Chris@16: #ifndef BOOST_MATH_NONFINITE_NUM_FACETS_HPP
Chris@16: #define BOOST_MATH_NONFINITE_NUM_FACETS_HPP
Chris@16: 
Chris@16: // Copyright 2006 Johan Rade
Chris@16: // Copyright 2012 K R Walker
Chris@16: // Copyright 2011, 2012 Paul A. Bristow 
Chris@16: 
Chris@16: // Distributed under the Boost Software License, Version 1.0.
Chris@16: // (See accompanying file LICENSE_1_0.txt
Chris@16: // or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: /*
Chris@16: \file
Chris@16: 
Chris@16: \brief non_finite_num facets for C99 standard output of infinity and NaN.
Chris@16: 
Chris@16: \details See fuller documentation at Boost.Math Facets
Chris@16:   for Floating-Point Infinities and NaNs.
Chris@16: */
Chris@16: 
Chris@16: #include <cstring>
Chris@16: #include <ios>
Chris@16: #include <limits>
Chris@16: #include <locale>
Chris@16: 
Chris@16: #include <boost/version.hpp>
Chris@16: 
Chris@16: #include <boost/math/special_functions/fpclassify.hpp>
Chris@16: #include <boost/math/special_functions/sign.hpp>
Chris@16: 
Chris@16: #ifdef _MSC_VER
Chris@16: #  pragma warning(push)
Chris@16: #  pragma warning(disable : 4127) // conditional expression is constant.
Chris@16: #  pragma warning(disable : 4706) // assignment within conditional expression.
Chris@16: #endif
Chris@16: 
Chris@16: namespace boost {
Chris@16:   namespace math {
Chris@16: 
Chris@16:     // flags (enums can be ORed together)       -----------------------------------
Chris@16: 
Chris@16:     const int legacy = 0x1; //!< get facet will recognize most string representations of infinity and NaN.
Chris@16:     const int signed_zero = 0x2; //!< put facet will distinguish between positive and negative zero.
Chris@16:     const int trap_infinity = 0x4; /*!< put facet will throw an exception of type std::ios_base::failure
Chris@16:        when an attempt is made to format positive or negative infinity.
Chris@16:        get will set the fail bit of the stream when an attempt is made
Chris@16:        to parse a string that represents positive or negative sign infinity.
Chris@16:     */
Chris@16:     const int trap_nan = 0x8; /*!< put facet will throw an exception of type std::ios_base::failure
Chris@16:        when an attempt is made to format positive or negative NaN.
Chris@16:        get will set the fail bit of the stream when an attempt is made
Chris@16:        to parse a string that represents positive or negative sign infinity.
Chris@16:        */
Chris@16: 
Chris@16:     // class nonfinite_num_put -----------------------------------------------------
Chris@16: 
Chris@16:     template<
Chris@16:       class CharType,
Chris@16:       class OutputIterator = std::ostreambuf_iterator<CharType>
Chris@16:             >
Chris@16:     class nonfinite_num_put : public std::num_put<CharType, OutputIterator>
Chris@16:     {
Chris@16:     public:
Chris@16:       explicit nonfinite_num_put(int flags = 0) : flags_(flags) {}
Chris@16: 
Chris@16:     protected:
Chris@16:       virtual OutputIterator do_put(
Chris@16:         OutputIterator it, std::ios_base& iosb, CharType fill, double val) const
Chris@16:       {
Chris@16:         put_and_reset_width(it, iosb, fill, val);
Chris@16:         return it;
Chris@16:       }
Chris@16: 
Chris@16:       virtual OutputIterator do_put(
Chris@16:         OutputIterator it, std::ios_base& iosb,  CharType fill, long double val) const
Chris@16:       {
Chris@16:         put_and_reset_width(it, iosb, fill, val);
Chris@16:         return it;
Chris@16:       }
Chris@16: 
Chris@16:     private:
Chris@16:       template<class ValType> void put_and_reset_width(
Chris@16:         OutputIterator& it, std::ios_base& iosb,
Chris@16:         CharType fill, ValType val) const
Chris@16:       {
Chris@16:         put_impl(it, iosb, fill, val);
Chris@16:         iosb.width(0);
Chris@16:       }
Chris@16: 
Chris@16:       template<class ValType> void put_impl(
Chris@16:         OutputIterator& it, std::ios_base& iosb,
Chris@16:         CharType fill, ValType val) const
Chris@16:       {
Chris@16:         static const CharType prefix_plus[2] = { '+', '\0' };
Chris@16:         static const CharType prefix_minus[2] = { '-', '\0' };
Chris@16:         static const CharType body_inf[4] = { 'i', 'n', 'f', '\0' };
Chris@16:         static const CharType body_nan[4] = { 'n', 'a', 'n', '\0' };
Chris@16:         static const CharType* null_string = 0;
Chris@16: 
Chris@16:         switch((boost::math::fpclassify)(val))
Chris@16:         {
Chris@16: 
Chris@16:         case FP_INFINITE:
Chris@16:           if(flags_ & trap_infinity)
Chris@16:           {
Chris@16:             throw std::ios_base::failure("Infinity");
Chris@16:           }
Chris@16:           else if((boost::math::signbit)(val))
Chris@16:           { // negative infinity.
