<!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++: numeric_traits.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('a01055_source.html','');}); /* @license-end */ </script> <div id="doc-content"> <div class="header"> <div class="headertitle"> <div class="title">numeric_traits.h</div> </div> </div><!--header--> <div class="contents"> <a href="a01055.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">// -*- 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 terms</span></div><div class="line"><a name="l00007"></a><span class="lineno"> 7</span> <span class="comment">// of the GNU General Public License as published by the Free Software</span></div><div class="line"><a name="l00008"></a><span class="lineno"> 8</span> <span class="comment">// Foundation; either version 3, or (at your option) any later</span></div><div class="line"><a name="l00009"></a><span class="lineno"> 9</span> <span class="comment">// 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, but</span></div><div class="line"><a name="l00012"></a><span class="lineno"> 12</span> <span class="comment">// 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 GNU</span></div><div class="line"><a name="l00014"></a><span class="lineno"> 14</span> <span class="comment">// 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 ext/numeric_traits.h</span></div><div class="line"><a name="l00026"></a><span class="lineno"> 26</span> <span class="comment"> * This file is a GNU extension to the Standard C++ Library.</span></div><div class="line"><a name="l00027"></a><span class="lineno"> 27</span> <span class="comment"> */</span></div><div class="line"><a name="l00028"></a><span class="lineno"> 28</span> </div><div class="line"><a name="l00029"></a><span class="lineno"> 29</span> <span class="preprocessor">#ifndef _EXT_NUMERIC_TRAITS</span></div><div class="line"><a name="l00030"></a><span class="lineno"> 30</span> <span class="preprocessor">#define _EXT_NUMERIC_TRAITS 1</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="preprocessor">#pragma GCC system_header</span></div><div class="line"><a name="l00033"></a><span class="lineno"> 33</span> </div><div class="line"><a name="l00034"></a><span class="lineno"> 34</span> <span class="preprocessor">#include <<a class="code" href="a00311.html">bits/cpp_type_traits.h</a>></span></div><div class="line"><a name="l00035"></a><span class="lineno"> 35</span> <span class="preprocessor">#include <<a class="code" href="a01088.html">ext/type_traits.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="a01544.html">__gnu_cxx</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> </div><div class="line"><a name="l00041"></a><span class="lineno"> 41</span>  <span class="comment">// Compile time constants for builtin types.</span></div><div class="line"><a name="l00042"></a><span class="lineno"> 42</span>  <span class="comment">// Sadly std::numeric_limits member functions cannot be used for this.</span></div><div class="line"><a name="l00043"></a><span class="lineno"> 43</span> <span class="preprocessor">#define __glibcxx_signed(_Tp) ((_Tp)(-1) < 0)</span></div><div class="line"><a name="l00044"></a><span class="lineno"> 44</span> <span class="preprocessor">#define __glibcxx_digits(_Tp) \</span></div><div class="line"><a name="l00045"></a><span class="lineno"> 45</span> <span class="preprocessor"> (sizeof(_Tp) * __CHAR_BIT__ - __glibcxx_signed(_Tp))</span></div><div class="line"><a name="l00046"></a><span class="lineno"> 46</span> </div><div class="line"><a name="l00047"></a><span class="lineno"> 47</span> <span class="preprocessor">#define __glibcxx_min(_Tp) \</span></div><div class="line"><a name="l00048"></a><span class="lineno"> 48</span> <span class="preprocessor"> (__glibcxx_signed(_Tp) ? (_Tp)1 << __glibcxx_digits(_Tp) : (_Tp)0)</span></div><div class="line"><a name="l00049"></a><span class="lineno"> 49</span> </div><div class="line"><a name="l00050"></a><span class="lineno"> 50</span> <span class="preprocessor">#define __glibcxx_max(_Tp) \</span></div><div