boost/math/special_functions/nonfinite_num_facets.hpp - platform/external/boost - Git at Google

 #ifndef BOOST_MATH_NONFINITE_NUM_FACETS_HPP
 #define BOOST_MATH_NONFINITE_NUM_FACETS_HPP

 // Copyright (c) 2006 Johan Rade
 // Copyright 2011 Paul A. Bristow (comments)

 // 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)

 /*
 \file

 \brief non_finite_num facets for C99 standard output of infinity and NaN.

 \details See fuller documentation at Boost.Math Facets
   for Floating-Point Infinities and NaNs.
 */

 #include <cstring>
 #include <ios>
 #include <limits>
 #include <locale>

 #include <boost/version.hpp>

 #include <boost/math/special_functions/fpclassify.hpp>
 #include <boost/math/special_functions/sign.hpp>

 #ifdef _MSC_VER
 #   pragma warning(push)
 #   pragma warning(disable : 4127) // conditional expression is constant.
 #   pragma warning(disable : 4706) // assignment within conditional expression.
 #   pragma warning(disable : 4224) // formal parameter 'version' was previously defined as a type.
 #endif

 namespace boost {
   namespace math {

     // flags (enums can be ORed together)       -----------------------------------

     const int legacy = 0x1; //!< get facet will recognize most string representations of infinity and NaN.
     const int signed_zero = 0x2; //!< put facet will distinguish between positive and negative zero.
     const int trap_infinity = 0x4; /*!< put facet will throw an exception of type std::ios_base::failure
        when an attempt is made to format positive or negative infinity.
        get will set the fail bit of the stream when an attempt is made
        to parse a string that represents positive or negative sign infinity.
     */
     const int trap_nan = 0x8; /*!< put facet will throw an exception of type std::ios_base::failure
        when an attempt is made to format positive or negative NaN.
        get will set the fail bit of the stream when an attempt is made
        to parse a string that represents positive or negative sign infinity.
        */

     // class nonfinite_num_put -----------------------------------------------------

     template<
       class CharType,
       class OutputIterator = std::ostreambuf_iterator<CharType>
             >
     class nonfinite_num_put : public std::num_put<CharType, OutputIterator>
     {
     public:
       explicit nonfinite_num_put(int flags = 0) : flags_(flags) {}

     protected:
       virtual OutputIterator do_put(
         OutputIterator it, std::ios_base& iosb,
         CharType fill, double val) const
       {
         put_and_reset_width(it, iosb, fill, val);
         return it;
       }

       virtual OutputIterator do_put(
         OutputIterator it, std::ios_base& iosb,
         CharType fill, long double val) const
       {
         put_and_reset_width(it, iosb, fill, val);
         return it;
       }

     private:
       template<class ValType> void put_and_reset_width(
         OutputIterator& it, std::ios_base& iosb,
         CharType fill, ValType val) const
       {
         put_impl(it, iosb, fill, val);
         iosb.width(0);
       }

       template<class ValType> void put_impl(
         OutputIterator& it, std::ios_base& iosb,
         CharType fill, ValType val) const
       {
         switch((boost::math::fpclassify)(val)) {

         case FP_INFINITE:
           if(flags_ & trap_infinity)
             throw std::ios_base::failure("Infinity");
           else if((boost::math::signbit)(val))
             put_num_and_fill(it, iosb, "-", "inf", fill);
           else if(iosb.flags() & std::ios_base::showpos)
             put_num_and_fill(it, iosb, "+", "inf", fill);
           else
             put_num_and_fill(it, iosb, "", "inf", fill);
           break;

         case FP_NAN:
           if(flags_ & trap_nan)
             throw std::ios_base::failure("NaN");
           else if((boost::math::signbit)(val))
             put_num_and_fill(it, iosb, "-", "nan", fill);
           else if(iosb.flags() & std::ios_base::showpos)
             put_num_and_fill(it, iosb, "+", "nan", fill);
           else
             put_num_and_fill(it, iosb, "", "nan", fill);
           break;

         case FP_ZERO:
           if(flags_ & signed_zero) {
             if((boost::math::signbit)(val))
               put_num_and_fill(it, iosb, "-", "0", fill);
             else if(iosb.flags() & std::ios_base::showpos)
               put_num_and_fill(it, iosb, "+", "0", fill);
             else
               put_num_and_fill(it, iosb, "", "0", fill);
           }
           else
             put_num_and_fill(it, iosb, "", "0", fill);
           break;

