<html> <head> <meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> <title>transform_view</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 1. Fusion 2.0"> <link rel="up" href="../view.html" title="View"> <link rel="prev" href="zip_view.html" title="zip_view"> <link rel="next" href="reverse_view.html" title="reverse_view"> </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="zip_view.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../view.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="reverse_view.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> </div> <div class="section"> <div class="titlepage"><div><div><h3 class="title"> <a name="fusion.view.transform_view"></a><a class="link" href="transform_view.html" title="transform_view">transform_view</a> </h3></div></div></div> <p> The unary version of <code class="computeroutput"><span class="identifier">transform_view</span></code> presents a view of its underlying sequence given a unary function object or function pointer. The binary version of <code class="computeroutput"><span class="identifier">transform_view</span></code> presents a view of 2 underlying sequences, given a binary function object or function pointer. The <code class="computeroutput"><span class="identifier">transform_view</span></code> inherits the traversal characteristics (see <a class="link" href="../sequence/concepts.html#fusion.sequence.concepts.traversal">Sequence Traversal Concept</a>) of its underlying sequence or sequences. </p> <a name="fusion.view.transform_view.header"></a><h5> <a name="id996450"></a> <a class="link" href="transform_view.html#fusion.view.transform_view.header">Header</a> </h5> <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">view</span><span class="special">/</span><span class="identifier">transform_view</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_view</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> </pre> <a name="fusion.view.transform_view.synopsis"></a><h5> <a name="id996558"></a> <a class="link" href="transform_view.html#fusion.view.transform_view.synopsis">Synopsis</a> </h5> <p> <span class="bold"><strong>Unary Version</strong></span> </p> <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">F1</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">transform_view</span><span class="special">;</span> </pre> <p> <span class="bold"><strong>Binary Version</strong></span> </p> <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">F2</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">transform_view</span><span class="special">;</span> </pre> <a name="fusion.view.transform_view.template_parameters"></a><h5> <a name="id996704"></a> <a class="link" href="transform_view.html#fusion.view.transform_view.template_parameters">Template parameters</a> </h5> <div class="informaltable"><table class="table"> <colgroup> <col> <col> <col> </colgroup> <thead><tr> <th> <p> Parameter </p> </th> <th> <p> Description </p> </th> <th> <p> Default </p> </th> </tr></thead> <tbody> <tr> <td> <p> <code class="computeroutput"><span class="identifier">Sequence</span></code> </p> </td> <td> <p> A <a class="link" href="../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward Sequence</a> </p> </td> <td> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">Sequence1</span></code> </p> </td> <td> <p> A <a class="link" href="../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward Sequence</a> </p> </td> <td> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">Sequence2</span></code> </p> </td> <td> <p> A <a class="link" href="../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward Sequence</a> </p> </td> <td> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">F1</span></code> </p> </td> <td> <p> A unary function object or function pointer. <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">F1</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 an instance of <code class="computeroutput"><span class="identifier">F1</span></code> when called with a value of each element type <code class="computeroutput"><span class="identifier">E</span></code> in the input sequence. </p> </td> <td> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">F2</span></code> </p> </td> <td> <p> A binary function object or function pointer. <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">F2</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 an instance of <code class="computeroutput"><span class="identifier">F2</span></code> when called with a value of each corresponding pair of element type <code class="computeroutput"><span class="identifier">E1</span></code> and <code class="computeroutput"><span class="identifier">E2</span></code> in the input sequences. </p> </td> <td> </td> </tr> </tbody> </table></div> <a name="fusion.view.transform_view.model_of"></a><h5> <a name="id997047"></a> <a class="link" href="transform_view.html#fusion.view.transform_view.model_of">Model of</a> </h5> <div class="itemizedlist"><ul class="itemizedlist" type="disc"><li class="listitem"> <a class="link" href="../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward Sequence</a>, <a class="link" href="../sequence/concepts/bidirectional_sequence.html" title="Bidirectional Sequence">Bidirectional Sequence</a> or <a class="link" href="../sequence/concepts/random_access_sequence.html" title="Random Access Sequence">Random Access Sequence</a> depending on the traversal characteristics (see <a class="link" href="../sequence/concepts.html#fusion.sequence.concepts.traversal">Sequence Traversal Concept</a>) of its underlying sequence. </li></ul></div> <div class="variablelist"> <p class="title"><b>Notation</b></p> <dl> <dt><span class="term"><code class="computeroutput"><span class="identifier">TV</span></code></span></dt> <dd><p> A <code class="computeroutput"><span class="identifier">transform_view</span></code> type </p></dd> <dt><span class="term"><code class="computeroutput"><span class="identifier">BTV</span></code></span></dt> <dd><p> A binary <code class="computeroutput"><span class="identifier">transform_view</span></code> type </p></dd> <dt><span class="term"><code class="computeroutput"><span class="identifier">UTV</span></code></span></dt> <dd><p> A unary <code class="computeroutput"><span class="identifier">transform_view</span></code> type </p></dd> <dt><span class="term"><code class="computeroutput"><span class="identifier">f1</span></code></span></dt> <dd><p> An instance of <code class="computeroutput"><span class="identifier">F1</span></code> </p></dd> <dt><span class="term"><code class="computeroutput"><span class="identifier">f2</span></code></span></dt> <dd><p> An instance of <code class="computeroutput"><span class="identifier">F2</span></code> </p></dd> <dt><span class="term"><code class="computeroutput"><span class="identifier">s</span></code></span></dt> <dd><p> An instance of <code class="computeroutput"><span class="identifier">Sequence</span></code> </p></dd> <dt><span class="term"><code class="computeroutput"><span class="identifier">s1</span></code></span></dt> <dd><p> An instance of <code