<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "https://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/xhtml;charset=UTF-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=9"/>
<meta name="generator" content="Doxygen 1.8.15"/>
<meta name="viewport" content="width=device-width, initial-scale=1"/>
<title>libstdc++: functional_hash.h Source File</title>
<link href="tabs.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="jquery.js"></script>
<script type="text/javascript" src="dynsections.js"></script>
<link href="navtree.css" rel="stylesheet" type="text/css"/>
<script type="text/javascript" src="resize.js"></script>
<script type="text/javascript" src="navtreedata.js"></script>
<script type="text/javascript" src="navtree.js"></script>
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&dn=gpl-2.0.txt GPL-v2 */
$(document).ready(initResizable);
/* @license-end */</script>
<link href="doxygen.css" rel="stylesheet" type="text/css" />
</head>
<body>
<div id="top"><!-- do not remove this div, it is closed by doxygen! -->
<div id="titlearea">
<table cellspacing="0" cellpadding="0">
<tbody>
<tr style="height: 56px;">
<td id="projectalign" style="padding-left: 0.5em;">
<div id="projectname">libstdc++
</div>
</td>
</tr>
</tbody>
</table>
</div>
<!-- end header part -->
<!-- Generated by Doxygen 1.8.15 -->
</div><!-- top -->
<div id="side-nav" class="ui-resizable side-nav-resizable">
<div id="nav-tree">
<div id="nav-tree-contents">
<div id="nav-sync" class="sync"></div>
</div>
</div>
<div id="splitbar" style="-moz-user-select:none;"
class="ui-resizable-handle">
</div>
</div>
<script type="text/javascript">
/* @license magnet:?xt=urn:btih:cf05388f2679ee054f2beb29a391d25f4e673ac3&dn=gpl-2.0.txt GPL-v2 */
$(document).ready(function(){initNavTree('a00359_source.html','');});
/* @license-end */
</script>
<div id="doc-content">
<div class="header">
<div class="headertitle">
<div class="title">functional_hash.h</div> </div>
</div><!--header-->
<div class="contents">
<a href="a00359.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">// functional_hash.h header -*- C++ -*-</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 (C) 2007-2018 Free Software Foundation, Inc.</span></div><div class="line"><a name="l00004"></a><span class="lineno"> 4</span> <span class="comment">//</span></div><div class="line"><a name="l00005"></a><span class="lineno"> 5</span> <span class="comment">// This file is part of the GNU ISO C++ Library. This library is free</span></div><div class="line"><a name="l00006"></a><span class="lineno"> 6</span> <span class="comment">// software; you can redistribute it and/or modify it under the</span></div><div class="line"><a name="l00007"></a><span class="lineno"> 7</span> <span class="comment">// terms of the GNU General Public License as published by the</span></div><div class="line"><a name="l00008"></a><span class="lineno"> 8</span> <span class="comment">// Free Software Foundation; either version 3, or (at your option)</span></div><div class="line"><a name="l00009"></a><span class="lineno"> 9</span> <span class="comment">// any later version.</span></div><div class="line"><a name="l00010"></a><span class="lineno"> 10</span> </div><div class="line"><a name="l00011"></a><span class="lineno"> 11</span> <span class="comment">// This library is distributed in the hope that it will be useful,</span></div><div class="line"><a name="l00012"></a><span class="lineno"> 12</span> <span class="comment">// but WITHOUT ANY WARRANTY; without even the implied warranty of</span></div><div class="line"><a name="l00013"></a><span class="lineno"> 13</span> <span class="comment">// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the</span></div><div class="line"><a name="l00014"></a><span class="lineno"> 14</span> <span class="comment">// GNU General Public License for more details.</span></div><div class="line"><a name="l00015"></a><span class="lineno"> 15</span> </div><div class="line"><a name="l00016"></a><span class="lineno"> 16</span> <span class="comment">// Under Section 7 of GPL version 3, you are granted additional</span></div><div class="line"><a name="l00017"></a><span class="lineno"> 17</span> <span class="comment">// permissions described in the GCC Runtime Library Exception, version</span></div><div class="line"><a name="l00018"></a><span class="lineno"> 18</span> <span class="comment">// 3.1, as published by the Free Software Foundation.</span></div><div class="line"><a name="l00019"></a><span class="lineno"> 19</span> </div><div class="line"><a name="l00020"></a><span class="lineno"> 20</span> <span class="comment">// You should have received a copy of the GNU General Public License and</span></div><div class="line"><a name="l00021"></a><span class="lineno"> 21</span> <span class="comment">// a copy of the GCC Runtime Library Exception along with this program;</span></div><div class="line"><a name="l00022"></a><span class="lineno"> 22</span> <span class="comment">// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see</span></div><div class="line"><a name="l00023"></a><span class="lineno"> 23</span> <span class="comment">// <http://www.gnu.org/licenses/>.