         default:
           it = std::num_put<CharType, OutputIterator>::do_put(
             it, iosb, fill, val);
           break;
         }
       }

       void put_num_and_fill(
         OutputIterator& it, std::ios_base& iosb, const char* prefix,
         const char* body, CharType fill) const
       {
         int width = (int)strlen(prefix) + (int)strlen(body);
         std::ios_base::fmtflags adjust
           = iosb.flags() & std::ios_base::adjustfield;
         const std::ctype<CharType>& ct
           = std::use_facet<std::ctype<CharType> >(iosb.getloc());

         if(adjust != std::ios_base::internal && adjust != std::ios_base::left)
           put_fill(it, iosb, fill, width);

         while(*prefix)
           *it = ct.widen(*(prefix++));

         if(adjust == std::ios_base::internal)
           put_fill(it, iosb, fill, width);

         if(iosb.flags() & std::ios_base::uppercase) {
           while(*body)
             *it = ct.toupper(ct.widen(*(body++)));
         }
         else {
           while(*body)
             *it = ct.widen(*(body++));
         }

         if(adjust == std::ios_base::left)
           put_fill(it, iosb, fill, width);
       }

       void put_fill(
         OutputIterator& it, std::ios_base& iosb,
         CharType fill, int width) const
       {
         for(std::streamsize i = iosb.width() - static_cast<std::streamsize>(width); i > 0; --i)
           *it = fill;
       }

     private:
       const int flags_;
     };


     // class nonfinite_num_get ------------------------------------------------------

     template<
       class CharType,
       class InputIterator = std::istreambuf_iterator<CharType>
     >
     class nonfinite_num_get : public std::num_get<CharType, InputIterator>
     {

     public:
       explicit nonfinite_num_get(int flags = 0) : flags_(flags)
       {}

     protected:  // float, double and long double versions of do_get.
       virtual InputIterator do_get(
         InputIterator it, InputIterator end, std::ios_base& iosb,
         std::ios_base::iostate& state, float& val) const
       {
         get_and_check_eof(it, end, iosb, state, val);
         return it;
       }

       virtual InputIterator do_get(
         InputIterator it, InputIterator end, std::ios_base& iosb,
         std::ios_base::iostate& state, double& val) const
       {
         get_and_check_eof(it, end, iosb, state, val);
         return it;
       }

       virtual InputIterator do_get(
         InputIterator it, InputIterator end, std::ios_base& iosb,
         std::ios_base::iostate& state, long double& val) const
       {
         get_and_check_eof(it, end, iosb, state, val);
         return it;
       }

       //..............................................................................

     private:
       template<class ValType> static ValType positive_nan()
       {
         // On some platforms quiet_NaN() may be negative.
         return (boost::math::copysign)(
           std::numeric_limits<ValType>::quiet_NaN(), static_cast<ValType>(1)
           );
         // static_cast<ValType>(1) added Paul A. Bristow 5 Apr 11
       }

       template<class ValType> void get_and_check_eof
       (
         InputIterator& it, InputIterator end, std::ios_base& iosb,
         std::ios_base::iostate& state, ValType& val
       ) const
       {
         get_signed(it, end, iosb, state, val);
         if(it == end)
           state |= std::ios_base::eofbit;
       }

       template<class ValType> void get_signed
       (
         InputIterator& it, InputIterator end, std::ios_base& iosb,
         std::ios_base::iostate& state, ValType& val
       ) const
       {
         const std::ctype<CharType>& ct
           = std::use_facet<std::ctype<CharType> >(iosb.getloc());

         char c = peek_char(it, end, ct);

         bool negative = (c == '-');

         if(negative || c == '+')
         {
           ++it;
           c = peek_char(it, end, ct);
           if(c == '-' || c == '+')
           { // Without this check, "++5" etc would be accepted.
             state |= std::ios_base::failbit;
             return;
           }
         }

         get_unsigned(it, end, iosb, ct, state, val);

         if(negative)
         {
           val = (boost::math::changesign)(val);
         }
       } // void get_signed

       template<class ValType> void get_unsigned
       ( //! Get an unsigned floating-point value into val,
         //! but checking for letters indicating non-finites.
         InputIterator& it, InputIterator end, std::ios_base& iosb,
         const std::ctype<CharType>& ct,
         std::ios_base::iostate& state, ValType& val
       ) const
       {
         switch(peek_char(it, end, ct))
         {
         case 'i':
           get_i(it, end, ct, state, val);
           break;

