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: transform</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="./copy-if.html" class="navigation-link">Prev</a> <a href="./replace.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./copy-if.html" class="navigation-link">Back</a> <a href="./replace.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./transformation-algorithms.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="./algorithms.html" class="navigation-link">Algorithms</a> / <a href="./transformation-algorithms.html" class="navigation-link">Transformation Algorithms</a> / <a href="./transform.html" class="navigation-link">transform</a></td> 13</tr></table><div class="header-separator"></div> 14<div class="section" id="transform"> 15<h1><a class="toc-backref" href="./transformation-algorithms.html#id1488">transform</a></h1> 16<div class="section" id="id633"> 17<h3><a class="subsection-title" href="#synopsis" name="synopsis">Synopsis</a></h3> 18<pre class="literal-block"> 19template< 20 typename Sequence 21 , typename Op 22 , typename In = <em>unspecified</em> 23 > 24struct <a href="./transform.html" class="identifier">transform</a> 25{ 26 typedef <em>unspecified</em> type; 27}; 28 29template< 30 typename Seq1 31 , typename Seq2 32 , typename BinaryOp 33 , typename In = <em>unspecified</em> 34 > 35struct <a href="./transform.html" class="identifier">transform</a> 36{ 37 typedef <em>unspecified</em> type; 38}; 39</pre> 40</div> 41<div class="section" id="id634"> 42<h3><a class="subsection-title" href="#description" name="description">Description</a></h3> 43<p><tt class="literal"><span class="pre"><a href="./transform.html" class="identifier">transform</a></span></tt> is an <a class="reference internal" href="./terminology.html#overloaded-name">overloaded name</a>:</p> 44<ul class="simple"> 45<li><tt class="literal"><span class="pre"><a href="./transform.html" class="identifier">transform</a><Sequence,Op></span></tt> returns a transformed copy of the original sequence 46produced by applying an unary transformation <tt class="literal"><span class="pre">Op</span></tt> to every element 47in the [<tt class="literal"><span class="pre"><a href="./begin.html" class="identifier">begin</a><Sequence>::type</span></tt>, <tt class="literal"><span class="pre"><a href="./end.html" class="identifier">end</a><Sequence>::type</span></tt>) range.</li> 48<li><tt class="literal"><span class="pre"><a href="./transform.html" class="identifier">transform</a><Seq1,Seq2,BinaryOp></span></tt> returns a new sequence produced by applying a 49binary transformation <tt class="literal"><span class="pre">BinaryOp</span></tt> to a pair of elements (e<sub>1</sub>, e2<sub>1</sub>) 50from the corresponding [<tt class="literal"><span class="pre"><a href="./begin.html" class="identifier">begin</a><Seq1>::type</span></tt>, <tt class="literal"><span class="pre"><a href="./end.html" class="identifier">end</a><Seq1>::type</span></tt>) and [<tt class="literal"><span class="pre"><a href="./begin.html" class="identifier">begin</a><Seq2>::type</span></tt>, <tt class="literal"><span class="pre"><a href="./end.html" class="identifier">end</a><Seq2>::type</span></tt>) ranges.</li> 51</ul> 52<p>[<em>Note:</em> This wording applies to a no-inserter version(s) of the algorithm. See the 53<cite>Expression semantics</cite> subsection for a precise specification of the algorithm's 54details in all cases — <em>end note</em>]</p> 55</div> 56<div class="section" id="id635"> 57<h3><a class="subsection-title" href="#header" name="header">Header</a></h3> 58<pre class="literal-block"> 59#include <<a href="../../../../boost/mpl/transform.hpp" class="header">boost/mpl/transform.hpp</a>> 60</pre> 61</div> 62<div class="section" id="id636"> 63<h3><a