Fix warnings.

warning C4244: conversion from 'const double' to 'const size_t'
warning C4800: 'MeshLib::PropertyVector<int> *' : forcing value to bool

Tests/MeshLib/TestVtkMeshConverter.cpp

@@ -102,10 +102,11 @@ TEST_F(TestVtkMeshConverter, Conversion)
     auto meshProperties = mesh->getProperties();
 
     // MaterialIDs are converted to an int property
-    auto materialIds = meshProperties.getPropertyVector<int>("MaterialIDs");
-    ASSERT_TRUE(static_cast<bool>(materialIds));
+    auto const* const materialIds =
+        meshProperties.getPropertyVector<int>("MaterialIDs");
+    ASSERT_NE(nullptr, materialIds);
     auto vtkMaterialIds = vtu->GetCellData()->GetArray("MaterialIDs");
-    ASSERT_EQ((*materialIds).size(), vtkMaterialIds->GetNumberOfTuples());
-    for(std::size_t i = 0; i < (*materialIds).size(); i++)
+    ASSERT_EQ(materialIds->size(), vtkMaterialIds->GetNumberOfTuples());
+    for(std::size_t i = 0; i < materialIds->size(); i++)
         ASSERT_EQ((*materialIds)[i], vtkMaterialIds->GetTuple1(i));
 }

Tests/NumLib/TestComponentNorms.cpp

@@ -48,11 +48,11 @@ struct DOFTableData
     NumLib::LocalToGlobalIndexMap const dof_table;
 
 private:
-    static const double mesh_length;
-    static const double mesh_elements_in_each_direction;
+    static const std::size_t mesh_length;
+    static const std::size_t mesh_elements_in_each_direction;
 };
-const double DOFTableData::mesh_length = 1.0;
-const double DOFTableData::mesh_elements_in_each_direction = 5.0;
+const std::size_t DOFTableData::mesh_length = 1;
+const std::size_t DOFTableData::mesh_elements_in_each_direction = 5;
 
 template <typename AccumulateCallback, typename AccumulateFinishCallback>
 void do_test(unsigned const num_components,