More forward declarations

Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d_1.h

@@ -201,7 +201,9 @@ public:
 
 
   }; // class Algebraic_real_traits
-            
+
+  class Construct_algebraic_real_1;
+  
   // Functors of Algebraic_kernel_d_1
   struct Solve_1 {
   public:

Arrangement_on_surface_2/include/CGAL/Arr_polycurve_traits_2.h

@@ -163,6 +163,9 @@ public:
   /// \name Construction functors(based on the subcurve traits).
   //@{
 
+#ifndef DOXYGEN_RUNNING
+  class Push_back_2;
+#endif  
   /*! \class
    * A functor that divides an arc into x-monotone arcs. That are, arcs that
    * do not cross the identification arc.

Polynomial/include/CGAL/Polynomial_traits_d.h

@@ -729,7 +729,9 @@ public:
       return gic( gc( p, exponent ), ev ); 
     }; 
   };
-     
+
+  typedef CGAL::internal::Monomial_representation<Polynomial_d> Monomial_representation;
+
   // Swap variable x_i with x_j
   struct Swap {
     typedef Polynomial_d        result_type;  
@@ -1537,10 +1539,6 @@ struct Construct_innermost_coefficient_const_iterator_range
   };
 
 
-  typedef
-  CGAL::internal::Monomial_representation<Polynomial_d> 
-  Monomial_representation;
-
   // returns the Exponten_vector of the innermost leading coefficient 
   struct Degree_vector{
     typedef Exponent_vector           result_type;