Chris@16:             put_num_and_fill(it, iosb, prefix_minus, body_inf, fill, val);
Chris@16:           }
Chris@16:           else if(iosb.flags() & std::ios_base::showpos)
Chris@16:           { // Explicit "+inf" wanted.
Chris@16:             put_num_and_fill(it, iosb, prefix_plus, body_inf, fill, val);
Chris@16:           }
Chris@16:           else
Chris@16:           { // just "inf" wanted.
Chris@16:             put_num_and_fill(it, iosb, null_string, body_inf, fill, val);
Chris@16:           }
Chris@16:           break;
Chris@16: 
Chris@16:         case FP_NAN:
Chris@16:           if(flags_ & trap_nan)
Chris@16:           {
Chris@16:             throw std::ios_base::failure("NaN");
Chris@16:           }
Chris@16:           else if((boost::math::signbit)(val))
Chris@16:           { // negative so "-nan".
Chris@16:             put_num_and_fill(it, iosb, prefix_minus, body_nan, fill, val);
Chris@16:           }
Chris@16:           else if(iosb.flags() & std::ios_base::showpos)
Chris@16:           { // explicit "+nan" wanted.
Chris@16:             put_num_and_fill(it, iosb, prefix_plus, body_nan, fill, val);
Chris@16:           }
Chris@16:           else
Chris@16:           { // Just "nan".
Chris@16:             put_num_and_fill(it, iosb, null_string, body_nan, fill, val);
Chris@16:           }
Chris@16:           break;
Chris@16: 
Chris@16:         case FP_ZERO:
Chris@16:           if((flags_ & signed_zero) && ((boost::math::signbit)(val)))
Chris@16:           { // Flag set to distinguish between positive and negative zero.
Chris@16:             // But string "0" should have stuff after decimal point if setprecision and/or exp format. 
Chris@16: 
Chris@16:             std::basic_ostringstream<CharType> zeros; // Needs to be CharType version.
Chris@16: 
Chris@16:             // Copy flags, fill, width and precision.
Chris@16:             zeros.flags(iosb.flags());
Chris@16:             zeros.unsetf(std::ios::showpos); // Ignore showpos because must be negative.
Chris@16:             zeros.precision(iosb.precision());
Chris@16:             //zeros.width is set by put_num_and_fill
Chris@16:             zeros.fill(static_cast<char>(fill));
Chris@16:             zeros << ValType(0);
Chris@16:             put_num_and_fill(it, iosb, prefix_minus, zeros.str().c_str(), fill, val);
Chris@16:           }
Chris@16:           else
Chris@16:           { // Output the platform default for positive and negative zero.
Chris@16:             put_num_and_fill(it, iosb, null_string, null_string, fill, val);
Chris@16:           }
Chris@16:           break;
Chris@16: 
Chris@16:         default:  // Normal non-zero finite value.
Chris@16:           it = std::num_put<CharType, OutputIterator>::do_put(it, iosb, fill, val);
Chris@16:           break;
Chris@16:         }
Chris@16:       }
Chris@16: 
Chris@16:       template<class ValType>
Chris@16:       void put_num_and_fill(
Chris@16:         OutputIterator& it, std::ios_base& iosb, const CharType* prefix,
Chris@16:           const CharType* body, CharType fill, ValType val) const
Chris@16:       {
Chris@16:         int prefix_length = prefix ? (int)std::char_traits<CharType>::length(prefix) : 0;
Chris@16:         int body_length = body ? (int)std::char_traits<CharType>::length(body) : 0;
Chris@16:         int width = prefix_length + body_length;
Chris@16:         std::ios_base::fmtflags adjust = iosb.flags() & std::ios_base::adjustfield;
Chris@16:         const std::ctype<CharType>& ct
Chris@16:           = std::use_facet<std::ctype<CharType> >(iosb.getloc());
Chris@16: 
Chris@16:         if(body || prefix)
Chris@16:         { // adjust == std::ios_base::right, so leading fill needed.
