1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Function template reverse_string_sort</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="Boost.Sort"> 8<link rel="up" href="../../../header/boost/sort/spreadsort/string_sort_hpp.html" title="Header <boost/sort/spreadsort/string_sort.hpp>"> 9<link rel="prev" href="string_s_idm45878543718144.html" title="Function template string_sort"> 10<link rel="next" href="reverse__idm45878543665984.html" title="Function template reverse_string_sort"> 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="string_s_idm45878543718144.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../header/boost/sort/spreadsort/string_sort_hpp.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__idm45878543665984.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="refentry"> 26<a name="boost.sort.spreadsort.reverse__idm45878543698320"></a><div class="titlepage"></div> 27<div class="refnamediv"> 28<h2><span class="refentrytitle">Function template reverse_string_sort</span></h2> 29<p>boost::sort::spreadsort::reverse_string_sort — String sort algorithm using random access iterators, allowing character-type overloads. </p> 30</div> 31<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 32<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="../../../header/boost/sort/spreadsort/string_sort_hpp.html" title="Header <boost/sort/spreadsort/string_sort.hpp>">boost/sort/spreadsort/string_sort.hpp</a>> 33 34</span> 35<span class="keyword">template</span><span class="special"><</span><span class="keyword">typename</span> RandomAccessIter<span class="special">,</span> <span class="keyword">typename</span> Compare<span class="special">,</span> 36 <span class="keyword">typename</span> Unsigned_char_type<span class="special">></span> 37 <span class="keyword">void</span> <span class="identifier">reverse_string_sort</span><span class="special">(</span><span class="identifier">RandomAccessIter</span> first<span class="special">,</span> <span class="identifier">RandomAccessIter</span> last<span class="special">,</span> 38 <span class="identifier">Compare</span> comp<span class="special">,</span> <span class="identifier">Unsigned_char_type</span> unused<span class="special">)</span><span class="special">;</span></pre></div> 39<div class="refsect1"> 40<a name="idm45477844519920"></a><h2>Description</h2> 41<p>(All variants fall back to <code class="computeroutput">boost::sort::pdqsort</code> if the data size is too small, < detail::min_sort_size).</p> 42<p><code class="computeroutput">string_sort</code> is a fast templated in-place hybrid radix/comparison algorithm, which in testing tends to be roughly 50% to 2X faster than <code class="computeroutput">std::sort</code> for large tests (>=100kB).<br> 43</p> 44<p><b> </b>Worst-case performance is <span class="emphasis"><em> O(N * (lg(range)/s + s)) </em></span>, so <code class="computeroutput">string_sort</code> is asymptotically faster than pure comparison-based algorithms. <br> 45<br> 46Some performance plots of runtime vs. n and log(range) are provided:<br> 47<a href="../../../../../doc/graph/windows_string_sort.htm" target="_top">windows_string_sort</a><br> 48<a href="../../../../../doc/graph/osx_string_sort.htm" target="_top">osx_string_sort</a></p> 49<p> 50 51 52 53 54 55 56 57 58 59</p> 60<div class="warning"><table border="0" summary="Warning"> 61<tr> 62<td rowspan="2" align="center" valign="top" width="25"><img alt="[Warning]" src="../../../../../../../doc/src/images/warning.png"></td> 63<th align="left">Warning</th> 64</tr> 65<tr><td align="left" valign="top"><p>Throwing an exception may cause data loss. This will also throw if a small vector resize throws, in which case there will be no data loss. </p></td></tr> 66</table></div> 67<p> 68</p> 69<div class="warning"><table border="0" summary="Warning"> 70<tr> 71<td rowspan="2" align="center" valign="top" width="25"><img alt="[Warning]" src="../../../../../../../doc/src/images/warning.png"></td> 72<th align="left">Warning</th> 73</tr> 74<tr><td align="left" valign="top"><p>Invalid arguments cause undefined behaviour. </p></td></tr> 75</table></div> 76<p> 77</p> 78<div class="note"><table border="0" summary="Note"> 79<tr> 80<td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../../doc/src/images/note.png"></td> 81<th align="left">Note</th> 82</tr> 83<tr><td align="left" valign="top"><p><code class="computeroutput">spreadsort</code> function provides a wrapper that calls the fastest sorting algorithm available for a data type, enabling faster generic-programming.