Add a const function datum() to AABB_tree and test.

AABB_tree/include/CGAL/AABB_tree.h

@@ -646,6 +646,18 @@ public:
 			else
 				return this->any_reference_point_and_id();
 		}
+		
+		//!
+		//! \brief datum
+		//! \param p
+		//! \return 
+		//!
+		typename internal::Primitive_helper<AABBTraits>::Datum_type 
+		datum(Primitive& p)const
+		{
+		  return internal::Primitive_helper<AABBTraits>::
+		      get_datum(p, this->traits());
+		}
 
 	private:
     //Traits class

AABB_tree/test/AABB_tree/aabb_test_datum.cpp

@@ -0,0 +1,52 @@
+
+#include <iostream>
+#include <fstream>
+#include <CGAL/Timer.h>
+
+#include <CGAL/Exact_predicates_inexact_constructions_kernel.h>
+
+#include <CGAL/AABB_tree.h>
+#include <CGAL/AABB_traits.h>
+#include <CGAL/AABB_face_graph_triangle_primitive.h>
+#include <CGAL/Surface_mesh.h>
+
+typedef CGAL::Epick K;
+typedef K::Point_3 Point;
+typedef K::Triangle_3 Triangle;
+typedef CGAL::Surface_mesh<Point> Mesh;
+typedef CGAL::AABB_face_graph_triangle_primitive<Mesh> Primitive;
+typedef CGAL::AABB_face_graph_triangle_primitive<Mesh,
+    CGAL::Default, CGAL::Tag_true, CGAL::Tag_true> Primitive_cached;
+
+typedef CGAL::AABB_traits<K, Primitive> Traits;
+typedef CGAL::AABB_traits<K, Primitive_cached> Traits_cached;
+typedef CGAL::AABB_tree<Traits> Tree;
+typedef CGAL::AABB_tree<Traits_cached> Tree_cached;
+typedef Tree::Primitive_id Primitive_id;
+typedef Tree_cached::Primitive_id Primitive_id_cached;
+
+int main(void)
+{
+  Mesh m;
+  std::ifstream in("data/cube.off");
+  if(in)
+    in >> m;
+  else{
+    std::cout << "error reading bunny" << std::endl;
+    return 1;
+  }
+  
+  Tree t1(faces(m).begin(), faces(m).end(), m);
+  Tree_cached t2(faces(m).begin(), faces(m).end(), m);
+  
+  t1.build();
+  t2.build();
+  Primitive p1(faces(m).begin(), m);
+  Primitive_cached p2(faces(m).begin(), m);
+  Triangle tr1 = t1.datum(p1);
+  Triangle tr2 = t2.datum(p2);
+  if(tr1 != tr2)
+    return 1;
+  return 0;
+}
+