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1 | // Copyright Kevlin Henney, 2000-2005. | |
2 | // Copyright Alexander Nasonov, 2006-2010. | |
3 | // Copyright Antony Polukhin, 2011-2014. | |
4 | // | |
5 | // Distributed under the Boost Software License, Version 1.0. (See | |
6 | // accompanying file LICENSE_1_0.txt or copy at | |
7 | // http://www.boost.org/LICENSE_1_0.txt) | |
8 | // | |
9 | // what: lexical_cast custom keyword cast | |
10 | // who: contributed by Kevlin Henney, | |
11 | // enhanced with contributions from Terje Slettebo, | |
12 | // with additional fixes and suggestions from Gennaro Prota, | |
13 | // Beman Dawes, Dave Abrahams, Daryle Walker, Peter Dimov, | |
14 | // Alexander Nasonov, Antony Polukhin, Justin Viiret, Michael Hofmann, | |
15 | // Cheng Yang, Matthew Bradbury, David W. Birdsall, Pavel Korzh and other Boosters | |
16 | // when: November 2000, March 2003, June 2005, June 2006, March 2011 - 2014 | |
17 | ||
18 | #ifndef BOOST_LEXICAL_CAST_DETAIL_INF_NAN_HPP | |
19 | #define BOOST_LEXICAL_CAST_DETAIL_INF_NAN_HPP | |
20 | ||
21 | #include <boost/config.hpp> | |
22 | #ifdef BOOST_HAS_PRAGMA_ONCE | |
23 | # pragma once | |
24 | #endif | |
25 | ||
26 | #if defined(BOOST_NO_STRINGSTREAM) || defined(BOOST_NO_STD_WSTRING) | |
27 | #define BOOST_LCAST_NO_WCHAR_T | |
28 | #endif | |
29 | ||
30 | #include <cstddef> | |
31 | #include <cstring> | |
32 | #include <boost/limits.hpp> | |
33 | #include <boost/detail/workaround.hpp> | |
34 | #include <boost/math/special_functions/sign.hpp> | |
35 | #include <boost/math/special_functions/fpclassify.hpp> | |
36 | ||
37 | #include <boost/lexical_cast/detail/lcast_char_constants.hpp> | |
38 | ||
39 | namespace boost { | |
40 | namespace detail | |
41 | { | |
42 | template <class CharT> | |
43 | bool lc_iequal(const CharT* val, const CharT* lcase, const CharT* ucase, unsigned int len) BOOST_NOEXCEPT { | |
44 | for( unsigned int i=0; i < len; ++i ) { | |
45 | if ( val[i] != lcase[i] && val[i] != ucase[i] ) return false; | |
46 | } | |
47 | ||
48 | return true; | |
49 | } | |
50 | ||
51 | /* Returns true and sets the correct value if found NaN or Inf. */ | |
52 | template <class CharT, class T> | |
53 | inline bool parse_inf_nan_impl(const CharT* begin, const CharT* end, T& value | |
54 | , const CharT* lc_NAN, const CharT* lc_nan | |
55 | , const CharT* lc_INFINITY, const CharT* lc_infinity | |
56 | , const CharT opening_brace, const CharT closing_brace) BOOST_NOEXCEPT | |
57 | { | |
58 | using namespace std; | |
59 | if (begin == end) return false; | |
60 | const CharT minus = lcast_char_constants<CharT>::minus; | |
61 | const CharT plus = lcast_char_constants<CharT>::plus; | |
62 | const int inifinity_size = 8; // == sizeof("infinity") - 1 | |
63 | ||
64 | /* Parsing +/- */ | |
65 | bool const has_minus = (*begin == minus); | |
66 | if (has_minus || *begin == plus) { | |
67 | ++ begin; | |
68 | } | |
69 | ||
70 | if (end - begin < 3) return false; | |
71 | if (lc_iequal(begin, lc_nan, lc_NAN, 3)) { | |
72 | begin += 3; | |
73 | if (end != begin) { | |
74 | /* It is 'nan(...)' or some bad input*/ | |
75 | ||
76 | if (end - begin < 2) return false; // bad input | |
77 | -- end; | |
78 | if (*begin != opening_brace || *end != closing_brace) return false; // bad input | |
79 | } | |
80 | ||
81 | if( !has_minus ) value = std::numeric_limits<T>::quiet_NaN(); | |
82 | else value = (boost::math::changesign) (std::numeric_limits<T>::quiet_NaN()); | |
83 | return true; | |
84 | } else if ( | |
85 | ( /* 'INF' or 'inf' */ | |
86 | end - begin == 3 // 3 == sizeof('inf') - 1 | |
87 | && lc_iequal(begin, lc_infinity, lc_INFINITY, 3) | |
88 | ) | |
89 | || | |
90 | ( /* 'INFINITY' or 'infinity' */ | |
91 | end - begin == inifinity_size | |
