added method to test if element is located on boundary

MeshLib/Elements/Element.cpp

@@ -163,6 +163,11 @@ bool Element::hasNeighbor(Element* elem) const
 	return false;
 }
 
+bool Element::isBoundaryElement() const
+{
+    return std::any_of(_neighbors, _neighbors + this->getNNeighbors(), 
+        [](MeshLib::Element* e){ return e == nullptr; });
+}
 
 }
 

MeshLib/Elements/Element.h

@@ -148,6 +148,8 @@ public:
 	 */
 	bool hasZeroVolume() const { return this->getContent() < std::numeric_limits<double>::epsilon(); }
 
+	/// Returns true if the element is located at a boundary (i.e. has at least one face without neighbour)
+	virtual bool isBoundaryElement() const;
 
 	/// Returns true if these two indeces form an edge and false otherwise
 	virtual bool isEdge(unsigned i, unsigned j) const = 0;

Tests/MeshLib/TestQuadMesh.cpp

@@ -209,6 +209,7 @@ TEST_F(MeshLibQuadMesh, ElementNeighbors)
             // Test the test
             EXPECT_EQ(1u, ij_neighbors.first.size());
             EXPECT_EQ(1u, ij_neighbors.second.size());
+            ASSERT_TRUE(e->isBoundaryElement());
 
             testNeighbors(e, i, j, ij_neighbors);
         });
@@ -222,6 +223,7 @@ TEST_F(MeshLibQuadMesh, ElementNeighbors)
             std::pair<Indices, Indices> const ij_neighbors = getNeighborIndices(i, j);
             // Test the test
             EXPECT_EQ(3u, ij_neighbors.first.size() + ij_neighbors.second.size());
+            ASSERT_TRUE(e->isBoundaryElement());
 
             testNeighbors(e, i, j, ij_neighbors);
         });
@@ -236,6 +238,7 @@ TEST_F(MeshLibQuadMesh, ElementNeighbors)
             // Test the test
             EXPECT_EQ(2u, ij_neighbors.first.size());
             EXPECT_EQ(2u, ij_neighbors.second.size());
+            ASSERT_FALSE(e->isBoundaryElement());
 
             testNeighbors(e, i, j, ij_neighbors);
         });