1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>transform</title> 5<link rel="stylesheet" href="../../../../../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="../../../../index.html" title="Chapter 1. Range 2.0"> 8<link rel="up" href="../mutating.html" title="Mutating algorithms"> 9<link rel="prev" href="swap_ranges.html" title="swap_ranges"> 10<link rel="next" href="unique.html" title="unique"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../../../boost.png"></td> 15<td align="center"><a href="../../../../../../../../index.html">Home</a></td> 16<td align="center"><a href="../../../../../../../../libs/libraries.htm">Libraries</a></td> 17<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td> 18<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td> 19<td align="center"><a href="../../../../../../../../more/index.htm">More</a></td> 20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="swap_ranges.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mutating.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="unique.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="section"> 26<div class="titlepage"><div><div><h5 class="title"> 27<a name="range.reference.algorithms.mutating.transform"></a><a class="link" href="transform.html" title="transform">transform</a> 28</h5></div></div></div> 29<h6> 30<a name="range.reference.algorithms.mutating.transform.h0"></a> 31 <span class="phrase"><a name="range.reference.algorithms.mutating.transform.prototype"></a></span><a class="link" href="transform.html#range.reference.algorithms.mutating.transform.prototype">Prototype</a> 32 </h6> 33<p> 34</p> 35<pre class="programlisting"><span class="keyword">template</span><span class="special"><</span> 36 <span class="keyword">class</span> <span class="identifier">SinglePassRange1</span><span class="special">,</span> 37 <span class="keyword">class</span> <span class="identifier">OutputIterator</span><span class="special">,</span> 38 <span class="keyword">class</span> <span class="identifier">UnaryOperation</span> 39<span class="special">></span> 40<span class="identifier">OutputIterator</span> <span class="identifier">transform</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">SinglePassRange1</span><span class="special">&</span> <span class="identifier">rng</span><span class="special">,</span> 41 <span class="identifier">OutputIterator</span> <span class="identifier">out</span><span class="special">,</span> 42 <span class="identifier">UnaryOperation</span> <span class="identifier">fun</span><span class="special">);</span> 43 44<span class="keyword">template</span><span class="special"><</span> 45 <span class="keyword">class</span> <span class="identifier">SinglePassRange1</span><span class="special">,</span> 46 <span class="keyword">class</span> <span class="identifier">SinglePassRange2</span><span class="special">,</span> 47 <span class="keyword">class</span> <span class="identifier">OutputIterator</span><span class="special">,</span> 48 <span class="keyword">class</span> <span class="identifier">BinaryOperation</span> 49<span class="special">></span> 50<span class="identifier">OutputIterator</span> <span class="identifier">transform</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">SinglePassRange1</span><span class="special">&</span> <span class="identifier">rng1</span><span class="special">,</span> 51 <span class="keyword">const</span> <span class="identifier">SinglePassRange2</span><span class="special">&</span> <span class="identifier">rng2</span><span class="special">,</span> 52 <span class="identifier">OutputIterator</span> <span class="identifier">out</span><span class="special">,</span> 53 <span class="identifier">BinaryOperation</span> <span class="identifier">fun</span><span class="special">);</span> 54</pre> 55<p> 56 </p> 57<h6> 58<a name="range.reference.algorithms.mutating.transform.h1"></a> 59 <span class="phrase"><a name="range.reference.algorithms.mutating.transform.description"></a></span><a class="link" href="transform.html#range.reference.algorithms.mutating.transform.description">Description</a> 60 </h6> 61<p> 62 <span class="bold"><strong>UnaryOperation version:</strong></span> 63 </p> 64<p> 65 <code class="computeroutput"><span class="identifier">transform</span></code> assigns the 66 value <code class="computeroutput"><span class="identifier">y</span></code> to each element 67 <code class="computeroutput"><span class="special">[</span><span class="identifier">out</span><span class="special">,</span> <span class="identifier">out</span> <span class="special">+</span> <span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng</span><span class="special">)),</span> <span class="identifier">y</span> <span class="special">=</span> <span class="identifier">fun</span><span class="special">(</span><span class="identifier">x</span><span class="special">)</span></code> where <code class="computeroutput"><span class="identifier">x</span></code> 68 is the corresponding value to <code class="computeroutput"><span class="identifier">y</span></code> 69 in <code class="computeroutput"><span class="identifier">rng1</span></code>. The return value 70 is <code class="computeroutput"><span class="identifier">out</span> <span class="special">+</span> 71 <span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng</span><span class="special">)</span></code>. 