referenceActiveType.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 "../misc/macros.hpp"
#include "../tapes/interfaces/gradientAccessTapeInterface.hpp"
#include "../traits/realTraits.hpp"
#include "assignmentOperators.hpp"
#include "incrementOperators.hpp"
#include "lhsExpressionInterface.hpp"

namespace codi {

  template<typename T_Type>
  struct ReferenceActiveType
      : public LhsExpressionInterface<typename T_Type::Real, typename T_Type::Gradient, typename T_Type::Tape,
                                      ReferenceActiveType<T_Type>>,
        public AssignmentOperators<typename T_Type::Tape::Real, T_Type::Tape::AllowJacobianOptimization,
                                   ReferenceActiveType<T_Type>>,
        public IncrementOperators<typename T_Type::Tape, ReferenceActiveType<T_Type>> {
    public:

      using Type = CODI_DD(T_Type, CODI_DEFAULT_LHS_EXPRESSION);
      using Tape = typename Type::Tape;  
 
      using Real = typename Tape::Real;                   
      using PassiveReal = RealTraits::PassiveReal<Real>;  
      using Identifier = typename Tape::Identifier;       
      using Gradient = typename Tape::Gradient;           
 
    protected:
 
      Type& reference;  
 
    public:
 
      // TODO: Implement const variant

      mutable Real jacobian;

      CODI_INLINE ReferenceActiveType(Type& v) : reference(v), jacobian() {}

      CODI_INLINE ReferenceActiveType(ReferenceActiveType const& o) : reference(o.reference), jacobian() {}

      CODI_INLINE ReferenceActiveType& operator=(ReferenceActiveType const& v) {
        static_cast<LhsExpressionInterface<Real, Gradient, Tape, ReferenceActiveType>&>(*this) = v;
        return *this;
      }
      using LhsExpressionInterface<Real, Gradient, Tape, ReferenceActiveType>::operator=;
 
      /*******************************************************************************/
 
      using StoreAs = ReferenceActiveType const&;  
      using ADLogic = Tape;                        

      CODI_INLINE Identifier& getIdentifier() {
        return reference.getIdentifier();
      }

      CODI_INLINE Identifier const& getIdentifier() const {
        return reference.getIdentifier();
      }

      CODI_INLINE Real& value() {
        return reference.value();
      }

      CODI_INLINE Real const& value() const {
        return reference.value();
      }

      static CODI_INLINE decltype(Type::getTape()) getTape() {
        return Type::getTape();
      }
  };
}