         case 'n':
           get_n(it, end, ct, state, val);
           break;

         case 'q':
         case 's':
           get_q(it, end, ct, state, val);
           break;

         default: // Got a normal floating-point value into val.
           it = std::num_get<CharType, InputIterator>::do_get(
             it, end, iosb, state, val);
           if((flags_ & legacy) && val == static_cast<ValType>(1)
             && peek_char(it, end, ct) == '#')
             get_one_hash(it, end, ct, state, val);
           break;
         }
       } //  get_unsigned

       //..........................................................................

       template<class ValType> void get_i
       ( // Get the rest of all strings starting with 'i', expect "inf", "infinity".
         InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
         std::ios_base::iostate& state, ValType& val
       ) const
       {
         if(!std::numeric_limits<ValType>::has_infinity
           || (flags_ & trap_infinity))
         {
             state |= std::ios_base::failbit;
             return;
         }

         ++it;
         if(!match_string(it, end, ct, "nf"))
         {
           state |= std::ios_base::failbit;
           return;
         }

         if(peek_char(it, end, ct) != 'i')
         {
           val = std::numeric_limits<ValType>::infinity();  // "inf"
           return;
         }

         ++it;
         if(!match_string(it, end, ct, "nity"))
         { // Expected "infinity"
           state |= std::ios_base::failbit;
           return;
         }

         val = std::numeric_limits<ValType>::infinity(); // "infinity"
       } // void get_i

       template<class ValType> void get_n
       ( // Get expected strings after 'n', "nan", "nanq", "nans", "nan(...)"
         InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
         std::ios_base::iostate& state, ValType& val
       ) const
       {
         if(!std::numeric_limits<ValType>::has_quiet_NaN
           || (flags_ & trap_nan)) {
             state |= std::ios_base::failbit;
             return;
         }

         ++it;
         if(!match_string(it, end, ct, "an"))
         {
           state |= std::ios_base::failbit;
           return;
         }

         switch(peek_char(it, end, ct)) {
         case 'q':
         case 's':
           if(flags_ && legacy)
             ++it;
           break;  // "nanq", "nans"

         case '(':   // Optional payload field in (...) follows.
          {
             ++it;
             char c;
             while((c = peek_char(it, end, ct))
               && c != ')' && c != ' ' && c != '\n' && c != '\t')
               ++it;
             if(c != ')')
             { // Optional payload field terminator missing!
               state |= std::ios_base::failbit;
               return;
             }
             ++it;
             break;  // "nan(...)"
           }

         default:
           break;  // "nan"
         }

         val = positive_nan<ValType>();
       } // void get_n

       template<class ValType> void get_q
       ( // Get expected rest of string starting with 'q': "qnan".
         InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
         std::ios_base::iostate& state, ValType& val
       ) const
       {
         if(!std::numeric_limits<ValType>::has_quiet_NaN
           || (flags_ & trap_nan) || !(flags_ & legacy))
         {
           state |= std::ios_base::failbit;
           return;
         }

         ++it;
         if(!match_string(it, end, ct, "nan"))
         {
           state |= std::ios_base::failbit;
           return;
         }

         val = positive_nan<ValType>(); // "QNAN"
       } //  void get_q

       template<class ValType> void get_one_hash
       ( // Get expected string after having read "1.#": "1.#IND", "1.#QNAN", "1.#SNAN".
         InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
         std::ios_base::iostate& state, ValType& val
       ) const
       {

         ++it;
         switch(peek_char(it, end, ct))
         {
         case 'i': // from IND (indeterminate), considered same a QNAN.
           get_one_hash_i(it, end, ct, state, val); // "1.#IND"
           return;

         case 'q': // from QNAN
         case 's': // from SNAN - treated the same as QNAN.
           if(std::numeric_limits<ValType>::has_quiet_NaN
             && !(flags_ & trap_nan))
           {
             ++it;
             if(match_string(it, end, ct, "nan"))
             { // "1.#QNAN", "1.#SNAN"
  //             ++it; // removed as caused assert() cannot increment iterator).
 // (match_string consumes string, so not needed?).
 // https://svn.boost.org/trac/boost/ticket/5467
 // Change in nonfinite_num_facet.hpp Paul A. Bristow 11 Apr 11 makes legacy_test.cpp work OK.
               val = positive_nan<ValType>(); // "1.#QNAN"
               return;
             }
           }
           break;

