identity.hpp

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#ifndef GKO_CORE_MATRIX_IDENTITY_HPP_
#define GKO_CORE_MATRIX_IDENTITY_HPP_


#include <ginkgo/core/base/lin_op.hpp>


namespace gko {
namespace matrix {


template <typename ValueType = default_precision>
class Identity : public EnableLinOp<Identity<ValueType>>,
                 public EnableCreateMethod<Identity<ValueType>> {
    friend class EnablePolymorphicObject<Identity, LinOp>;
    friend class EnableCreateMethod<Identity>;

public:
    using EnableLinOp<Identity>::convert_to;
    using EnableLinOp<Identity>::move_to;

    using value_type = ValueType;

protected:
    explicit Identity(std::shared_ptr<const Executor> exec)
        : EnableLinOp<Identity>(exec)
    {}

    Identity(std::shared_ptr<const Executor> exec, size_type size)
        : EnableLinOp<Identity>(exec, dim<2>{size})
    {}

    void apply_impl(const LinOp *b, LinOp *x) const override;

    void apply_impl(const LinOp *alpha, const LinOp *b, const LinOp *beta,
                    LinOp *x) const override;
};


template <typename ValueType = default_precision>
class IdentityFactory
    : public EnablePolymorphicObject<IdentityFactory<ValueType>, LinOpFactory> {
    friend class EnablePolymorphicObject<IdentityFactory, LinOpFactory>;

public:
    using value_type = ValueType;

    static std::unique_ptr<IdentityFactory> create(
        std::shared_ptr<const Executor> exec)
    {
        return std::unique_ptr<IdentityFactory>(
            new IdentityFactory(std::move(exec)));
    }

protected:
    std::unique_ptr<LinOp> generate_impl(
        std::shared_ptr<const LinOp> base) const override;

    IdentityFactory(std::shared_ptr<const Executor> exec)
        : EnablePolymorphicObject<IdentityFactory, LinOpFactory>(exec)
    {}
};


}  // namespace matrix
}  // namespace gko


#endif  // GKO_CORE_MATRIX_IDENTITY_HPP_