Area.h

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/* Copyright (C) 2002 - 2009, Bernd Speiser */

/* This file is part of Quantities.

PhysicalQuantities is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.

PhysicalQuantities 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.
  
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
02111-1307, USA.
*/

#ifndef _Area_h
#define _Area_h

// Quantity includes
#include "Quantity/Variable.h"
#include "Quantity/Constant.h"
#include "Quantity/QuantityCluster.h"
#include "PhysicalQuantities/Length.h"

namespace quantity {
  namespace area {

class Class;

class Unit;

/* declaration of Area units */
class BarnUnit;
class AcreUnit;
class AreUnit;
class HectareUnit;

/* the SquareMetre and prefixed SquareMetres */

typedef LOKI_TYPELIST_3(length::Metre, length::CentiMetre, 
                                        length::MilliMetre) LengthList;

typedef unit::ComposeElement<Unit, LengthList, 
                               BSUtilities::Rational<2> > LengthElement;
typedef LOKI_TYPELIST_1(LengthElement) AreaCompositeList;

typedef unit::ComposeBase<Unit, AreaCompositeList> SquareMetreUnits;

typedef 
  unit::Composed<SquareMetreUnits, LOKI_TYPELIST_1(length::Metre)> 
                                                            SquareMetre;

typedef
  unit::Composed<SquareMetreUnits, LOKI_TYPELIST_1(length::CentiMetre)>
                                                       SquareCentiMetre;

typedef unit::Composed<SquareMetreUnits, 
                  LOKI_TYPELIST_1(length::MilliMetre)> SquareMilliMetre;

typedef unit::NonPrefixable<Unit, BarnUnit> Barn;

typedef unit::NonPrefixable<Unit, AcreUnit> Acre;

typedef unit::NonPrefixable<Unit, AreUnit> Are;

typedef unit::NonPrefixable<Unit, HectareUnit> Hectare;

typedef
  LOKI_TYPELIST_7(SquareMetre, SquareCentiMetre, SquareMilliMetre, Barn,
                                              Acre, Are, Hectare) Units;

/* Area quantity */

typedef Quantity<Class> Quantity;

class DerivedArea;

  } // end namespace area


  template<typename ST>
    struct Standard<area::SquareMetreUnits, ST>
    {
      static const ST ratio;
      static const bool exact;
    };

template<typename ST> const ST Standard<area::SquareMetreUnits, ST>::ratio = 1.0;

template<typename ST> const bool Standard<area::SquareMetreUnits, ST>::exact = true;


  template<typename ST>
    struct Standard<area::Barn, ST>
    {
      static const ST ratio;
      static const bool exact;
    };

template<typename ST> const ST Standard<area::Barn, ST>::ratio = 1.0e-28;

template<typename ST> const bool Standard<area::Barn, ST>::exact = true;


  template<typename ST>
    struct Standard<area::Acre, ST>
    {
      static const ST ratio;
      static const bool exact;
    };

template<typename ST> const ST Standard<area::Acre, ST>::ratio = 4046.856;

template<typename ST> const bool Standard<area::Acre, ST>::exact = false;


  template<typename ST>
    struct Standard<area::Are, ST>
    {
      static const ST ratio;
      static const bool exact;
    };

template<typename ST> const ST Standard<area::Are, ST>::ratio = 1.0e2;

template<typename ST> const bool Standard<area::Are, ST>::exact = true;


  template<typename ST>
    struct Standard<area::Hectare, ST>
    {
      static const ST ratio;
      static const bool exact;
    };

template<typename ST> const ST Standard<area::Hectare, ST>::ratio = 1.0e4;

template<typename ST> const bool Standard<area::Hectare, ST>::exact = true;

template<>
  struct QuantityTraits<area::Class>
  {
    typedef
      dimension::Dimension<BSUtilities::Rational<2>,
        BSUtilities::Rational<0>, BSUtilities::Rational<0>,
          BSUtilities::Rational<0>, BSUtilities::Rational<0>,
            BSUtilities::Rational<0>, BSUtilities::Rational<0> > Dimension;
    typedef area::Unit UnitType;
    typedef area::Units UnitList;
    typedef area::SquareMetre DefaultUnit;

    typedef area::DerivedArea DefaultDerivedQuantityType;

    static const std::string NameString;
    static const std::string SymbolString;
  };

// the derived quantity traits template for derived Areas
template<>
  struct DerivedQuantityTraits<area::Class, area::DerivedArea>
  {
    static const bool OverwriteName = false;
    static const bool OverwriteSymbol = false;

    static const std::string NameString;
    static const std::string SymbolString;

  };


typedef Variable<area::Quantity> Area;

typedef Constant<area::Quantity> AreaConstant;

typedef QuantityVector<Variable, area::Quantity> AreaVector;

} // end namespace quantity

#endif /* _Area_h */

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