class="line"><a name="l00051"></a><span class="lineno"> 51</span> <span class="preprocessor"> (__glibcxx_signed(_Tp) ? \</span></div><div class="line"><a name="l00052"></a><span class="lineno"> 52</span> <span class="preprocessor"> (((((_Tp)1 << (__glibcxx_digits(_Tp) - 1)) - 1) << 1) + 1) : ~(_Tp)0)</span></div><div class="line"><a name="l00053"></a><span class="lineno"> 53</span> </div><div class="line"><a name="l00054"></a><span class="lineno"> 54</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Value></div><div class="line"><a name="l00055"></a><span class="lineno"> 55</span>  <span class="keyword">struct </span>__numeric_traits_integer</div><div class="line"><a name="l00056"></a><span class="lineno"> 56</span>  {</div><div class="line"><a name="l00057"></a><span class="lineno"> 57</span>  <span class="comment">// Only integers for initialization of member constant.</span></div><div class="line"><a name="l00058"></a><span class="lineno"> 58</span>  <span class="keyword">static</span> <span class="keyword">const</span> _Value __min = __glibcxx_min(_Value);</div><div class="line"><a name="l00059"></a><span class="lineno"> 59</span>  <span class="keyword">static</span> <span class="keyword">const</span> _Value __max = __glibcxx_max(_Value);</div><div class="line"><a name="l00060"></a><span class="lineno"> 60</span> </div><div class="line"><a name="l00061"></a><span class="lineno"> 61</span>  <span class="comment">// NB: these two also available in std::numeric_limits as compile</span></div><div class="line"><a name="l00062"></a><span class="lineno"> 62</span>  <span class="comment">// time constants, but <limits> is big and we avoid including it.</span></div><div class="line"><a name="l00063"></a><span class="lineno"> 63</span>  <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">bool</span> __is_signed = __glibcxx_signed(_Value);</div><div class="line"><a name="l00064"></a><span class="lineno"> 64</span>  <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">int</span> __digits = __glibcxx_digits(_Value); </div><div class="line"><a name="l00065"></a><span class="lineno"> 65</span>  };</div><div class="line"><a name="l00066"></a><span class="lineno"> 66</span> </div><div class="line"><a name="l00067"></a><span class="lineno"> 67</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Value></div><div class="line"><a name="l00068"></a><span class="lineno"> 68</span>  <span class="keyword">const</span> _Value __numeric_traits_integer<_Value>::__min;</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> _Value></div><div class="line"><a name="l00071"></a><span class="lineno"> 71</span>  <span class="keyword">const</span> _Value __numeric_traits_integer<_Value>::__max;</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">template</span><<span class="keyword">typename</span> _Value></div><div class="line"><a name="l00074"></a><span class="lineno"> 74</span>  <span class="keyword">const</span> <span class="keywordtype">bool</span> __numeric_traits_integer<_Value>::__is_signed;</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="keyword">template</span><<span class="keyword">typename</span> _Value></div><div class="line"><a name="l00077"></a><span class="lineno"> 77</span>  <span class="keyword">const</span> <span class="keywordtype">int</span> __numeric_traits_integer<_Value>::__digits;</div><div class="line"><a name="l00078"></a><span class="lineno"> 78</span> </div><div class="line"><a name="l00079"></a><span class="lineno"> 79</span> <span class="preprocessor">#undef __glibcxx_signed</span></div><div class="line"><a name="l00080"></a><span class="lineno"> 80</span> <span class="preprocessor">#undef __glibcxx_digits</span></div><div class="line"><a name="l00081"></a><span class="lineno"> 81</span> <span class="preprocessor">#undef __glibcxx_min</span></div><div class="line"><a name="l00082"></a><span class="lineno"> 82</span> <span class="preprocessor">#undef __glibcxx_max</span></div><div class="line"><a name="l00083"></a><span class="lineno"> 