/*
  *  MoMEMta: a modular implementation of the Matrix Element Method
  *  Copyright (C) 2016  Universite catholique de Louvain (UCL), Belgium
  *
  *  This program 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.
  *
  *  This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
 #pragma once
 
 #include <memory>
 #include <type_traits>
 #include <vector>
 
 class Pool;
 struct InputTag;
 
 template <typename T>
 class ValueProxy {
 public:
     virtual T& operator*() = 0;
     virtual T* operator->() = 0;
     virtual T* get() = 0;
 
     static std::shared_ptr<ValueProxy<T>> create(const Pool*, const InputTag&);
 
 protected:
     template <typename U>
     std::shared_ptr<const U> get_from_pool(const Pool*, const InputTag&);
 };
 
 template <typename T>
 class NonIndexedValueProxy: public ValueProxy<T> {
 public:
     using container_t = typename std::remove_const<T>::type;
 
     NonIndexedValueProxy(const Pool*, const InputTag& tag);
     virtual T& operator*() override;
     virtual T* operator->() override;
     virtual T* get() override;
 
 private:
     std::shared_ptr<const container_t> raw_value;
 };
 
 template <typename T>
 class IndexedValueProxy: public ValueProxy<T> {
 public:
     using container_t = std::vector<typename std::remove_const<T>::type>;
 
     IndexedValueProxy(const Pool*, const InputTag& tag);
     virtual T& operator*() override;
     virtual T* operator->() override;
     virtual T* get() override;
 
 private:
     size_t index;
     std::shared_ptr<const container_t> raw_value;
 };