diff --git a/Advancing_front_surface_reconstruction/include/CGAL/Advancing_front_surface_reconstruction.h b/Advancing_front_surface_reconstruction/include/CGAL/Advancing_front_surface_reconstruction.h
index 333448dc000..ff1eb8cadfc 100644
--- a/Advancing_front_surface_reconstruction/include/CGAL/Advancing_front_surface_reconstruction.h
+++ b/Advancing_front_surface_reconstruction/include/CGAL/Advancing_front_surface_reconstruction.h
@@ -2311,7 +2311,7 @@ namespace CGAL {
     }
 
 
-    struct Remove : public std::unary_function<Vertex_handle, bool>
+    struct Remove : public CGAL::unary_function<Vertex_handle, bool>
     {
 
       Extract& E;
@@ -2449,7 +2449,7 @@ namespace CGAL {
   namespace AFSR {
 
     template <typename T>
-    struct Auto_count : public std::unary_function<const T&,std::pair<T,std::size_t> >{
+    struct Auto_count : public CGAL::unary_function<const T&,std::pair<T,std::size_t> >{
       mutable std::size_t i;
 
       Auto_count()
@@ -2462,7 +2462,7 @@ namespace CGAL {
     };
 
     template <typename T, typename CC>
-    struct Auto_count_cc : public std::unary_function<const T&,std::pair<T,std::size_t> >{
+    struct Auto_count_cc : public CGAL::unary_function<const T&,std::pair<T,std::size_t> >{
       mutable std::size_t i;
       CC cc;
 
diff --git a/Algebraic_foundations/include/CGAL/Algebraic_extension_traits.h b/Algebraic_foundations/include/CGAL/Algebraic_extension_traits.h
index e43fde416c9..bceff5b293b 100644
--- a/Algebraic_foundations/include/CGAL/Algebraic_extension_traits.h
+++ b/Algebraic_foundations/include/CGAL/Algebraic_extension_traits.h
@@ -29,7 +29,6 @@
 #define CGAL_ALGEBRAIC_NUMBER_TRAITS_H 1
 
 #include <numeric> // for std::accumulate
-#include <functional> // for std::unary_function
 #include <CGAL/tags.h>
 #include <CGAL/Algebraic_structure_traits.h>
 
@@ -47,7 +46,7 @@ public:
     //! computes the factor which normalizes a number to be integral after 
     //  multiplication
     class Normalization_factor 
-        : public std::unary_function<Type,Type> {
+        : public CGAL::unary_function<Type,Type> {
     private:
         static Type 
         normalization_factor(const Type&,Integral_domain_without_division_tag){
@@ -68,7 +67,7 @@ public:
     };
     
     class Denominator_for_algebraic_integers 
-        : public std::unary_function<Type,Type> {
+        : public CGAL::unary_function<Type,Type> {
     public: 
         //! determine normalization factor
         Type operator () (const Type&) {
diff --git a/Algebraic_foundations/include/CGAL/Algebraic_structure_traits.h b/Algebraic_foundations/include/CGAL/Algebraic_structure_traits.h
index 4418617bc4c..730150c5540 100644
--- a/Algebraic_foundations/include/CGAL/Algebraic_structure_traits.h
+++ b/Algebraic_foundations/include/CGAL/Algebraic_structure_traits.h
@@ -111,7 +111,7 @@ class Algebraic_structure_traits_base< Type_, Null_tag > {
 
     // does nothing by default
     class Simplify 
-      : public std::unary_function< Type&, void > {
+      : public CGAL::unary_function< Type&, void > {
       public:
         void operator()( Type& ) const {}
     };
@@ -150,7 +150,7 @@ class Algebraic_structure_traits_base< Type_,
 