83</span> </div><div class="line"><a name="l00084"></a><span class="lineno"> 84</span> <span class="preprocessor">#define __glibcxx_floating(_Tp, _Fval, _Dval, _LDval) \</span></div><div class="line"><a name="l00085"></a><span class="lineno"> 85</span> <span class="preprocessor"> (std::__are_same<_Tp, float>::__value ? _Fval \</span></div><div class="line"><a name="l00086"></a><span class="lineno"> 86</span> <span class="preprocessor"> : std::__are_same<_Tp, double>::__value ? _Dval : _LDval)</span></div><div class="line"><a name="l00087"></a><span class="lineno"> 87</span> </div><div class="line"><a name="l00088"></a><span class="lineno"> 88</span> <span class="preprocessor">#define __glibcxx_max_digits10(_Tp) \</span></div><div class="line"><a name="l00089"></a><span class="lineno"> 89</span> <span class="preprocessor"> (2 + __glibcxx_floating(_Tp, __FLT_MANT_DIG__, __DBL_MANT_DIG__, \</span></div><div class="line"><a name="l00090"></a><span class="lineno"> 90</span> <span class="preprocessor"> __LDBL_MANT_DIG__) * 643L / 2136)</span></div><div class="line"><a name="l00091"></a><span class="lineno"> 91</span> </div><div class="line"><a name="l00092"></a><span class="lineno"> 92</span> <span class="preprocessor">#define __glibcxx_digits10(_Tp) \</span></div><div class="line"><a name="l00093"></a><span class="lineno"> 93</span> <span class="preprocessor"> __glibcxx_floating(_Tp, __FLT_DIG__, __DBL_DIG__, __LDBL_DIG__)</span></div><div class="line"><a name="l00094"></a><span class="lineno"> 94</span> </div><div class="line"><a name="l00095"></a><span class="lineno"> 95</span> <span class="preprocessor">#define __glibcxx_max_exponent10(_Tp) \</span></div><div class="line"><a name="l00096"></a><span class="lineno"> 96</span> <span class="preprocessor"> __glibcxx_floating(_Tp, __FLT_MAX_10_EXP__, __DBL_MAX_10_EXP__, \</span></div><div class="line"><a name="l00097"></a><span class="lineno"> 97</span> <span class="preprocessor"> __LDBL_MAX_10_EXP__)</span></div><div class="line"><a name="l00098"></a><span class="lineno"> 98</span> </div><div class="line"><a name="l00099"></a><span class="lineno"> 99</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Value></div><div class="line"><a name="l00100"></a><span class="lineno"> 100</span>  <span class="keyword">struct </span>__numeric_traits_floating</div><div class="line"><a name="l00101"></a><span class="lineno"> 101</span>  {</div><div class="line"><a name="l00102"></a><span class="lineno"> 102</span>  <span class="comment">// Only floating point types. See N1822. </span></div><div class="line"><a name="l00103"></a><span class="lineno"> 103</span>  <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">int</span> __max_digits10 = __glibcxx_max_digits10(_Value);</div><div class="line"><a name="l00104"></a><span class="lineno"> 104</span> </div><div class="line"><a name="l00105"></a><span class="lineno"> 105</span>  <span class="comment">// See above comment...</span></div><div class="line"><a name="l00106"></a><span class="lineno"> 106</span>  <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">bool</span> __is_signed = <span class="keyword">true</span>;</div><div class="line"><a name="l00107"></a><span class="lineno"> 107</span>  <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">int</span> __digits10 = __glibcxx_digits10(_Value);</div><div class="line"><a name="l00108"></a><span class="lineno"> 108</span>  <span class="keyword">static</span> <span class="keyword">const</span> <span class="keywordtype">int</span> __max_exponent10 = __glibcxx_max_exponent10(_Value);</div><div class="line"><a name="l00109"></a><span class="lineno"> 109</span>  };</div><div class="line"><a name="l00110"></a><span class="lineno"> 110</span> </div><div class="line"><a name="l00111"></a><span class="lineno"> 111</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Value></div><div class="line"><a name="l00112"></a><span class="lineno"> 112</span>  <span class="keyword">const</span> <span class="keywordtype">int</span> __numeric_traits_floating<_Value>::__max_digits10;</div><div