Chris@16:           if(adjust != std::ios_base::internal && adjust != std::ios_base::left)
Chris@16:             put_fill(it, iosb, fill, width);
Chris@16:         }
Chris@16: 
Chris@16:         if(prefix)
Chris@16:         { // Adjust width for prefix.
Chris@16:           while(*prefix)
Chris@16:             *it = *(prefix++);
Chris@16:           iosb.width( iosb.width() - prefix_length );
Chris@16:           width -= prefix_length;
Chris@16:         }
Chris@16: 
Chris@16:         if(body)
Chris@16:         { // 
Chris@16:           if(adjust == std::ios_base::internal)
Chris@16:           { // Put fill between sign and digits.
Chris@16:             put_fill(it, iosb, fill, width);
Chris@16:           }
Chris@16:           if(iosb.flags() & std::ios_base::uppercase)
Chris@16:           {
Chris@16:               while(*body)
Chris@16:                 *it = ct.toupper(*(body++));
Chris@16:           }
Chris@16:           else
Chris@16:           {
Chris@16:             while(*body)
Chris@16:               *it = *(body++);
Chris@16:           }
Chris@16: 
Chris@16:           if(adjust == std::ios_base::left)
Chris@16:             put_fill(it, iosb, fill, width);
Chris@16:         }
Chris@16:         else
Chris@16:         {
Chris@16:           it = std::num_put<CharType, OutputIterator>::do_put(it, iosb, fill, val);
Chris@16:         }
Chris@16:       }
Chris@16: 
Chris@16:       void put_fill(
Chris@16:         OutputIterator& it, std::ios_base& iosb, CharType fill, int width) const
Chris@16:       { // Insert fill chars.
Chris@16:         for(std::streamsize i = iosb.width() - static_cast<std::streamsize>(width); i > 0; --i)
Chris@16:           *it = fill;
Chris@16:       }
Chris@16: 
Chris@16:     private:
Chris@16:       const int flags_;
Chris@16:     };
Chris@16: 
Chris@16: 
Chris@16:     // class nonfinite_num_get ------------------------------------------------------
Chris@16: 
Chris@16:     template<
Chris@16:       class CharType,
Chris@16:       class InputIterator = std::istreambuf_iterator<CharType>
Chris@16:     >
Chris@16:     class nonfinite_num_get : public std::num_get<CharType, InputIterator>
Chris@16:     {
Chris@16: 
Chris@16:     public:
Chris@16:       explicit nonfinite_num_get(int flags = 0) : flags_(flags)
Chris@16:       {}
Chris@16: 
Chris@16:     protected:  // float, double and long double versions of do_get.
Chris@16:       virtual InputIterator do_get(
Chris@16:         InputIterator it, InputIterator end, std::ios_base& iosb,
Chris@16:         std::ios_base::iostate& state, float& val) const
Chris@16:       {
Chris@16:         get_and_check_eof(it, end, iosb, state, val);
Chris@16:         return it;
Chris@16:       }
Chris@16: 
Chris@16:       virtual InputIterator do_get(
Chris@16:         InputIterator it, InputIterator end, std::ios_base& iosb,
Chris@16:         std::ios_base::iostate& state, double& val) const
Chris@16:       {
Chris@16:         get_and_check_eof(it, end, iosb, state, val);
Chris@16:         return it;
Chris@16:       }
Chris@16: 
Chris@16:       virtual InputIterator do_get(
Chris@16:         InputIterator it, InputIterator end, std::ios_base& iosb,
Chris@16:         std::ios_base::iostate& state, long double& val) const
Chris@16:       {
Chris@16:         get_and_check_eof(it, end, iosb, state, val);
Chris@16:         return it;
Chris@16:       }
Chris@16: 
Chris@16:       //..............................................................................
Chris@16: 
Chris@16:     private:
Chris@16:       template<class ValType> static ValType positive_nan()
Chris@16:       {
Chris@16:         // On some platforms quiet_NaN() may be negative.