72 </p> 73<p> 74 <span class="bold"><strong>BinaryOperation version:</strong></span> 75 </p> 76<p> 77 <code class="computeroutput"><span class="identifier">transform</span></code> assigns the 78 value <code class="computeroutput"><span class="identifier">z</span></code> to each element 79 <code class="computeroutput"><span class="special">[</span><span class="identifier">out</span><span class="special">,</span> <span class="identifier">out</span> <span class="special">+</span> <span class="identifier">min</span><span class="special">(</span><span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng1</span><span class="special">),</span> <span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng2</span><span class="special">))),</span> <span class="identifier">z</span> <span class="special">=</span> <span class="identifier">fun</span><span class="special">(</span><span class="identifier">x</span><span class="special">,</span><span class="identifier">y</span><span class="special">)</span></code> where <code class="computeroutput"><span class="identifier">x</span></code> 80 is the corresponding value in <code class="computeroutput"><span class="identifier">rng1</span></code> 81 and <code class="computeroutput"><span class="identifier">y</span></code> is the corresponding 82 value in <code class="computeroutput"><span class="identifier">rng2</span></code>. This version 83 of <code class="computeroutput"><span class="identifier">transform</span></code> stops upon 84 reaching either the end of <code class="computeroutput"><span class="identifier">rng1</span></code>, 85 or the end of <code class="computeroutput"><span class="identifier">rng2</span></code>. Hence 86 there isn't a requirement for <code class="computeroutput"><span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng1</span><span class="special">)</span> <span class="special">==</span> <span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng2</span><span class="special">)</span></code> 87 since there is a safe guaranteed behaviour, unlike with the iterator 88 counterpart in the standard library. 89 </p> 90<p> 91 The return value is <code class="computeroutput"><span class="identifier">out</span> <span class="special">+</span> <span class="identifier">min</span><span class="special">(</span><span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng1</span><span class="special">),</span> <span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng2</span><span class="special">))</span></code>. 92 </p> 93<h6> 94<a name="range.reference.algorithms.mutating.transform.h2"></a> 95 <span class="phrase"><a name="range.reference.algorithms.mutating.transform.definition"></a></span><a class="link" href="transform.html#range.reference.algorithms.mutating.transform.definition">Definition</a> 96 </h6> 97<p> 98 Defined in the header file <code class="computeroutput"><span class="identifier">boost</span><span class="special">/</span><span class="identifier">range</span><span class="special">/</span><span class="identifier">algorithm</span><span class="special">/</span><span class="identifier">transform</span><span class="special">.</span><span class="identifier">hpp</span></code> 99 </p> 100<h6> 101<a name="range.reference.algorithms.mutating.transform.h3"></a> 102 <span class="phrase"><a name="range.reference.algorithms.mutating.transform.requirements"></a></span><a class="link" href="transform.html#range.reference.algorithms.mutating.transform.requirements">Requirements</a> 103 </h6> 104<p> 105 <span class="bold"><strong>For the unary versions of transform:</strong></span> 106 </p> 107<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 108<li class="listitem"> 109 <code class="computeroutput"><span class="identifier">SinglePassRange1</span></code> 110 is a model of the <a class="link" href="../../../concepts/single_pass_range.html" title="Single Pass Range">Single 111 Pass Range</a> Concept. 112 </li> 113<li class="listitem"> 114 <code class="computeroutput"><span class="identifier">OutputIterator</span></code> is 115 a model of the <code class="computeroutput"><span class="identifier">OutputIteratorConcept</span></code>. 116 </li> 117<li class="listitem"> 118 <code class="computeroutput"><span class="identifier">UnaryOperation</span></code> is 119 a model of the <code class="computeroutput"><span class="identifier">UnaryFunctionConcept</span></code>. 120 </li> 121<li class="listitem"> 122 <code class="computeroutput"><span class="identifier">SinglePassRange1</span></code>'s 123 value type must be convertible to <code class="computeroutput"><span class="identifier">UnaryFunction</span></code>'s 124 argument type. 125 </li> 126<li class="listitem"> 127 <code class="computeroutput"><span class="identifier">UnaryFunction</span></code>'s result 128 type must be convertible to a type in <code class="computeroutput"><span class="identifier">OutputIterator</span></code>'s 129 set of value types. 130 </li> 131</ul></div> 132<p> 133 <span class="bold"><strong>For the binary versions of transform:</strong></span> 134 </p> 135<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 136<li class="listitem"> 137 <code class="computeroutput"><span class="identifier">SinglePassRange1</span></code> 138 is a model of the <a class="link" href="../../../concepts/single_pass_range.html" title="Single Pass Range">Single 139 Pass Range</a> Concept. 140 </li> 141<li class="listitem"> 142 <code class="computeroutput"><span class="identifier">SinglePassRange2</span></code> 143 is a model of the <a class="link" href="../../../concepts/single_pass_range.html" title="Single Pass Range">Single 144 Pass Range</a> Concept. 145 </li> 146<li class="listitem"> 147 <code class="computeroutput"><span class="identifier">OutputIterator</span></code> is 148 a model of the <code class="computeroutput"><span class="identifier">OutputIteratorConcept</span></code>. 149 </li> 150<li class="listitem"> 151 <code class="computeroutput"><span class="identifier">BinaryOperation</span></code> is 152 a model of the <code class="computeroutput"><span class="identifier">BinaryFunctionConcept</span></code>. 