</span></div><div class="line"><a name="l00024"></a><span class="lineno"> 24</span> <span class="comment"></span></div><div class="line"><a name="l00025"></a><span class="lineno"> 25</span> <span class="comment">/** @file bits/functional_hash.h</span></div><div class="line"><a name="l00026"></a><span class="lineno"> 26</span> <span class="comment"> * This is an internal header file, included by other library headers.</span></div><div class="line"><a name="l00027"></a><span class="lineno"> 27</span> <span class="comment"> * Do not attempt to use it directly. @headername{functional}</span></div><div class="line"><a name="l00028"></a><span class="lineno"> 28</span> <span class="comment"> */</span></div><div class="line"><a name="l00029"></a><span class="lineno"> 29</span> </div><div class="line"><a name="l00030"></a><span class="lineno"> 30</span> <span class="preprocessor">#ifndef _FUNCTIONAL_HASH_H</span></div><div class="line"><a name="l00031"></a><span class="lineno"> 31</span> <span class="preprocessor">#define _FUNCTIONAL_HASH_H 1</span></div><div class="line"><a name="l00032"></a><span class="lineno"> 32</span> </div><div class="line"><a name="l00033"></a><span class="lineno"> 33</span> <span class="preprocessor">#pragma GCC system_header</span></div><div class="line"><a name="l00034"></a><span class="lineno"> 34</span> </div><div class="line"><a name="l00035"></a><span class="lineno"> 35</span> <span class="preprocessor">#include <<a class="code" href="a00368.html">bits/hash_bytes.h</a>></span></div><div class="line"><a name="l00036"></a><span class="lineno"> 36</span> </div><div class="line"><a name="l00037"></a><span class="lineno"> 37</span> <span class="keyword">namespace </span><a class="code" href="a01541.html">std</a> _GLIBCXX_VISIBILITY(default)</div><div class="line"><a name="l00038"></a><span class="lineno"> 38</span> {</div><div class="line"><a name="l00039"></a><span class="lineno"> 39</span> _GLIBCXX_BEGIN_NAMESPACE_VERSION</div><div class="line"><a name="l00040"></a><span class="lineno"> 40</span> <span class="comment"></span></div><div class="line"><a name="l00041"></a><span class="lineno"> 41</span> <span class="comment"> /** @defgroup hashes Hashes</span></div><div class="line"><a name="l00042"></a><span class="lineno"> 42</span> <span class="comment"> * @ingroup functors</span></div><div class="line"><a name="l00043"></a><span class="lineno"> 43</span> <span class="comment"> *</span></div><div class="line"><a name="l00044"></a><span class="lineno"> 44</span> <span class="comment"> * Hashing functors taking a variable type and returning a @c std::size_t.</span></div><div class="line"><a name="l00045"></a><span class="lineno"> 45</span> <span class="comment"> *</span></div><div class="line"><a name="l00046"></a><span class="lineno"> 46</span> <span class="comment"> * @{</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> </div><div class="line"><a name="l00049"></a><span class="lineno"> 49</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Result, <span class="keyword">typename</span> _Arg></div><div class="line"><a name="l00050"></a><span class="lineno"> 50</span>  <span class="keyword">struct </span>__hash_base</div><div class="line"><a name="l00051"></a><span class="lineno"> 51</span>  {</div><div class="line"><a name="l00052"></a><span class="lineno"> 52</span>  <span class="keyword">typedef</span> _Result result_type _GLIBCXX17_DEPRECATED;</div><div class="line"><a name="l00053"></a><span class="lineno"> 53</span>  <span class="keyword">typedef</span> _Arg argument_type _GLIBCXX17_DEPRECATED;</div><div class="line"><a name="l00054"></a><span class="lineno"> 54</span>  };</div><div class="line"><a name="l00055"></a><span class="lineno"> 55</span> <span class="comment"></span></div><div class="line"><a name="l00056"></a><span class="lineno"> 56</span> <span class="comment"> /// Primary class template hash.</span></div><div class="line"><a name="l00057"></a><span class="lineno"> 57</span> <span class="comment"></span> <span class="keyword">template</span><<span class="keyword">typename</span> _Tp></div><div class="line"><a name="l00058"></a><span class="lineno"> 58</span>  <span class="keyword">struct </span>hash;</div><div class="line"><a name="l00059"></a><span class="lineno"> 59</span> </div><div class="line"><a name="l00060"></a><span class="lineno"> 60</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Tp, <span class="keyword">typename</span> = <span class="keywordtype">void</span>></div><div class="line"><a name="l00061"></a><span class="lineno"> 61</span>  <span class="keyword">struct </span>__poison_hash</div><div class="line"><a name="l00062"></a><span class="lineno"> 62</span>  {</div><div class="line"><a name="l00063"></a><span class="lineno"> 63</span>  <span class="keyword">static</span> constexpr <span class="keywordtype">bool</span> __enable_hash_call = <span class="keyword">false</span>;</div><div class="line"><a name="l00064"></a><span class="lineno"> 64</span>  <span class="keyword">private</span>:</div><div class="line"><a name="l00065"></a><span class="lineno"> 65</span>  <span class="comment">// Private rather than deleted to be non-trivially-copyable.