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<a href="integer__sort_8hpp.html">Go to the documentation of this file.</a><div class="fragment"><div class="line"><a name="l00001"></a><span class="lineno"> 1</span> <span class="comment">//Templated Spreadsort-based implementation of integer_sort</span></div>
<div class="line"><a name="l00002"></a><span class="lineno"> 2</span> </div>
<div class="line"><a name="l00003"></a><span class="lineno"> 3</span> <span class="comment">// Copyright Steven J. Ross 2001 - 2014.</span></div>
<div class="line"><a name="l00004"></a><span class="lineno"> 4</span> <span class="comment">// Distributed under the Boost Software License, Version 1.0.</span></div>
<div class="line"><a name="l00005"></a><span class="lineno"> 5</span> <span class="comment">// (See accompanying file LICENSE_1_0.txt or copy at</span></div>
<div class="line"><a name="l00006"></a><span class="lineno"> 6</span> <span class="comment">// http://www.boost.org/LICENSE_1_0.txt)</span></div>
<div class="line"><a name="l00007"></a><span class="lineno"> 7</span> </div>
<div class="line"><a name="l00008"></a><span class="lineno"> 8</span> <span class="comment">// See http://www.boost.org/libs/sort/ for library home page.</span></div>
<div class="line"><a name="l00009"></a><span class="lineno"> 9</span> </div>
<div class="line"><a name="l00010"></a><span class="lineno"> 10</span> <span class="comment">/*</span></div>
<div class="line"><a name="l00011"></a><span class="lineno"> 11</span> <span class="comment">Some improvements suggested by:</span></div>
<div class="line"><a name="l00012"></a><span class="lineno"> 12</span> <span class="comment">Phil Endecott and Frank Gennari</span></div>
<div class="line"><a name="l00013"></a><span class="lineno"> 13</span> <span class="comment"></span></div>
<div class="line"><a name="l00014"></a><span class="lineno"> 14</span> <span class="comment">Doxygen comments by Paul A. Bristow Jan 2015</span></div>
<div class="line"><a name="l00015"></a><span class="lineno"> 15</span> <span class="comment"></span></div>
<div class="line"><a name="l00016"></a><span class="lineno"> 16</span> <span class="comment">*/</span></div>
<div class="line"><a name="l00017"></a><span class="lineno"> 17</span> </div>
<div class="line"><a name="l00018"></a><span class="lineno"> 18</span> <span class="preprocessor">#ifndef BOOST_INTEGER_SORT_HPP</span></div>
<div class="line"><a name="l00019"></a><span class="lineno"> 19</span> <span class="preprocessor">#define BOOST_INTEGER_SORT_HPP</span></div>
<div class="line"><a name="l00020"></a><span class="lineno"> 20</span> <span class="preprocessor">#include <algorithm></span></div>
<div class="line"><a name="l00021"></a><span class="lineno"> 21</span> <span class="preprocessor">#include <vector></span></div>
<div class="line"><a name="l00022"></a><span class="lineno"> 22</span> <span class="preprocessor">#include <cstring></span></div>
<div class="line"><a name="l00023"></a><span class="lineno"> 23</span> <span class="preprocessor">#include <limits></span></div>
<div class="line"><a name="l00024"></a><span class="lineno"> 24</span> <span class="preprocessor">#include <boost/static_assert.hpp></span></div>
<div class="line"><a name="l00025"></a><span class="lineno"> 25</span> <span class="preprocessor">#include <boost/sort/spreadsort/detail/constants.hpp></span></div>
<div class="line"><a name="l00026"></a><span class="lineno"> 26</span> <span class="preprocessor">#include <boost/sort/spreadsort/detail/integer_sort.hpp></span></div>
<div class="line"><a name="l00027"></a><span class="lineno"> 27</span> </div>
<div class="line"><a name="l00028"></a><span class="lineno"> 28</span> <span class="keyword">namespace </span><a class="code" href="namespaceboost.html">boost</a> {</div>
<div class="line"><a name="l00029"></a><span class="lineno"> 29</span> <span class="keyword">namespace </span>sort {</div>
<div class="line"><a name="l00030"></a><span class="lineno"> 30</span>  <span class="comment">//Top-level sorting call for integers.</span></div>
