ItemValue.hpp

#ifndef ITEM_VALUE_HPP
#define ITEM_VALUE_HPP

#include <PastisAssert.hpp>
#include <PastisOStream.hpp>

#include <Array.hpp>

#include <ItemType.hpp>
#include <ItemId.hpp>

#include <IConnectivity.hpp>
#include <memory>

template <typename DataType,
          ItemType item_type,
          typename ConnectivityPtr = std::shared_ptr<const IConnectivity>>
class ItemValue
{
 public:
  static const ItemType item_t{item_type};
  using data_type = DataType;

  using ItemId = ItemIdT<item_type>;
  using index_type = ItemId;

 private:
  using ConnectivitySharedPtr = std::shared_ptr<const IConnectivity>;
  using ConnectivityWeakPtr = std::weak_ptr<const IConnectivity>;

  static_assert(std::is_same_v<ConnectivityPtr, ConnectivitySharedPtr> or
                std::is_same_v<ConnectivityPtr, ConnectivityWeakPtr>);

  ConnectivityPtr m_connectivity_ptr;

  bool m_is_built{false};

  Array<DataType> m_values;

  // Allow const std:shared_ptr version to access our data
  friend ItemValue<std::add_const_t<DataType>, item_type,
                   ConnectivitySharedPtr>;

  // Allow const std:weak_ptr version to access our data
  friend ItemValue<std::add_const_t<DataType>, item_type,
                   ConnectivityWeakPtr>;

  friend PASTIS_INLINE
  ItemValue<std::remove_const_t<DataType>,item_type, ConnectivityPtr>
  copy(const ItemValue<DataType, item_type, ConnectivityPtr>& source)
  {
    ItemValue<std::remove_const_t<DataType>, item_type, ConnectivityPtr> image(source);

    image.m_values = copy(source.m_values);
    return image;
  }

 public:
  PASTIS_INLINE
  bool isBuilt() const
  {
    return m_connectivity_ptr.use_count() != 0;
  }

  PASTIS_INLINE
  std::shared_ptr<const IConnectivity> connectivity_ptr() const
  {
    if constexpr (std::is_same_v<ConnectivityPtr, ConnectivitySharedPtr>) {
      return m_connectivity_ptr;
    } else {