Chris@102: // Copyright Kevlin Henney, 2000-2005.
Chris@102: // Copyright Alexander Nasonov, 2006-2010.
Chris@102: // Copyright Antony Polukhin, 2011-2014.
Chris@102: //
Chris@102: // Distributed under the Boost Software License, Version 1.0. (See
Chris@102: // accompanying file LICENSE_1_0.txt or copy at
Chris@102: // http://www.boost.org/LICENSE_1_0.txt)
Chris@102: //
Chris@102: // what:  lexical_cast custom keyword cast
Chris@102: // who:   contributed by Kevlin Henney,
Chris@102: //        enhanced with contributions from Terje Slettebo,
Chris@102: //        with additional fixes and suggestions from Gennaro Prota,
Chris@102: //        Beman Dawes, Dave Abrahams, Daryle Walker, Peter Dimov,
Chris@102: //        Alexander Nasonov, Antony Polukhin, Justin Viiret, Michael Hofmann,
Chris@102: //        Cheng Yang, Matthew Bradbury, David W. Birdsall, Pavel Korzh and other Boosters
Chris@102: // when:  November 2000, March 2003, June 2005, June 2006, March 2011 - 2014
Chris@102: 
Chris@102: #ifndef BOOST_LEXICAL_CAST_DETAIL_INF_NAN_HPP
Chris@102: #define BOOST_LEXICAL_CAST_DETAIL_INF_NAN_HPP
Chris@102: 
Chris@102: #include <boost/config.hpp>
Chris@102: #ifdef BOOST_HAS_PRAGMA_ONCE
Chris@102: #   pragma once
Chris@102: #endif
Chris@102: 
Chris@102: #if defined(BOOST_NO_STRINGSTREAM) || defined(BOOST_NO_STD_WSTRING)
Chris@102: #define BOOST_LCAST_NO_WCHAR_T
Chris@102: #endif
Chris@102: 
Chris@102: #include <cstddef>
Chris@102: #include <cstring>
Chris@102: #include <boost/limits.hpp>
Chris@102: #include <boost/detail/workaround.hpp>
Chris@102: #include <boost/math/special_functions/sign.hpp>
Chris@102: #include <boost/math/special_functions/fpclassify.hpp>
Chris@102: 
Chris@102: #include <boost/lexical_cast/detail/lcast_char_constants.hpp>
Chris@102: 
Chris@102: namespace boost {
Chris@102:     namespace detail
Chris@102:     {
Chris@102:         template <class CharT>
Chris@102:         bool lc_iequal(const CharT* val, const CharT* lcase, const CharT* ucase, unsigned int len) BOOST_NOEXCEPT {
Chris@102:             for( unsigned int i=0; i < len; ++i ) {
Chris@102:                 if ( val[i] != lcase[i] && val[i] != ucase[i] ) return false;
Chris@102:             }
Chris@102: 
Chris@102:             return true;
Chris@102:         }
Chris@102: 
Chris@102:         /* Returns true and sets the correct value if found NaN or Inf. */
Chris@102:         template <class CharT, class T>
Chris@102:         inline bool parse_inf_nan_impl(const CharT* begin, const CharT* end, T& value
Chris@102:             , const CharT* lc_NAN, const CharT* lc_nan
Chris@102:             , const CharT* lc_INFINITY, const CharT* lc_infinity
Chris@102:             , const CharT opening_brace, const CharT closing_brace) BOOST_NOEXCEPT
Chris@102:         {
Chris@102:             using namespace std;
Chris@102:             if (begin == end) return false;
Chris@102:             const CharT minus = lcast_char_constants<CharT>::minus;
Chris@102:             const CharT plus = lcast_char_constants<CharT>::plus;
Chris@102:             const int inifinity_size = 8; // == sizeof("infinity") - 1
Chris@102: 
Chris@102:             /* Parsing +/- */
Chris@102:             bool const has_minus = (*begin == minus);
Chris@102:             if (has_minus || *begin == plus) {
Chris@102:                 ++ begin;
Chris@102:             }
Chris@102: 
Chris@102:             if (end - begin < 3) return false;
Chris@102:             if (lc_iequal(begin, lc_nan, lc_NAN, 3)) {
Chris@102:                 begin += 3;
Chris@102:                 if (end != begin) {
Chris@102:                     /* It is 'nan(...)' or some bad input*/
Chris@102:                     
Chris@102:                     if (end - begin < 2) return false; // bad input
Chris@102:                     -- end;
Chris@102:                     if (*begin != opening_brace || *end != closing_brace) return false; // bad input
Chris@102:                 }
Chris@102: 
Chris@102:                 if( !has_minus ) value = std::numeric_limits<T>::quiet_NaN();
Chris@102:                 else value = (boost::math::changesign) (std::numeric_limits<T>::quiet_NaN());
Chris@102:                 return true;
Chris@102:             } else if (
Chris@102:                 ( /* 'INF' or 'inf' */
Chris@102:                   end - begin == 3      // 3 == sizeof('inf') - 1
Chris@102:                   && lc_iequal(begin, lc_infinity, lc_INFINITY, 3)
Chris@102:                 )
Chris@102:                 ||
Chris@102:                 ( /* 'INFINITY' or 'infinity' */
Chris@102:                   end - begin == inifinity_size
Chris@102:                   && lc_iequal(begin, lc_infinity, lc_INFINITY, inifinity_size)
Chris@102:                 )
Chris@102:              )
Chris@102:             {
Chris@102:                 if( !has_minus ) value = std::numeric_limits<T>::infinity();
Chris@102:                 else value = (boost::math::changesign) (std::numeric_limits<T>::infinity());
Chris@102:                 return true;
Chris@102:             }
Chris@102: 
Chris@102:             return false;
Chris@102:         }
Chris@102: 
Chris@102:         template <class CharT, class T>
Chris@102:         bool put_inf_nan_impl(CharT* begin, CharT*& end, const T& value
Chris@102:                          , const CharT* lc_nan
Chris@102:                          , const CharT* lc_infinity) BOOST_NOEXCEPT
Chris@102:         {
Chris@102:             using namespace std;
Chris@102:             const CharT minus = lcast_char_constants<CharT>::minus;
Chris@102:             if ((boost::math::isnan)(value)) {
Chris@102:                 if ((boost::math::signbit)(value)) {
Chris@102:                     *begin = minus;
Chris@102:                     ++ begin;
Chris@102:                 }
Chris@102: 
Chris@102:                 memcpy(begin, lc_nan, 3 * sizeof(CharT));
Chris@102:                 end = begin + 3;
Chris@102:                 return true;
Chris@102:             } else if ((boost::math::isinf)(value)) {
Chris@102:                 if ((boost::math::signbit)(value)) {
Chris@102:                     *begin = minus;
Chris@102:                     ++ begin;
Chris@102:                 }
Chris@102: 
Chris@102:                 memcpy(begin, lc_infinity, 3 * sizeof(CharT));
Chris@102:                 end = begin + 3;
Chris@102:                 return true;
Chris@102:             }
Chris@102: 
Chris@102:             return false;
Chris@102:         }
Chris@102: 
Chris@102: 
Chris@102: #ifndef BOOST_LCAST_NO_WCHAR_T
Chris@102:         template <class T>
Chris@102:         bool parse_inf_nan(const wchar_t* begin, const wchar_t* end, T& value) BOOST_NOEXCEPT {
Chris@102:             return parse_inf_nan_impl(begin, end, value
Chris@102:                                , L"NAN", L"nan"
Chris@102:                                , L"INFINITY", L"infinity"
Chris@102:                                , L'(', L')');
Chris@102:         }
Chris@102: 
Chris@102:         template <class T>
Chris@102:         bool put_inf_nan(wchar_t* begin, wchar_t*& end, const T& value) BOOST_NOEXCEPT {
Chris@102:             return put_inf_nan_impl(begin, end, value, L"nan", L"infinity");
Chris@102:         }
Chris@102: 
Chris@102: #endif
Chris@102: #if !defined(BOOST_NO_CXX11_CHAR16_T) && !defined(BOOST_NO_CXX11_UNICODE_LITERALS)
Chris@102:         template <class T>
Chris@102:         bool parse_inf_nan(const char16_t* begin, const char16_t* end, T& value) BOOST_NOEXCEPT {
Chris@102:             return parse_inf_nan_impl(begin, end, value
Chris@102:                                , u"NAN", u"nan"
Chris@102:                                , u"INFINITY", u"infinity"
Chris@102:                                , u'(', u')');
Chris@102:         }
Chris@102: 
Chris@102:         template <class T>
Chris@102:         bool put_inf_nan(char16_t* begin, char16_t*& end, const T& value) BOOST_NOEXCEPT {
Chris@102:             return put_inf_nan_impl(begin, end, value, u"nan", u"infinity");
Chris@102:         }
Chris@102: #endif
Chris@102: #if !defined(BOOST_NO_CXX11_CHAR32_T) && !defined(BOOST_NO_CXX11_UNICODE_LITERALS)
Chris@102:         template <class T>
Chris@102:         bool parse_inf_nan(const char32_t* begin, const char32_t* end, T& value) BOOST_NOEXCEPT {
Chris@102:             return parse_inf_nan_impl(begin, end, value
Chris@102:                                , U"NAN", U"nan"
Chris@102:                                , U"INFINITY", U"infinity"
Chris@102:                                , U'(', U')');
Chris@102:         }
Chris@102: 
Chris@102:         template <class T>
Chris@102:         bool put_inf_nan(char32_t* begin, char32_t*& end, const T& value) BOOST_NOEXCEPT {
Chris@102:             return put_inf_nan_impl(begin, end, value, U"nan", U"infinity");
Chris@102:         }
Chris@102: #endif
Chris@102: 
Chris@102:         template <class CharT, class T>
Chris@102:         bool parse_inf_nan(const CharT* begin, const CharT* end, T& value) BOOST_NOEXCEPT {
Chris@102:             return parse_inf_nan_impl(begin, end, value
Chris@102:                                , "NAN", "nan"
Chris@102:                                , "INFINITY", "infinity"
Chris@102:                                , '(', ')');
Chris@102:         }
Chris@102: 
Chris@102:         template <class CharT, class T>
Chris@102:         bool put_inf_nan(CharT* begin, CharT*& end, const T& value) BOOST_NOEXCEPT {
Chris@102:             return put_inf_nan_impl(begin, end, value, "nan", "infinity");
Chris@102:         }
Chris@102:     }
Chris@102: } // namespace boost
Chris@102: 
Chris@102: #undef BOOST_LCAST_NO_WCHAR_T
Chris@102: 
Chris@102: #endif // BOOST_LEXICAL_CAST_DETAIL_INF_NAN_HPP
Chris@102: