Fix all warnings in demo/Polyhedron/

The compilation was fix g++-4.8, and the flags:
  --std=c++11 -frounding-math Wall -Wno-array-bounds -Wno-uninitialized

Algebraic_foundations/include/CGAL/Algebraic_structure_traits.h

@@ -29,6 +29,7 @@
 #include <CGAL/type_traits.h>
 #include <CGAL/Coercion_traits.h>
 #include <CGAL/assertions.h>
+#include <CGAL/use.h>
 
 namespace CGAL {
 
@@ -263,6 +264,7 @@ class Algebraic_structure_traits_base< Type_,
                 const Type& y) const { 
             typedef Algebraic_structure_traits<Type> AST; 
             typedef typename AST::Is_exact Is_exact;
+            CGAL_USE_TYPE(Is_exact);
             typename AST::Div actual_div;
             
             CGAL_precondition_msg( 
@@ -358,6 +360,7 @@ class Algebraic_structure_traits_base< Type_,
                 Type& r ) const {
             typedef Coercion_traits< NT1, NT2 > CT;
             typedef typename CT::Type Type; 
+            CGAL_USE_TYPE(Type);
             CGAL_static_assertion(( 
               ::boost::is_same<Type , Type >::value));
             
@@ -459,6 +462,7 @@ class Algebraic_structure_traits_base< Type_, Field_tag >
                                         const Type& y) const { 
             typedef Algebraic_structure_traits<Type> AST; 
             typedef typename AST::Is_exact Is_exact;
+            CGAL_USE_TYPE(Is_exact);
 	    CGAL_precondition_code( bool ie = Is_exact::value; )
             CGAL_precondition_msg( !ie || (x / y) * y  == x,
                     "'x' must be divisible by 'y' in "

Arrangement_on_surface_2/include/CGAL/Arrangement_2/Arrangement_on_surface_2_global.h

@@ -40,6 +40,8 @@
 #include <CGAL/Arrangement_2/Arr_traits_adaptor_2.h>
 #include <CGAL/Sweep_line_2/Sweep_line_2_utils.h>
 #include <CGAL/Sweep_line_2/Sweep_line_2_visitors.h>
+#include <CGAL/assertions.h>
+#include <CGAL/use.h>
 
 #include <boost/type_traits.hpp>
 
@@ -614,6 +616,7 @@ insert_non_intersecting_curve
                                                          Traits_adaptor_2;
   typedef typename Arr::Vertex_const_handle              Vertex_const_handle;
   typedef typename Arr::Halfedge_const_handle            Halfedge_const_handle;
+  CGAL_USE_TYPE(Halfedge_const_handle);
 
   const Traits_adaptor_2 * geom_traits =
     static_cast<const Traits_adaptor_2*> (arr.geometry_traits());

Convex_decomposition_3/include/CGAL/Convex_decomposition_3/is_reflex_sedge.h

@@ -23,6 +23,7 @@
 #undef CGAL_NEF_DEBUG
 #define CGAL_NEF_DEBUG 239
 #include <CGAL/Nef_2/debug.h>
+#include <CGAL/use.h>
 
 namespace CGAL {
 
@@ -144,6 +145,7 @@ int is_reflex_sedge(typename SNC_structure::SHalfedge_handle se,
     result |= 2;
   
   typedef typename SNC_structure::Sphere_segment Sphere_segment;
+  CGAL_USE_TYPE(Sphere_segment);
   if(os1 == ON_POSITIVE_SIDE && 
      se2->twin()->source()->point() == dir)
     CGAL_assertion(Sphere_segment(se2->source()->point(), se2->twin()->source()->point(), se2->circle()).is_long());

Convex_hull_2/include/CGAL/Convex_hull_2/ch_graham_andrew_impl.h

@@ -41,7 +41,6 @@ ch_graham_andrew_scan( BidirectionalIterator first,
                        OutputIterator        result,
                        const Traits&         ch_traits)
 {
-  typedef  typename Traits::Point_2     Point_2;
   typedef  typename Traits::Left_turn_2  Left_turn;
 
   std::vector< BidirectionalIterator >    S;
@@ -100,6 +99,7 @@ ch_graham_andrew_scan( BidirectionalIterator first,
     || defined(NDEBUG)
   OutputIterator  res(result);
   #else
+  typedef  typename Traits::Point_2     Point_2;
   Tee_for_output_iterator<OutputIterator,Point_2> res(result);
   #endif // no postconditions ...
   for ( ++stack_iter;  stack_iter != S.end(); ++stack_iter)

Mesh_3/include/CGAL/Mesh_3/Protect_edges_sizing_field.h

@@ -375,6 +375,7 @@ Protect_edges_sizing_field<C3T3, MD, Sf>::
 insert_point(const Bare_point& p, const Weight& w, int dim, const Index& index)
 {
   typedef typename Tr::size_type size_type;
+  CGAL_USE_TYPE(size_type);
   
   // Insert point
   CGAL_assertion_code(size_type nb_vertices_before = c3t3_.triangulation().number_of_vertices());

Polyhedron/include/CGAL/intersection_of_Polyhedra_3_refinement_visitor.h

@@ -1393,13 +1393,9 @@ public:
   
   void new_input_polyhedron(Polyhedron& P)
   {
-    #ifndef NDEBUG
-    std::pair<typename Poly_to_map_node::iterator,bool> res = 
-    #endif
+    CGAL_assertion_code((std::pair<typename Poly_to_map_node::iterator,bool>) res = )
       polyhedron_to_map_node_to_polyhedron_vertex.insert(std::make_pair( &P,Node_to_polyhedron_vertex_map() ));
-    #ifndef NDEBUG
     CGAL_assertion(res.second == true);
-    #endif    
   }
   
   //1) split_halfedges and retriangulate faces with no intersection point interior to the facet

Surface_mesher/include/CGAL/Surface_mesher/Surface_mesher_edges_level.h

@@ -30,6 +30,7 @@
 #include <CGAL/circulator.h> // for CGAL::Circulator_from_container<C>
 #include <sstream>
 #include <boost/format.hpp>
+#include <CGAL/use.h>
 
 namespace CGAL {
 namespace Surface_mesher {
@@ -121,7 +122,6 @@ namespace Surface_mesher {
       tr.geom_traits().compute_squared_length_3_object();
 
     typedef std::vector<Point_3> Edge_dual;
-    typedef typename Edge_dual::size_type size_type;
     Edge_dual edge_dual;
     edge_dual.reserve(12);
 
@@ -145,6 +145,8 @@ namespace Surface_mesher {
 					// incident cell.
     typename Tr::Cell_circulator begin = circ;
 
+    typedef typename Edge_dual::size_type size_type;
+    CGAL_USE_TYPE(size_type);
     CGAL_assertion_code(size_type number_of_finite_incident_cells = 0);
     CGAL_assertion_code(size_type number_of_infinite_incident_cells = 0);