data/src/finiteVolume/fields/pointPatchFields/pointPatchField/pointPatchFieldExpression.H

/*---------------------------------------------------------------------------*\
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License
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    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
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\*---------------------------------------------------------------------------*/

#include "expressions.H"

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

namespace Foam
{
namespace expression
{

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

//- A pointPatchField is expressionable (yes, really ...)
template<class Type>
struct Expressionable<pointPatchField<Type>>
:
    public std::integral_constant<signed char, 1>
{};

//- Define access to a pointPatchField as returning a Field, but do not
//  actually provide an implementation. This just facilitates generation of the
//  identity value for reduction.
template<class Type>
struct Operate<pointPatchField<Type>, Arguments<Base>>
{
    using type = const Field<Type>&;

    static type access(const pointPatchField<Type>& f, const Base&)
    {
        return static_cast<type>(f.primitiveField());
    }
};

//- Define the types returned by pointPatchField expressions
template<class Type>
struct Result<pointPatchField<Type>>
{
    template<class Expression>
    using operateType =
        typename Operate<std::decay_t<Expression>, Arguments<>>::type;

    template<class Expression>
    using elementType =
        typename Result
        <
            Field<Type>
        >::template elementType<operateType<Expression>>;

    template<class Expression>
    using type = nil;
};

//- Define reduction of a pointPatchField as returning the identity for the
//  given operation
template<class Type>
struct Reduce<pointPatchField<Type>>
{
    template<class Op, class Expression>
    static typename Result
    <
        pointPatchField<Type>
    >::template elementType<Expression> value(const Expression& e)
    {
        return
            Op::template identity
            <
                typename Result
                <
                    pointPatchField<Type>
                >::template elementType<Expression>
            >();
    }
};

//- Implement selection of a pointPatchField within an expression. Construct a
//  calculated field type on non-constrained patch types, and pass through a
//  reference to the internal field if this was provided.
template<class Type>
struct Select
<
    pointPatchField<Type>,
    true,
    EnableIfExpressionable<pointPatchField<Type>>
>
{
    using type = autoPtr<pointPatchField<Type>>;

    template<class Expression>
    static type New
    (
        const Expression& e,
        const DimensionedField<Type, pointMesh, Field>& iF
    )
    {
        autoPtr<pointPatchField<Type>> tResult =
            pointPatchField<Type>::New
            (
                pointPatchField<Type>::calculatedType(),
                getFirst<Patch<pointPatch>>(e),
                iF
            );

        tResult() = e;

        return tResult;
    }

    template<class Expression>
    static type New(const Expression& e)
    {
        return
            New
            (
                e,
                NullObjectRef<DimensionedField<Type, pointMesh, Field>>()
            );
    }
};

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

} // End namespace expression
} // End namespace Foam

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