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  28 <h2><span class="refentrytitle">Function template string_sort</span></h2>
  29 <p>boost::sort::spreadsort::string_sort &#8212; String sort algorithm using random access iterators, wraps using default of unsigned char. (All variants fall back to <code class="computeroutput">std::sort</code> if the data size is too small, &lt; <code class="computeroutput">detail::min_sort_size</code>). </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: &lt;<a class="link" href="../../../header/boost/sort/spreadsort/string_sort_hpp.html" title="Header &lt;boost/sort/spreadsort/string_sort.hpp&gt;">boost/sort/spreadsort/string_sort.hpp</a>&gt;
  33
  34 </span>
  35 <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> RandomAccessIter<span class="special">&gt;</span>
  36   <span class="keyword">void</span> <span class="identifier">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><span class="special">;</span></pre></div>
  37 <div class="refsect1">
  38 <a name="idp79046672"></a><h2>Description</h2>
  39 <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 (&gt;=100kB).<br>
  40 Worst-case performance is <span class="emphasis"><em> O(N * (lg(range)/s + s)) </em></span>, so <code class="computeroutput">integer_sort</code> is asymptotically faster than pure comparison-based algorithms. <code class="computeroutput">s</code> is <code class="computeroutput">max_splits</code>, which defaults to 11, so its worst-case with default settings for 32-bit integers is <span class="emphasis"><em> O(N * ((32/11) </em></span> slow radix-based iterations fast comparison-based iterations).<br>
  41 <br>
  42 Some performance plots of runtime vs. n and log(range) are provided:<br>
  43  <a href="../../../../../doc/graph/windows_string_sort.htm" target="_top">windows_string_sort</a> <br>
  44  <a href="../../../../../doc/graph/osx_string_sort.htm" target="_top">osx_string_sort</a></p>
  45 <p>
  46
  47
  48
  49 </p>
  50 <div class="warning"><table border="0" summary="Warning">
  51 <tr>
  52 <td rowspan="2" align="center" valign="top" width="25"><img alt="[Warning]" src="../../../../../../../doc/src/images/warning.png"></td>
  53 <th align="left">Warning</th>
  54 </tr>
  55 <tr><td align="left" valign="top">
  56 <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>
  57 <p>Invalid arguments cause undefined behaviour. </p>
  58 </td></tr>
  59 </table></div>
  60 <p>
  61 </p>
  62 <div class="note"><table border="0" summary="Note">
  63 <tr>
  64 <td rowspan="2" align="center" valign="top" width="25"><img alt="[Note]" src="../../../../../../../doc/src/images/note.png"></td>
  65 <th align="left">Note</th>
  66 </tr>
  67 <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>
  68 </table></div>
  69 <p>
  70 </p>
  71 <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>
  72 <p>* N is <code class="computeroutput">last</code> - <code class="computeroutput">first</code>, </p>
  73 <p>* K is the log of the range in bits (32 for 32-bit integers using their full range), </p>
  74 <p>* S is a constant called max_splits, defaulting to 11 (except for strings where it is the log of the character size). </p>
  75 <p>
  76 </p>
  77 <div class="variablelist"><table border="0" class="variablelist compact">
  78 <colgroup>
  79 <col align="left" valign="top">
  80 <col>
  81 </colgroup>
  82 <tbody>
  83 <tr>
  84 <td><p><span class="term">Parameters:</span></p></td>
  85 <td><div class="variablelist"><table border="0" class="variablelist compact">
  86 <colgroup>
  87 <col align="left" valign="top">
  88 <col>
  89 </colgroup>
  90 <tbody>
  91 <tr>
  92 <td><p><span class="term"><code class="computeroutput">first</code></span></p></td>
  93 <td><p>Iterator pointer to first element. </p></td>
  94 </tr>
  95 <tr>
  96 <td><p><span class="term"><code class="computeroutput">last</code></span></p></td>
  97 <td><p>Iterator pointing to one beyond the end of data.</p></td>
  98 </tr>
  99 </tbody>
 100 </table></div></td>
 101 </tr>
 102 <tr>
 103 <td><p><span class="term">Requires:</span></p></td>
 104 <td>
 105 <p>[<code class="computeroutput">first</code>, <code class="computeroutput">last</code>) is a valid range. </p>
 106 <p><code class="computeroutput">RandomAccessIter</code> <code class="computeroutput">value_type</code> is mutable. </p>
 107 <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>
 108 <p><code class="computeroutput">RandomAccessIter</code> <code class="computeroutput">value_type</code> supports the <code class="computeroutput">operator&gt;&gt;</code>, which returns an integer-type right-shifted a specified number of bits. </p>
 109 </td>
 110 </tr>
 111 <tr>
 112 <td><p><span class="term">Postconditions:</span></p></td>
 113 <td><p>The elements in the range [<code class="computeroutput">first</code>, <code class="computeroutput">last</code>) are sorted in ascending order.</p></td>
 114 </tr>
 115 <tr>
 116 <td><p><span class="term">Throws:</span></p></td>
 117 <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>
 118 </tr>
 119 </tbody>
 120 </table></div>
 121 </div>
 122 </div>
 123 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 124 <td align="left"></td>
 125 <td align="right"><div class="copyright-footer">Copyright &#169; 2014 Steven Ross<p>
 126         Distributed under the <a href="http://boost.org/LICENSE_1_0.txt" target="_top">Boost
 127         Software License, Version 1.0</a>.
 128       </p>
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