</span></div><div class="line"><a name="l00066"></a><span class="lineno"> 66</span>  __poison_hash(__poison_hash&&);</div><div class="line"><a name="l00067"></a><span class="lineno"> 67</span>  ~__poison_hash();</div><div class="line"><a name="l00068"></a><span class="lineno"> 68</span>  };</div><div class="line"><a name="l00069"></a><span class="lineno"> 69</span> </div><div class="line"><a name="l00070"></a><span class="lineno"> 70</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Tp></div><div class="line"><a name="l00071"></a><span class="lineno"> 71</span>  <span class="keyword">struct </span>__poison_hash<_Tp, __void_t<decltype(hash<_Tp>()(declval<_Tp>()))>></div><div class="line"><a name="l00072"></a><span class="lineno"> 72</span>  {</div><div class="line"><a name="l00073"></a><span class="lineno"> 73</span>  <span class="keyword">static</span> constexpr <span class="keywordtype">bool</span> __enable_hash_call = <span class="keyword">true</span>;</div><div class="line"><a name="l00074"></a><span class="lineno"> 74</span>  };</div><div class="line"><a name="l00075"></a><span class="lineno"> 75</span> </div><div class="line"><a name="l00076"></a><span class="lineno"> 76</span>  <span class="comment">// Helper struct for SFINAE-poisoning non-enum types.</span></div><div class="line"><a name="l00077"></a><span class="lineno"> 77</span>  template<typename _Tp, bool = is_enum<_Tp>::value></div><div class="line"><a name="l00078"></a><span class="lineno"> 78</span>  <span class="keyword">struct </span>__hash_enum</div><div class="line"><a name="l00079"></a><span class="lineno"> 79</span>  {</div><div class="line"><a name="l00080"></a><span class="lineno"> 80</span>  <span class="keyword">private</span>:</div><div class="line"><a name="l00081"></a><span class="lineno"> 81</span>  <span class="comment">// Private rather than deleted to be non-trivially-copyable.</span></div><div class="line"><a name="l00082"></a><span class="lineno"> 82</span>  __hash_enum(__hash_enum&&);</div><div class="line"><a name="l00083"></a><span class="lineno"> 83</span>  ~__hash_enum();</div><div class="line"><a name="l00084"></a><span class="lineno"> 84</span>  };</div><div class="line"><a name="l00085"></a><span class="lineno"> 85</span> </div><div class="line"><a name="l00086"></a><span class="lineno"> 86</span>  <span class="comment">// Helper struct for hash with enum types.</span></div><div class="line"><a name="l00087"></a><span class="lineno"> 87</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Tp></div><div class="line"><a name="l00088"></a><span class="lineno"> 88</span>  <span class="keyword">struct </span>__hash_enum<_Tp, true> : <span class="keyword">public</span> __hash_base<size_t, _Tp></div><div class="line"><a name="l00089"></a><span class="lineno"> 89</span>  {</div><div class="line"><a name="l00090"></a><span class="lineno"> 90</span>  <span class="keywordtype">size_t</span></div><div class="line"><a name="l00091"></a><span class="lineno"> 91</span>  operator()(_Tp __val) <span class="keyword">const</span> noexcept</div><div class="line"><a name="l00092"></a><span class="lineno"> 92</span>  {</div><div class="line"><a name="l00093"></a><span class="lineno"> 93</span>  <span class="keyword">using</span> __type = <span class="keyword">typename</span> underlying_type<_Tp>::type;</div><div class="line"><a name="l00094"></a><span class="lineno"> 94</span>  <span class="keywordflow">return</span> hash<__type>{}(static_cast<__type>(__val));</div><div class="line"><a name="l00095"></a><span class="lineno"> 95</span>  }</div><div class="line"><a name="l00096"></a><span class="lineno"> 96</span>  };</div><div class="line"><a name="l00097"></a><span class="lineno"> 97</span> <span class="comment"></span></div><div class="line"><a name="l00098"></a><span class="lineno"> 98</span> <span class="comment"> /// Primary class template hash, usable for enum types only.</span></div><div class="line"><a name="l00099"></a><span class="lineno"> 99</span> <span class="comment"></span> <span class="comment">// Use with non-enum types still SFINAES.</span></div><div class="line"><a name="l00100"></a><span class="lineno"> 100</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Tp></div><div class="line"><a name="l00101"></a><span class="lineno"> 101</span>  <span class="keyword">struct </span>hash : __hash_enum<_Tp></div><div class="line"><a name="l00102"></a><span class="lineno"> 102</span>  { };</div><div class="line"><a name="l00103"></a><span class="lineno"> 103</span> <span class="comment"></span></div><div class="line"><a name="l00104"></a><span class="lineno"> 104</span> <span class="comment"> /// Partial specializations for pointer types.