> <span class="special"><</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">transform</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> </pre> <a name="fusion.algorithm.transformation.functions.transform.example"></a><h6> <a name="id769525"></a> <a class="link" href="transform.html#fusion.algorithm.transformation.functions.transform.example">Example</a> </h6> <pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">triple</span> <span class="special">{</span> <span class="keyword">typedef</span> <span class="keyword">int</span> <span class="identifier">result_type</span><span class="special">;</span> <span class="keyword">int</span> <span class="keyword">operator</span><span class="special">()(</span><span class="keyword">int</span> <span class="identifier">t</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">t</span> <span class="special">*</span> <span class="number">3</span><span class="special">;</span> <span class="special">};</span> <span class="special">};</span> <span class="special">...</span> <span class="identifier">assert</span><span class="special">(</span><a class="link" href="transform.html" title="transform"><code class="computeroutput"><span class="identifier">transform</span></code></a><span class="special">(</span><a class="link" href="../../../container/generation/functions/make_vector.html" title="make_vector"><code class="computeroutput"><span class="identifier">make_vector</span></code></a><span class="special">(</span><span class="number">1</span><span class="special">,</span><span class="number">2</span><span class="special">,</span><span class="number">3</span><span class="special">),</span> <span class="identifier">triple</span><span class="special">())</span> <span class="special">==</span> <a class="link" href="../../../container/generation/functions/make_vector.html" title="make_vector"><code class="computeroutput"><span class="identifier">make_vector</span></code></a><span class="special">(</span><span class="number">3</span><span class="special">,</span><span class="number">6</span><span class="special">,</span><span class="number">9</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"><div class="copyright-footer">Copyright © 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="filter_if.html"><img src="../../../../../../../../doc/html/images/prev.png" alt="Prev"></a><a accesskey="u" href="../functions.html"><img src="../../../../../../../../doc/html/images/up.png" alt="Up"></a><a accesskey="h" href="../../../../index.html"><img src="../../../../../../../../doc/html/images/home.png" alt="Home"></a><a accesskey="n" href="replace.html"><img src="../../../../../../../../doc/html/images/next.png" alt="Next"></a> </div> </body> </html>