EclipseWriter: Store the Cartesian sizes internally

because it this array can be deleted after calling the
constructor. TODO (?): Do the same for the compressed-to-Cartesian
cell index map.

opm/core/io/eclipse/EclipseWriter.cpp

@@ -1003,10 +1003,12 @@ EclipseWriter::EclipseWriter(const parameter::ParameterGroup& params,
                              const int* cartesianSize)
     : deck_ (deck)
     , numCells_(numCells)
-    , cartesianSize_(cartesianSize)
     , compressedToCartesianCellIdx_(compressedToCartesianCellIdx)
     , phaseUsage_(phaseUsageFromDeck(deck_))
 {
+    for (int i = 0; i < 3; ++i)
+        cartesianSize_[i] = cartesianSize[i];
+
     init(params);
 }
 

opm/core/io/eclipse/EclipseWriter.hpp

@@ -28,7 +28,8 @@
 
 #include <string>
 #include <vector>
-#include <memory>  // std::unique_ptr
+#include <array>
+#include <memory>
 
 struct UnstructuredGrid;
 
@@ -99,7 +100,7 @@ public:
 private:
     Opm::DeckConstPtr deck_;
     int numCells_;
-    const int* cartesianSize_;
+    std::array<int, 3> cartesianSize_;
     const int* compressedToCartesianCellIdx_;
     bool enableOutput_;
     int outputInterval_;