1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>map_values</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="../reference.html" title="Reference"> 9<link rel="prev" href="map_keys.html" title="map_keys"> 10<link rel="next" href="ref_unwrapped.html" title="ref_unwrapped"> 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="map_keys.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.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="ref_unwrapped.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.adaptors.reference.map_values"></a><a class="link" href="map_values.html" title="map_values">map_values</a> 28</h5></div></div></div> 29<div class="toc"><dl class="toc"><dt><span class="section"><a href="map_values.html#range.reference.adaptors.reference.map_values.map_values_example">map_values 30 example</a></span></dt></dl></div> 31<div class="informaltable"><table class="table"> 32<colgroup> 33<col> 34<col> 35</colgroup> 36<thead><tr> 37<th> 38 <p> 39 Syntax 40 </p> 41 </th> 42<th> 43 <p> 44 Code 45 </p> 46 </th> 47</tr></thead> 48<tbody> 49<tr> 50<td> 51 <p> 52 Pipe 53 </p> 54 </td> 55<td> 56 <p> 57 <code class="computeroutput"><span class="identifier">rng</span> <span class="special">|</span> 58 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">adaptors</span><span class="special">::</span><span class="identifier">map_values</span></code> 59 </p> 60 </td> 61</tr> 62<tr> 63<td> 64 <p> 65 Function 66 </p> 67 </td> 68<td> 69 <p> 70 <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">adaptors</span><span class="special">::</span><span class="identifier">values</span><span class="special">(</span><span class="identifier">rng</span><span class="special">)</span></code> 71 </p> 72 </td> 73</tr> 74</tbody> 75</table></div> 76<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 77<li class="listitem"> 78 <span class="bold"><strong>Precondition:</strong></span> The <code class="computeroutput"><span class="identifier">value_type</span></code> of the range is an instantiation 79 of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span></code>. 80 </li> 81<li class="listitem"> 82 <span class="bold"><strong>Postcondition:</strong></span> For all elements 83 <code class="computeroutput"><span class="identifier">x</span></code> in the returned 84 range, <code class="computeroutput"><span class="identifier">x</span></code> is the result 85 of <code class="computeroutput"><span class="identifier">y</span><span class="special">.</span><span class="identifier">second</span></code> where <code class="computeroutput"><span class="identifier">y</span></code> 86 is the corresponding element in the original range. 87 </li> 88<li class="listitem"> 89 <span class="bold"><strong>Range Category:</strong></span> <a class="link" href="../../../concepts/single_pass_range.html" title="Single Pass Range">Single 90 Pass Range</a> 91 </li> 92<li class="listitem"> 93 <span class="bold"><strong>Range Return Type:</strong></span> for constant 94 ranges, <code class="computeroutput"><span class="identifier">boost</span><span class="special">::</span><span class="identifier">select_second_const</span><span class="special"><</span><span class="keyword">decltype</span><span class="special">(</span><span class="identifier">rng</span><span class="special">)></span></code> 95 otherwise <code class="computeroutput"><span class="identifier">boost</span><span class="special">:</span><span class="identifier">select_second_mutable</span><span class="special"><</span><span class="keyword">decltype</span><span class="special">(</span><span class="identifier">rng</span><span class="special">)></span></code> 96 </li> 97<li class="listitem"> 98 <span class="bold"><strong>Returned Range Category:</strong></span> The range 99 category of <code class="computeroutput"><span class="identifier">rng</span></code>. 100 </li> 101</ul></div> 102<div class="section"> 103<div class="titlepage"><div><div><h6 class="title"> 104<a name="range.reference.adaptors.reference.map_values.map_values_example"></a><a class="link" href="map_values.html#range.reference.adaptors.reference.map_values.map_values_example" title="map_values example">map_values 105 example</a> 106</h6></div></div></div> 107<p> 108</p> 109<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">range</span><span class="special">/</span><span class="identifier">adaptor</span><span class="special">/</span><span class="identifier">map</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 110<span class="preprocessor">#include</span> <span class="special"><</span><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">copy</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 111<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">assign</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span> 112<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iterator</span><span class="special">></span> 113<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span> 114<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">map</span><span class="special">></span> 115<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">vector</span><span class="special">></span> 116 117<span class="keyword">int</span> <span class="identifier">main</span><span class="special">(</span><span class="keyword">int</span> <span class="identifier">argc</span><span class="special">,</span> <span class="keyword">const</span> <span class="keyword">char</span><span class="special">*</span> <span class="identifier">argv</span><span class="special">[])</span> 118<span class="special">{</span> 119 <span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">assign</span><span class="special">;</span> 120 <span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">adaptors</span><span class="special">;</span> 121 122 <span class="identifier">std</span><span class="special">::</span><span class="identifier">map</span><span class="special"><</span><span class="keyword">int</span><span class="special">,</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">input</span><span class="special">;</span> 123 <span class="keyword">for</span> <span class="special">(</span><span class="keyword">int</span> <span class="identifier">i</span> <span class="special">=</span> <span class="number">0</span><span class="special">;</span> <span class="identifier">i</span> <span class="special"><</span> <span class="number">10</span><span class="special">;</span> <span class="special">++</span><span class="identifier">i</span><span class="special">)</span> 124 <span class="identifier">input</span><span class="special">.</span><span class="identifier">insert</span><span class="special">(</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">make_pair</span><span class="special">(</span><span class="identifier">i</span><span class="special">,</span> <span class="identifier">i</span> <span class="special">*</span> <span class="number">10</span><span class="special">));</span> 125 126 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">copy</span><span class="special">(</span> 127 <span class="identifier">input</span> <span class="special">|</span> <span class="identifier">map_values</span><span class="special">,</span> 128 <span class="identifier">std</span><span class="special">::</span><span class="identifier">ostream_iterator</span><span class="special"><</span><span class="keyword">int</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="string">","</span><span class="special">));</span> 129 130 <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span> 131<span class="special">}</span> 132</pre> 133<p> 134 </p> 135</div> 136<p> 137 This would produce the output: 138</p> 139<pre class="programlisting"><span class="number">0</span><span class="special">,</span><span class="number">10</span><span class="special">,</span><span class="number">20</span><span class="special">,</span><span class="number">30</span><span class="special">,</span><span class="number">40</span><span class="special">,</span><span class="number">50</span><span class="special">,</span><span class="number">60</span><span class="special">,</span><span class="number">70</span><span class="special">,</span><span class="number">80</span><span class="special">,</span><span class="number">90</span><span class="special">,</span> 140</pre> 141<p> 142 </p> 143</div> 144<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 145<td align="left"></td> 146<td align="right"><div class="copyright-footer">Copyright © 2003-2010 Thorsten Ottosen, 147 Neil Groves<p> 148 Distributed under the Boost Software License, Version 1.0. (See accompanying 149 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>) 150 </p> 151</div></td> 152</tr></table> 153<hr> 154<div class="spirit-nav"> 155<a accesskey="p" href="map_keys.html"><img src="../../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../reference.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="ref_unwrapped.html"><img src="../../../../../../../../doc/src/images/next.png" alt="Next"></a> 156</div> 157</body> 158</html> 159