</span></div><div class="line"><a name="l00105"></a><span class="lineno"> 105</span> <span class="comment"></span> <span class="keyword">template</span><<span class="keyword">typename</span> _Tp></div><div class="line"><a name="l00106"></a><span class="lineno"><a class="line" href="a05483.html"> 106</a></span>  <span class="keyword">struct </span><a class="code" href="a02839.html">hash</a><_Tp*> : <span class="keyword">public</span> __hash_base<size_t, _Tp*></div><div class="line"><a name="l00107"></a><span class="lineno"> 107</span>  {</div><div class="line"><a name="l00108"></a><span class="lineno"> 108</span>  <span class="keywordtype">size_t</span></div><div class="line"><a name="l00109"></a><span class="lineno"> 109</span>  operator()(_Tp* __p) <span class="keyword">const</span> noexcept</div><div class="line"><a name="l00110"></a><span class="lineno"> 110</span>  { <span class="keywordflow">return</span> reinterpret_cast<size_t>(__p); }</div><div class="line"><a name="l00111"></a><span class="lineno"> 111</span>  };</div><div class="line"><a name="l00112"></a><span class="lineno"> 112</span> </div><div class="line"><a name="l00113"></a><span class="lineno"> 113</span>  <span class="comment">// Explicit specializations for integer types.</span></div><div class="line"><a name="l00114"></a><span class="lineno"> 114</span> <span class="preprocessor">#define _Cxx_hashtable_define_trivial_hash(_Tp) \</span></div><div class="line"><a name="l00115"></a><span class="lineno"> 115</span> <span class="preprocessor"> template<> \</span></div><div class="line"><a name="l00116"></a><span class="lineno"> 116</span> <span class="preprocessor"> struct hash<_Tp> : public __hash_base<size_t, _Tp> \</span></div><div class="line"><a name="l00117"></a><span class="lineno"> 117</span> <span class="preprocessor"> { \</span></div><div class="line"><a name="l00118"></a><span class="lineno"> 118</span> <span class="preprocessor"> size_t \</span></div><div class="line"><a name="l00119"></a><span class="lineno"> 119</span> <span class="preprocessor"> operator()(_Tp __val) const noexcept \</span></div><div class="line"><a name="l00120"></a><span class="lineno"> 120</span> <span class="preprocessor"> { return static_cast<size_t>(__val); } \</span></div><div class="line"><a name="l00121"></a><span class="lineno"> 121</span> <span class="preprocessor"> };</span></div><div class="line"><a name="l00122"></a><span class="lineno"> 122</span> <span class="comment"></span></div><div class="line"><a name="l00123"></a><span class="lineno"> 123</span> <span class="comment"> /// Explicit specialization for bool.</span></div><div class="line"><a name="l00124"></a><span class="lineno"><a class="line" href="a05487.html"> 124</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(<span class="keywordtype">bool</span>)</div><div class="line"><a name="l00125"></a><span class="lineno"> 125</span> </div><div class="line"><a name="l00126"></a><span class="lineno"> 126</span>  <span class="comment">/// Explicit specialization for char.</span></div><div class="line"><a name="l00127"></a><span class="lineno"><a class="line" href="a05491.html"> 127</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(<span class="keywordtype">char</span>)</div><div class="line"><a name="l00128"></a><span class="lineno"> 128</span> <span class="comment"></span></div><div class="line"><a name="l00129"></a><span class="lineno"> 129</span> <span class="comment"> /// Explicit specialization for signed char.</span></div><div class="line"><a name="l00130"></a><span class="lineno"><a class="line" href="a05495.html"> 130</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(<span class="keywordtype">signed</span> <span class="keywordtype">char</span>)</div><div class="line"><a name="l00131"></a><span class="lineno"> 131</span> <span class="comment"></span></div><div class="line"><a name="l00132"></a><span class="lineno"> 132</span> <span class="comment"> /// Explicit specialization for unsigned char.</span></div><div class="line"><a name="l00133"></a><span class="lineno"><a class="line" href="a05499.html"> 133</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(<span class="keywordtype">unsigned</span> <span class="keywordtype">char</span>)</div><div class="line"><a name="l00134"></a><span class="lineno"> 134</span> <span class="comment"></span></div><div class="line"><a name="l00135"></a><span class="lineno"> 135</span> <span class="comment"> /// Explicit specialization for wchar_t.</span></div><div class="line"><a name="l00136"></a><span class="lineno"><a class="line" href="a05503.html"> 136</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(<span class="keywordtype">wchar_t</span>)</div><div class="line"><a name="l00137"></a><span class="lineno"> 137</span> <span class="comment"></span></div><div class="line"><a name="l00138"></a><span class="lineno"> 138</span> <span class="comment"> /// Explicit specialization for char16_t.