tagTapeForward.hpp

/*
 * CoDiPack, a Code Differentiation Package
 *
 * Copyright (C) 2015-2025 Chair for Scientific Computing (SciComp), University of Kaiserslautern-Landau
 * Homepage: http://scicomp.rptu.de
 * Contact:  Prof. Nicolas R. Gauger (codi@scicomp.uni-kl.de)
 *
 * Lead developers: Max Sagebaum, Johannes Blühdorn (SciComp, University of Kaiserslautern-Landau)
 *
 * This file is part of CoDiPack (http://scicomp.rptu.de/software/codi).
 *
 * CoDiPack 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.
 *
 * CoDiPack 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 CoDiPack.
 * If not, see <http://www.gnu.org/licenses/>.
 *
 * For other licensing options please contact us.
 *
 * Authors:
 *  - SciComp, University of Kaiserslautern-Landau:
 *    - Max Sagebaum
 *    - Johannes Blühdorn
 *    - Former members:
 *      - Tim Albring
 */
#pragma once
 
#include "../../config.h"
#include "../../expressions/lhsExpressionInterface.hpp"
#include "../../misc/macros.hpp"
#include "../../traits/realTraits.hpp"
#include "../interfaces/gradientAccessTapeInterface.hpp"
#include "../interfaces/internalStatementRecordingTapeInterface.hpp"
#include "tagData.hpp"
#include "tagTapeBase.hpp"

namespace codi {

  template<typename T_Real, typename T_Tag>
  struct TagTapeForward : public InternalStatementRecordingTapeInterface<T_Tag>,
                          public GradientAccessTapeInterface<T_Tag, T_Tag>,
                          public TagTapeBase<T_Real, T_Tag, TagData<T_Tag>, TagTapeForward<T_Real, T_Tag>> {
    public:
 
      using Real = CODI_DD(T_Real, double);  
      using Tag = CODI_DD(T_Tag, double);    

      struct TapeTypes {
          struct IndexManager {
              using Index = int;
          };
      };
 
      using Gradient = TagData<Tag>;   
      using Identifier = Gradient;     
      using Position = EmptyPosition;  
 
      using PassiveReal = RealTraits::PassiveReal<Real>;  
 
      using Base = TagTapeBase<T_Real, T_Tag, TagData<T_Tag>, TagTapeForward>;  
 
    private:

      Gradient tempGradient;
 
    public:

      TagTapeForward() : Base(), tempGradient() {}
 
      /*******************************************************************************/
 
      static bool constexpr AllowJacobianOptimization = false;  

      template<typename Real>
      void initIdentifier(Real& value, Identifier& identifier) {
        CODI_UNUSED(value);
        identifier = Identifier();
      }

      template<typename Real>
      void destroyIdentifier(Real& value, Identifier& identifier) {
        CODI_UNUSED(value, identifier);
      }

      template<typename Lhs, typename Rhs>
      void store(LhsExpressionInterface<Real, Gradient, TagTapeForward, Lhs>& lhs,
                 ExpressionInterface<Real, Rhs> const& rhs) {
        typename Base::ValidateTags validate;
        ValidationIndicator<Real, Tag> vi;
 
        validate.eval(rhs, vi, *this);
 
        Base::checkLhsError(lhs, rhs.cast().getValue());
 
        Base::handleError(vi);
 
        if (vi.isActive) {
          Base::setTag(lhs.cast().getIdentifier().tag);
        } else {
          Base::resetTag(lhs.cast().getIdentifier().tag);
        }
 
        lhs.cast().value() = rhs.cast().getValue();
      }

      template<typename Lhs, typename Rhs>
      void store(LhsExpressionInterface<Real, Gradient, TagTapeForward, Lhs>& lhs,
                 LhsExpressionInterface<Real, Gradient, TagTapeForward, Rhs> const& rhs) {
        store<Lhs, Rhs>(lhs, static_cast<ExpressionInterface<Real, Rhs> const&>(rhs));
      }

      template<typename Lhs>
      void store(LhsExpressionInterface<Real, Gradient, TagTapeForward, Lhs>& lhs, Real const& rhs) {
        Base::checkLhsError(lhs, rhs);
 
        Base::resetTag(lhs.cast().getIdentifier().tag);
 
        lhs.cast().value() = rhs;
      }

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

      void setGradient(Identifier& identifier, Gradient const& gradient) {
        CODI_UNUSED(gradient);
 
        Base::verifyTagAndProperties(identifier.tag, 0.0, identifier.properties);
      }

      Gradient const& getGradient(Identifier const& identifier) const {
        Base::verifyTagAndProperties(identifier.tag, 0.0, identifier.properties);
 
        return tempGradient;
      }

      Gradient& gradient(Identifier& identifier) {
        Base::verifyTagAndProperties(identifier.tag, 0.0, identifier.properties);
 
        return tempGradient;
      }

      Gradient const& gradient(Identifier const& identifier) const {
        Base::verifyTagAndProperties(identifier.tag, 0.0, identifier.properties);
 
        return tempGradient;
      }

      void setGradient(Identifier const& identifier, Gradient const& gradient) = delete;

      Gradient& gradient(Identifier const& identifier) = delete;

  };
}