// Temperature and TempChange classes (Copyright 1994, 
// ---------------------------------       Information Disciplines, Inc.)

//  These classes support operations on temperatures.  

#ifndef TEMPERATURE
#define TEMP_CHANGE const TempChange
#define TEMPERATURE const Temperature

//   Temperature Change (extent) class 
//   ------------------

class TempChange {
friend class Temperature; // Allow Temperature methods to retrieve value

    double value;         // Internal representation degrees Kelvin or Celsius



//  Constructor 
//  -----------

public:
    TempChange(DOUBLE x = 0) : value(x) {}

//    Compiler will supply acceptable copy constructor, destructor,
//    and assignment operator

    
//  Arithmetic Operators 
//  --------------------

#define Class TempChange          
#define PureType double
#include "Additive.hpp"     /*  Additive pattern for binary operators */



//  Relational operators
//  --------------------

 bool operator== (TEMP_CHANGE rs) const {return value == rs.value;}
 bool operator<  (TEMP_CHANGE rs) const {return value <  rs.value;}



//  I-O operations
//  -------------- 

 static char*  unit;        //  Unit name ("degree") for messages
 ostream& put(ostream& s) const;
 istream& get(istream& s);

};               //  ************   End of class definition


//  Inline member and non-member functions
//  --------------------------------------

inline ostream& operator<< (ostream& ls, TEMP_CHANGE rs) {return rs.put(ls);}
inline istream& operator>> (istream& ls, TempChange& rs){return rs.get(ls);}

inline TempChange& TempChange::operator+=(TEMP_CHANGE rs) 
                       {value += rs.value; return *this; }
inline TempChange& TempChange::operator-=(TEMP_CHANGE rs) 
                       {value -= rs.value; return *this; }
inline TempChange& TempChange::operator*=(DOUBLE rs) 
                       {value *= rs;       return *this; }
inline TempChange& TempChange::operator/=(DOUBLE rs) 
                       {value /= rs;       return *this; }
inline double TempChange::operator/ (TEMP_CHANGE rs) const 
                       {  return value / rs.value; }


//   Temperature class 
//   ----------

//  This class defines Temperature objects.  


class Temperature  {
    double  value;              //  Internal representation
public:
    static DOUBLE zeroCelsius;
    

 
//  Constructor, accessors, and conversion functions
//  ------------------------------------------------

   Temperature(double kelvin=0.0) : value(kelvin) {assert(value>=0.0);}                            

//   Compiler will supply acceptable copy constructor, destructor,
//   and assignment operator

       double      toKelvin()               {return value;}
       double      toCelsius()              {return value - zeroCelsius;}
       double      toFahrenheit()           {return 1.8*toCelsius()+32;}
    inline static 
       Temperature fromCelsius   (DOUBLE x) {return x+zeroCelsius;}
    inline static 
       Temperature fromFahrenheit(DOUBLE x) {return fromCelsius((x-32)/1.8);}

//  Arithmetic Operators

#define PointClass Temperature
  #include "PointExt.hpp"


//  Relational operators
//  --------------------

 bool operator== (Temperature rs) const {return value == rs.value;}
 bool operator<  (Temperature rs) const {return value <  rs.value;}

 

//  I-O operations
//  --------------

static char*  unit;        //  Unit name ("K") for messages
ostream& put(ostream& s) const;
istream& get(istream& s);

};


//  Inline member and non-member functions
//  --------------------------------------
inline ostream& operator<< (ostream& ls, Temperature rs) {return rs.put(ls);}
inline istream& operator>> (istream& ls, Temperature& rs){return rs.get(ls);}

inline Temperature& Temperature::operator+= (TEMP_CHANGE rs) 
                            {assert(value >= -rs.value); value += rs.value; return *this;}
inline Temperature& Temperature::operator-= (TEMP_CHANGE rs) 
                            {assert(value >=  rs.value); value -= rs.value; return *this;}


#undef Class
#undef PointClass
#endif