153 </li> 154<li class="listitem"> 155 <code class="computeroutput"><span class="identifier">SinglePassRange1</span></code>'s 156 value type must be convertible to <code class="computeroutput"><span class="identifier">BinaryFunction</span></code>'s 157 first argument type. 158 </li> 159<li class="listitem"> 160 <code class="computeroutput"><span class="identifier">SinglePassRange2</span></code>'s 161 value type must be convertible to <code class="computeroutput"><span class="identifier">BinaryFunction</span></code>'s 162 second argument type. 163 </li> 164<li class="listitem"> 165 <code class="computeroutput"><span class="identifier">BinaryOperation</span></code>'s 166 result type must be convertible to a type in <code class="computeroutput"><span class="identifier">OutputIterator</span></code>'s 167 set of value types. 168 </li> 169</ul></div> 170<h6> 171<a name="range.reference.algorithms.mutating.transform.h4"></a> 172 <span class="phrase"><a name="range.reference.algorithms.mutating.transform.precondition_"></a></span><a class="link" href="transform.html#range.reference.algorithms.mutating.transform.precondition_">Precondition:</a> 173 </h6> 174<p> 175 <span class="bold"><strong>For the unary version of transform:</strong></span> 176 </p> 177<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 178<li class="listitem"> 179 <code class="computeroutput"><span class="identifier">out</span></code> is not an iterator 180 within the range <code class="computeroutput"><span class="special">[</span><span class="identifier">begin</span><span class="special">(</span><span class="identifier">rng1</span><span class="special">)</span> <span class="special">+</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">end</span><span class="special">(</span><span class="identifier">rng1</span><span class="special">))</span></code>. 181 </li> 182<li class="listitem"> 183 <code class="computeroutput"><span class="special">[</span><span class="identifier">out</span><span class="special">,</span> <span class="identifier">out</span> 184 <span class="special">+</span> <span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng1</span><span class="special">))</span></code> is a valid range. 185 </li> 186</ul></div> 187<p> 188 <span class="bold"><strong>For the binary version of transform:</strong></span> 189 </p> 190<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 191<li class="listitem"> 192 <code class="computeroutput"><span class="identifier">out</span></code> is not an iterator 193 within the range <code class="computeroutput"><span class="special">[</span><span class="identifier">begin</span><span class="special">(</span><span class="identifier">rng1</span><span class="special">)</span> <span class="special">+</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">end</span><span class="special">(</span><span class="identifier">rng1</span><span class="special">))</span></code>. 194 </li> 195<li class="listitem"> 196 <code class="computeroutput"><span class="identifier">out</span></code> is not an iterator 197 within the range <code class="computeroutput"><span class="special">[</span><span class="identifier">begin</span><span class="special">(</span><span class="identifier">rng2</span><span class="special">)</span> <span class="special">+</span> <span class="number">1</span><span class="special">,</span> <span class="identifier">end</span><span class="special">(</span><span class="identifier">rng2</span><span class="special">))</span></code>. 198 </li> 199<li class="listitem"> 200 <code class="computeroutput"><span class="special">[</span><span class="identifier">out</span><span class="special">,</span> <span class="identifier">out</span> 201 <span class="special">+</span> <span class="identifier">min</span><span class="special">(</span><span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng1</span><span class="special">),</span> <span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng2</span><span class="special">)))</span></code> is a valid range. 202 </li> 203</ul></div> 204<h6> 205<a name="range.reference.algorithms.mutating.transform.h5"></a> 206 <span class="phrase"><a name="range.reference.algorithms.mutating.transform.complexity"></a></span><a class="link" href="transform.html#range.reference.algorithms.mutating.transform.complexity">Complexity</a> 207 </h6> 208<p> 209 Linear. The operation is applied exactly <code class="computeroutput"><span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng1</span><span class="special">)</span></code> for the unary version and <code class="computeroutput"><span class="identifier">min</span><span class="special">(</span><span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng1</span><span class="special">),</span> <span class="identifier">distance</span><span class="special">(</span><span class="identifier">rng2</span><span class="special">))</span></code> 210 for the binary version. 211 </p> 212</div> 213<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 214<td align="left"></td> 215<td align="right"><div class="copyright-footer">Copyright © 2003-2010 Thorsten Ottosen, 216 Neil Groves<p> 217 Distributed under the Boost Software License, Version 1.0. (See accompanying 218 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>) 219 </p> 220</div></td> 221</tr></table> 222<hr> 223<div class="spirit-nav"> 224<a accesskey="p" href="swap_ranges.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../mutating.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="unique.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 225</div> 226</body> 227</html> 228