92 | && lc_iequal(begin, lc_infinity, lc_INFINITY, inifinity_size) | |
93 | ) | |
94 | ) | |
95 | { | |
96 | if( !has_minus ) value = std::numeric_limits<T>::infinity(); | |
97 | else value = (boost::math::changesign) (std::numeric_limits<T>::infinity()); | |
98 | return true; | |
99 | } | |
100 | ||
101 | return false; | |
102 | } | |
103 | ||
104 | template <class CharT, class T> | |
105 | bool put_inf_nan_impl(CharT* begin, CharT*& end, const T& value | |
106 | , const CharT* lc_nan | |
107 | , const CharT* lc_infinity) BOOST_NOEXCEPT | |
108 | { | |
109 | using namespace std; | |
110 | const CharT minus = lcast_char_constants<CharT>::minus; | |
111 | if ((boost::math::isnan)(value)) { | |
112 | if ((boost::math::signbit)(value)) { | |
113 | *begin = minus; | |
114 | ++ begin; | |
115 | } | |
116 | ||
117 | memcpy(begin, lc_nan, 3 * sizeof(CharT)); | |
118 | end = begin + 3; | |
119 | return true; | |
120 | } else if ((boost::math::isinf)(value)) { | |
121 | if ((boost::math::signbit)(value)) { | |
122 | *begin = minus; | |
123 | ++ begin; | |
124 | } | |
125 | ||
126 | memcpy(begin, lc_infinity, 3 * sizeof(CharT)); | |
127 | end = begin + 3; | |
128 | return true; | |
129 | } | |
130 | ||
131 | return false; | |
132 | } | |
133 | ||
134 | ||
135 | #ifndef BOOST_LCAST_NO_WCHAR_T | |
136 | template <class T> | |
137 | bool parse_inf_nan(const wchar_t* begin, const wchar_t* end, T& value) BOOST_NOEXCEPT { | |
138 | return parse_inf_nan_impl(begin, end, value | |
139 | , L"NAN", L"nan" | |
140 | , L"INFINITY", L"infinity" | |
141 | , L'(', L')'); | |
142 | } | |
143 | ||
144 | template <class T> | |
145 | bool put_inf_nan(wchar_t* begin, wchar_t*& end, const T& value) BOOST_NOEXCEPT { | |
146 | return put_inf_nan_impl(begin, end, value, L"nan", L"infinity"); | |
147 | } | |
148 | ||
149 | #endif | |
150 | #if !defined(BOOST_NO_CXX11_CHAR16_T) && !defined(BOOST_NO_CXX11_UNICODE_LITERALS) | |
151 | template <class T> | |
152 | bool parse_inf_nan(const char16_t* begin, const char16_t* end, T& value) BOOST_NOEXCEPT { | |
153 | return parse_inf_nan_impl(begin, end, value | |
154 | , u"NAN", u"nan" | |
155 | , u"INFINITY", u"infinity" | |
156 | , u'(', u')'); | |
157 | } | |
158 | ||
159 | template <class T> | |
160 | bool put_inf_nan(char16_t* begin, char16_t*& end, const T& value) BOOST_NOEXCEPT { | |
161 | return put_inf_nan_impl(begin, end, value, u"nan", u"infinity"); | |
162 | } | |
163 | #endif | |
164 | #if !defined(BOOST_NO_CXX11_CHAR32_T) && !defined(BOOST_NO_CXX11_UNICODE_LITERALS) | |
165 | template <class T> | |
166 | bool parse_inf_nan(const char32_t* begin, const char32_t* end, T& value) BOOST_NOEXCEPT { | |
167 | return parse_inf_nan_impl(begin, end, value | |
168 | , U"NAN", U"nan" | |
169 | , U"INFINITY", U"infinity" | |
170 | , U'(', U')'); | |
171 | } | |
172 | ||
173 | template <class T> | |
174 | bool put_inf_nan(char32_t* begin, char32_t*& end, const T& value) BOOST_NOEXCEPT { | |
175 | return put_inf_nan_impl(begin, end, value, U"nan", U"infinity"); | |
176 | } | |
177 | #endif | |
178 | ||
179 | template <class CharT, class T> | |
180 | bool parse_inf_nan(const CharT* begin, const CharT* end, T& value) BOOST_NOEXCEPT { | |
181 | return parse_inf_nan_impl(begin, end, value | |
182 | , "NAN", "nan" | |
183 | , "INFINITY", "infinity" | |
184 | , '(', ')'); | |
185 | } | |
186 | ||
187 | template <class CharT, class T> | |
188 | bool put_inf_nan(CharT* begin, CharT*& end, const T& value) BOOST_NOEXCEPT { | |
189 | return put_inf_nan_impl(begin, end, value, "nan", "infinity"); | |
190 | } | |
191 | } | |
192 | } // namespace boost | |
193 | ||
194 | #undef BOOST_LCAST_NO_WCHAR_T | |
195 | ||
196 | #endif // BOOST_LEXICAL_CAST_DETAIL_INF_NAN_HPP | |
197 |