Chris@16:         return (boost::math::copysign)(
Chris@16:           std::numeric_limits<ValType>::quiet_NaN(), static_cast<ValType>(1)
Chris@16:           );
Chris@16:         // static_cast<ValType>(1) added Paul A. Bristow 5 Apr 11
Chris@16:       }
Chris@16: 
Chris@16:       template<class ValType> void get_and_check_eof
Chris@16:       (
Chris@16:         InputIterator& it, InputIterator end, std::ios_base& iosb,
Chris@16:         std::ios_base::iostate& state, ValType& val
Chris@16:       ) const
Chris@16:       {
Chris@16:         get_signed(it, end, iosb, state, val);
Chris@16:         if(it == end)
Chris@16:           state |= std::ios_base::eofbit;
Chris@16:       }
Chris@16: 
Chris@16:       template<class ValType> void get_signed
Chris@16:       (
Chris@16:         InputIterator& it, InputIterator end, std::ios_base& iosb,
Chris@16:         std::ios_base::iostate& state, ValType& val
Chris@16:       ) const
Chris@16:       {
Chris@16:         const std::ctype<CharType>& ct
Chris@16:           = std::use_facet<std::ctype<CharType> >(iosb.getloc());
Chris@16: 
Chris@16:         char c = peek_char(it, end, ct);
Chris@16: 
Chris@16:         bool negative = (c == '-');
Chris@16: 
Chris@16:         if(negative || c == '+')
Chris@16:         {
Chris@16:           ++it;
Chris@16:           c = peek_char(it, end, ct);
Chris@16:           if(c == '-' || c == '+')
Chris@16:           { // Without this check, "++5" etc would be accepted.
Chris@16:             state |= std::ios_base::failbit;
Chris@16:             return;
Chris@16:           }
Chris@16:         }
Chris@16: 
Chris@16:         get_unsigned(it, end, iosb, ct, state, val);
Chris@16: 
Chris@16:         if(negative)
Chris@16:         {
Chris@16:           val = (boost::math::changesign)(val);
Chris@16:         }
Chris@16:       } // void get_signed
Chris@16: 
Chris@16:       template<class ValType> void get_unsigned
Chris@16:       ( //! Get an unsigned floating-point value into val,
Chris@16:         //! but checking for letters indicating non-finites.
Chris@16:         InputIterator& it, InputIterator end, std::ios_base& iosb,
Chris@16:         const std::ctype<CharType>& ct,
Chris@16:         std::ios_base::iostate& state, ValType& val
Chris@16:       ) const
Chris@16:       {
Chris@16:         switch(peek_char(it, end, ct))
Chris@16:         {
Chris@16:         case 'i':
Chris@16:           get_i(it, end, ct, state, val);
Chris@16:           break;
Chris@16: 
Chris@16:         case 'n':
Chris@16:           get_n(it, end, ct, state, val);
Chris@16:           break;
Chris@16: 
Chris@16:         case 'q':
Chris@16:         case 's':
Chris@16:           get_q(it, end, ct, state, val);
Chris@16:           break;
Chris@16: 
Chris@16:         default: // Got a normal floating-point value into val.
Chris@16:           it = std::num_get<CharType, InputIterator>::do_get(
Chris@16:             it, end, iosb, state, val);
Chris@16:           if((flags_ & legacy) && val == static_cast<ValType>(1)
Chris@16:             && peek_char(it, end, ct) == '#')
Chris@16:             get_one_hash(it, end, ct, state, val);
Chris@16:           break;
Chris@16:         }
Chris@16:       } //  get_unsigned
Chris@16: 
Chris@16:       //..........................................................................
Chris@16: 
Chris@16:       template<class ValType> void get_i
Chris@16:       ( // Get the rest of all strings starting with 'i', expect "inf", "infinity".