class="line"><a name="l00113"></a><span class="lineno"> 113</span> </div><div class="line"><a name="l00114"></a><span class="lineno"> 114</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Value></div><div class="line"><a name="l00115"></a><span class="lineno"> 115</span>  <span class="keyword">const</span> <span class="keywordtype">bool</span> __numeric_traits_floating<_Value>::__is_signed;</div><div class="line"><a name="l00116"></a><span class="lineno"> 116</span> </div><div class="line"><a name="l00117"></a><span class="lineno"> 117</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Value></div><div class="line"><a name="l00118"></a><span class="lineno"> 118</span>  <span class="keyword">const</span> <span class="keywordtype">int</span> __numeric_traits_floating<_Value>::__digits10;</div><div class="line"><a name="l00119"></a><span class="lineno"> 119</span> </div><div class="line"><a name="l00120"></a><span class="lineno"> 120</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Value></div><div class="line"><a name="l00121"></a><span class="lineno"> 121</span>  <span class="keyword">const</span> <span class="keywordtype">int</span> __numeric_traits_floating<_Value>::__max_exponent10;</div><div class="line"><a name="l00122"></a><span class="lineno"> 122</span> </div><div class="line"><a name="l00123"></a><span class="lineno"> 123</span>  <span class="keyword">template</span><<span class="keyword">typename</span> _Value></div><div class="line"><a name="l00124"></a><span class="lineno"> 124</span>  <span class="keyword">struct </span>__numeric_traits</div><div class="line"><a name="l00125"></a><span class="lineno"> 125</span>  : <span class="keyword">public</span> __conditional_type<std::__is_integer<_Value>::__value,</div><div class="line"><a name="l00126"></a><span class="lineno"> 126</span>  __numeric_traits_integer<_Value>,</div><div class="line"><a name="l00127"></a><span class="lineno"> 127</span>  __numeric_traits_floating<_Value> >::__type</div><div class="line"><a name="l00128"></a><span class="lineno"> 128</span>  { };</div><div class="line"><a name="l00129"></a><span class="lineno"> 129</span> </div><div class="line"><a name="l00130"></a><span class="lineno"> 130</span> _GLIBCXX_END_NAMESPACE_VERSION</div><div class="line"><a name="l00131"></a><span class="lineno"> 131</span> } <span class="comment">// namespace</span></div><div class="line"><a name="l00132"></a><span class="lineno"> 132</span> </div><div class="line"><a name="l00133"></a><span class="lineno"> 133</span> <span class="preprocessor">#undef __glibcxx_floating</span></div><div class="line"><a name="l00134"></a><span class="lineno"> 134</span> <span class="preprocessor">#undef __glibcxx_max_digits10</span></div><div class="line"><a name="l00135"></a><span class="lineno"> 135</span> <span class="preprocessor">#undef __glibcxx_digits10</span></div><div class="line"><a name="l00136"></a><span class="lineno"> 136</span> <span class="preprocessor">#undef __glibcxx_max_exponent10</span></div><div class="line"><a name="l00137"></a><span class="lineno"> 137</span> </div><div class="line"><a name="l00138"></a><span class="lineno"> 138</span> <span class="preprocessor">#endif </span></div><div class="ttc" id="a01544_html"><div class="ttname"><a href="a01544.html">__gnu_cxx</a></div><div class="ttdoc">GNU extensions for public use.</div></div> <div class="ttc" id="a01088_html"><div class="ttname"><a href="a01088.html">type_traits.h</a></div></div> <div class="ttc" id="a00311_html"><div class="ttname"><a href="a00311.html">cpp_type_traits.h</a></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_3a83f109ff04170a1f8448445d1bdcba.html">include</a></li><li class="navelem"><a class="el" href="dir_d6815ee4ad7be618f033845800be3017.html">ext</a></li><li class="navelem"><a class="el" href="a01055.html">numeric_traits.h</a></li> <li class="footer">Generated by <a href="http://www.doxygen.org/index.html"> <img class="footer" 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