Identity.H

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License
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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 initializing the SphericalTensor to 1
    Identity()
    :
        SphericalTensor<Cmpt>(1)
    {}

    //- The identity type in the dual space
    class dual
    :
        public SphericalTensor<Cmpt>
    {
        //- Construct initializing the SphericalTensor to 1
        dual()
        :
            SphericalTensor<Cmpt>(1)
        {}
    };

    //- Return the identity in the dual space
    dual operator*()
    {
        return dual();
    }

    //- Return 1 for label
    explicit operator label() const noexcept
    {
        return 1;
    }

    //- Return 1 for scalar
    explicit operator scalar() const noexcept
    {
        return 1;
    }
};


// Global Identity tensor
static const Identity<scalar> I;


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace Foam

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

#endif

// ************************************************************************* //