Convert.h

/* Copyright (C) 2013 Marc Boris Duerner
 
  This library is free software; you can redistribute it and/or
  modify it under the terms of the GNU Lesser General Public
  License as published by the Free Software Foundation; either
  version 2.1 of the License, or (at your option) any later version.
 
  As a special exception, you may use this file as part of a free
  software library without restriction. Specifically, if other files
  instantiate templates or use macros or inline functions from this
  file, or you compile this file and link it with other files to
  produce an executable, this file does not by itself cause the
  resulting executable to be covered by the GNU General Public
  License. This exception does not however invalidate any other
  reasons why the executable file might be covered by the GNU Library
  General Public License.
 
  This library is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  Lesser General Public License for more details.
 
  You should have received a copy of the GNU Lesser General Public
  License along with this library; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, 
  MA 02110-1301 USA
*/
 
#ifndef Pt_Convert_h
#define Pt_Convert_h
 
#include <Pt/Api.h>
#include <Pt/ConversionError.h>
#include <Pt/TypeTraits.h>
 
#include <string>
#include <limits>
#include <algorithm>
#include <iterator>
#include <cctype>
#include <cmath>
#include <cassert>
 
namespace Pt {
 
template <bool signedX, bool signedY>
struct LessThanMin
{
    template <class X, class Y>
    static bool check(X x, Y y_min)
    { return x < y_min; }
};
 
 
template <>
struct LessThanMin<false, true>
{
    template <class X, class Y>
    static bool check(X, Y)
    { return false; }
};
 
 
template <>
struct LessThanMin<true, false>
{
    template <class X, class Y>
    static bool check(X x, Y)
    { return x < 0; }
};
 
 
template <bool signedX, bool signedY>
struct GreaterThanMax
{
    // both signed or both unsigned
    template <class X, class Y>
    static bool check(X x, Y ymax)
    { return x > ymax; }
};
 
 
template <>
struct GreaterThanMax<false, true>
{
    // x is unsigned, y is signed
    template <class X, class Y>
    static bool check(X x, Y ymax)
    { 
        return x > static_cast<X>(ymax);
    }
};
 
 
template <>
struct GreaterThanMax<true, false>
{
    // x is signed, y is unsigned
    template <class X, class Y>
    static bool check(X x, Y ymax)
    { 
        return x > 0 && static_cast<Y>(x) > ymax;
    }
};
 

template<typename R, typename T>
inline R narrow(T from)
{
    typedef std::numeric_limits<T> SourceTraits;
    typedef std::numeric_limits<R> ResultTraits;
 
    const bool fromSigned = SourceTraits::is_signed;
    const bool toSigned = ResultTraits::is_signed;
 
    if( LessThanMin<fromSigned, toSigned>::check( from, ResultTraits::min() )
     || GreaterThanMax<fromSigned, toSigned>::check( from, ResultTraits::max() ) )
    {
        throw ConversionError("numeric conversion failed");
    }
    
    return static_cast<R>(from);
}
 

template <typename OutIterT, typename T, typename FormatT>
inline OutIterT formatInt(OutIterT it, T i, const FormatT& fmt);

template <typename OutIterT, typename T>
inline OutIterT formatInt(OutIterT it, T i);

template <typename CharT, typename T, typename FormatT>
inline CharT* formatInt(CharT* buf, std::size_t buflen, T si, const FormatT& fmt);
 

template <typename OutIterT, typename T, typename FormatT>
OutIterT formatFloat(OutIterT it, T d, 
                     const FormatT& fmt, int precision, bool fixed = false);

template <typename OutIterT, typename T>
OutIterT formatFloat(OutIterT it, T d);

template <typename OutIterT, typename T>
OutIterT formatFloat(OutIterT it, T d, int precision, bool fixed = false);
 

template <typename InIterT, typename T, typename FormatT>
InIterT parseInt(InIterT it, InIterT end, T& n, const FormatT& fmt, bool& ok);

template <typename InIterT, typename T, typename FormatT>
InIterT parseInt(InIterT it, InIterT end, T& n, const FormatT& fmt)
{
    bool ok = false;
 