     // returns Type(1) by default
     class Unit_part 
-      : public std::unary_function< Type, Type > { 
+      : public CGAL::unary_function< Type, Type > { 
       public:
         Type operator()( const Type& x ) const {
           return( x < Type(0)) ? 
@@ -159,7 +159,7 @@ class Algebraic_structure_traits_base< Type_,
     };
     
     class Square 
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:        
         Type operator()( const Type& x ) const {
           return x*x;
@@ -167,7 +167,7 @@ class Algebraic_structure_traits_base< Type_,
     };
     
     class Is_zero 
-      : public std::unary_function< Type, bool > {
+      : public CGAL::unary_function< Type, bool > {
       public:        
         bool operator()( const Type& x ) const {
           return x == Type(0);
@@ -175,7 +175,7 @@ class Algebraic_structure_traits_base< Type_,
     };
 
     class Is_one 
-      : public std::unary_function< Type, bool > {
+      : public CGAL::unary_function< Type, bool > {
       public:        
         bool operator()( const Type& x ) const {
           return x == Type(1);
@@ -447,7 +447,7 @@ class Algebraic_structure_traits_base< Type_, Field_tag >
 
     // returns the argument \a a by default
     class Unit_part 
-      : public std::unary_function< Type, Type > { 
+      : public CGAL::unary_function< Type, Type > { 
       public:
         Type operator()( const Type& x ) const {
             return( x == Type(0)) ? Type(1) : x;
@@ -474,7 +474,7 @@ class Algebraic_structure_traits_base< Type_, Field_tag >
   
   // maps to \c 1/x by default.
   class Inverse 
-    : public std::unary_function< Type, Type > { 
+    : public CGAL::unary_function< Type, Type > { 
   public:
     Type operator()( const Type& x ) const { 
       return Type(1)/x;
diff --git a/Algebraic_foundations/include/CGAL/Real_embeddable_traits.h b/Algebraic_foundations/include/CGAL/Real_embeddable_traits.h
index 671a7c9c79e..d0157464b2e 100644
--- a/Algebraic_foundations/include/CGAL/Real_embeddable_traits.h
+++ b/Algebraic_foundations/include/CGAL/Real_embeddable_traits.h
@@ -36,7 +36,7 @@ struct  Is_zero_selector{ typedef AST_is_zero Type; };
 template< class T >
 struct Is_zero_selector< T, Null_functor >
 {
-  struct Type : public std::unary_function< T, bool >{
+  struct Type : public CGAL::unary_function< T, bool >{
     bool operator()( const T& x ) const {
       return x == T(0);
     }
@@ -80,7 +80,7 @@ public:
   Is_zero;
   
   //! The generic \c Is_finite functor returns true
-  class Is_finite : public std::unary_function< Type, Boolean > {
+  class Is_finite : public CGAL::unary_function< Type, Boolean > {
   public:
     Boolean operator()( const Type& ) const {
       return true;
@@ -90,7 +90,7 @@ public:
   //! The generic \c Abs functor implementation
   //! uses one comparisons and the unary minus if necessary.
   class Abs
-    : public std::unary_function< Type, Type > {
+    : public CGAL::unary_function< Type, Type > {
   public:
     //! the function call.
     Type  operator()( const Type& x ) const {
@@ -100,7 +100,7 @@ public:
     
   //! The generic \c Sgn functor implementation uses two comparisons.
   class Sgn 
-    : public std::unary_function< Type, ::CGAL::Sign > {
+    : public CGAL::unary_function< Type, ::CGAL::Sign > {
   public:
     //! the function call.
     ::CGAL::Sign operator()( const Type& x ) const {
@@ -114,7 +114,7 @@ public:
     
   //! The generic \c Is_positive functor implementation uses one comparison.
   class Is_positive 
-    : public std::unary_function< Type, Boolean > {
+    : public CGAL::unary_function< Type, Boolean > {
   public:        
     //! the function call.
     Boolean operator()( const Type& x ) const {
@@ -124,7 +124,7 @@ public:
     
   //! The generic \c Is_negative functor implementation uses one comparison.
   class Is_negative 
-    : public std::unary_function< Type, Boolean > {
+    : public CGAL::unary_function< Type, Boolean > {
   public:        
     //! the function call.
     Boolean operator()( const Type& x ) const {
@@ -151,7 +151,7 @@ public:
         Comparison_result )
       };
   
-  class To_double : public std::unary_function< Type, double > {     
+  class To_double : public CGAL::unary_function< Type, double > {     
   public:
     double operator()( const Type& x ) const {
       return static_cast<double>(x);
@@ -159,7 +159,7 @@ public:
   };
   
   class To_interval 
-    : public std::unary_function< Type, std::pair<double,double> > {     
+    : public CGAL::unary_function< Type, std::pair<double,double> > {     
   public:
     std::pair<double,double> operator()( const Type& x ) const {
       double dx(static_cast<double>(x));
diff --git a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Algebraic_curve_kernel_2.h b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Algebraic_curve_kernel_2.h
index c6dfb9bee6f..9273c11f2db 100644
--- a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Algebraic_curve_kernel_2.h
+++ b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Algebraic_curve_kernel_2.h
@@ -193,7 +193,7 @@ protected:
    