         default:
           break;
         }

         state |= std::ios_base::failbit;
       } //  void get_one_hash

       template<class ValType> void get_one_hash_i
       ( // Get expected strings after 'i', "1.#INF", 1.#IND".
         InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
         std::ios_base::iostate& state, ValType& val
       ) const
       {
         ++it;

         if(peek_char(it, end, ct) == 'n')
         {
           ++it;
           switch(peek_char(it, end, ct))
           {
           case 'f':  // "1.#INF"
             if(std::numeric_limits<ValType>::has_infinity
               && !(flags_ & trap_infinity))
             {
                 ++it;
                 val = std::numeric_limits<ValType>::infinity();
                 return;
             }
             break;

           case 'd':   // 1.#IND"
             if(std::numeric_limits<ValType>::has_quiet_NaN
               && !(flags_ & trap_nan))
             {
                 ++it;
                 val = positive_nan<ValType>();
                 return;
             }
             break;

           default:
             break;
           }
         }

         state |= std::ios_base::failbit;
       } //  void get_one_hash_i

       //..........................................................................

       char peek_char
       ( //! \return next char in the input buffer, ensuring lowercase (but do not 'consume' char).
         InputIterator& it, InputIterator end,
         const std::ctype<CharType>& ct
       ) const
       {
         if(it == end) return 0;
         return ct.narrow(ct.tolower(*it), 0); // Always tolower to ensure case insensitive.
       }

       bool match_string
       ( //! Match remaining chars to expected string (case insensitive),
         //! consuming chars that match OK.
         //! \return true if matched expected string, else false.
         InputIterator& it, InputIterator end,
         const std::ctype<CharType>& ct,
         const char* s
       ) const
       {
         while(it != end && *s && *s == ct.narrow(ct.tolower(*it), 0))
         {
           ++s;
           ++it; //
         }
         return !*s;
       } // bool match_string

     private:
       const int flags_;
     }; //

     //------------------------------------------------------------------------------

   }   // namespace math
 }   // namespace boost

 #ifdef _MSC_VER
 #   pragma warning(pop)
 #endif

 #endif
	#ifndef BOOST_MATH_NONFINITE_NUM_FACETS_HPP
	#define BOOST_MATH_NONFINITE_NUM_FACETS_HPP

	// Copyright (c) 2006 Johan Rade
	// Copyright 2011 Paul A. Bristow (comments)

	// 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)

	/*
	\file

	\brief non_finite_num facets for C99 standard output of infinity and NaN.

	\details See fuller documentation at Boost.Math Facets
	for Floating-Point Infinities and NaNs.
	*/

	#include <cstring>
	#include <ios>
	#include <limits>
	#include <locale>

	#include <boost/version.hpp>

	#include <boost/math/special_functions/fpclassify.hpp>
	#include <boost/math/special_functions/sign.hpp>

	#ifdef _MSC_VER
	# pragma warning(push)
	# pragma warning(disable : 4127) // conditional expression is constant.
	# pragma warning(disable : 4706) // assignment within conditional expression.
	# pragma warning(disable : 4224) // formal parameter 'version' was previously defined as a type.
	#endif

	namespace boost {
	namespace math {

	// flags (enums can be ORed together) -----------------------------------

	const int legacy = 0x1; //!< get facet will recognize most string representations of infinity and NaN.
	const int signed_zero = 0x2; //!< put facet will distinguish between positive and negative zero.
	const int trap_infinity = 0x4; /*!< put facet will throw an exception of type std::ios_base::failure
	when an attempt is made to format positive or negative infinity.
	get will set the fail bit of the stream when an attempt is made
	to parse a string that represents positive or negative sign infinity.
	*/
	const int trap_nan = 0x8; /*!< put facet will throw an exception of type std::ios_base::failure
	when an attempt is made to format positive or negative NaN.
	get will set the fail bit of the stream when an attempt is made
	to parse a string that represents positive or negative sign infinity.
	*/

