fraction.h

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// OSB library ********************************************* -*- C++ -*-
/*
  AUTHOR(S): Darryl Kang (dk)

  RCS information
   $Name: OSB_060808 $
   $Revision: 1.13 $

  License
   OSB rating and billing library for communication networks
   Copyright (C) 2004, 2005, 2006  OSB systems

   This file may be distributed and/or modify under the terms of the
   GNU General Public License (GPL) as published by the Free Software
   Foundation which is provided in the file LICENSE.GPL included in the
   packaging of this file.

   The file 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 General Public License
   for more details.

   Holders of a OSB Commercial License may use this file under the terms
   and conditions of this commercial license.
 */
#ifndef _FRACTION_H_
#define _FRACTION_H_

// *********************************************************************
// included header files
// + standard includes
#include <string>
#include <iosfwd>
#include <utility>
#include <cmath>

// + local headers
#include "osberror.h"

// *********************************************************************
// namespace extensions
namespace OSB_LIB {

    class Fraction {
    public:
        Fraction()
          : nominator_(0), denominator_(1)
        {
            // empty
        }

        Fraction(long nominator, long denominator = 1);

        long nominator() const { return nominator_; }
        long denominator() const { return denominator_; }
        double dbl() const
        {
            double rc = nominator_;
            rc /= denominator_;
            return rc;
        }

        std::string str() const;

        inline Fraction& operator-();
        Fraction& operator+=(const Fraction&);
        Fraction& operator-=(const Fraction&);
        Fraction& operator*=(const Fraction&);
        Fraction& operator/=(const Fraction&);

    private:
        void reduce();

        void divide(long& higher, long& lower);
    private:
        long nominator_;
        long denominator_;
    };                                  // class Fraction

    inline Fraction operator*(const Fraction&, const Fraction&);
    inline Fraction operator/(const Fraction&, const Fraction&);
    inline Fraction operator+(const Fraction&, const Fraction&);
    inline Fraction operator-(const Fraction&, const Fraction&);
    inline bool operator==(const Fraction& lhs, const Fraction& rhs);
    inline bool operator!=(const Fraction& lhs, const Fraction& rhs);

    std::ostream& operator<<(std::ostream& os, const Fraction& f);
}                                   // namespace OSB_LIB

// ************************************************************************
// inline definitions
namespace OSB_LIB {
    inline Fraction& Fraction::operator-()
    {
        nominator_ *= -1;
        return *this;
    }

    inline Fraction operator+(const Fraction& f1, const Fraction& f2)
    {
        Fraction r(f1);
        return r += f2;
    }

    inline Fraction operator-(const Fraction& f1, const Fraction& f2)
    {
        Fraction r(f1);
        return r -= f2;
    }

    inline Fraction operator*(const Fraction& f1, const Fraction& f2)
    {
        Fraction r(f1);
        return r *= f2;
    }

    inline Fraction operator/(const Fraction& f1, const Fraction& f2)
    {
        Fraction r(f1);
        return r /= f2;
    }

    inline bool operator==(const Fraction& lhs, const Fraction& rhs)
    {
        return (lhs.nominator()   == rhs.nominator() &&
                lhs.denominator() == rhs.denominator());
    }

    inline bool operator!=(const Fraction& lhs, const Fraction& rhs)
    {
        return lhs != rhs;
    }
}                                       // namespace OSB_LIB
#endif                              // #ifndef _FRACTION_H_

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