     //! polynomial canonicalizer, needed for the cache
     template <class Poly> 
-    struct Poly_canonicalizer : public std::unary_function< Poly, Poly >
+    struct Poly_canonicalizer : public CGAL::unary_function< Poly, Poly >
     {
     // use Polynomial_traits_d<>::Canonicalize ?
         Poly operator()(Poly p) 
@@ -349,7 +349,7 @@ public:
     // Composition of two unary functors
     template<typename InnerFunctor,typename OuterFunctor>
       class Unary_compose 
-      : public std::unary_function<typename InnerFunctor::argument_type,
+      : public CGAL::unary_function<typename InnerFunctor::argument_type,
                                    typename OuterFunctor::result_type> {
 				     
     public:
@@ -412,7 +412,7 @@ public:
      * when appropriate
      */
     class Construct_curve_2 :
-        public std::unary_function< Polynomial_2, Curve_analysis_2 > {
+        public CGAL::unary_function< Polynomial_2, Curve_analysis_2 > {
 
     public:
 
@@ -629,7 +629,7 @@ public:
 
     
     class Compute_polynomial_x_2 :
-      public std::unary_function<Algebraic_real_2, Polynomial_1> {
+      public CGAL::unary_function<Algebraic_real_2, Polynomial_1> {
 
     public:
 
@@ -649,7 +649,7 @@ public:
 			       compute_polynomial_x_2_object);
 
     class Compute_polynomial_y_2 :
-      public std::unary_function<Algebraic_real_2, Polynomial_1> {
+      public CGAL::unary_function<Algebraic_real_2, Polynomial_1> {
 
     public:
 
@@ -880,7 +880,7 @@ public:
             
     //! returns the x-coordinate of an \c Algebraic_real_2 object
     class Compute_x_2 :
-        public std::unary_function<Algebraic_real_2, Algebraic_real_1> {
+        public CGAL::unary_function<Algebraic_real_2, Algebraic_real_1> {
 
     public:
 
@@ -915,7 +915,7 @@ public:
      * return approximation of the y-coordinate. 
      */
     class Compute_y_2 :
-        public std::unary_function<Algebraic_real_2, Algebraic_real_1> {
+        public CGAL::unary_function<Algebraic_real_2, Algebraic_real_1> {
         
     public:
         
@@ -1500,7 +1500,7 @@ public:
      * the polynomial \c p is square free.
      */
     class Has_finite_number_of_self_intersections_2 :
-            public std::unary_function< Polynomial_2, bool > {
+            public CGAL::unary_function< Polynomial_2, bool > {
         
     public:
 
@@ -1713,7 +1713,7 @@ public:
     //! Non-Algebraic name
     typedef Algebraic_real_2 Coordinate_2;
 
-    class Is_square_free_2 : public std::unary_function<Polynomial_2,bool> {
+    class Is_square_free_2 : public CGAL::unary_function<Polynomial_2,bool> {
 
     public:
 
@@ -1735,7 +1735,7 @@ public:
     typedef Has_finite_number_of_intersections_2 Is_coprime_2;
     CGAL_Algebraic_Kernel_cons(Is_coprime_2, is_coprime_2_object);
 
-    class Make_square_free_2 : public std::unary_function<Polynomial_2,
+    class Make_square_free_2 : public CGAL::unary_function<Polynomial_2,
                                                           Polynomial_2> {
 
     public:
@@ -2593,7 +2593,7 @@ public:
 
     //! Refines the x-coordinate of an Algebraic_real_2 object
     class Refine_x_2 :
-        public std::unary_function<Algebraic_real_2, void> {
+        public CGAL::unary_function<Algebraic_real_2, void> {
 
     public:
         