class="subsection-title" href="#model-of" name="model-of">Model of</a></h3> 64<p><a class="reference internal" href="./reversible-algorithm.html">Reversible Algorithm</a></p> 65</div> 66<div class="section" id="id637"> 67<h3><a class="subsection-title" href="#parameters" name="parameters">Parameters</a></h3> 68<table border="1" class="docutils table"> 69<colgroup> 70<col width="21%" /> 71<col width="39%" /> 72<col width="39%" /> 73</colgroup> 74<thead valign="bottom"> 75<tr><th class="head">Parameter</th> 76<th class="head">Requirement</th> 77<th class="head">Description</th> 78</tr> 79</thead> 80<tbody valign="top"> 81<tr><td><tt class="literal"><span class="pre">Sequence</span></tt>, 82<tt class="literal"><span class="pre">Seq1</span></tt>, <tt class="literal"><span class="pre">Seq2</span></tt></td> 83<td><a class="reference internal" href="./forward-sequence.html">Forward Sequence</a></td> 84<td>Sequences to transform.</td> 85</tr> 86<tr><td><tt class="literal"><span class="pre">Op</span></tt>, 87<tt class="literal"><span class="pre">BinaryOp</span></tt></td> 88<td><a class="reference internal" href="./lambda-expression.html">Lambda Expression</a></td> 89<td>A transformation.</td> 90</tr> 91<tr><td><tt class="literal"><span class="pre">In</span></tt></td> 92<td><a class="reference internal" href="./inserter.html">Inserter</a></td> 93<td>An inserter.</td> 94</tr> 95</tbody> 96</table> 97</div> 98<div class="section" id="id638"> 99<h3><a class="subsection-title" href="#expression-semantics" name="expression-semantics">Expression semantics</a></h3> 100<p>The semantics of an expression are defined only 101where they differ from, or are not defined in <a class="reference internal" href="./reversible-algorithm.html">Reversible Algorithm</a>.</p> 102<p>For any <a class="reference internal" href="./forward-sequence.html">Forward Sequence</a>s <tt class="literal"><span class="pre">s</span></tt>, <tt class="literal"><span class="pre">s1</span></tt> and <tt class="literal"><span class="pre">s2</span></tt>, <a class="reference internal" href="./lambda-expression.html">Lambda Expression</a>s <tt class="literal"><span class="pre">op</span></tt> and <tt class="literal"><span class="pre">op2</span></tt>, 103and an <a class="reference internal" href="./inserter.html">Inserter</a> <tt class="literal"><span class="pre">in</span></tt>:</p> 104<pre class="literal-block"> 105typedef <a href="./transform.html" class="identifier">transform</a><s,op,in>::type r; 106</pre> 107<table class="docutils field-list" frame="void" rules="none"> 108<col class="field-name" /> 109<col class="field-body" /> 110<tbody valign="top"> 111<tr class="field"><th class="field-name">Return type:</th><td class="field-body"><p class="first">A type.</p> 112</td> 113</tr> 114<tr class="field"><th class="field-name">Postcondition:</th><td class="field-body"><p class="first">Equivalent to</p> 115<pre class="last literal-block"> 116typedef <a href="./lambda.html" class="identifier">lambda</a><op>::type f; 117typedef <a href="./lambda.html" class="identifier">lambda</a><in::operation>::type in_op; 118 119typedef <a href="./fold.html" class="identifier">fold</a>< 120 s 121 , in::state 122 , <a href="./bind.html" class="identifier">bind</a>< in_op, <a href="./placeholders.html" class="identifier">_1</a>, <a href="./bind.html" class="identifier">bind</a><f, <a href="./placeholders.html" class="identifier">_2</a>> > 123 >::type r; 124</pre> 125</td> 126</tr> 127</tbody> 128</table> 129<pre class="literal-block"> 130typedef <a href="./transform.html" class="identifier">transform</a><s1,s2,op,in>::type r; 131</pre> 132<table class="docutils field-list" frame="void" rules="none"> 133<col class="field-name" /> 134<col class="field-body" /> 135<tbody valign="top"> 136<tr class="field"><th class="field-name">Return type:</th><td class="field-body"><p class="first">A type.