    InIterT r = parseInt(it, end, n, fmt, ok);
    if( ! ok )
        throw ConversionError("conversion failed");
    
    return r;
}

template <typename InIterT, typename T>
InIterT parseInt(InIterT it, InIterT end, T& n, bool& ok);

template <typename InIterT, typename T>
InIterT parseInt(InIterT it, InIterT end, T& n)
{
    bool ok = false;
 
    InIterT r = parseInt(it, end, n, ok);
    if( ! ok )
        throw ConversionError("conversion failed");
    
    return r;
}
    
template <typename T, typename InIter>
T parseInt(InIter it, InIter end)
{
    T n = T();
    bool ok = false;
    
    InIter r = parseInt(it, end, n, ok);
    if( ! ok || r != end )
        throw ConversionError("conversion failed");
 
    return n;
}
 

template <typename InIterT, typename T, typename FormatT>
InIterT parseFloat(InIterT it, InIterT end, T& n, const FormatT& fmt, bool& ok);

template <typename InIterT, typename T, typename FormatT>
InIterT parseFloat(InIterT it, InIterT end, T& n, const FormatT& fmt)
{
    bool ok = false;
 
    InIterT r = parseFloat(it, end, n, fmt, ok);
    if( ! ok )
        throw ConversionError("conversion failed");
    
    return r;
}

template <typename InIterT, typename T>
InIterT parseFloat(InIterT it, InIterT end, T& n, bool& ok);

template <typename InIterT, typename T>
InIterT parseFloat(InIterT it, InIterT end, T& n)
{
    bool ok = false;
 
    InIterT r = parseFloat(it, end, n, ok);
    if( ! ok )
        throw ConversionError("conversion failed");
    
    return r;
}
 
 
template <typename CharType>
struct NumberFormat
{
    typedef CharType CharT;
 
    static bool isSpace(CharT ch)
    { return (ch == 0x20) || (ch > 0x08 && ch < 0x0e); }
 
    static CharT plus()
    { return '+'; }
 
    static CharT minus()
    { return '-'; }
};
 
 
template <typename CharType>
struct DecimalFormat : public NumberFormat<CharType>
{
    typedef CharType CharT;
 
    static const unsigned base = 10;
    
    static CharT toChar(unsigned char n)
    {
        return '0' + n; 
    }

    static bool isDigit(CharT ch)
    {
        typename std::char_traits<CharT>::int_type cc = std::char_traits<CharT>::to_int_type(ch);
        return cc > 47 && cc < 58;
    }
    
    static unsigned toDigit(CharT ch)
    {
        typename std::char_traits<CharT>::int_type cc = std::char_traits<CharT>::to_int_type(ch);
        return static_cast<unsigned>(cc - 48);
    }
};
 
 
template <typename CharType>
struct OctalFormat : public NumberFormat<CharType>
{
    typedef CharType CharT;
 
    static const unsigned base = 8;

    static CharT toChar(unsigned char n)
    {
        return '0' + n; 
    }

    static bool isDigit(CharT ch)
    {
        typename std::char_traits<CharT>::int_type cc = std::char_traits<CharT>::to_int_type(ch);
        return cc > 47 && cc < 56;
    }

    static unsigned toDigit(CharT ch)
    {
        typename std::char_traits<CharT>::int_type cc = std::char_traits<CharT>::to_int_type(ch);
        
        // let negatives overrun
        return static_cast<unsigned>(cc - 48);
    }
};
 
 
template <typename CharType>
struct HexFormat : public NumberFormat<CharType>
{
    typedef CharType CharT;
 
    static const unsigned base = 16;

    static CharT toChar(unsigned char n)
    {
        n &= 0x1F; // prevent overrun
        static const char* digtab = "0123456789abcdef";
        return digtab[n]; 
    }

    static bool isDigit(CharT ch)
    {
        typename std::char_traits<CharT>::int_type cc = std::char_traits<CharT>::to_int_type(ch);
        return (cc > 47 && cc < 59) || (cc > 64 && cc < 71) || (cc > 96 && cc < 103);
    }

    static unsigned toDigit(CharT ch)
    {
        static const unsigned char chartab[64] = 
        {
            0, 1, 2, 3, 4, 5, 6, 7, 8, 9,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
            0xFF,10,11,12,13,14,15,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
            0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
            0xFF,10,11,12,13,14,15,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
        };
 