@@ -2617,7 +2617,7 @@ public:
     CGAL_Algebraic_Kernel_pred(Refine_x_2, refine_x_2_object);
     
     class Refine_y_2 :
-        public std::unary_function<Algebraic_real_2, void> {
+        public CGAL::unary_function<Algebraic_real_2, void> {
 
     public:
 
diff --git a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Algebraic_real_d_1.h b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Algebraic_real_d_1.h
index 03929eec31d..d237c83dfa0 100644
--- a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Algebraic_real_d_1.h
+++ b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Algebraic_real_d_1.h
@@ -413,7 +413,7 @@ public:
   };
 
   class Sgn
-    : public std::unary_function< Type, CGAL::Sign > {
+    : public CGAL::unary_function< Type, CGAL::Sign > {
   public:
     CGAL::Sign operator()( const Type& a ) const {
       return a.compare( Rational(0) );
@@ -421,7 +421,7 @@ public:
   };
 
   class To_double
-    : public std::unary_function< Type, double > {
+    : public CGAL::unary_function< Type, double > {
   public:
     double operator()(const Type& a) const {
       return a.to_double();
@@ -429,7 +429,7 @@ public:
   };
 
   class To_interval
-    : public std::unary_function< Type, std::pair<double, double> > {
+    : public CGAL::unary_function< Type, std::pair<double, double> > {
   public:
     typename std::pair<double, double> operator()(const Type& a) const {
       return a.to_interval();
diff --git a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Bitstream_coefficient_kernel.h b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Bitstream_coefficient_kernel.h
index fdf1b4715c1..17597e5704a 100644
--- a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Bitstream_coefficient_kernel.h
+++ b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Bitstream_coefficient_kernel.h
@@ -49,7 +49,7 @@ template <typename Coefficient_> struct Bitstream_coefficient_kernel {
         return Is_zero();
     }
 
-    struct Convert_to_bfi : public std::unary_function
+    struct Convert_to_bfi : public CGAL::unary_function
         <Coefficient,Bigfloat_interval> {
         
         Bigfloat_interval operator() (Coefficient c) const {
diff --git a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Bitstream_coefficient_kernel_at_alpha.h b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Bitstream_coefficient_kernel_at_alpha.h
index 41162d25745..a150c558058 100644
--- a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Bitstream_coefficient_kernel_at_alpha.h
+++ b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Bitstream_coefficient_kernel_at_alpha.h
@@ -117,7 +117,7 @@ public:
     //! \name Functors
     //! @{
 
-    struct Is_zero : public std::unary_function<Coefficient,bool> {
+    struct Is_zero : public CGAL::unary_function<Coefficient,bool> {
         
         Is_zero(Algebraic_kernel_d_1* kernel,Algebraic_real_1 alpha) 
             : _m_kernel(kernel),_m_alpha(alpha) {}
@@ -137,7 +137,7 @@ public:
     }
 
     struct Convert_to_bfi 
-        : public std::unary_function<Coefficient,Bigfloat_interval> {
+        : public CGAL::unary_function<Coefficient,Bigfloat_interval> {
         
         Convert_to_bfi(Algebraic_kernel_d_1* kernel,
 		       Algebraic_real_1 alpha) 
diff --git a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Float_traits.h b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Float_traits.h
index 7733de308a3..e2d65ae4268 100644
--- a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Float_traits.h
+++ b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Float_traits.h
@@ -65,7 +65,7 @@ template<>
 class Float_traits< leda_bigfloat > {
 public:
   struct Get_mantissa
-    : public std::unary_function< leda_bigfloat, leda_integer > {
+    : public CGAL::unary_function< leda_bigfloat, leda_integer > {
     leda_integer operator()( const leda_bigfloat& x ) const {
       //std::cout << x.get_significant() << std::endl;
       return x.get_significant();                
@@ -73,7 +73,7 @@ public:
   };
         
   struct Get_exponent
-    : public std::unary_function< leda_bigfloat, long > {
+    : public CGAL::unary_function< leda_bigfloat, long > {
     long operator()( const leda_bigfloat& x ) const {
       return x.get_exponent().to_long();                
     }
@@ -97,14 +97,14 @@ class Float_traits< CORE::BigFloat > {
 public:
       
   struct Get_mantissa
-    : public std::unary_function< CORE::BigFloat, CORE::BigInt > {
+    : public CGAL::unary_function< CORE::BigFloat, CORE::BigInt > {
     CORE::BigInt operator()( const CORE::BigFloat& x ) const { 
       return x.m();
     }
   };
         