<div class="line"><a name="l00031"></a><span class="lineno"> 31</span> </div>
<div class="line"><a name="l00032"></a><span class="lineno"> 32</span> <span class="comment"></span></div>
<div class="line"><a name="l00033"></a><span class="lineno"> 33</span> <span class="comment">/*! \brief Integer sort algorithm using random access iterators.</span></div>
<div class="line"><a name="l00034"></a><span class="lineno"> 34</span> <span class="comment"> (All variants fall back to @c std::sort if the data size is too small, < @c detail::min_sort_size).</span></div>
<div class="line"><a name="l00035"></a><span class="lineno"> 35</span> <span class="comment"></span></div>
<div class="line"><a name="l00036"></a><span class="lineno"> 36</span> <span class="comment"> \details @c integer_sort is a fast templated in-place hybrid radix/comparison algorithm,</span></div>
<div class="line"><a name="l00037"></a><span class="lineno"> 37</span> <span class="comment">which in testing tends to be roughly 50% to 2X faster than @c std::sort for large tests (>=100kB).\n</span></div>
<div class="line"><a name="l00038"></a><span class="lineno"> 38</span> <span class="comment">Worst-case performance is <em> O(N * (lg(range)/s + s)) </em>,</span></div>
<div class="line"><a name="l00039"></a><span class="lineno"> 39</span> <span class="comment">so @c integer_sort is asymptotically faster</span></div>
<div class="line"><a name="l00040"></a><span class="lineno"> 40</span> <span class="comment">than pure comparison-based algorithms. @c s is @c max_splits, which defaults to 11,</span></div>
<div class="line"><a name="l00041"></a><span class="lineno"> 41</span> <span class="comment">so its worst-case with default settings for 32-bit integers is</span></div>
<div class="line"><a name="l00042"></a><span class="lineno"> 42</span> <span class="comment"><em> O(N * ((32/11) </em> slow radix-based iterations fast comparison-based iterations).\n\n</span></div>
<div class="line"><a name="l00043"></a><span class="lineno"> 43</span> <span class="comment">Some performance plots of runtime vs. n and log(range) are provided:\n</span></div>
<div class="line"><a name="l00044"></a><span class="lineno"> 44</span> <span class="comment"> <a href="../../doc/graph/windows_integer_sort.htm"> windows_integer_sort</a></span></div>
<div class="line"><a name="l00045"></a><span class="lineno"> 45</span> <span class="comment"> \n</span></div>
<div class="line"><a name="l00046"></a><span class="lineno"> 46</span> <span class="comment"> <a href="../../doc/graph/osx_integer_sort.htm"> osx_integer_sort</a></span></div>
<div class="line"><a name="l00047"></a><span class="lineno"> 47</span> <span class="comment"></span></div>
<div class="line"><a name="l00048"></a><span class="lineno"> 48</span> <span class="comment"></span></div>
<div class="line"><a name="l00049"></a><span class="lineno"> 49</span> <span class="comment"> \tparam RandomAccessIter <a href="http://www.cplusplus.com/reference/iterator/RandomAccessIterator/">Random access iterator</a></span></div>
<div class="line"><a name="l00050"></a><span class="lineno"> 50</span> <span class="comment"> \param[in] first Iterator pointer to first element.</span></div>
<div class="line"><a name="l00051"></a><span class="lineno"> 51</span> <span class="comment"> \param[in] last Iterator pointing to one beyond the end of data.</span></div>
<div class="line"><a name="l00052"></a><span class="lineno"> 52</span> <span class="comment"></span></div>
<div class="line"><a name="l00053"></a><span class="lineno"> 53</span> <span class="comment"> \pre [@c first, @c last) is a valid range.</span></div>
<div class="line"><a name="l00054"></a><span class="lineno"> 54</span> <span class="comment"> \pre @c RandomAccessIter @c value_type is mutable.</span></div>
<div class="line"><a name="l00055"></a><span class="lineno"> 55</span> <span class="comment"> \pre @c RandomAccessIter @c value_type is <a href="http://en.cppreference.com/w/cpp/concept/LessThanComparable">LessThanComparable</a></span></div>
<div class="line"><a name="l00056"></a><span class="lineno"> 56</span> <span class="comment"> \pre @c RandomAccessIter @c value_type supports the @c operator>>,</span></div>