	// class nonfinite_num_put -----------------------------------------------------

	template<
	class CharType,
	class OutputIterator = std::ostreambuf_iterator<CharType>
	>
	class nonfinite_num_put : public std::num_put<CharType, OutputIterator>
	{
	public:
	explicit nonfinite_num_put(int flags = 0) : flags_(flags) {}

	protected:
	virtual OutputIterator do_put(
	OutputIterator it, std::ios_base& iosb,
	CharType fill, double val) const
	{
	put_and_reset_width(it, iosb, fill, val);
	return it;
	}

	virtual OutputIterator do_put(
	OutputIterator it, std::ios_base& iosb,
	CharType fill, long double val) const
	{
	put_and_reset_width(it, iosb, fill, val);
	return it;
	}

	private:
	template<class ValType> void put_and_reset_width(
	OutputIterator& it, std::ios_base& iosb,
	CharType fill, ValType val) const
	{
	put_impl(it, iosb, fill, val);
	iosb.width(0);
	}

	template<class ValType> void put_impl(
	OutputIterator& it, std::ios_base& iosb,
	CharType fill, ValType val) const
	{
	switch((boost::math::fpclassify)(val)) {

	case FP_INFINITE:
	if(flags_ & trap_infinity)
	throw std::ios_base::failure("Infinity");
	else if((boost::math::signbit)(val))
	put_num_and_fill(it, iosb, "-", "inf", fill);
	else if(iosb.flags() & std::ios_base::showpos)
	put_num_and_fill(it, iosb, "+", "inf", fill);
	else
	put_num_and_fill(it, iosb, "", "inf", fill);
	break;

	case FP_NAN:
	if(flags_ & trap_nan)
	throw std::ios_base::failure("NaN");
	else if((boost::math::signbit)(val))
	put_num_and_fill(it, iosb, "-", "nan", fill);
	else if(iosb.flags() & std::ios_base::showpos)
	put_num_and_fill(it, iosb, "+", "nan", fill);
	else
	put_num_and_fill(it, iosb, "", "nan", fill);
	break;

	case FP_ZERO:
	if(flags_ & signed_zero) {
	if((boost::math::signbit)(val))
	put_num_and_fill(it, iosb, "-", "0", fill);
	else if(iosb.flags() & std::ios_base::showpos)
	put_num_and_fill(it, iosb, "+", "0", fill);
	else
	put_num_and_fill(it, iosb, "", "0", fill);
	}
	else
	put_num_and_fill(it, iosb, "", "0", fill);
	break;

	default:
	it = std::num_put<CharType, OutputIterator>::do_put(
	it, iosb, fill, val);
	break;
	}
	}

	void put_num_and_fill(
	OutputIterator& it, std::ios_base& iosb, const char* prefix,
	const char* body, CharType fill) const
	{
	int width = (int)strlen(prefix) + (int)strlen(body);
	std::ios_base::fmtflags adjust
	= iosb.flags() & std::ios_base::adjustfield;
	const std::ctype<CharType>& ct
	= std::use_facet<std::ctype<CharType> >(iosb.getloc());

	if(adjust != std::ios_base::internal && adjust != std::ios_base::left)
	put_fill(it, iosb, fill, width);

	while(*prefix)
	it = ct.widen((prefix++));

	if(adjust == std::ios_base::internal)
	put_fill(it, iosb, fill, width);

	if(iosb.flags() & std::ios_base::uppercase) {
	while(*body)
	it = ct.toupper(ct.widen((body++)));
	}
	else {
	while(*body)
	it = ct.widen((body++));
	}

	if(adjust == std::ios_base::left)
	put_fill(it, iosb, fill, width);
	}

	void put_fill(
	OutputIterator& it, std::ios_base& iosb,
	CharType fill, int width) const
	{
	for(std::streamsize i = iosb.width() - static_cast<std::streamsize>(width); i > 0; --i)
	*it = fill;
	}

	private:
	const int flags_;
	};


	// class nonfinite_num_get ------------------------------------------------------

	template<
	class CharType,
	class InputIterator = std::istreambuf_iterator<CharType>
	>
	class nonfinite_num_get : public std::num_get<CharType, InputIterator>
	{

	public:
	explicit nonfinite_num_get(int flags = 0) : flags_(flags)
	{}

	protected: // float, double and long double versions of do_get.
	virtual InputIterator do_get(
	InputIterator it, InputIterator end, std::ios_base& iosb,
	std::ios_base::iostate& state, float& val) const
	{
	get_and_check_eof(it, end, iosb, state, val);
	return it;
	}

	virtual InputIterator do_get(
	InputIterator it, InputIterator end, std::ios_base& iosb,
	std::ios_base::iostate& state, double& val) const
	{
	get_and_check_eof(it, end, iosb, state, val);
	return it;
	}

	virtual InputIterator do_get(
	InputIterator it, InputIterator end, std::ios_base& iosb,
	std::ios_base::iostate& state, long double& val) const
	{
	get_and_check_eof(it, end, iosb, state, val);
	return it;
	}

