1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
|
// -*- C++ -*-
// Copyright (C) 2007-2020 Free Software Foundation, Inc.
//
// This file is part of the GNU ISO C++ Library. This library is free
// software; you can redistribute it and/or modify it under the terms
// of the GNU General Public License as published by the Free Software
// Foundation; either version 3, or (at your option) any later
// version.
// This library is distributed in the hope that it will be useful, but
// WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
// General Public License for more details.
// Under Section 7 of GPL version 3, you are granted additional
// permissions described in the GCC Runtime Library Exception, version
// 3.1, as published by the Free Software Foundation.
// You should have received a copy of the GNU General Public License and
// a copy of the GCC Runtime Library Exception along with this program;
// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
// <http://www.gnu.org/licenses/>.
/** @file ext/numeric_traits.h
* This file is a GNU extension to the Standard C++ Library.
*/
#ifndef _EXT_NUMERIC_TRAITS
#define _EXT_NUMERIC_TRAITS 1
#pragma GCC system_header
#include <bits/cpp_type_traits.h>
#include <ext/type_traits.h>
namespace __gnu_cxx _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
// Compile time constants for builtin types.
// In C++98 std::numeric_limits member functions are not constant expressions
// (that changed in C++11 with the addition of 'constexpr').
// Even for C++11, this header is smaller than <limits> and can be used
// when only is_signed, digits, min, or max values are needed for integers,
// or is_signed, digits10, max_digits10, or max_exponent10 for floats.
// Unlike __is_integer (and std::is_integral) this trait is true for
// non-standard built-in integer types such as __int128 and __int20.
template<typename _Tp>
struct __is_integer_nonstrict
: public std::__is_integer<_Tp>
{
using std::__is_integer<_Tp>::__value;
// The number of bits in the value representation.
enum { __width = __value ? sizeof(_Tp) * __CHAR_BIT__ : 0 };
};
template<typename _Value>
struct __numeric_traits_integer
{
#if __cplusplus >= 201103L
static_assert(__is_integer_nonstrict<_Value>::__value,
"invalid specialization");
#endif
// NB: these two are also available in std::numeric_limits as compile
// time constants, but <limits> is big and we can avoid including it.
static const bool __is_signed = (_Value)(-1) < 0;
static const int __digits
= __is_integer_nonstrict<_Value>::__width - __is_signed;
// The initializers must be constants so that __max and __min are too.
static const _Value __max = __is_signed
? (((((_Value)1 << (__digits - 1)) - 1) << 1) + 1)
: ~(_Value)0;
static const _Value __min = __is_signed ? -__max - 1 : (_Value)0;
};
template<typename _Value>
const _Value __numeric_traits_integer<_Value>::__min;
template<typename _Value>
const _Value __numeric_traits_integer<_Value>::__max;
template<typename _Value>
const bool __numeric_traits_integer<_Value>::__is_signed;
template<typename _Value>
const int __numeric_traits_integer<_Value>::__digits;
// Enable __numeric_traits_integer for types where the __is_integer_nonstrict
// primary template doesn't give the right answer.
#define _GLIBCXX_INT_N_TRAITS(T, WIDTH) \
template<> struct __is_integer_nonstrict<T> \
{ \
enum { __value = 1 }; \
typedef std::__true_type __type; \
enum { __width = WIDTH }; \
}; \
template<> struct __is_integer_nonstrict<unsigned T> \
{ \
enum { __value = 1 }; \
typedef std::__true_type __type; \
enum { __width = WIDTH }; \
};
// We need to specify the width for some __intNN types because they
// have padding bits, e.g. the object representation of __int20 has 32 bits,
// but its width (number of bits in the value representation) is only 20.
#if defined __GLIBCXX_TYPE_INT_N_0 && __GLIBCXX_BITSIZE_INT_N_0 % __CHAR_BIT__
_GLIBCXX_INT_N_TRAITS(__GLIBCXX_TYPE_INT_N_0, __GLIBCXX_BITSIZE_INT_N_0)
#endif
#if defined __GLIBCXX_TYPE_INT_N_1 && __GLIBCXX_BITSIZE_INT_N_1 % __CHAR_BIT__
_GLIBCXX_INT_N_TRAITS(__GLIBCXX_TYPE_INT_N_1, __GLIBCXX_BITSIZE_INT_N_1)
#endif
#if defined __GLIBCXX_TYPE_INT_N_2 && __GLIBCXX_BITSIZE_INT_N_2 % __CHAR_BIT__
_GLIBCXX_INT_N_TRAITS(__GLIBCXX_TYPE_INT_N_2, __GLIBCXX_BITSIZE_INT_N_2)
#endif
#if defined __GLIBCXX_TYPE_INT_N_3 && __GLIBCXX_BITSIZE_INT_N_3 % __CHAR_BIT__
_GLIBCXX_INT_N_TRAITS(__GLIBCXX_TYPE_INT_N_3, __GLIBCXX_BITSIZE_INT_N_3)
#endif
#if defined __STRICT_ANSI__ && defined __SIZEOF_INT128__
// In strict modes __is_integer<__int128> is false,
// but we still want to define __numeric_traits_integer<__int128>.
_GLIBCXX_INT_N_TRAITS(__int128, 128)
#endif
#undef _GLIBCXX_INT_N_TRAITS
#if __cplusplus >= 201103L
/// Convenience alias for __numeric_traits<integer-type>.
template<typename _Tp>
using __int_traits = __numeric_traits_integer<_Tp>;
#endif
#define __glibcxx_floating(_Tp, _Fval, _Dval, _LDval) \
(std::__are_same<_Tp, float>::__value ? _Fval \
: std::__are_same<_Tp, double>::__value ? _Dval : _LDval)
#define __glibcxx_max_digits10(_Tp) \
(2 + __glibcxx_floating(_Tp, __FLT_MANT_DIG__, __DBL_MANT_DIG__, \
__LDBL_MANT_DIG__) * 643L / 2136)
#define __glibcxx_digits10(_Tp) \
__glibcxx_floating(_Tp, __FLT_DIG__, __DBL_DIG__, __LDBL_DIG__)
#define __glibcxx_max_exponent10(_Tp) \
__glibcxx_floating(_Tp, __FLT_MAX_10_EXP__, __DBL_MAX_10_EXP__, \
__LDBL_MAX_10_EXP__)
// N.B. this only supports float, double and long double (no __float128 etc.)
template<typename _Value>
struct __numeric_traits_floating
{
// Only floating point types. See N1822.
static const int __max_digits10 = __glibcxx_max_digits10(_Value);
// See above comment...
static const bool __is_signed = true;
static const int __digits10 = __glibcxx_digits10(_Value);
static const int __max_exponent10 = __glibcxx_max_exponent10(_Value);
};
template<typename _Value>
const int __numeric_traits_floating<_Value>::__max_digits10;
template<typename _Value>
const bool __numeric_traits_floating<_Value>::__is_signed;
template<typename _Value>
const int __numeric_traits_floating<_Value>::__digits10;
template<typename _Value>
const int __numeric_traits_floating<_Value>::__max_exponent10;
#undef __glibcxx_floating
#undef __glibcxx_max_digits10
#undef __glibcxx_digits10
#undef __glibcxx_max_exponent10
template<typename _Value>
struct __numeric_traits
: public __numeric_traits_integer<_Value>
{ };
template<>
struct __numeric_traits<float>
: public __numeric_traits_floating<float>
{ };
template<>
struct __numeric_traits<double>
: public __numeric_traits_floating<double>
{ };
template<>
struct __numeric_traits<long double>
: public __numeric_traits_floating<long double>
{ };
#ifdef _GLIBCXX_LONG_DOUBLE_ALT128_COMPAT
# if defined __LONG_DOUBLE_IEEE128__
// long double is __ieee128, define traits for __ibm128
template<>
struct __numeric_traits_floating<__ibm128>
{
static const int __max_digits10 = 33;
static const bool __is_signed = true;
static const int __digits10 = 31;
static const int __max_exponent10 = 308;
};
template<>
struct __numeric_traits<__ibm128>
: public __numeric_traits_floating<__ibm128>
{ };
# elif defined __LONG_DOUBLE_IBM128__
// long double is __ibm128, define traits for __ieee128
template<>
struct __numeric_traits_floating<__ieee128>
{
static const int __max_digits10 = 36;
static const bool __is_signed = true;
static const int __digits10 = 33;
static const int __max_exponent10 = 4932;
};
template<>
struct __numeric_traits<__ieee128>
: public __numeric_traits_floating<__ieee128>
{ };
# endif
#endif
_GLIBCXX_END_NAMESPACE_VERSION
} // namespace
#endif
|