<div class="line"><a name="l00057"></a><span class="lineno"> 57</span> <span class="comment"> which returns an integer-type right-shifted a specified number of bits.</span></div>
<div class="line"><a name="l00058"></a><span class="lineno"> 58</span> <span class="comment"> \post The elements in the range [@c first, @c last) are sorted in ascending order.</span></div>
<div class="line"><a name="l00059"></a><span class="lineno"> 59</span> <span class="comment"></span></div>
<div class="line"><a name="l00060"></a><span class="lineno"> 60</span> <span class="comment"> \throws std::exception Propagates exceptions if any of the element comparisons, the element swaps (or moves),</span></div>
<div class="line"><a name="l00061"></a><span class="lineno"> 61</span> <span class="comment"> the right shift, subtraction of right-shifted elements, functors, or any operations on iterators throw.</span></div>
<div class="line"><a name="l00062"></a><span class="lineno"> 62</span> <span class="comment"></span></div>
<div class="line"><a name="l00063"></a><span class="lineno"> 63</span> <span class="comment"> \warning 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.</span></div>
<div class="line"><a name="l00064"></a><span class="lineno"> 64</span> <span class="comment"> \warning Invalid arguments cause undefined behaviour.</span></div>
<div class="line"><a name="l00065"></a><span class="lineno"> 65</span> <span class="comment"> \note @c spreadsort function provides a wrapper that calls the fastest sorting algorithm available for a data type,</span></div>
<div class="line"><a name="l00066"></a><span class="lineno"> 66</span> <span class="comment"> enabling faster generic-programming.</span></div>
<div class="line"><a name="l00067"></a><span class="lineno"> 67</span> <span class="comment"></span></div>
<div class="line"><a name="l00068"></a><span class="lineno"> 68</span> <span class="comment"> \remark The lesser of <em> O(N*log(N)) </em> comparisons and <em> O(N*log(K/S + S)) </em>operations worst-case, where:</span></div>
<div class="line"><a name="l00069"></a><span class="lineno"> 69</span> <span class="comment"> \remark * N is @c last - @c first,</span></div>
<div class="line"><a name="l00070"></a><span class="lineno"> 70</span> <span class="comment"> \remark * K is the log of the range in bits (32 for 32-bit integers using their full range),</span></div>
<div class="line"><a name="l00071"></a><span class="lineno"> 71</span> <span class="comment"> \remark * S is a constant called max_splits, defaulting to 11 (except for strings where it is the log of the character size).</span></div>
<div class="line"><a name="l00072"></a><span class="lineno"> 72</span> <span class="comment"></span></div>
<div class="line"><a name="l00073"></a><span class="lineno"> 73</span> <span class="comment">*/</span></div>
<div class="line"><a name="l00074"></a><span class="lineno"> 74</span>  <span class="keyword">template</span> <<span class="keyword">class</span> RandomAccessIter></div>
<div class="line"><a name="l00075"></a><span class="lineno"><a class="line" href="namespaceboost_1_1sort.html#ae6ffbcf932699589fd2b93879f209013"> 75</a></span>  <span class="keyword">inline</span> <span class="keywordtype">void</span> <a class="code" href="namespaceboost_1_1sort.html#ae6ffbcf932699589fd2b93879f209013">integer_sort</a>(RandomAccessIter first, RandomAccessIter last)</div>
<div class="line"><a name="l00076"></a><span class="lineno"> 76</span>  {</div>
<div class="line"><a name="l00077"></a><span class="lineno"> 77</span>  <span class="comment">// Don't sort if it's too small to optimize.</span></div>
<div class="line"><a name="l00078"></a><span class="lineno"> 78</span>  <span class="keywordflow">if</span> (last - first < detail::min_sort_size)</div>
<div class="line"><a name="l00079"></a><span class="lineno"> 79</span>  std::sort(first, last);</div>
<div class="line"><a name="l00080"></a><span class="lineno"> 80</span>  <span class="keywordflow">else</span></div>
<div class="line"><a name="l00081"></a><span class="lineno"> 81</span>  <a class="code" href="namespaceboost_1_1sort.html#ae50349854aad811f67a540d9b3aa4d4a">detail::integer_sort</a>(first, last, *first >> 0);</div>
<div class="line"><a name="l00082"></a><span class="lineno"> 82</span>  }</div>
<div class="line"><a name="l00083"></a><span class="lineno"> 83</span> <span class="comment"></span></div>
<div class="line"><a name="l00084"></a><span class="lineno"> 84</span> <span class="comment">/*! \brief Integer sort algorithm using random access iterators with both right-shift and user-defined comparison operator.</span></div>
<div class="line"><a name="l00085"></a><span class="lineno"> 85</span> <span class="comment"> (All variants fall back to @c std::sort if the data size is too small, < @c detail::min_sort_size).</span></div>
<div class="line"><a name="l00086"></a><span class="lineno"> 86</span> <span class="comment"></span></div>
<div class="line"><a name="l00087"></a><span class="lineno"> 87</span> <span class="comment"> \details @c integer_sort is a fast templated in-place hybrid radix/comparison algorithm,</span></div>
<div class="line"><a name="l00088"></a><span class="lineno"> 88</span> <span class="comment">which in testing tends to be roughly 50% to 2X faster than @c std::sort for large tests (>=100kB).\n</span></div>
<div class="line"><a name="l00089"></a><span class="lineno"> 89</span> <span class="comment">Worst-case performance is <em> O(N * (lg(range)/s + s)) </em>,</span></div>
<div class="line"><a name="l00090"></a><span class="lineno"> 90</span> <span class="comment">so @c integer_sort is asymptotically faster</span></div>
<div class="line"><a name="l00091"></a><span class="lineno"> 91</span> <span class="comment">than pure comparison-based algorithms. @c s is @c max_splits, which defaults to 11,</span></div>
<div class="line"><a name="l00092"></a><span class="lineno"> 92</span> <span class="comment">so its worst-case with default settings for 32-bit integers is</span></div>
<div class="line"><a name="l00093"></a><span class="lineno"> 93</span> <span class="comment"><em> O(N * ((32/11) </em> slow radix-based iterations fast comparison-based iterations).\n\n</span></div>
<div class="line"><a name="l00094"></a><span class="lineno"> 94</span> <span class="comment">Some performance plots of runtime vs. n and log(range) are provided:\n</span></div>
<div class="line"><a name="l00095"></a><span class="lineno"> 95</span> <span class="comment"> <a href="../../doc/graph/windows_integer_sort.htm"> windows_integer_sort</a></span></div>
<div class="line"><a name="l00096"></a><span class="lineno"> 96</span> <span class="comment"> \n</span></div>
<div class="line"><a name="l00097"></a><span class="lineno"> 97</span> <span class="comment"> <a href="../../doc/graph/osx_integer_sort.htm"> osx_integer_sort</a></span></div>
<div class="line"><a name="l00098"></a><span class="lineno"> 98</span> <span class="comment"></span></div>
<div class="line"><a name="l00099"></a><span class="lineno"> 99</span> <span class="comment"> \tparam RandomAccessIter <a href="http://www.cplusplus.com/reference/iterator/RandomAccessIterator/">Random access iterator</a></span></div>
<div class="line"><a name="l00100"></a><span class="lineno"> 100</span> <span class="comment"> \tparam Right_shift functor for right-shift by parameter @c shift bits.</span></div>
<div class="line"><a name="l00101"></a><span class="lineno"> 101</span> <span class="comment"> \tparam Comp To provide @c operator< for user-defined comparison.</span></div>
<div class="line"><a name="l00102"></a><span class="lineno"> 102</span> <span class="comment"></span></div>
<div class="line"><a name="l00103"></a><span class="lineno"> 103</span> <span class="comment"> \param[in] first Iterator pointer to first element.</span></div>
<div class="line"><a name="l00104"></a><span class="lineno"> 104</span> <span class="comment"> \param[in] last Iterator pointing to one beyond the end of data.</span></div>
<div class="line"><a name="l00105"></a><span class="lineno"> 105</span> <span class="comment"> \param[in] shift Number of bits to right-shift (using functor).</span></div>