        typename std::char_traits<CharT>::int_type cc = std::char_traits<CharT>::to_int_type(ch);
        
        unsigned idx = static_cast<unsigned>(cc - 48);
        return chartab[ idx ];
    }
};
 
 
template <typename CharType>
struct BinaryFormat : public NumberFormat<CharType>
{
    typedef CharType CharT;
 
    static const unsigned base = 2;

    static CharT toChar(unsigned char n)
    {
        return '0' + n; 
    }
    
    static bool isDigit(CharT ch)
    {
        typename std::char_traits<CharT>::int_type cc = std::char_traits<CharT>::to_int_type(ch);
        return cc > 47 && cc < 50;
    }

    static unsigned toDigit(CharT ch)
    {
        typename std::char_traits<CharT>::int_type cc = std::char_traits<CharT>::to_int_type(ch);
        return static_cast<unsigned>(cc - 48);
    }
};
 
 
template <typename CharType>
struct FloatFormat : public DecimalFormat<CharType>
{
    typedef CharType CharT;
 
    static CharT point()
    { return '.'; }
 
    static CharT e()
    { return 'e'; }
 
    static bool isE(CharT ch)
    { return ch == 'E' || ch == 'e'; }
 
    static bool isNan(CharT ch, unsigned pos, bool& isNan)
    {
        switch(pos)
        {
            case 0: return ch == 'n' || ch == 'N';
            case 1: return ch == 'a' || ch == 'A';
            case 2: isNan = ch == 'n' || ch == 'N'; return isNan;
        }
 
        return (ch > 46 && ch < 58) || (ch > 64 && ch < 91) || (ch > 96 && ch < 123);
    }
 
    static bool isInfinity(CharT ch, unsigned pos, bool& isInf)
    {
        switch(pos)
        {
            case 0: return ch == 'i' || ch == 'I';
            case 1: return ch == 'n' || ch == 'N';
            case 2: isInf = ch == 'f' || ch == 'F'; return isInf;
            case 3: return ch == 'i' || ch == 'I';
            case 4: return ch == 'n' || ch == 'N';
            case 5: return ch == 'i' || ch == 'I';
            case 6: return ch == 't' || ch == 'T';
            case 7: isInf = ch == 'y' || ch == 'Y'; return isInf;
        }
 
        return false;
    }
 
    static const CharT* nan()
    { 
        static const CharT nanstr[] = { 'n', 'a', 'n', 0 };
        return nanstr; 
    }
 
    static const CharT* infinity()
    { 
        static const CharT nanstr[] = { 'i', 'n', 'f', 0 };
        return nanstr; 
    }
};
 
 
inline unsigned char getAbs(char i, bool& isNeg)
{
    isNeg = i < 0;
    unsigned char u = isNeg ? -i : static_cast<unsigned char>(i);
    return u;
}
 
 
inline unsigned char getAbs(unsigned char i, bool& isNeg)
{
    isNeg = false;
    return i;
}
 
 
inline unsigned short getAbs(short i, bool& isNeg)
{
    isNeg = i < 0;
    unsigned short u = isNeg ? -i : static_cast<unsigned short>(i);
    return u;
}
 
 
inline unsigned short getAbs(unsigned short i, bool& isNeg)
{
    isNeg = false;
    return i;
}
 
 
inline unsigned int getAbs(int i, bool& isNeg)
{
    isNeg = i < 0;
    unsigned int u = isNeg ? -i : static_cast<unsigned int>(i);
    return u;
}
 
 
inline unsigned int getAbs(unsigned int i, bool& isNeg)
{
    isNeg = false;
    return i;
}
 
 
inline unsigned long getAbs(long i, bool& isNeg)
{
    isNeg = i < 0;
    unsigned long u = isNeg ? -i : static_cast<unsigned long>(i);
    return u;
}
 
 
inline unsigned long getAbs(unsigned long i, bool& isNeg)
{
    isNeg = false;
    return i;
}
 
 
inline unsigned long long getAbs(long long i, bool& isNeg)
{
    isNeg = i < 0;
    unsigned long long u = isNeg ? -i : static_cast<unsigned long long>(i);
    return u;
}
 
 
inline unsigned long long getAbs(unsigned long long i, bool& isNeg)
{
    isNeg = false;
    return i;
}
 
 
template <typename CharT, typename T, typename FormatT>
inline CharT* formatInt(CharT* buf, std::size_t buflen, T si, const FormatT& fmt)
{
    typedef typename IntTraits<T>::Unsigned UnsignedInt;
 