	//..............................................................................

	private:
	template<class ValType> static ValType positive_nan()
	{
	// On some platforms quiet_NaN() may be negative.
	return (boost::math::copysign)(
	std::numeric_limits<ValType>::quiet_NaN(), static_cast<ValType>(1)
	);
	// static_cast<ValType>(1) added Paul A. Bristow 5 Apr 11
	}

	template<class ValType> void get_and_check_eof
	(
	InputIterator& it, InputIterator end, std::ios_base& iosb,
	std::ios_base::iostate& state, ValType& val
	) const
	{
	get_signed(it, end, iosb, state, val);
	if(it == end)
	state \|= std::ios_base::eofbit;
	}

	template<class ValType> void get_signed
	(
	InputIterator& it, InputIterator end, std::ios_base& iosb,
	std::ios_base::iostate& state, ValType& val
	) const
	{
	const std::ctype<CharType>& ct
	= std::use_facet<std::ctype<CharType> >(iosb.getloc());

	char c = peek_char(it, end, ct);

	bool negative = (c == '-');

	if(negative \|\| c == '+')
	{
	++it;
	c = peek_char(it, end, ct);
	if(c == '-' \|\| c == '+')
	{ // Without this check, "++5" etc would be accepted.
	state \|= std::ios_base::failbit;
	return;
	}
	}

	get_unsigned(it, end, iosb, ct, state, val);

	if(negative)
	{
	val = (boost::math::changesign)(val);
	}
	} // void get_signed

	template<class ValType> void get_unsigned
	( //! Get an unsigned floating-point value into val,
	//! but checking for letters indicating non-finites.
	InputIterator& it, InputIterator end, std::ios_base& iosb,
	const std::ctype<CharType>& ct,
	std::ios_base::iostate& state, ValType& val
	) const
	{
	switch(peek_char(it, end, ct))
	{
	case 'i':
	get_i(it, end, ct, state, val);
	break;

	case 'n':
	get_n(it, end, ct, state, val);
	break;

	case 'q':
	case 's':
	get_q(it, end, ct, state, val);
	break;

	default: // Got a normal floating-point value into val.
	it = std::num_get<CharType, InputIterator>::do_get(
	it, end, iosb, state, val);
	if((flags_ & legacy) && val == static_cast<ValType>(1)
	&& peek_char(it, end, ct) == '#')
	get_one_hash(it, end, ct, state, val);
	break;
	}
	} // get_unsigned

	//..........................................................................

	template<class ValType> void get_i
	( // Get the rest of all strings starting with 'i', expect "inf", "infinity".
	InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
	std::ios_base::iostate& state, ValType& val
	) const
	{
	if(!std::numeric_limits<ValType>::has_infinity
	\|\| (flags_ & trap_infinity))
	{
	state \|= std::ios_base::failbit;
	return;
	}

	++it;
	if(!match_string(it, end, ct, "nf"))
	{
	state \|= std::ios_base::failbit;
	return;
	}

	if(peek_char(it, end, ct) != 'i')
	{
	val = std::numeric_limits<ValType>::infinity(); // "inf"
	return;
	}

	++it;
	if(!match_string(it, end, ct, "nity"))
	{ // Expected "infinity"
	state \|= std::ios_base::failbit;
	return;
	}

	val = std::numeric_limits<ValType>::infinity(); // "infinity"
	} // void get_i

	template<class ValType> void get_n
	( // Get expected strings after 'n', "nan", "nanq", "nans", "nan(...)"
	InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
	std::ios_base::iostate& state, ValType& val
	) const
	{
	if(!std::numeric_limits<ValType>::has_quiet_NaN
	\|\| (flags_ & trap_nan)) {
	state \|= std::ios_base::failbit;
	return;
	}