Chris@16:         InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
Chris@16:         std::ios_base::iostate& state, ValType& val
Chris@16:       ) const
Chris@16:       {
Chris@16:         if(!std::numeric_limits<ValType>::has_infinity
Chris@16:           || (flags_ & trap_infinity))
Chris@16:         {
Chris@16:             state |= std::ios_base::failbit;
Chris@16:             return;
Chris@16:         }
Chris@16: 
Chris@16:         ++it;
Chris@16:         if(!match_string(it, end, ct, "nf"))
Chris@16:         {
Chris@16:           state |= std::ios_base::failbit;
Chris@16:           return;
Chris@16:         }
Chris@16: 
Chris@16:         if(peek_char(it, end, ct) != 'i')
Chris@16:         {
Chris@16:           val = std::numeric_limits<ValType>::infinity();  // "inf"
Chris@16:           return;
Chris@16:         }
Chris@16: 
Chris@16:         ++it;
Chris@16:         if(!match_string(it, end, ct, "nity"))
Chris@16:         { // Expected "infinity"
Chris@16:           state |= std::ios_base::failbit;
Chris@16:           return;
Chris@16:         }
Chris@16: 
Chris@16:         val = std::numeric_limits<ValType>::infinity(); // "infinity"
Chris@16:       } // void get_i
Chris@16: 
Chris@16:       template<class ValType> void get_n
Chris@16:       ( // Get expected strings after 'n', "nan", "nanq", "nans", "nan(...)"
Chris@16:         InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
Chris@16:         std::ios_base::iostate& state, ValType& val
Chris@16:       ) const
Chris@16:       {
Chris@16:         if(!std::numeric_limits<ValType>::has_quiet_NaN
Chris@16:           || (flags_ & trap_nan)) {
Chris@16:             state |= std::ios_base::failbit;
Chris@16:             return;
Chris@16:         }
Chris@16: 
Chris@16:         ++it;
Chris@16:         if(!match_string(it, end, ct, "an"))
Chris@16:         {
Chris@16:           state |= std::ios_base::failbit;
Chris@16:           return;
Chris@16:         }
Chris@16: 
Chris@16:         switch(peek_char(it, end, ct)) {
Chris@16:         case 'q':
Chris@16:         case 's':
Chris@16:           if(flags_ && legacy)
Chris@16:             ++it;
Chris@16:           break;  // "nanq", "nans"
Chris@16: 
Chris@16:         case '(':   // Optional payload field in (...) follows.
Chris@16:          {
Chris@16:             ++it;
Chris@16:             char c;
Chris@16:             while((c = peek_char(it, end, ct))
Chris@16:               && c != ')' && c != ' ' && c != '\n' && c != '\t')
Chris@16:               ++it;
Chris@16:             if(c != ')')
Chris@16:             { // Optional payload field terminator missing!
Chris@16:               state |= std::ios_base::failbit;
Chris@16:               return;
Chris@16:             }
Chris@16:             ++it;
Chris@16:             break;  // "nan(...)"
Chris@16:           }
Chris@16: 
Chris@16:         default:
Chris@16:           break;  // "nan"
Chris@16:         }
Chris@16: 
Chris@16:         val = positive_nan<ValType>();
Chris@16:       } // void get_n
Chris@16: 
Chris@16:       template<class ValType> void get_q
Chris@16:       ( // Get expected rest of string starting with 'q': "qnan".
Chris@16:         InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
Chris@16:         std::ios_base::iostate& state, ValType& val
Chris@16:       ) const
Chris@16:       {
Chris@16:         if(!std::numeric_limits<ValType>::has_quiet_NaN
Chris@16:           || (flags_ & trap_nan) || !(flags_ & legacy))
Chris@16:         {
Chris@16:           state |= std::ios_base::failbit;
Chris@16:           return;
Chris@16:         }
Chris@16: 
Chris@16:         ++it;
Chris@16:         if(!match_string(it, end, ct, "nan"))
Chris@16:         {
Chris@16:           state |= std::ios_base::failbit;
Chris@16:           return;
Chris@16:         }
Chris@16: 
Chris@16:         val = positive_nan<ValType>(); // "QNAN"
Chris@16:       } //  void get_q
Chris@16: 
Chris@16:       template<class ValType> void get_one_hash
Chris@16:       ( // Get expected string after having read "1.#": "1.#IND", "1.#QNAN", "1.#SNAN".
Chris@16:         InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
Chris@16:         std::ios_base::iostate& state, ValType& val
Chris@16:       ) const
Chris@16:       {
Chris@16: 
Chris@16:         ++it;
Chris@16:         switch(peek_char(it, end, ct))
Chris@16:         {
Chris@16:         case 'i': // from IND (indeterminate), considered same a QNAN.
Chris@16:           get_one_hash_i(it, end, ct, state, val); // "1.#IND"
Chris@16:           return;
Chris@16: 
Chris@16:         case 'q': // from QNAN
Chris@16:         case 's': // from SNAN - treated the same as QNAN.