<div class="line"><a name="l00106"></a><span class="lineno"> 106</span> <span class="comment"> \param[in] comp comparison functor.</span></div>
<div class="line"><a name="l00107"></a><span class="lineno"> 107</span> <span class="comment"></span></div>
<div class="line"><a name="l00108"></a><span class="lineno"> 108</span> <span class="comment"> \pre [@c first, @c last) is a valid range.</span></div>
<div class="line"><a name="l00109"></a><span class="lineno"> 109</span> <span class="comment"> \pre @c RandomAccessIter @c value_type is mutable.</span></div>
<div class="line"><a name="l00110"></a><span class="lineno"> 110</span> <span class="comment"> \pre @c RandomAccessIter @c value_type is <a href="http://en.cppreference.com/w/cpp/concept/LessThanComparable">LessThanComparable</a></span></div>
<div class="line"><a name="l00111"></a><span class="lineno"> 111</span> <span class="comment"> \pre @c RandomAccessIter @c value_type supports the @c operator>>,</span></div>
<div class="line"><a name="l00112"></a><span class="lineno"> 112</span> <span class="comment"> which returns an integer-type right-shifted a specified number of bits.</span></div>
<div class="line"><a name="l00113"></a><span class="lineno"> 113</span> <span class="comment"> \post The elements in the range [@c first, @c last) are sorted in ascending order.</span></div>
<div class="line"><a name="l00114"></a><span class="lineno"> 114</span> <span class="comment"></span></div>
<div class="line"><a name="l00115"></a><span class="lineno"> 115</span> <span class="comment"> \return @c void.</span></div>
<div class="line"><a name="l00116"></a><span class="lineno"> 116</span> <span class="comment"></span></div>
<div class="line"><a name="l00117"></a><span class="lineno"> 117</span> <span class="comment"> \throws std::exception Propagates exceptions if any of the element comparisons, the element swaps (or moves),</span></div>
<div class="line"><a name="l00118"></a><span class="lineno"> 118</span> <span class="comment"> the right shift, subtraction of right-shifted elements, functors,</span></div>
<div class="line"><a name="l00119"></a><span class="lineno"> 119</span> <span class="comment"> or any operations on iterators throw.</span></div>
<div class="line"><a name="l00120"></a><span class="lineno"> 120</span> <span class="comment"></span></div>
<div class="line"><a name="l00121"></a><span class="lineno"> 121</span> <span class="comment"> \warning 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.</span></div>
<div class="line"><a name="l00122"></a><span class="lineno"> 122</span> <span class="comment"> \warning Invalid arguments cause undefined behaviour.</span></div>
<div class="line"><a name="l00123"></a><span class="lineno"> 123</span> <span class="comment"> \note @c spreadsort function provides a wrapper that calls the fastest sorting algorithm available for a data type,</span></div>
<div class="line"><a name="l00124"></a><span class="lineno"> 124</span> <span class="comment"> enabling faster generic-programming.</span></div>
<div class="line"><a name="l00125"></a><span class="lineno"> 125</span> <span class="comment"></span></div>
<div class="line"><a name="l00126"></a><span class="lineno"> 126</span> <span class="comment"> \remark The lesser of <em> O(N*log(N)) </em> comparisons and <em> O(N*log(K/S + S)) </em>operations worst-case, where:</span></div>
<div class="line"><a name="l00127"></a><span class="lineno"> 127</span> <span class="comment"> \remark * N is @c last - @c first,</span></div>
<div class="line"><a name="l00128"></a><span class="lineno"> 128</span> <span class="comment"> \remark * K is the log of the range in bits (32 for 32-bit integers using their full range),</span></div>
<div class="line"><a name="l00129"></a><span class="lineno"> 129</span> <span class="comment"> \remark * S is a constant called max_splits, defaulting to 11 (except for strings where it is the log of the character size).</span></div>
<div class="line"><a name="l00130"></a><span class="lineno"> 130</span> <span class="comment">*/</span></div>