	++it;
	if(!match_string(it, end, ct, "an"))
	{
	state \|= std::ios_base::failbit;
	return;
	}

	switch(peek_char(it, end, ct)) {
	case 'q':
	case 's':
	if(flags_ && legacy)
	++it;
	break; // "nanq", "nans"

	case '(': // Optional payload field in (...) follows.
	{
	++it;
	char c;
	while((c = peek_char(it, end, ct))
	&& c != ')' && c != ' ' && c != '\n' && c != '\t')
	++it;
	if(c != ')')
	{ // Optional payload field terminator missing!
	state \|= std::ios_base::failbit;
	return;
	}
	++it;
	break; // "nan(...)"
	}

	default:
	break; // "nan"
	}

	val = positive_nan<ValType>();
	} // void get_n

	template<class ValType> void get_q
	( // Get expected rest of string starting with 'q': "qnan".
	InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
	std::ios_base::iostate& state, ValType& val
	) const
	{
	if(!std::numeric_limits<ValType>::has_quiet_NaN
	\|\| (flags_ & trap_nan) \|\| !(flags_ & legacy))
	{
	state \|= std::ios_base::failbit;
	return;
	}

	++it;
	if(!match_string(it, end, ct, "nan"))
	{
	state \|= std::ios_base::failbit;
	return;
	}

	val = positive_nan<ValType>(); // "QNAN"
	} // void get_q

	template<class ValType> void get_one_hash
	( // Get expected string after having read "1.#": "1.#IND", "1.#QNAN", "1.#SNAN".
	InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
	std::ios_base::iostate& state, ValType& val
	) const
	{

	++it;
	switch(peek_char(it, end, ct))
	{
	case 'i': // from IND (indeterminate), considered same a QNAN.
	get_one_hash_i(it, end, ct, state, val); // "1.#IND"
	return;

	case 'q': // from QNAN
	case 's': // from SNAN - treated the same as QNAN.
	if(std::numeric_limits<ValType>::has_quiet_NaN
	&& !(flags_ & trap_nan))
	{
	++it;
	if(match_string(it, end, ct, "nan"))
	{ // "1.#QNAN", "1.#SNAN"
	// ++it; // removed as caused assert() cannot increment iterator).
	// (match_string consumes string, so not needed?).
	// https://svn.boost.org/trac/boost/ticket/5467
	// Change in nonfinite_num_facet.hpp Paul A. Bristow 11 Apr 11 makes legacy_test.cpp work OK.
	val = positive_nan<ValType>(); // "1.#QNAN"
	return;
	}
	}
	break;

	default:
	break;
	}

	state \|= std::ios_base::failbit;
	} // void get_one_hash

	template<class ValType> void get_one_hash_i
	( // Get expected strings after 'i', "1.#INF", 1.#IND".
	InputIterator& it, InputIterator end, const std::ctype<CharType>& ct,
	std::ios_base::iostate& state, ValType& val
	) const
	{
	++it;

	if(peek_char(it, end, ct) == 'n')
	{
	++it;
	switch(peek_char(it, end, ct))
	{
	case 'f': // "1.#INF"
	if(std::numeric_limits<ValType>::has_infinity
	&& !(flags_ & trap_infinity))
	{
	++it;
	val = std::numeric_limits<ValType>::infinity();
	return;
	}
	break;

	case 'd': // 1.#IND"
	if(std::numeric_limits<ValType>::has_quiet_NaN
	&& !(flags_ & trap_nan))
	{
	++it;
	val = positive_nan<ValType>();
	return;
	}
	break;

	default:
	break;
	}
	}

	state \|= std::ios_base::failbit;
	} // void get_one_hash_i

	//..........................................................................

	char peek_char
	( //! \return next char in the input buffer, ensuring lowercase (but do not 'consume' char).
	InputIterator& it, InputIterator end,
	const std::ctype<CharType>& ct
	) const
	{
	if(it == end) return 0;
	return ct.narrow(ct.tolower(*it), 0); // Always tolower to ensure case insensitive.
	}

	bool match_string
	( //! Match remaining chars to expected string (case insensitive),
	//! consuming chars that match OK.
	//! \return true if matched expected string, else false.
	InputIterator& it, InputIterator end,
	const std::ctype<CharType>& ct,
	const char* s
	) const
	{
	while(it != end && s && s == ct.narrow(ct.tolower(*it), 0))
	{
	++s;
	++it; //
	}
	return !*s;
	} // bool match_string

	private:
	const int flags_;
	}; //

	//------------------------------------------------------------------------------

	} // namespace math
	} // namespace boost

	#ifdef _MSC_VER
	# pragma warning(pop)
	#endif

	#endif