1// -*- C++ -*- 
2 
3// Copyright (C) 2007-2019 Free Software Foundation, Inc. 
4// 
5// This file is part of the GNU ISO C++ Library. This library is free 
6// software; you can redistribute it and/or modify it under the terms 
7// of the GNU General Public License as published by the Free Software 
8// Foundation; either version 3, or (at your option) any later 
9// version. 
10 
11// This library is distributed in the hope that it will be useful, but 
12// WITHOUT ANY WARRANTY; without even the implied warranty of 
13// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 
14// General Public License for more details. 
15 
16// Under Section 7 of GPL version 3, you are granted additional 
17// permissions described in the GCC Runtime Library Exception, version 
18// 3.1, as published by the Free Software Foundation. 
19 
20// You should have received a copy of the GNU General Public License and 
21// a copy of the GCC Runtime Library Exception along with this program; 
22// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see 
23// <http://www.gnu.org/licenses/>. 
24 
25/** @file ext/numeric_traits.h 
26 * This file is a GNU extension to the Standard C++ Library. 
27 */ 
28 
29#ifndef _EXT_NUMERIC_TRAITS 
30#define _EXT_NUMERIC_TRAITS 1 
31 
32#pragma GCC system_header 
33 
34#include <bits/cpp_type_traits.h> 
35#include <ext/type_traits.h> 
36 
37namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) 
38{ 
39_GLIBCXX_BEGIN_NAMESPACE_VERSION 
40 
41 // Compile time constants for builtin types. 
42 // Sadly std::numeric_limits member functions cannot be used for this. 
43#define __glibcxx_signed(_Tp) ((_Tp)(-1) < 0) 
44#define __glibcxx_digits(_Tp) \ 
45 (sizeof(_Tp) * __CHAR_BIT__ - __glibcxx_signed(_Tp)) 
46 
47#define __glibcxx_min(_Tp) \ 
48 (__glibcxx_signed(_Tp) ? (_Tp)1 << __glibcxx_digits(_Tp) : (_Tp)0) 
49 
50#define __glibcxx_max(_Tp) \ 
51 (__glibcxx_signed(_Tp) ? \ 
52 (((((_Tp)1 << (__glibcxx_digits(_Tp) - 1)) - 1) << 1) + 1) : ~(_Tp)0) 
53 
54 template<typename _Value> 
55 struct __numeric_traits_integer 
56 { 
57 // Only integers for initialization of member constant. 
58 static const _Value __min = __glibcxx_min(_Value); 
59 static const _Value __max = __glibcxx_max(_Value); 
60 
61 // NB: these two also available in std::numeric_limits as compile 
62 // time constants, but <limits> is big and we avoid including it. 
63 static const bool __is_signed = __glibcxx_signed(_Value); 
64 static const int __digits = __glibcxx_digits(_Value);  
65 }; 
66 
67 template<typename _Value> 
68 const _Value __numeric_traits_integer<_Value>::__min; 
69 
70 template<typename _Value> 
71 const _Value __numeric_traits_integer<_Value>::__max; 
72 
73 template<typename _Value> 
74 const bool __numeric_traits_integer<_Value>::__is_signed; 
75 
76 template<typename _Value> 
77 const int __numeric_traits_integer<_Value>::__digits; 
78 
79#undef __glibcxx_signed 
80#undef __glibcxx_digits 
81#undef __glibcxx_min 
82#undef __glibcxx_max 
83 
84#define __glibcxx_floating(_Tp, _Fval, _Dval, _LDval) \ 
85 (std::__are_same<_Tp, float>::__value ? _Fval \ 
86 : std::__are_same<_Tp, double>::__value ? _Dval : _LDval) 
87 
88#define __glibcxx_max_digits10(_Tp) \ 
89 (2 + __glibcxx_floating(_Tp, __FLT_MANT_DIG__, __DBL_MANT_DIG__, \ 
90 __LDBL_MANT_DIG__) * 643L / 2136) 
91 
92#define __glibcxx_digits10(_Tp) \ 
93 __glibcxx_floating(_Tp, __FLT_DIG__, __DBL_DIG__, __LDBL_DIG__) 
94 
95#define __glibcxx_max_exponent10(_Tp) \ 
96 __glibcxx_floating(_Tp, __FLT_MAX_10_EXP__, __DBL_MAX_10_EXP__, \ 
97 __LDBL_MAX_10_EXP__) 
98 
99 template<typename _Value> 
100 struct __numeric_traits_floating 
101 { 
102 // Only floating point types. See N1822.  
103 static const int __max_digits10 = __glibcxx_max_digits10(_Value); 
104 
105 // See above comment... 
106 static const bool __is_signed = true; 
107 static const int __digits10 = __glibcxx_digits10(_Value); 
108 static const int __max_exponent10 = __glibcxx_max_exponent10(_Value); 
109 }; 
110 
111 template<typename _Value> 
112 const int __numeric_traits_floating<_Value>::__max_digits10; 
113 
114 template<typename _Value> 
115 const bool __numeric_traits_floating<_Value>::__is_signed; 
116 
117 template<typename _Value> 
118 const int __numeric_traits_floating<_Value>::__digits10; 
119 
120 template<typename _Value> 
121 const int __numeric_traits_floating<_Value>::__max_exponent10; 
122 
123 template<typename _Value> 
124 struct __numeric_traits 
125 : public __conditional_type<std::__is_integer<_Value>::__value, 
126 __numeric_traits_integer<_Value>, 
127 __numeric_traits_floating<_Value> >::__type 
128 { }; 
129 
130_GLIBCXX_END_NAMESPACE_VERSION 
131} // namespace 
132 
133#undef __glibcxx_floating 
134#undef __glibcxx_max_digits10 
135#undef __glibcxx_digits10 
136#undef __glibcxx_max_exponent10 
137 
138#endif  
139