<div class="line"><a name="l00131"></a><span class="lineno"> 131</span>  <span class="keyword">template</span> <<span class="keyword">class</span> RandomAccessIter, <span class="keyword">class</span> Right_shift, <span class="keyword">class</span> Compare></div>
<div class="line"><a name="l00132"></a><span class="lineno"><a class="line" href="namespaceboost_1_1sort.html#aa4ebb2541be58f9f0fecd8d7c108b817"> 132</a></span>  <span class="keyword">inline</span> <span class="keywordtype">void</span> <a class="code" href="namespaceboost_1_1sort.html#ae6ffbcf932699589fd2b93879f209013">integer_sort</a>(RandomAccessIter first, RandomAccessIter last,</div>
<div class="line"><a name="l00133"></a><span class="lineno"> 133</span>  Right_shift shift, Compare comp) {</div>
<div class="line"><a name="l00134"></a><span class="lineno"> 134</span>  <span class="keywordflow">if</span> (last - first < detail::min_sort_size)</div>
<div class="line"><a name="l00135"></a><span class="lineno"> 135</span>  std::sort(first, last, comp);</div>
<div class="line"><a name="l00136"></a><span class="lineno"> 136</span>  <span class="keywordflow">else</span></div>
<div class="line"><a name="l00137"></a><span class="lineno"> 137</span>  <a class="code" href="namespaceboost_1_1sort.html#ae50349854aad811f67a540d9b3aa4d4a">detail::integer_sort</a>(first, last, shift(*first, 0), shift, comp);</div>
<div class="line"><a name="l00138"></a><span class="lineno"> 138</span>  }</div>
<div class="line"><a name="l00139"></a><span class="lineno"> 139</span> <span class="comment"></span></div>
<div class="line"><a name="l00140"></a><span class="lineno"> 140</span> <span class="comment">/*! \brief Integer sort algorithm using random access iterators with just right-shift functor.</span></div>
<div class="line"><a name="l00141"></a><span class="lineno"> 141</span> <span class="comment"> (All variants fall back to @c std::sort if the data size is too small, < @c detail::min_sort_size).</span></div>
<div class="line"><a name="l00142"></a><span class="lineno"> 142</span> <span class="comment"></span></div>
<div class="line"><a name="l00143"></a><span class="lineno"> 143</span> <span class="comment"> \details @c integer_sort is a fast templated in-place hybrid radix/comparison algorithm,</span></div>
<div class="line"><a name="l00144"></a><span class="lineno"> 144</span> <span class="comment">which in testing tends to be roughly 50% to 2X faster than @c std::sort for large tests (>=100kB).\n</span></div>
<div class="line"><a name="l00145"></a><span class="lineno"> 145</span> <span class="comment"></span></div>
<div class="line"><a name="l00146"></a><span class="lineno"> 146</span> <span class="comment">\par Performance:</span></div>
<div class="line"><a name="l00147"></a><span class="lineno"> 147</span> <span class="comment">Worst-case performance is <em> O(N * (lg(range)/s + s)) </em>,</span></div>
<div class="line"><a name="l00148"></a><span class="lineno"> 148</span> <span class="comment">so @c integer_sort is asymptotically faster</span></div>
<div class="line"><a name="l00149"></a><span class="lineno"> 149</span> <span class="comment">than pure comparison-based algorithms. @c s is @c max_splits, which defaults to 11,</span></div>
<div class="line"><a name="l00150"></a><span class="lineno"> 150</span> <span class="comment">so its worst-case with default settings for 32-bit integers is</span></div>
<div class="line"><a name="l00151"></a><span class="lineno"> 151</span> <span class="comment"><em> O(N * ((32/11) </em> slow radix-based iterations fast comparison-based iterations).\n\n</span></div>
<div class="line"><a name="l00152"></a><span class="lineno"> 152</span> <span class="comment">Some performance plots of runtime vs. n and log(range) are provided:\n</span></div>
<div class="line"><a name="l00153"></a><span class="lineno"> 153</span> <span class="comment"> * <a href="../../doc/graph/windows_integer_sort.htm"> windows_integer_sort</a>\n</span></div>