</p> 137</td> 138</tr> 139<tr class="field"><th class="field-name">Postcondition:</th><td class="field-body"><p class="first">Equivalent to</p> 140<pre class="last literal-block"> 141typedef <a href="./lambda.html" class="identifier">lambda</a><op2>::type f; 142typedef <a href="./lambda.html" class="identifier">lambda</a><in::operation>::type in_op; 143 144typedef <a href="./fold.html" class="identifier">fold</a>< 145 pair_view<s1,s2> 146 , in::state 147 , <a href="./bind.html" class="identifier">bind</a>< 148 in_op 149 , <a href="./placeholders.html" class="identifier">_1</a> 150 , <a href="./bind.html" class="identifier">bind</a><f, <a href="./bind.html" class="identifier">bind</a><first<>,<a href="./placeholders.html" class="identifier">_2</a>>, <a href="./bind.html" class="identifier">bind</a><second<>,<a href="./placeholders.html" class="identifier">_2</a>> > 151 > 152 >::type r; 153</pre> 154</td> 155</tr> 156</tbody> 157</table> 158</div> 159<div class="section" id="id639"> 160<h3><a class="subsection-title" href="#complexity" name="complexity">Complexity</a></h3> 161<p>Linear. Exactly <tt class="literal"><span class="pre"><a href="./size.html" class="identifier">size</a><s>::value</span></tt> / <tt class="literal"><span class="pre"><a href="./size.html" class="identifier">size</a><s1>::value</span></tt> applications of 162<tt class="literal"><span class="pre">op</span></tt> / <tt class="literal"><span class="pre">op2</span></tt> and <tt class="literal"><span class="pre">in::operation</span></tt>.</p> 163</div> 164<div class="section" id="id640"> 165<h3><a class="subsection-title" href="#example" name="example">Example</a></h3> 166<pre class="literal-block"> 167typedef <a href="./vector.html" class="identifier">vector</a><char,short,int,long,float,double> types; 168typedef <a href="./vector.html" class="identifier">vector</a><char*,short*,int*,long*,float*,double*> pointers; 169typedef <a href="./transform.html" class="identifier">transform</a>< types,boost::add_pointer<<a href="./placeholders.html" class="identifier">_1</a>> >::type result; 170 171<a href="./assert.html" class="identifier">BOOST_MPL_ASSERT</a>(( <a href="./equal.html" class="identifier">equal</a><result,pointers> )); 172</pre> 173</div> 174<div class="section" id="id641"> 175<h3><a class="subsection-title" href="#see-also" name="see-also">See also</a></h3> 176<p><a class="reference internal" href="./transformation-algorithms.html">Transformation Algorithms</a>, <a class="reference internal" href="./reversible-algorithm.html">Reversible Algorithm</a>, <a class="reference internal" href="./reverse-transform.html">reverse_transform</a>, <a class="reference internal" href="./copy.html">copy</a>, <a class="reference internal" href="./replace-if.html">replace_if</a></p> 177<!-- Algorithms/Transformation Algorithms//replace |40 --> 178</div> 179</div> 180 181<div class="footer-separator"></div> 182<table class="footer"><tr class="footer"><td class="header-group navigation-bar"><span class="navigation-group"><a href="./copy-if.html" class="navigation-link">Prev</a> <a href="./replace.html" class="navigation-link">Next</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./copy-if.html" class="navigation-link">Back</a> <a href="./replace.html" class="navigation-link">Along</a></span><span class="navigation-group-separator"> | </span><span class="navigation-group"><a href="./transformation-algorithms.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> 183<td><div class="copyright-footer"><div class="copyright">Copyright © 2001-2009 Aleksey Gurtovoy and David Abrahams</div> 184Distributed under the Boost Software License, Version 1.0. (See accompanying 185file 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> 186</html> 187