Chris@16:           if(std::numeric_limits<ValType>::has_quiet_NaN
Chris@16:             && !(flags_ & trap_nan))
Chris@16:           {
Chris@16:             ++it;
Chris@16:             if(match_string(it, end, ct, "nan"))
Chris@16:             { // "1.#QNAN", "1.#SNAN"
Chris@16:  //             ++it; // removed as caused assert() cannot increment iterator).
Chris@16: // (match_string consumes string, so not needed?).
Chris@16: // https://svn.boost.org/trac/boost/ticket/5467
Chris@16: // Change in nonfinite_num_facet.hpp Paul A. Bristow 11 Apr 11 makes legacy_test.cpp work OK.
Chris@16:               val = positive_nan<ValType>(); // "1.#QNAN"
Chris@16:               return;
Chris@16:             }
Chris@16:           }
Chris@16:           break;
Chris@16: 
Chris@16:         default:
Chris@16:           break;
Chris@16:         }
Chris@16: 
Chris@16:         state |= std::ios_base::failbit;
Chris@16:       } //  void get_one_hash
Chris@16: 
Chris@16:       template<class ValType> void get_one_hash_i
Chris@16:       ( // Get expected strings after 'i', "1.#INF", 1.#IND".
Chris@16:         InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
Chris@16:         std::ios_base::iostate& state, ValType& val
Chris@16:       ) const
Chris@16:       {
Chris@16:         ++it;
Chris@16: 
Chris@16:         if(peek_char(it, end, ct) == 'n')
Chris@16:         {
Chris@16:           ++it;
Chris@16:           switch(peek_char(it, end, ct))
Chris@16:           {
Chris@16:           case 'f':  // "1.#INF"
Chris@16:             if(std::numeric_limits<ValType>::has_infinity
Chris@16:               && !(flags_ & trap_infinity))
Chris@16:             {
Chris@16:                 ++it;
Chris@16:                 val = std::numeric_limits<ValType>::infinity();
Chris@16:                 return;
Chris@16:             }
Chris@16:             break;
Chris@16: 
Chris@16:           case 'd':   // 1.#IND"
Chris@16:             if(std::numeric_limits<ValType>::has_quiet_NaN
Chris@16:               && !(flags_ & trap_nan))
Chris@16:             {
Chris@16:                 ++it;
Chris@16:                 val = positive_nan<ValType>();
Chris@16:                 return;
Chris@16:             }
Chris@16:             break;
Chris@16: 
Chris@16:           default:
Chris@16:             break;
Chris@16:           }
Chris@16:         }
Chris@16: 
Chris@16:         state |= std::ios_base::failbit;
Chris@16:       } //  void get_one_hash_i
Chris@16: 
Chris@16:       //..........................................................................
Chris@16: 
Chris@16:       char peek_char
Chris@16:       ( //! \return next char in the input buffer, ensuring lowercase (but do not 'consume' char).
Chris@16:         InputIterator& it, InputIterator end,
Chris@16:         const std::ctype<CharType>& ct
Chris@16:       ) const
Chris@16:       {
Chris@16:         if(it == end) return 0;
Chris@16:         return ct.narrow(ct.tolower(*it), 0); // Always tolower to ensure case insensitive.
Chris@16:       }
Chris@16: 
Chris@16:       bool match_string
Chris@16:       ( //! Match remaining chars to expected string (case insensitive),
Chris@16:         //! consuming chars that match OK.
Chris@16:         //! \return true if matched expected string, else false.
Chris@16:         InputIterator& it, InputIterator end,
Chris@16:         const std::ctype<CharType>& ct,
Chris@16:         const char* s
Chris@16:       ) const
Chris@16:       {
Chris@16:         while(it != end && *s && *s == ct.narrow(ct.tolower(*it), 0))
Chris@16:         {
Chris@16:           ++s;
Chris@16:           ++it; //
Chris@16:         }
Chris@16:         return !*s;
Chris@16:       } // bool match_string
Chris@16: 
Chris@16:     private:
Chris@16:       const int flags_;
Chris@16:     }; //
Chris@16: 
Chris@16:     //------------------------------------------------------------------------------
Chris@16: 
Chris@16:   }   // namespace math
Chris@16: }   // namespace boost
Chris@16: 
Chris@16: #ifdef _MSC_VER
Chris@16: #   pragma warning(pop)
Chris@16: #endif
Chris@16: 
Chris@16: #endif // BOOST_MATH_NONFINITE_NUM_FACETS_HPP
Chris@16: