Feature/itemvalue

src/mesh/ItemToItemMatrix.hpp

+#ifndef ITEM_TO_ITEM_MATRIX_HPP
+#define ITEM_TO_ITEM_MATRIX_HPP
+
+#include <ItemType.hpp>
+#include <ItemId.hpp>
+
+#include <Kokkos_Core.hpp>
+#include <ConnectivityMatrix.hpp>
+
+template <ItemType SourceItemType,
+          ItemType TargetItemType>
+class ItemToItemMatrix
+{
+ public:
+  using SourceItemId = ItemIdT<SourceItemType>;
+  using TargetItemId = ItemIdT<TargetItemType>;
+
+  template <typename RowType>
+  class SubItemList
+  {
+   private:
+    const RowType m_row;
+
+   public:
+
+    KOKKOS_INLINE_FUNCTION
+    size_t size() const
+    {
+      return m_row.length;
+    }
+
+    KOKKOS_INLINE_FUNCTION
+    TargetItemId operator[](const size_t& j) const
+    {
+      return m_row(j);
+    }
+
+    KOKKOS_INLINE_FUNCTION
+    SubItemList(const RowType& row)
+        : m_row{row}
+    {
+      ;
+    }
+
+    KOKKOS_INLINE_FUNCTION
+    SubItemList& operator=(const SubItemList&) = default;
+
+    KOKKOS_INLINE_FUNCTION
+    SubItemList& operator=(SubItemList&&) = default;
+
+    KOKKOS_INLINE_FUNCTION
+    SubItemList(const SubItemList&) = default;
+
+    KOKKOS_INLINE_FUNCTION
+    SubItemList(SubItemList&&) = default;
+
+    KOKKOS_INLINE_FUNCTION
+    ~SubItemList() = default;
+  };
+
+ private:
+  const ConnectivityMatrix& m_connectivity_matrix;
+
+ public:
+  KOKKOS_INLINE_FUNCTION
+  const auto operator[](const SourceItemId& source_id) const
+  {
+    using RowType = decltype(m_connectivity_matrix.rowConst(source_id));
+    return SubItemList<RowType>(m_connectivity_matrix.rowConst(source_id));
+  }
+
+  template <typename IndexType>
+  KOKKOS_INLINE_FUNCTION
+  const auto operator[](const IndexType& source_id) const
+  {
+    static_assert(std::is_same<IndexType, SourceItemId>(),
+                  "ItemToItemMatrix must be indexed using correct ItemId");
+    using RowType = decltype(m_connectivity_matrix.rowConst(source_id));
+    return SubItemList<RowType>(m_connectivity_matrix.rowConst(source_id));
+  }
+
+  KOKKOS_INLINE_FUNCTION
+  ItemToItemMatrix(const ConnectivityMatrix& connectivity_matrix)
+      : m_connectivity_matrix{connectivity_matrix}
+  {
+    ;
+  }
+
+  KOKKOS_INLINE_FUNCTION
+  ItemToItemMatrix& operator=(const ItemToItemMatrix&) = default;
+
+  KOKKOS_INLINE_FUNCTION
+  ItemToItemMatrix& operator=(ItemToItemMatrix&&) = default;
+
+  KOKKOS_INLINE_FUNCTION
+  ItemToItemMatrix(ItemToItemMatrix&&) = default;
+
+  KOKKOS_INLINE_FUNCTION
+  ItemToItemMatrix(const ItemToItemMatrix&) = default;
+
+  KOKKOS_INLINE_FUNCTION
+  ~ItemToItemMatrix() = default;
+};
+
+#endif // ITEM_TO_ITEM_MATRIX_HPP