</span></div><div class="line"><a name="l00139"></a><span class="lineno"><a class="line" href="a05507.html"> 139</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(char16_t)</div><div class="line"><a name="l00140"></a><span class="lineno"> 140</span> <span class="comment"></span></div><div class="line"><a name="l00141"></a><span class="lineno"> 141</span> <span class="comment"> /// Explicit specialization for char32_t.</span></div><div class="line"><a name="l00142"></a><span class="lineno"><a class="line" href="a05511.html"> 142</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(char32_t)</div><div class="line"><a name="l00143"></a><span class="lineno"> 143</span> <span class="comment"></span></div><div class="line"><a name="l00144"></a><span class="lineno"> 144</span> <span class="comment"> /// Explicit specialization for short.</span></div><div class="line"><a name="l00145"></a><span class="lineno"><a class="line" href="a05515.html"> 145</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(<span class="keywordtype">short</span>)</div><div class="line"><a name="l00146"></a><span class="lineno"> 146</span> <span class="comment"></span></div><div class="line"><a name="l00147"></a><span class="lineno"> 147</span> <span class="comment"> /// Explicit specialization for int.</span></div><div class="line"><a name="l00148"></a><span class="lineno"><a class="line" href="a05519.html"> 148</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(<span class="keywordtype">int</span>)</div><div class="line"><a name="l00149"></a><span class="lineno"> 149</span> <span class="comment"></span></div><div class="line"><a name="l00150"></a><span class="lineno"> 150</span> <span class="comment"> /// Explicit specialization for long.</span></div><div class="line"><a name="l00151"></a><span class="lineno"><a class="line" href="a05523.html"> 151</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(<span class="keywordtype">long</span>)</div><div class="line"><a name="l00152"></a><span class="lineno"> 152</span> <span class="comment"></span></div><div class="line"><a name="l00153"></a><span class="lineno"> 153</span> <span class="comment"> /// Explicit specialization for long long.</span></div><div class="line"><a name="l00154"></a><span class="lineno"><a class="line" href="a05527.html"> 154</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(<span class="keywordtype">long</span> <span class="keywordtype">long</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"> /// Explicit specialization for unsigned short.</span></div><div class="line"><a name="l00157"></a><span class="lineno"><a class="line" href="a05531.html"> 157</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(<span class="keywordtype">unsigned</span> <span class="keywordtype">short</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"> /// Explicit specialization for unsigned int.</span></div><div class="line"><a name="l00160"></a><span class="lineno"><a class="line" href="a05535.html"> 160</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(<span class="keywordtype">unsigned</span> <span class="keywordtype">int</span>)</div><div class="line"><a name="l00161"></a><span class="lineno"> 161</span> <span class="comment"></span></div><div class="line"><a name="l00162"></a><span class="lineno"> 162</span> <span class="comment"> /// Explicit specialization for unsigned long.</span></div><div class="line"><a name="l00163"></a><span class="lineno"><a class="line" href="a05539.html"> 163</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(<span class="keywordtype">unsigned</span> <span class="keywordtype">long</span>)</div><div class="line"><a name="l00164"></a><span class="lineno"> 164</span> <span class="comment"></span></div><div class="line"><a name="l00165"></a><span class="lineno"> 165</span> <span class="comment"> /// Explicit specialization for unsigned long long.</span></div><div class="line"><a name="l00166"></a><span class="lineno"><a class="line" href="a05543.html"> 166</a></span> <span class="comment"></span> _Cxx_hashtable_define_trivial_hash(<span class="keywordtype">unsigned</span> <span class="keywordtype">long</span> <span class="keywordtype">long</span>)</div><div class="line"><a name="l00167"></a><span class="lineno"> 167</span> </div><div class="line"><a name="l00168"></a><span class="lineno"> 168</span> <span class="preprocessor">#ifdef __GLIBCXX_TYPE_INT_N_0</span></div><div class="line"><a name="l00169"></a><span class="lineno"> 169</span>  _Cxx_hashtable_define_trivial_hash(__GLIBCXX_TYPE_INT_N_0)</div><div class="line"><a name="l00170"></a><span class="lineno"> 170</span>  _Cxx_hashtable_define_trivial_hash(__GLIBCXX_TYPE_INT_N_0 <span class="keywordtype">unsigned</span>)</div><div class="line"><a name="l00171"></a><span class="lineno"> 171</span> <span class="preprocessor">#endif</span></div><div class="line"><a name="l00172"></a><span class="lineno"> 172</span> <span class="preprocessor">#ifdef __GLIBCXX_TYPE_INT_N_1</span></div><div class="line"><a name="l00173"></a><span class="lineno"> 173</span>  _Cxx_hashtable_define_trivial_hash(__GLIBCXX_TYPE_INT_N_1)</div><div class="line"><a name="l00174"></a><span class="lineno"> 174</span>  _Cxx_hashtable_define_trivial_hash(__GLIBCXX_TYPE_INT_N_1 <span class="keywordtype">unsigned</span>)</div><div class="line"><a name="l00175"></a><span class="lineno"> 175</span> <span class="preprocessor">#endif</span></div><div class="line"><a name="l00176"></a><span class="lineno"> 176</span> <span class="preprocessor">#ifdef __GLIBCXX_TYPE_INT_N_2</span></div><div class="line"><a name="l00177"></a><span class="lineno"> 177</span>  _Cxx_hashtable_define_trivial_hash(__GLIBCXX_TYPE_INT_N_2)</div><div class="line"><a name="l00178"></a><span class="lineno"> 178</span>  _Cxx_hashtable_define_trivial_hash(__GLIBCXX_TYPE_INT_N_2 <span class="keywordtype">unsigned</span>)</div><div class="line"><a name="l00179"></a><span class="lineno"> 179</span> <span class="preprocessor">#endif</span></div><div class="line"><a name="l00180"></a><span class="lineno"> 180</span> <span class="preprocessor">#ifdef __GLIBCXX_TYPE_INT_N_3</span></div><div class="line"><a name="l00181"></a><span class="lineno"> 181</span>  _Cxx_hashtable_define_trivial_hash(__GLIBCXX_TYPE_INT_N_3)</div><div class="line"><a name="l00182"></a><span class="lineno"> 182</span>  _Cxx_hashtable_define_trivial_hash(__GLIBCXX_TYPE_INT_N_3 <span class="keywordtype">unsigned</span>)</div><div class="line"><a name="l00183"></a><span class="lineno"> 183</span> <span class="preprocessor">#endif</span></div><div class="line"><a name="l00184"></a><span class="lineno"> 184</span> </div><div class="line"><a name="l00185"></a><span class="lineno"> 185</span> <span class="preprocessor">#undef _Cxx_hashtable_define_trivial_hash</span></div><div class="line"><a name="l00186"></a><span class="lineno"> 186</span> </div><div class="line"><a name="l00187"></a><span class="lineno"> 187</span>  <span class="keyword">struct </span>_Hash_impl</div><div class="line"><a name="l00188"></a><span class="lineno"> 188</span>  {</div><div class="line"><a name="l00189"></a><span class="lineno"> 189</span>  <span class="keyword">static</span> <span class="keywordtype">size_t</span></div><div class="line"><a name="l00190"></a><span class="lineno"> 190</span>  <a class="code" href="a02839.html">hash</a>(<span class="keyword">const</span> <span class="keywordtype">void</span>* __ptr, <span class="keywordtype">size_t</span> __clength,</div><div class="line"><a name="l00191"></a><span class="lineno"> 191</span>  <span class="keywordtype">size_t</span> __seed = static_cast<size_t>(0xc70f6907UL))</div><div class="line"><a name="l00192"></a><span class="lineno"> 192</span>  { <span class="keywordflow">return</span> _Hash_bytes(__ptr, __clength, __seed); }</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>  <span class="keyword">template</span><<span class="keyword">typename</span> _Tp></div><div class="line"><a name="l00195"></a><span class="lineno"> 195</span>  <span class="keyword">static</span> <span class="keywordtype">size_t</span></div><div class="line"><a name="l00196"></a><span class="lineno"> 196</span>  <a class="code" href="a02839.html">hash</a>(<span class="keyword">const</span> _Tp& __val)</div><div class="line"><a name="l00197"></a><span class="lineno"> 197</span>  { <span class="keywordflow">return</span> <a class="code" href="a02839.html">hash</a>(&__val, <span class="keyword">sizeof</span>(__val)); }</div><div class="line"><a name="l00198"></a><span class="lineno"> 198</span> </div><div class="line"><a name="l00199"></a><span class="lineno"> 199</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Tp></div><div class="line"><a name="l00200"></a><span class="lineno"> 200</span>  <span class="keyword">static</span> <span class="keywordtype">size_t</span></div><div class="line"><a name="l00201"></a><span class="lineno"> 201</span>  __hash_combine(<span class="keyword">const</span> _Tp& __val, <span class="keywordtype">size_t</span> __hash)</div><div class="line"><a name="l00202"></a><span class="lineno"> 202</span>  { <span class="keywordflow">return</span> <a class="code" href="a02839.html">hash</a>(&__val, <span class="keyword">sizeof</span>(__val), __hash); }</div><div class="line"><a name="l00203"></a><span class="lineno"> 203</span>  };</div><div class="line"><a name="l00204"></a><span class="lineno"> 204</span> </div><div class="line"><a name="l00205"></a><span class="lineno"> 205</span>  <span class="comment">// A hash function similar to FNV-1a (see PR59406 for how it differs).