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Diffstat (limited to 'src/third_party/boost-1.69.0/boost/lexical_cast/detail/inf_nan.hpp')
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1 files changed, 197 insertions, 0 deletions
diff --git a/src/third_party/boost-1.69.0/boost/lexical_cast/detail/inf_nan.hpp b/src/third_party/boost-1.69.0/boost/lexical_cast/detail/inf_nan.hpp new file mode 100644 index 00000000000..2861a369e8c --- /dev/null +++ b/src/third_party/boost-1.69.0/boost/lexical_cast/detail/inf_nan.hpp @@ -0,0 +1,197 @@ +// Copyright Kevlin Henney, 2000-2005. +// Copyright Alexander Nasonov, 2006-2010. +// Copyright Antony Polukhin, 2011-2018. +// +// 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 + |