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
|
// Copyright Kevlin Henney, 2000-2005.
// Copyright Alexander Nasonov, 2006-2010.
// Copyright Antony Polukhin, 2011-2014.
//
// Distributed under the Boost Software License, Version 1.0. (See
// accompanying file LICENSE_1_0.txt or copy at
// http://www.boost.org/LICENSE_1_0.txt)
//
// what: lexical_cast custom keyword cast
// who: contributed by Kevlin Henney,
// enhanced with contributions from Terje Slettebo,
// with additional fixes and suggestions from Gennaro Prota,
// Beman Dawes, Dave Abrahams, Daryle Walker, Peter Dimov,
// Alexander Nasonov, Antony Polukhin, Justin Viiret, Michael Hofmann,
// Cheng Yang, Matthew Bradbury, David W. Birdsall, Pavel Korzh and other Boosters
// when: November 2000, March 2003, June 2005, June 2006, March 2011 - 2014
#ifndef BOOST_LEXICAL_CAST_DETAIL_INF_NAN_HPP
#define BOOST_LEXICAL_CAST_DETAIL_INF_NAN_HPP
#include <boost/config.hpp>
#ifdef BOOST_HAS_PRAGMA_ONCE
# pragma once
#endif
#if defined(BOOST_NO_STRINGSTREAM) || defined(BOOST_NO_STD_WSTRING)
#define BOOST_LCAST_NO_WCHAR_T
#endif
#include <cstddef>
#include <cstring>
#include <boost/limits.hpp>
#include <boost/detail/workaround.hpp>
#include <boost/math/special_functions/sign.hpp>
#include <boost/math/special_functions/fpclassify.hpp>
#include <boost/lexical_cast/detail/lcast_char_constants.hpp>
namespace boost {
namespace detail
{
template <class CharT>
bool lc_iequal(const CharT* val, const CharT* lcase, const CharT* ucase, unsigned int len) BOOST_NOEXCEPT {
for( unsigned int i=0; i < len; ++i ) {
if ( val[i] != lcase[i] && val[i] != ucase[i] ) return false;
}
return true;
}
/* Returns true and sets the correct value if found NaN or Inf. */
template <class CharT, class T>
inline bool parse_inf_nan_impl(const CharT* begin, const CharT* end, T& value
, const CharT* lc_NAN, const CharT* lc_nan
, const CharT* lc_INFINITY, const CharT* lc_infinity
, const CharT opening_brace, const CharT closing_brace) BOOST_NOEXCEPT
{
using namespace std;
if (begin == end) return false;
const CharT minus = lcast_char_constants<CharT>::minus;
const CharT plus = lcast_char_constants<CharT>::plus;
const int inifinity_size = 8; // == sizeof("infinity") - 1
/* Parsing +/- */
bool const has_minus = (*begin == minus);
if (has_minus || *begin == plus) {
++ begin;
}
if (end - begin < 3) return false;
if (lc_iequal(begin, lc_nan, lc_NAN, 3)) {
begin += 3;
if (end != begin) {
/* It is 'nan(...)' or some bad input*/
if (end - begin < 2) return false; // bad input
-- end;
if (*begin != opening_brace || *end != closing_brace) return false; // bad input
}
if( !has_minus ) value = std::numeric_limits<T>::quiet_NaN();
else value = (boost::math::changesign) (std::numeric_limits<T>::quiet_NaN());
return true;
} else if (
( /* 'INF' or 'inf' */
end - begin == 3 // 3 == sizeof('inf') - 1
&& lc_iequal(begin, lc_infinity, lc_INFINITY, 3)
)
||
( /* 'INFINITY' or 'infinity' */
end - begin == inifinity_size
&& lc_iequal(begin, lc_infinity, lc_INFINITY, inifinity_size)
)
)
{
if( !has_minus ) value = std::numeric_limits<T>::infinity();
else value = (boost::math::changesign) (std::numeric_limits<T>::infinity());
return true;
}
return false;
}
template <class CharT, class T>
bool put_inf_nan_impl(CharT* begin, CharT*& end, const T& value
, const CharT* lc_nan
, const CharT* lc_infinity) BOOST_NOEXCEPT
{
using namespace std;
const CharT minus = lcast_char_constants<CharT>::minus;
if ((boost::math::isnan)(value)) {
if ((boost::math::signbit)(value)) {
*begin = minus;
++ begin;
}
memcpy(begin, lc_nan, 3 * sizeof(CharT));
end = begin + 3;
return true;
} else if ((boost::math::isinf)(value)) {
if ((boost::math::signbit)(value)) {
*begin = minus;
++ begin;
}
memcpy(begin, lc_infinity, 3 * sizeof(CharT));
end = begin + 3;
return true;
}
return false;
}
#ifndef BOOST_LCAST_NO_WCHAR_T
template <class T>
bool parse_inf_nan(const wchar_t* begin, const wchar_t* end, T& value) BOOST_NOEXCEPT {
return parse_inf_nan_impl(begin, end, value
, L"NAN", L"nan"
, L"INFINITY", L"infinity"
, L'(', L')');
}
template <class T>
bool put_inf_nan(wchar_t* begin, wchar_t*& end, const T& value) BOOST_NOEXCEPT {
return put_inf_nan_impl(begin, end, value, L"nan", L"infinity");
}
#endif
#if !defined(BOOST_NO_CXX11_CHAR16_T) && !defined(BOOST_NO_CXX11_UNICODE_LITERALS)
template <class T>
bool parse_inf_nan(const char16_t* begin, const char16_t* end, T& value) BOOST_NOEXCEPT {
return parse_inf_nan_impl(begin, end, value
, u"NAN", u"nan"
, u"INFINITY", u"infinity"
, u'(', u')');
}
template <class T>
bool put_inf_nan(char16_t* begin, char16_t*& end, const T& value) BOOST_NOEXCEPT {
return put_inf_nan_impl(begin, end, value, u"nan", u"infinity");
}
#endif
#if !defined(BOOST_NO_CXX11_CHAR32_T) && !defined(BOOST_NO_CXX11_UNICODE_LITERALS)
template <class T>
bool parse_inf_nan(const char32_t* begin, const char32_t* end, T& value) BOOST_NOEXCEPT {
return parse_inf_nan_impl(begin, end, value
, U"NAN", U"nan"
, U"INFINITY", U"infinity"
, U'(', U')');
}
template <class T>
bool put_inf_nan(char32_t* begin, char32_t*& end, const T& value) BOOST_NOEXCEPT {
return put_inf_nan_impl(begin, end, value, U"nan", U"infinity");
}
#endif
template <class CharT, class T>
bool parse_inf_nan(const CharT* begin, const CharT* end, T& value) BOOST_NOEXCEPT {
return parse_inf_nan_impl(begin, end, value
, "NAN", "nan"
, "INFINITY", "infinity"
, '(', ')');
}
template <class CharT, class T>
bool put_inf_nan(CharT* begin, CharT*& end, const T& value) BOOST_NOEXCEPT {
return put_inf_nan_impl(begin, end, value, "nan", "infinity");
}
}
} // namespace boost
#undef BOOST_LCAST_NO_WCHAR_T
#endif // BOOST_LEXICAL_CAST_DETAIL_INF_NAN_HPP
|
