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5d29a4d1 | 1 | // -*- C++ -*- |
2 | ||
71e45bc2 | 3 | // Copyright (C) 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc. |
5d29a4d1 | 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 | |
6bc9506f | 8 | // Foundation; either version 3, or (at your option) any later |
5d29a4d1 | 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 | ||
6bc9506f | 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/>. | |
5d29a4d1 | 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 | ||
5d29a4d1 | 34 | #include <bits/cpp_type_traits.h> |
35 | #include <ext/type_traits.h> | |
36 | ||
2948dd21 | 37 | namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) |
38 | { | |
39 | _GLIBCXX_BEGIN_NAMESPACE_VERSION | |
5d29a4d1 | 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); | |
ee620c0d | 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); | |
5d29a4d1 | 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 | ||
ee620c0d | 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__, \ | |
d14ad2bf | 90 | __LDBL_MANT_DIG__) * 643L / 2136) |
ee620c0d | 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 | ||
5d29a4d1 | 99 | template<typename _Value> |
100 | struct __numeric_traits_floating | |
101 | { | |
102 | // Only floating point types. See N1822. | |
ee620c0d | 103 | static const int __max_digits10 = __glibcxx_max_digits10(_Value); |
104 | ||
105 | // See above comment... | |
82785173 | 106 | static const bool __is_signed = true; |
ee620c0d | 107 | static const int __digits10 = __glibcxx_digits10(_Value); |
108 | static const int __max_exponent10 = __glibcxx_max_exponent10(_Value); | |
5d29a4d1 | 109 | }; |
110 | ||
111 | template<typename _Value> | |
112 | const int __numeric_traits_floating<_Value>::__max_digits10; | |
113 | ||
82785173 | 114 | template<typename _Value> |
115 | const bool __numeric_traits_floating<_Value>::__is_signed; | |
116 | ||
ee620c0d | 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 | ||
5d29a4d1 | 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 | ||
2948dd21 | 130 | _GLIBCXX_END_NAMESPACE_VERSION |
131 | } // namespace | |
5d29a4d1 | 132 | |
ee620c0d | 133 | #undef __glibcxx_floating |
134 | #undef __glibcxx_max_digits10 | |
135 | #undef __glibcxx_digits10 | |
136 | #undef __glibcxx_max_exponent10 | |
5d29a4d1 | 137 | |
138 | #endif |