   struct Get_exponent
-    : public std::unary_function< CORE::BigFloat, long > {
+    : public CGAL::unary_function< CORE::BigFloat, long > {
     long operator()( const CORE::BigFloat& x ) const {
       return CORE::CHUNK_BIT*x.exp(); // The basis is 2^CORE::CHUNK_BIT
     }
@@ -126,7 +126,7 @@ public:
 template<> class Float_traits< Gmpfr > {
   
   struct Get_mantissa_exponent
-    : public std::unary_function< Gmpfr, std::pair<Gmpz,long> > {
+    : public CGAL::unary_function< Gmpfr, std::pair<Gmpz,long> > {
     
     std::pair<Gmpz,long> operator()( const Gmpfr& x ) const {
       return x.to_integer_exp(); 
@@ -134,14 +134,14 @@ template<> class Float_traits< Gmpfr > {
   };
 public:  
   struct Get_mantissa
-    : public std::unary_function< Gmpfr, Gmpz > {
+    : public CGAL::unary_function< Gmpfr, Gmpz > {
     Gmpz operator()( const Gmpfr& x ) const {
       return Get_mantissa_exponent()(x).first;      
     }
   };
   
   struct Get_exponent
-    : public std::unary_function< Gmpfr, long > {
+    : public CGAL::unary_function< Gmpfr, long > {
     long operator()( const Gmpfr& x ) const { 
       return Get_mantissa_exponent()(x).second;      
     }
diff --git a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Real_embeddable_extension.h b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Real_embeddable_extension.h
index 2438fd07f0b..e524c9d2294 100644
--- a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Real_embeddable_extension.h
+++ b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d/Real_embeddable_extension.h
@@ -102,7 +102,7 @@ template<>
 class Real_embeddable_extension< long > {            
 public:      
   struct Ceil_log2_abs
-    : public std::unary_function< long, long > {
+    : public CGAL::unary_function< long, long > {
     long operator()( long x ) {
       if (x < 0) x = -x;
       CGAL_precondition(x > 0);
@@ -112,7 +112,7 @@ public:
   };
 
   struct Floor_log2_abs
-    : public std::unary_function< long, long > {
+    : public CGAL::unary_function< long, long > {
   private:          
     signed char floor_log2_4bit[16];
   public:
@@ -148,11 +148,11 @@ public:
   };
 
   struct Floor
-    : public std::unary_function< long, long > {
+    : public CGAL::unary_function< long, long > {
     long operator() (long x) { return x;}
   };
   struct Ceil
-    : public std::unary_function< long, long > {
+    : public CGAL::unary_function< long, long > {
     long operator() (long x) { return x;}
   };
 };
@@ -167,7 +167,7 @@ public:
   typedef leda_integer Type;
 
   struct Ceil_log2_abs
-    : public std::unary_function< leda_integer, long > {
+    : public CGAL::unary_function< leda_integer, long > {
     long operator()( const leda_integer& x ) const {
       CGAL_precondition(x != leda_integer(0));
       ::leda::digit_sz ldgzeros = ::leda::digLeadingZeros(x.highword());
@@ -187,7 +187,7 @@ public:
   };
 
   struct Floor_log2_abs
-    : public std::unary_function< leda_integer, long > {
+    : public CGAL::unary_function< leda_integer, long > {
     long operator()( const leda_integer& x ) const {
       CGAL_precondition(x != leda_integer(0));
       ::leda::digit_sz ldgzeros 
@@ -199,11 +199,11 @@ public:
   };
 
   struct Floor
-    : public std::unary_function< leda_integer, leda_integer > {
+    : public CGAL::unary_function< leda_integer, leda_integer > {
     leda_integer operator() (const leda_integer& x) const { return x;}
   };
   struct Ceil
-    : public std::unary_function< leda_integer, leda_integer > {
+    : public CGAL::unary_function< leda_integer, leda_integer > {
     leda_integer operator() (const leda_integer& x) const { return x;}
   };
 };
@@ -215,7 +215,7 @@ public:
   typedef leda_bigfloat Type;
 
