[ceph.git] / ceph / src / boost / boost / lexical_cast / detail / inf_nan.hpp

// Copyright Kevlin Henney, 2000-2005.
// Copyright Alexander Nasonov, 2006-2010.
// Copyright Antony Polukhin, 2011-2019.
//
// 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
Commit	Line	Data
7c673cae FG	1	// Copyright Kevlin Henney, 2000-2005.
7c673cae FG	2	// Copyright Alexander Nasonov, 2006-2010.
92f5a8d4	3	// Copyright Antony Polukhin, 2011-2019.
7c673cae FG	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