source: XMLIO_V2/external/include/Poco/FPEnvironment.h @ 80

//
// FPEnvironment.h
//
// $Id: //poco/1.3/Foundation/include/Poco/FPEnvironment.h#1 $
//
// Library: Foundation
// Package: Core
// Module:  FPEnvironment
//
// Definitions of class FPEnvironment.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#ifndef Foundation_FPEnvironment_INCLUDED
#define Foundation_FPEnvironment_INCLUDED


#include "Poco/Foundation.h"


#if defined(POCO_NO_FPENVIRONMENT)
#include "Poco/FPEnvironment_DUMMY.h"
#elif defined(__osf__) || defined(__VMS)
#include "Poco/FPEnvironment_DEC.h"
#elif defined(sun) || defined(__sun)
#include "Poco/FPEnvironment_SUN.h"
#elif defined(POCO_OS_FAMILY_UNIX)
#include "Poco/FPEnvironment_C99.h"
#elif defined(POCO_OS_FAMILY_WINDOWS)
#include "Poco/FPEnvironment_WIN32.h"
#else
#include "Poco/FPEnvironment_DUMMY.h"
#endif


namespace Poco {


class Foundation_API FPEnvironment: private FPEnvironmentImpl
        /// Instances of this class can be used to save
        /// and later restore the current floating
        /// point environment (consisting of rounding
        /// mode and floating-point flags).
        /// The class also provides various static
        /// methods to query certain properties
        /// of a floating-point number. 
{
public:
        enum RoundingMode
        {
                FP_ROUND_DOWNWARD   = FP_ROUND_DOWNWARD_IMPL,
                FP_ROUND_UPWARD     = FP_ROUND_UPWARD_IMPL,
                FP_ROUND_TONEAREST  = FP_ROUND_TONEAREST_IMPL,
                FP_ROUND_TOWARDZERO = FP_ROUND_TOWARDZERO_IMPL
        };

        enum Flag
        {
                FP_DIVIDE_BY_ZERO = FP_DIVIDE_BY_ZERO_IMPL,
                FP_INEXACT        = FP_INEXACT_IMPL,
                FP_OVERFLOW       = FP_OVERFLOW_IMPL,
                FP_UNDERFLOW      = FP_UNDERFLOW_IMPL,
                FP_INVALID        = FP_INVALID_IMPL
        };

        FPEnvironment();
                /// Standard constructor.
                /// Remembers the current environment.

        FPEnvironment(RoundingMode mode);
                /// Remembers the current environment and
                /// sets the given rounding mode.
                
        FPEnvironment(const FPEnvironment& env);
                /// Copy constructor.
                
        ~FPEnvironment();
                /// Restores the previous environment (unless
                /// keepCurrent() has been called previously)
                
        FPEnvironment& operator = (const FPEnvironment& env);
                /// Assignment operator

        void keepCurrent();
                /// Keep the current environment even after
                /// destroying the FPEnvironment object.

        static void clearFlags();
                /// Resets all flags.

        static bool isFlag(Flag flag);
                /// Returns true iff the given flag is set.
                
        static void setRoundingMode(RoundingMode mode);
                /// Sets the rounding mode.
                
        static RoundingMode getRoundingMode();
                /// Returns the current rounding mode.
                
        static bool isInfinite(float value);            
        static bool isInfinite(double value);
        static bool isInfinite(long double value);
                /// Returns true iff the given number is infinite.

        static bool isNaN(float value);         
        static bool isNaN(double value);
        static bool isNaN(long double value);
                /// Returns true iff the given number is NaN.

        static float copySign(float target, float source);              
        static double copySign(double target, double source);
        static long double copySign(long double target, long double source);
                /// Copies the sign from source to target.
};


//
// For convenience, we provide a shorter name for
// the FPEnvironment class.
//
typedef FPEnvironment FPE;


//
// inline's
//
inline bool FPEnvironment::isFlag(Flag flag)
{
        return isFlagImpl(FlagImpl(flag));
}


inline void FPEnvironment::setRoundingMode(RoundingMode mode)
{
        setRoundingModeImpl(RoundingModeImpl(mode));
}

        
inline FPEnvironment::RoundingMode FPEnvironment::getRoundingMode()
{
        return RoundingMode(getRoundingModeImpl());
}

        
inline bool FPEnvironment::isInfinite(float value)
{
        return isInfiniteImpl(value);
}


inline bool FPEnvironment::isInfinite(double value)
{
        return isInfiniteImpl(value);
}


inline bool FPEnvironment::isInfinite(long double value)
{
        return isInfiniteImpl(value);
}


inline bool FPEnvironment::isNaN(float value)
{
        return isNaNImpl(value);
}


inline bool FPEnvironment::isNaN(double value)
{
        return isNaNImpl(value);
}


inline bool FPEnvironment::isNaN(long double value)
{
        return isNaNImpl(value);
}


inline float FPEnvironment::copySign(float target, float source)
{
        return copySignImpl(target, source);
}


inline double FPEnvironment::copySign(double target, double source)
{
        return copySignImpl(target, source);
}


inline long double FPEnvironment::copySign(long double target, long double source)
{
        return copySignImpl(target, source);
}


} // namespace Poco


#endif // Foundation_FPEnvironment_INCLUDED