<div class="line"><a name="l00154"></a><span class="lineno"> 154</span> <span class="comment"> * <a href="../../doc/graph/osx_integer_sort.htm"> osx_integer_sort</a></span></div>
<div class="line"><a name="l00155"></a><span class="lineno"> 155</span> <span class="comment"></span></div>
<div class="line"><a name="l00156"></a><span class="lineno"> 156</span> <span class="comment"> \tparam RandomAccessIter <a href="http://www.cplusplus.com/reference/iterator/RandomAccessIterator/">Random access iterator</a></span></div>
<div class="line"><a name="l00157"></a><span class="lineno"> 157</span> <span class="comment"> \tparam Right_shift functor for right-shift by parameter @c shift bits.</span></div>
<div class="line"><a name="l00158"></a><span class="lineno"> 158</span> <span class="comment"></span></div>
<div class="line"><a name="l00159"></a><span class="lineno"> 159</span> <span class="comment"> \param[in] first Iterator pointer to first element.</span></div>
<div class="line"><a name="l00160"></a><span class="lineno"> 160</span> <span class="comment"> \param[in] last Iterator pointing to one beyond the end of data.</span></div>
<div class="line"><a name="l00161"></a><span class="lineno"> 161</span> <span class="comment"> \param[in] shift Number of bits to right-shift (using functor).</span></div>
<div class="line"><a name="l00162"></a><span class="lineno"> 162</span> <span class="comment"></span></div>
<div class="line"><a name="l00163"></a><span class="lineno"> 163</span> <span class="comment"> \pre [@c first, @c last) is a valid range.</span></div>
<div class="line"><a name="l00164"></a><span class="lineno"> 164</span> <span class="comment"> \pre @c RandomAccessIter @c value_type is mutable.</span></div>
<div class="line"><a name="l00165"></a><span class="lineno"> 165</span> <span class="comment"> \pre @c RandomAccessIter @c value_type is <a href="http://en.cppreference.com/w/cpp/concept/LessThanComparable">LessThanComparable</a></span></div>
<div class="line"><a name="l00166"></a><span class="lineno"> 166</span> <span class="comment"> \pre @c RandomAccessIter @c value_type supports the @c operator>>,</span></div>
<div class="line"><a name="l00167"></a><span class="lineno"> 167</span> <span class="comment"> which returns an integer-type right-shifted a specified number of bits.</span></div>
<div class="line"><a name="l00168"></a><span class="lineno"> 168</span> <span class="comment"> \post The elements in the range [@c first, @c last) are sorted in ascending order.</span></div>
<div class="line"><a name="l00169"></a><span class="lineno"> 169</span> <span class="comment"></span></div>
<div class="line"><a name="l00170"></a><span class="lineno"> 170</span> <span class="comment"> \throws std::exception Propagates exceptions if any of the element comparisons, the element swaps (or moves),</span></div>
<div class="line"><a name="l00171"></a><span class="lineno"> 171</span> <span class="comment"> the right shift, subtraction of right-shifted elements, functors,</span></div>
<div class="line"><a name="l00172"></a><span class="lineno"> 172</span> <span class="comment"> or any operations on iterators throw.</span></div>
<div class="line"><a name="l00173"></a><span class="lineno"> 173</span> <span class="comment"></span></div>
<div class="line"><a name="l00174"></a><span class="lineno"> 174</span> <span class="comment"> \warning 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.</span></div>
<div class="line"><a name="l00175"></a><span class="lineno"> 175</span> <span class="comment"> \warning Invalid arguments cause undefined behaviour.</span></div>
<div class="line"><a name="l00176"></a><span class="lineno"> 176</span> <span class="comment"> \note @c spreadsort function provides a wrapper that calls the fastest sorting algorithm available for a data type,</span></div>
<div class="line"><a name="l00177"></a><span class="lineno"> 177</span> <span class="comment"> enabling faster generic-programming.</span></div>
<div class="line"><a name="l00178"></a><span class="lineno"> 178</span> <span class="comment"></span></div>