    CharT* end = buf + buflen;
    CharT* cur = end;
 
    const unsigned base = fmt.base;
 
    bool isNeg = false;
    UnsignedInt u = getAbs(si, isNeg);
 
    do
    {
        unsigned char lsd = static_cast<unsigned char>(u % base);
        u /= base;
        --cur;
        *cur = fmt.toChar(lsd);
    } 
    while(u != 0 && cur != buf);
    
    if(cur == buf)
        return buf;
    
    if(isNeg)
    {
        --cur;
        *cur = fmt.minus();
    }
 
    return cur;
}
 
 
template <typename CharT, typename T>
inline CharT* formatInt(CharT* buf, std::size_t buflen, T i, const BinaryFormat<CharT>& fmt)
{
    CharT* end = buf + buflen;
    CharT* cur = end;
    T mask = 1;
    
    do
    {
        --cur;
        unsigned char d = static_cast<unsigned char>(i & mask);
        *cur = fmt.toChar(d);
        i = i >> 1;
    } 
    while(i != 0 && cur != buf);
    
    if(cur == buf)
        return buf;
    
    return cur;
}
   
 
template <typename OutIterT, typename T, typename FormatT>
inline OutIterT formatInt(OutIterT it, T i, const FormatT& fmt)
{
    // large enough even for binary and a sign
    const std::size_t buflen = (sizeof(T) * 8) + 1;
    typename FormatT::CharT buf[buflen];
    typename FormatT::CharT* p = Pt::formatInt(buf, buflen, i, fmt);
 
    typename FormatT::CharT* end = buf + buflen;
    for(; p != end; ++p)
        *it++ = *p;
 
    return it;
}
 
 
template <typename OutIterT, typename T>
inline OutIterT formatInt(OutIterT it, T i)
{
    DecimalFormat<char> fmt;
    return formatInt(it, i, fmt);
}
 
 
template <typename CharT, typename T, typename FormatT>
inline int formatFloat(CharT* fraction, int fractSize, int& intpart, int& exp, T n,
                       const FormatT& fmt, int precision, bool fixed)
{
    intpart = 0;
    exp = 0;
    
    if(n == T(0.0) || n != n)
        return 0;
 
    const bool neg = n < 0;
    if(n < 0)
        n = -n;
    
    if( n == std::numeric_limits<T>::infinity() )
        return 0;
    
    exp = static_cast<int>( std::floor( std::log10(n) ) );
    
    // precision for fixed notation is the maximum number of digits after the
    // decimal point, otherwise the maximum number of significant digits
    if(fixed)
        precision += exp + 1;
 
    if(precision > fractSize)
        precision = fractSize;
 
    // intpart is first significant digit
    --precision;
 
    // move remaining significant digits before dot and add 0.5 to round
    // last significant digit. This might increase the exponent, for which
    // we check later.
    n *= std::pow(T(10.0), precision - exp);
    n += 0.5;
 
    int places = 0;
    bool trailZero = true;
    for(int d = precision - 1; d >= 0; --d)
    {
        T p = n / T(10.0);
        T q = std::floor(p) * T(10.0);
        int digit = static_cast<int>( std::floor(n - q) );
        n = p;
 
        // ignore trailing zeros
        trailZero = trailZero && (digit == 0);
 
        if( trailZero )
            continue;
 
        CharT c = fmt.toChar( static_cast<unsigned char>(digit) );
        assert(d < fractSize);
        fraction[d] = c;
 
        ++places;
    }
 
    intpart = static_cast<int>( std::floor(n) );
 
    // check if rounding increased the exponent 
    if(intpart == 10)
    {
      ++exp;
      intpart = 1;
    }
 
    if(neg)
        intpart = -intpart;
 
    return places;
}
 
 
template <typename OutIterT, typename T, typename FormatT>
inline OutIterT formatFloat(OutIterT it, T d, 
                            const FormatT& fmt, int precision, bool fixed)
{
    typedef typename FormatT::CharT CharT;
    CharT zero = fmt.toChar(0);
 
