Identity.H

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License
    This file is part of OpenFOAM.
 
    OpenFOAM 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 3 of the License, or
    (at your option) any later version.
 
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    for more details.
 
    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.
 
Class
    Foam::Identity
 
Description
    Templated identity and dual space identity tensors derived from
    SphericalTensor.
 
\*---------------------------------------------------------------------------*/
 
#ifndef Identity_H
#define Identity_H
 
#include "SphericalTensor.H"
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
namespace Foam
{
 
/*---------------------------------------------------------------------------*\
                          Class Identity Declaration
\*---------------------------------------------------------------------------*/
 
template<class Cmpt>
class Identity
:
    public SphericalTensor<Cmpt>
{
 
public:
 
    //- Construct initialising the SphericalTensor to 1
    Identity()
    :
        SphericalTensor<Cmpt>(1)
    {}
 
    //- The identity type in the dual space
    class dual
    :
        public SphericalTensor<Cmpt>
    {
        //- Construct initialising the SphericalTensor to 1
        dual()
        :
            SphericalTensor<Cmpt>(1)
        {}
    };
 
    //- Return the identity in the dual space
    inline dual operator*()
    {
        return dual();
    }
 
    //- Return 1 for label
    inline explicit operator label() const
    {
        return 1;
    }
 
    //- Return 1 for scalar
    inline explicit operator scalar() const
    {
        return 1;
    }
};
 
 
// Global Identity tensor
static const Identity<scalar> I;
 
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
} // End namespace Foam
 
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
 
#endif
 
// ************************************************************************* //