<div class="line"><a name="l00179"></a><span class="lineno"> 179</span> <span class="comment"> \remark The lesser of <em> O(N*log(N)) </em> comparisons and <em> O(N*log(K/S + S)) </em>operations worst-case, where:</span></div>
<div class="line"><a name="l00180"></a><span class="lineno"> 180</span> <span class="comment"> \remark * N is @c last - @c first,</span></div>
<div class="line"><a name="l00181"></a><span class="lineno"> 181</span> <span class="comment"> \remark * K is the log of the range in bits (32 for 32-bit integers using their full range),</span></div>
<div class="line"><a name="l00182"></a><span class="lineno"> 182</span> <span class="comment"> \remark * S is a constant called max_splits, defaulting to 11 (except for strings where it is the log of the character size).</span></div>
<div class="line"><a name="l00183"></a><span class="lineno"> 183</span> <span class="comment"></span></div>
<div class="line"><a name="l00184"></a><span class="lineno"> 184</span> <span class="comment">*/</span></div>
<div class="line"><a name="l00185"></a><span class="lineno"> 185</span>  <span class="keyword">template</span> <<span class="keyword">class</span> RandomAccessIter, <span class="keyword">class</span> Right_shift></div>
<div class="line"><a name="l00186"></a><span class="lineno"><a class="line" href="namespaceboost_1_1sort.html#ae50349854aad811f67a540d9b3aa4d4a"> 186</a></span>  <span class="keyword">inline</span> <span class="keywordtype">void</span> <a class="code" href="namespaceboost_1_1sort.html#ae6ffbcf932699589fd2b93879f209013">integer_sort</a>(RandomAccessIter first, RandomAccessIter last,</div>
<div class="line"><a name="l00187"></a><span class="lineno"> 187</span>  Right_shift shift) {</div>
<div class="line"><a name="l00188"></a><span class="lineno"> 188</span>  <span class="keywordflow">if</span> (last - first < detail::min_sort_size)</div>
<div class="line"><a name="l00189"></a><span class="lineno"> 189</span>  std::sort(first, last);</div>
<div class="line"><a name="l00190"></a><span class="lineno"> 190</span>  <span class="keywordflow">else</span></div>
<div class="line"><a name="l00191"></a><span class="lineno"> 191</span>  <a class="code" href="namespaceboost_1_1sort.html#ae50349854aad811f67a540d9b3aa4d4a">detail::integer_sort</a>(first, last, shift(*first, 0), shift);</div>
<div class="line"><a name="l00192"></a><span class="lineno"> 192</span>  }</div>
<div class="line"><a name="l00193"></a><span class="lineno"> 193</span> }</div>
<div class="line"><a name="l00194"></a><span class="lineno"> 194</span> }</div>
<div class="line"><a name="l00195"></a><span class="lineno"> 195</span> </div>
<div class="line"><a name="l00196"></a><span class="lineno"> 196</span> <span class="preprocessor">#endif</span></div>
<div class="line"><a name="l00197"></a><span class="lineno"> 197</span> </div>
<div class="ttc" id="namespaceboost_1_1sort_html_ae6ffbcf932699589fd2b93879f209013"><div class="ttname"><a href="namespaceboost_1_1sort.html#ae6ffbcf932699589fd2b93879f209013">boost::sort::integer_sort</a></div><div class="ttdeci">void integer_sort(RandomAccessIter first, RandomAccessIter last)</div><div class="ttdoc">Integer sort algorithm using random access iterators. (All variants fall back to std::sort if the dat...</div><div class="ttdef"><b>Definition:</b> integer_sort.hpp:75</div></div>
<div class="ttc" id="namespaceboost_html"><div class="ttname"><a href="namespaceboost.html">boost</a></div><div class="ttdef"><b>Definition:</b> float_sort.hpp:27</div></div>
<div class="ttc" id="namespaceboost_1_1sort_html_ae50349854aad811f67a540d9b3aa4d4a"><div class="ttname"><a href="namespaceboost_1_1sort.html#ae50349854aad811f67a540d9b3aa4d4a">boost::sort::integer_sort</a></div><div class="ttdeci">void integer_sort(RandomAccessIter first, RandomAccessIter last, Right_shift shift)</div><div class="ttdoc">Integer sort algorithm using random access iterators with just right-shift functor. (All variants fall back to std::sort if the data size is too small, < detail::min_sort_size). </div><div class="ttdef"><b>Definition:</b> integer_sort.hpp:186</div></div>
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