    // 1. Test for not-a-number with d != d
    if( d != d ) 
    {
        for(const CharT* nanstr = fmt.nan(); *nanstr != 0; ++nanstr)
        {
            *it = *nanstr;
            ++it;
        }
 
        return it;
    }
 
    // 2. check sign
    if(d < 0.0)
    {
        *it = fmt.minus();
        ++it;
    }
 
    T num = std::fabs(d);
 
    // 3. Test for infinity
    if( num == std::numeric_limits<T>::infinity() ) 
    {
        for(const CharT* infstr = fmt.infinity(); *infstr != 0; ++infstr)
        {
            *it = *infstr;
            ++it;
        }
 
        return it;
    }
    
    const int bufsize = std::numeric_limits<T>::digits10;
    CharT fract[bufsize];
    int i = 0;
    int e = 0;
    int fractSize = Pt::formatFloat(fract, bufsize, i, e, num, fmt, precision, fixed);
    int fillSize = fractSize;
 
    int n = 0;
    if(e >= 0)
    {
        *it++ = fmt.toChar(i);
 
        for(; n < e; ++n)
            *it++ = (n < fractSize) ? fract[n] : zero;
 
        *it++ = fmt.point();
        
        // show at least one digit after decimal point
        *it++ = (n < fractSize) ? fract[n] : zero;
        ++n;
 
        // fill zeros to fixed precision
        if(fixed)
          fillSize = n + precision - 1;
    }
    else // e < 0
    {
        *it++ = zero;
        *it++ = fmt.point();
 
        if(fixed)
        {
          e = std::max(-precision, e);
          fillSize = precision + e;
        }
 
        while(++e < 0)
            *it++ = zero;
 
        *it++ = fmt.toChar(i);
    }
 
    for(; n < fillSize; ++n)
        *it++ = (n < fractSize) ?  fract[n] : zero;
 
    return it;
}
 
 
template <typename OutIterT, typename T>
inline OutIterT formatFloat(OutIterT it, T d)
{
    const int precision = std::numeric_limits<T>::digits10;
    FloatFormat<char> fmt;
    return formatFloat(it, d, fmt, precision);
}
 
 
template <typename OutIterT, typename T>
OutIterT formatFloat(OutIterT it, T d, int precision, bool fixed)
{
    FloatFormat<char> fmt;
    return formatFloat(it, d, fmt, precision, fixed);
}
 
 
template <typename InIterT, typename FormatT>
InIterT getWhitespace(InIterT it, InIterT end, const FormatT& fmt)
{   
    while( it != end && fmt.isSpace(*it) )
        ++it;
 
    return it;
}
 
 
template <typename InIterT, typename FormatT>
InIterT getSign(InIterT it, InIterT end, bool& pos, const FormatT& fmt)
{
    pos = true;
 
    if(it == end)
      return it;
 
    if( *it == fmt.minus() )
    {
        pos = false;
        ++it;
    }
    else if( *it == fmt.plus() )
    {
        ++it;
    }
 
    return it;
}
 
 
template <typename InIterT, typename T, typename FormatT>
InIterT parseInt(InIterT it, InIterT end, T& n, const FormatT& fmt, bool& ok)
{
    typedef typename IntTraits<T>::Unsigned UnsignedInt;
    typedef typename IntTraits<T>::Signed SignedInt;
 
    n = 0;
    ok = false;
    UnsignedInt max = static_cast<UnsignedInt>( std::numeric_limits<T>::max() );
 
    it = getWhitespace(it, end, fmt);
 
    bool pos = false;
    it = getSign(it, end, pos, fmt);
 
    if (it == end)
        return it;
 
    bool isNeg = ! pos;
    if( isNeg )
    {
        // return if minus sign was parsed for unsigned type
        if( isNeg != std::numeric_limits<T>::is_signed)
            return it;
 
        // abs(min) is max for negative signed types
        SignedInt smin = std::numeric_limits<T>::min();
        max = static_cast<UnsignedInt>(-smin);
    }
 