</span></div><div class="line"><a name="l00206"></a><span class="lineno"> 206</span>  <span class="keyword">struct </span>_Fnv_hash_impl</div><div class="line"><a name="l00207"></a><span class="lineno"> 207</span>  {</div><div class="line"><a name="l00208"></a><span class="lineno"> 208</span>  <span class="keyword">static</span> <span class="keywordtype">size_t</span></div><div class="line"><a name="l00209"></a><span class="lineno"> 209</span>  <a class="code" href="a02839.html">hash</a>(<span class="keyword">const</span> <span class="keywordtype">void</span>* __ptr, <span class="keywordtype">size_t</span> __clength,</div><div class="line"><a name="l00210"></a><span class="lineno"> 210</span>  <span class="keywordtype">size_t</span> __seed = static_cast<size_t>(2166136261UL))</div><div class="line"><a name="l00211"></a><span class="lineno"> 211</span>  { <span class="keywordflow">return</span> _Fnv_hash_bytes(__ptr, __clength, __seed); }</div><div class="line"><a name="l00212"></a><span class="lineno"> 212</span> </div><div class="line"><a name="l00213"></a><span class="lineno"> 213</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Tp></div><div class="line"><a name="l00214"></a><span class="lineno"> 214</span>  <span class="keyword">static</span> <span class="keywordtype">size_t</span></div><div class="line"><a name="l00215"></a><span class="lineno"> 215</span>  hash(<span class="keyword">const</span> _Tp& __val)</div><div class="line"><a name="l00216"></a><span class="lineno"> 216</span>  { <span class="keywordflow">return</span> hash(&__val, <span class="keyword">sizeof</span>(__val)); }</div><div class="line"><a name="l00217"></a><span class="lineno"> 217</span> </div><div class="line"><a name="l00218"></a><span class="lineno"> 218</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Tp></div><div class="line"><a name="l00219"></a><span class="lineno"> 219</span>  <span class="keyword">static</span> <span class="keywordtype">size_t</span></div><div class="line"><a name="l00220"></a><span class="lineno"> 220</span>  __hash_combine(<span class="keyword">const</span> _Tp& __val, <span class="keywordtype">size_t</span> __hash)</div><div class="line"><a name="l00221"></a><span class="lineno"> 221</span>  { <span class="keywordflow">return</span> hash(&__val, <span class="keyword">sizeof</span>(__val), __hash); }</div><div class="line"><a name="l00222"></a><span class="lineno"> 222</span>  };</div><div class="line"><a name="l00223"></a><span class="lineno"> 223</span> <span class="comment"></span></div><div class="line"><a name="l00224"></a><span class="lineno"> 224</span> <span class="comment"> /// Specialization for float.</span></div><div class="line"><a name="l00225"></a><span class="lineno"> 225</span> <span class="comment"></span> <span class="keyword">template</span><></div><div class="line"><a name="l00226"></a><span class="lineno"><a class="line" href="a05555.html"> 226</a></span>  <span class="keyword">struct </span><a class="code" href="a02839.html">hash</a><float> : <span class="keyword">public</span> __hash_base<size_t, float></div><div class="line"><a name="l00227"></a><span class="lineno"> 227</span>  {</div><div class="line"><a name="l00228"></a><span class="lineno"> 228</span>  <span class="keywordtype">size_t</span></div><div class="line"><a name="l00229"></a><span class="lineno"> 229</span>  operator()(<span class="keywordtype">float</span> __val) <span class="keyword">const</span> noexcept</div><div class="line"><a name="l00230"></a><span class="lineno"> 230</span>  {</div><div class="line"><a name="l00231"></a><span class="lineno"> 231</span>  <span class="comment">// 0 and -0 both hash to zero.</span></div><div class="line"><a name="l00232"></a><span class="lineno"> 232</span>  <span class="keywordflow">return</span> __val != 0.0f ? std::_Hash_impl::hash(__val) : 0;</div><div class="line"><a name="l00233"></a><span class="lineno"> 233</span>  }</div><div class="line"><a name="l00234"></a><span class="lineno"> 234</span>  };</div><div class="line"><a name="l00235"></a><span class="lineno"> 235</span> <span class="comment"></span></div><div class="line"><a name="l00236"></a><span class="lineno"> 236</span> <span class="comment"> /// Specialization for double.</span></div><div class="line"><a name="l00237"></a><span class="lineno"> 237</span> <span class="comment"></span> <span class="keyword">template</span><></div><div class="line"><a name="l00238"></a><span class="lineno"><a class="line" href="a05559.html"> 238</a></span>  <span class="keyword">struct </span><a class="code" href="a02839.html">hash</a><double> : <span class="keyword">public</span> __hash_base<size_t, double></div><div class="line"><a name="l00239"></a><span class="lineno"> 239</span>  {</div><div class="line"><a name="l00240"></a><span class="lineno"> 240</span>  <span class="keywordtype">size_t</span></div><div class="line"><a name="l00241"></a><span class="lineno"> 241</span>  operator()(<span class="keywordtype">double</span> __val) <span class="keyword">const</span> noexcept</div><div class="line"><a name="l00242"></a><span class="lineno"> 242</span>  {</div><div class="line"><a name="l00243"></a><span class="lineno"> 243</span>  <span class="comment">// 0 and -0 both hash to zero.</span></div><div class="line"><a name="l00244"></a><span class="lineno"> 244</span>  <span class="keywordflow">return</span> __val != 0.0 ? std::_Hash_impl::hash(__val) : 0;</div><div class="line"><a name="l00245"></a><span class="lineno"> 245</span>  }</div><div class="line"><a name="l00246"></a><span class="lineno"> 246</span>  };</div><div class="line"><a name="l00247"></a><span class="lineno"> 247</span> <span class="comment"></span></div><div class="line"><a name="l00248"></a><span class="lineno"> 248</span> <span class="comment"> /// Specialization for long double.