</p></td></tr> 84</table></div> 85<p> 86</p> 87<p>The lesser of <span class="emphasis"><em> O(N*log(N)) </em></span> comparisons and <span class="emphasis"><em> O(N*log(K/S + S)) </em></span>operations worst-case, where: </p> 88<p> 89 90</p> 91<p>* N is <code class="computeroutput">last</code> - <code class="computeroutput">first</code>, </p> 92<p> 93 94</p> 95<p>* K is the log of the range in bits (32 for 32-bit integers using their full range), </p> 96<p> 97 98</p> 99<p>* S is a constant called max_splits, defaulting to 11 (except for strings where it is the log of the character size). </p> 100<p> 101 102</p> 103<div class="variablelist"><table border="0" class="variablelist compact"> 104<colgroup> 105<col align="left" valign="top"> 106<col> 107</colgroup> 108<tbody> 109<tr> 110<td><p><span class="term">Parameters:</span></p></td> 111<td><div class="variablelist"><table border="0" class="variablelist compact"> 112<colgroup> 113<col align="left" valign="top"> 114<col> 115</colgroup> 116<tbody> 117<tr> 118<td><p><span class="term"><code class="computeroutput">comp</code></span></p></td> 119<td><p>A binary functor that returns whether the first element passed to it should go before the second in order. </p></td> 120</tr> 121<tr> 122<td><p><span class="term"><code class="computeroutput">first</code></span></p></td> 123<td><p>Iterator pointer to first element. </p></td> 124</tr> 125<tr> 126<td><p><span class="term"><code class="computeroutput">last</code></span></p></td> 127<td><p>Iterator pointing to one beyond the end of data. </p></td> 128</tr> 129<tr> 130<td><p><span class="term"><code class="computeroutput">unused</code></span></p></td> 131<td><p>value with the same type as the result of the [] operator, defining the Unsigned_char_type. The actual value is unused.</p></td> 132</tr> 133</tbody> 134</table></div></td> 135</tr> 136<tr> 137<td><p><span class="term">Template Parameters:</span></p></td> 138<td><div class="variablelist"><table border="0" class="variablelist compact"> 139<colgroup> 140<col align="left" valign="top"> 141<col> 142</colgroup> 143<tbody> 144<tr> 145<td><p><span class="term"><code class="computeroutput">RandomAccessIter</code></span></p></td> 146<td><p><a href="http://www.cplusplus.com/reference/iterator/RandomAccessIterator/" target="_top">Random access iterator</a> </p></td> 147</tr> 148<tr> 149<td><p><span class="term"><code class="computeroutput">Unsigned_char_type</code></span></p></td> 150<td><p>Unsigned character type used for string.</p></td> 151</tr> 152</tbody> 153</table></div></td> 154</tr> 155<tr> 156<td><p><span class="term">Requires:</span></p></td> 157<td><p>[<code class="computeroutput">first</code>, <code class="computeroutput">last</code>) is a valid range. </p></td> 158</tr> 159<tr> 160<td><p><span class="term">Requires:</span></p></td> 161<td><p><code class="computeroutput">RandomAccessIter</code> <code class="computeroutput">value_type</code> is mutable. </p></td> 162</tr> 163<tr> 164<td><p><span class="term">Requires:</span></p></td> 165<td><p><code class="computeroutput">RandomAccessIter</code> <code class="computeroutput">value_type</code> is <a href="http://en.cppreference.com/w/cpp/concept/LessThanComparable" target="_top">LessThanComparable</a> </p></td> 166</tr> 167<tr> 168<td><p><span class="term">Requires:</span></p></td> 169<td><p><code class="computeroutput">RandomAccessIter</code> <code class="computeroutput">value_type</code> supports the <code class="computeroutput">operator>></code>, which returns an integer-type right-shifted a specified number of bits. </p></td> 170</tr> 171<tr> 172<td><p><span class="term">Postconditions:</span></p></td> 173<td><p>The elements in the range [<code class="computeroutput">first</code>, <code class="computeroutput">last</code>) are sorted in ascending order.</p></td> 174</tr> 175<tr> 176<td><p><span class="term">Returns:</span></p></td> 177<td><p><code class="computeroutput">void</code>.</p></td> 178</tr> 179<tr> 180<td><p><span class="term">Throws:</span></p></td> 181<td>std::exception Propagates exceptions if any of the element comparisons, the element swaps (or moves), the right shift, subtraction of right-shifted elements, functors, or any operations on iterators throw.</td> 182</tr> 183</tbody> 184</table></div> 185</div> 186</div> 187<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 188<td align="left"></td> 189<td align="right"><div class="copyright-footer">Copyright © 2014-2017 Steven 190 Ross, Francisco Tapia, Orson Peters<p> 191 Distributed under the <a href="http://boost.org/LICENSE_1_0.txt" target="_top">Boost 192 Software License, Version 1.0</a>. 193 </p> 194</div></td> 195</tr></table> 196<hr> 197<div class="spirit-nav"> 198<a accesskey="p" href="string_s_idm45878543718144.html"><img src="../../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../../header/boost/sort/spreadsort/string_sort_hpp.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__idm45878543665984.html"><img src="../../../../../../../doc/src/images/next.png" alt="Next"></a> 199</div> 200</body> 201</html> 202