    // parse number
    UnsignedInt u = 0;
    const UnsignedInt base = fmt.base;
    unsigned d = 0;
    while(it != end)
    {    
        if( ! fmt.isDigit(*it) )
            break;
 
        d = fmt.toDigit(*it);
        
        if ( u != 0u && base > (max/u) )
          return it;
 
        u *= base;
 
        if(static_cast<UnsignedInt>(d) > max - u)
            return it;
 
        u += static_cast<UnsignedInt>(d);
        ++it;
    }
 
    if( isNeg ) 
        n = static_cast<T>(u * -1);
    else
        n = static_cast<T>(u);
 
    ok = true;
    return it;
}
 
 
template <typename InIterT, typename T>
InIterT parseInt(InIterT it, InIterT end, T& n, bool& ok)
{
    typedef typename std::iterator_traits<InIterT>::value_type CharType;    
    return parseInt(it, end, n, DecimalFormat<CharType>(), ok );
}
 
 
template <typename InIterT, typename T, typename FormatT>
InIterT parseFloat(InIterT it, InIterT end, T& n, const FormatT& fmt, bool& ok)
{
    typedef typename FormatT::CharT CharT;
    CharT zero = fmt.toChar(0);
    n = 0.0;
    ok = false;
 
    it = getWhitespace(it, end, fmt);
 
    bool pos = false;
    it = getSign(it, end, pos, fmt);
    
    if(it == end)
        return it;
 
    unsigned strpos = 0;
    if( fmt.isNan(*it, strpos, ok) )
    {
        while( ++it != end && fmt.isNan(*it, ++strpos, ok) )
            ;
 
        if(ok)
            n = std::numeric_limits<T>::quiet_NaN();
 
        return it;
    }
 
    strpos = 0;
    if( fmt.isInfinity(*it, strpos, ok) )
    {
        while( ++it != end && fmt.isInfinity(*it, ++strpos, ok) )
            ;
 
        if(ok)
        {
            n = pos ? std::numeric_limits<T>::infinity() 
                    : std::numeric_limits<T>::infinity() * -1;
        }
 
        return it;
    }
 
    if(it == end)
        return it;
 
    // integral part
    bool withFractional = false;
    for( ; it != end; ++it)
    {
        if( *it == fmt.point() )
        {
            withFractional = true;
            ++it;
            break;
        }
        
        if( ! fmt.isDigit(*it) )
            break;
 
        unsigned digit = fmt.toDigit(*it); 
        
        n *= 10;
        n += digit; 
    }
    
    // it is ok, if fraction is missing
    if(it == end)
    {
        if( ! pos )
            n *= -1;
 
        ok = true;
        return it;
    }
 
    T base = 10.0;
    if(withFractional)
    {
        // fractional part, ignore 0 digits after dot
        unsigned short fractDigits = 0;
        std::size_t maxDigits = std::numeric_limits<unsigned short>::max() - std::numeric_limits<T>::digits10;
        while(it != end && *it == zero)
        {
            if( fractDigits > maxDigits )
                return it;
 
            ++fractDigits;
            ++it;
        }
 
        // fractional part, parse like integer, skip insignificant digits
        unsigned short significants = 0;
        T fraction = 0.0;
        for( ; it != end; ++it)
        {
            if( ! fmt.isDigit(*it) )
                break;
 
            unsigned digit = fmt.toDigit(*it); 
 
            if( significants <= std::numeric_limits<T>::digits10 )
            {
                fraction *= 10;
                fraction += digit;
 
                ++fractDigits;
                ++significants;
            }
        }
 
        // fractional part, scale down
        fraction /= std::pow(base, T(fractDigits));
        n += fraction;
    }
    
    // exponent [e|E][+|-][0-9]*
    if(it != end && fmt.isE(*it) )
    {
        if(++it == end)
            return it;
 
        long exp = 0;
        it = parseInt(it, end, exp, fmt, ok);
        if( ! ok )
            return it;
            
        n *= std::pow(base, T(exp));
    }
 
    if( ! pos )
        n *= -1;
 
    ok = true;
    return it;
}
 
 
template <typename InIterT, typename T>
InIterT parseFloat(InIterT it, InIterT end, T& n, bool& ok)
{
    typedef typename std::iterator_traits<InIterT>::value_type CharType;
    return parseFloat( it, end, n, FloatFormat<CharType>(), ok);
}
 
} // namespace Pt
 
#endif