</span></div><div class="line"><a name="l00249"></a><span class="lineno"> 249</span> <span class="comment"></span> <span class="keyword">template</span><></div><div class="line"><a name="l00250"></a><span class="lineno"><a class="line" href="a05563.html"> 250</a></span>  <span class="keyword">struct </span><a class="code" href="a02839.html">hash</a><long double></div><div class="line"><a name="l00251"></a><span class="lineno"> 251</span>  : <span class="keyword">public</span> __hash_base<size_t, long double></div><div class="line"><a name="l00252"></a><span class="lineno"> 252</span>  {</div><div class="line"><a name="l00253"></a><span class="lineno"> 253</span>  _GLIBCXX_PURE <span class="keywordtype">size_t</span></div><div class="line"><a name="l00254"></a><span class="lineno"> 254</span>  operator()(<span class="keywordtype">long</span> <span class="keywordtype">double</span> __val) <span class="keyword">const</span> noexcept;</div><div class="line"><a name="l00255"></a><span class="lineno"> 255</span>  };</div><div class="line"><a name="l00256"></a><span class="lineno"> 256</span> </div><div class="line"><a name="l00257"></a><span class="lineno"> 257</span>  <span class="comment">// @} group hashes</span></div><div class="line"><a name="l00258"></a><span class="lineno"> 258</span> </div><div class="line"><a name="l00259"></a><span class="lineno"> 259</span>  <span class="comment">// Hint about performance of hash functor. If not fast the hash-based</span></div><div class="line"><a name="l00260"></a><span class="lineno"> 260</span>  <span class="comment">// containers will cache the hash code.</span></div><div class="line"><a name="l00261"></a><span class="lineno"> 261</span>  <span class="comment">// Default behavior is to consider that hashers are fast unless specified</span></div><div class="line"><a name="l00262"></a><span class="lineno"> 262</span>  <span class="comment">// otherwise.</span></div><div class="line"><a name="l00263"></a><span class="lineno"> 263</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Hash></div><div class="line"><a name="l00264"></a><span class="lineno"> 264</span>  <span class="keyword">struct </span>__is_fast_hash : <span class="keyword">public</span> <a class="code" href="a03043.html">std::true_type</a></div><div class="line"><a name="l00265"></a><span class="lineno"> 265</span>  { };</div><div class="line"><a name="l00266"></a><span class="lineno"> 266</span> </div><div class="line"><a name="l00267"></a><span class="lineno"> 267</span>  <span class="keyword">template</span><></div><div class="line"><a name="l00268"></a><span class="lineno"> 268</span>  <span class="keyword">struct </span>__is_fast_hash<hash<long double>> : <span class="keyword">public</span> <a class="code" href="a03043.html">std::false_type</a></div><div class="line"><a name="l00269"></a><span class="lineno"> 269</span>  { };</div><div class="line"><a name="l00270"></a><span class="lineno"> 270</span> </div><div class="line"><a name="l00271"></a><span class="lineno"> 271</span> _GLIBCXX_END_NAMESPACE_VERSION</div><div class="line"><a name="l00272"></a><span class="lineno"> 272</span> } <span class="comment">// namespace</span></div><div class="line"><a name="l00273"></a><span class="lineno"> 273</span> </div><div class="line"><a name="l00274"></a><span class="lineno"> 274</span> <span class="preprocessor">#endif // _FUNCTIONAL_HASH_H</span></div><div class="ttc" id="a00368_html"><div class="ttname"><a href="a00368.html">hash_bytes.h</a></div></div>
<div class="ttc" id="a02839_html"><div class="ttname"><a href="a02839.html">std::hash</a></div><div class="ttdoc">Primary class template hash.</div><div class="ttdef"><b>Definition:</b> <a href="a00155_source.html#l00142">system_error:142</a></div></div>
<div class="ttc" id="a03043_html"><div class="ttname"><a href="a03043.html">std::integral_constant</a></div><div class="ttdoc">integral_constant</div><div class="ttdef"><b>Definition:</b> <a href="a00167_source.html#l00057">type_traits:57</a></div></div>
<div class="ttc" id="a01541_html"><div class="ttname"><a href="a01541.html">std</a></div><div class="ttdoc">ISO C++ entities toplevel namespace is std.</div></div>
</div><!-- fragment --></div><!-- contents -->
</div><!-- doc-content -->
<!-- start footer part -->
<div id="nav-path" class="navpath"><!-- id is needed for treeview function! -->
<ul>
<li class="navelem"><a class="el" href="dir_47f59b4ef76325ed55a7fd4bed4be05b.html">include</a></li><li class="navelem"><a class="el" href="dir_d56d7bef09446c5da887ab10055bb2f4.html">bits</a></li><li class="navelem"><a class="el" href="a00359.html">functional_hash.h</a></li>
<li class="footer">Generated by
<a href="http://www.doxygen.org/index.html">
<img class="footer" src="doxygen.png" alt="doxygen"/></a> 1.8.15 </li>
</ul>
</div>
</body>
</html>
distrib
>
Mageia
>
7
>
armv7hl
>
media
>
core-updates
>
by-pkgid
>
bfb47da7e0322bcb0e23e4b1838d9db9
>
files
>
333