class="computeroutput"><span class="identifier">Sequence1</span></code> </p></dd> <dt><span class="term"><code class="computeroutput"><span class="identifier">s2</span></code></span></dt> <dd><p> An instance of <code class="computeroutput"><span class="identifier">Sequence2</span></code> </p></dd> <dt><span class="term"><code class="computeroutput"><span class="identifier">tv</span></code>, <code class="computeroutput"><span class="identifier">tv2</span></code></span></dt> <dd><p> Instances of <code class="computeroutput"><span class="identifier">transform_view</span></code> </p></dd> </dl> </div> <a name="fusion.view.transform_view.expression_semantics"></a><h5> <a name="id997344"></a> <a class="link" href="transform_view.html#fusion.view.transform_view.expression_semantics">Expression Semantics</a> </h5> <p> Semantics of an expression is defined only where it differs from, or is not defined in <a class="link" href="../sequence/concepts/forward_sequence.html" title="Forward Sequence">Forward Sequence</a>, <a class="link" href="../sequence/concepts/bidirectional_sequence.html" title="Bidirectional Sequence">Bidirectional Sequence</a> or <a class="link" href="../sequence/concepts/random_access_sequence.html" title="Random Access Sequence">Random Access Sequence</a> depending on the traversal characteristics (see <a class="link" href="../sequence/concepts.html#fusion.sequence.concepts.traversal">Sequence Traversal Concept</a>) of its underlying sequence or sequences. </p> <div class="informaltable"><table class="table"> <colgroup> <col> <col> </colgroup> <thead><tr> <th> <p> Expression </p> </th> <th> <p> Semantics </p> </th> </tr></thead> <tbody> <tr> <td> <p> <code class="computeroutput"><span class="identifier">UTV</span><span class="special">(</span><span class="identifier">s</span><span class="special">,</span> <span class="identifier">f1</span><span class="special">)</span></code> </p> </td> <td> <p> Creates a unary <code class="computeroutput"><span class="identifier">transform_view</span></code> given sequence, <code class="computeroutput"><span class="identifier">s</span></code> and unary function object or function pointer, <code class="computeroutput"><span class="identifier">f1</span></code>. </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">BTV</span><span class="special">(</span><span class="identifier">s1</span><span class="special">,</span> <span class="identifier">s2</span><span class="special">,</span> <span class="identifier">f2</span><span class="special">)</span></code> </p> </td> <td> <p> Creates a binary <code class="computeroutput"><span class="identifier">transform_view</span></code> given sequences, <code class="computeroutput"><span class="identifier">s1</span></code> and <code class="computeroutput"><span class="identifier">s2</span></code> and binary function object or function pointer, <code class="computeroutput"><span class="identifier">f2</span></code>. </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">TV</span><span class="special">(</span><span class="identifier">tv</span><span class="special">)</span></code> </p> </td> <td> <p> Copy constructs a <code class="computeroutput"><span class="identifier">transform_view</span></code> from another <code class="computeroutput"><span class="identifier">transform_view</span></code>, <code class="computeroutput"><span class="identifier">tv</span></code>. </p> </td> </tr> <tr> <td> <p> <code class="computeroutput"><span class="identifier">tv</span> <span class="special">=</span> <span class="identifier">tv2</span></code> </p> </td> <td> <p> Assigns to a <code class="computeroutput"><span class="identifier">transform_view</span></code>, <code class="computeroutput"><span class="identifier">tv</span></code>, from another <code class="computeroutput"><span class="identifier">transform_view</span></code>, <code class="computeroutput"><span class="identifier">tv2</span></code>. </p> </td> </tr> </tbody> </table></div> <a name="fusion.view.transform_view.example"></a><h5> <a name="id997684"></a> <a class="link" href="transform_view.html#fusion.view.transform_view.example">Example</a> </h5> <pre class="programlisting"><span class="keyword">struct</span> <span class="identifier">square</span> <span class="special">{</span> <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">Sig</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">result</span><span class="special">;</span> <span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> <span class="identifier">U</span><span class="special">></span> <span class="keyword">struct</span> <span class="identifier">result</span><span class="special"><</span><span class="identifier">square</span><span class="special">(</span><span class="identifier">U</span><span class="special">)></span> <span class="special">:</span> <span class="identifier">remove_reference</span><span class="special"><</span><span class="identifier">U</span><span class="special">></span> <span class="special">{};</span> <span class="keyword">template</span> <span class="special"><</span><span class="keyword">typename</span> <span class="identifier">T</span><span class="special">></span> <span class="identifier">T</span> <span class="keyword">operator</span><span class="special">()(</span><span class="identifier">T</span> <span class="identifier">x</span><span class="special">)</span> <span class="keyword">const</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">x</span> <span class="special">*</span> <span class="identifier">x</span><span class="special">;</span> <span class="special">}</span> <span class="special">};</span> <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"><</span><span class="keyword">int</span><span class="special">,</span> <span class="keyword">short</span><span class="special">,</span> <span class="keyword">double</span><span class="special">></span> <span class="identifier">vector_type</span><span class="special">;</span> <span class="identifier">vector_type</span> <span class="identifier">vec</span><span class="special">(</span><span class="number">2</span><span class="special">,</span> <span class="number">5</span><span class="special">,</span> <span class="number">3.3</span><span class="special">);</span> <span class="identifier">transform_view</span><span class="special"><</span><span class="identifier">vector_type</span><span class="special">,</span> <span class="identifier">square</span><span class="special">></span> <span class="identifier">transform</span><span class="special">(</span><span class="identifier">vec</span><span class="special">,</span> <span class="identifier">square</span><span class="special">());</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special"><<</span> <span class="identifier">transform</span> <span class="special"><<</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">endl</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="zip_view.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../view.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="reverse_view.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a> </div> </body> </html>