   struct Floor_log2_abs
-    : public std::unary_function< leda_bigfloat, long > {
+    : public CGAL::unary_function< leda_bigfloat, long > {
     long operator()( const leda_bigfloat& x ) const {
       CGAL_precondition(CGAL::sign(x) != CGAL::ZERO);
       ::leda::integer abs_sign = abs(x.get_significant());
@@ -225,7 +225,7 @@ public:
   };
         
   struct Ceil_log2_abs
-    : public std::unary_function< leda_bigfloat, long > {
+    : public CGAL::unary_function< leda_bigfloat, long > {
     long operator()( const leda_bigfloat& x ) const {
       CGAL_precondition(CGAL::sign(x) != CGAL::ZERO);
       return ::leda::ilog2(x).to_long();                
@@ -233,14 +233,14 @@ public:
   };
 
   struct Floor
-    : public std::unary_function< leda_bigfloat, leda_integer > {
+    : public CGAL::unary_function< leda_bigfloat, leda_integer > {
     leda_integer operator() ( const leda_bigfloat& x ) const { 
       return leda::to_integer( x, leda::TO_N_INF );
     }
   };
         
   struct Ceil
-    : public std::unary_function< leda_bigfloat, leda_integer > {
+    : public CGAL::unary_function< leda_bigfloat, leda_integer > {
     leda_integer operator() ( const leda_bigfloat& x ) const { 
       return leda::to_integer( x, leda::TO_P_INF );
     }
@@ -254,7 +254,7 @@ public:
   typedef leda_bigfloat_interval Type;
 
   struct Floor_log2_abs
-    : public std::unary_function< leda_bigfloat_interval, long > {
+    : public CGAL::unary_function< leda_bigfloat_interval, long > {
               
     result_type operator() (const argument_type& x) const {
       CGAL_precondition(! ::boost::numeric::in_zero(x));
@@ -263,7 +263,7 @@ public:
   };
         
   struct Ceil_log2_abs
-    : public std::unary_function< leda_bigfloat_interval, long > {
+    : public CGAL::unary_function< leda_bigfloat_interval, long > {
     long operator()( const leda_bigfloat_interval& x ) const {
       CGAL_precondition(!(::boost::numeric::in_zero(x) && 
               ::boost::numeric::singleton(x)));
@@ -272,7 +272,7 @@ public:
   };
 
   struct Floor
-    : public std::unary_function< leda_bigfloat_interval, leda_integer > {
+    : public CGAL::unary_function< leda_bigfloat_interval, leda_integer > {
     leda_integer operator() ( const leda_bigfloat_interval& x ) 
       const { 
       return internal::floor( x.lower() );
@@ -280,7 +280,7 @@ public:
   };
         
   struct Ceil
-    : public std::unary_function< leda_bigfloat_interval, leda_integer > {
+    : public CGAL::unary_function< leda_bigfloat_interval, leda_integer > {
     leda_integer operator() ( const leda_bigfloat_interval& x ) 
       const { 
       return internal::ceil( x.upper() );
@@ -298,27 +298,27 @@ class Real_embeddable_extension< CORE::BigInt > {
 public:
   typedef CORE::BigInt Type;
   struct Floor_log2_abs
-    : public std::unary_function< CORE::BigInt, long > {
+    : public CGAL::unary_function< CORE::BigInt, long > {
     long operator()( const CORE::BigInt& x ) const {
       return CORE::floorLg(x);
     }            
   };
         
   struct Ceil_log2_abs
-    : public std::unary_function< CORE::BigInt, long > {
+    : public CGAL::unary_function< CORE::BigInt, long > {
     long operator()( const CORE::BigInt& x ) const {
       return CORE::ceilLg(x);
     }
   };
 
   struct Floor
-    : public std::unary_function< CORE::BigInt, CORE::BigInt > {
+    : public CGAL::unary_function< CORE::BigInt, CORE::BigInt > {
     CORE::BigInt operator() (const CORE::BigInt& x) const { 
       return x;
     }
   };
   struct Ceil
-    : public std::unary_function< CORE::BigInt, CORE::BigInt > {
+    : public CGAL::unary_function< CORE::BigInt, CORE::BigInt > {
     CORE::BigInt operator() (const CORE::BigInt& x) const { 
       return x;
     }
@@ -331,7 +331,7 @@ class Real_embeddable_extension< CORE::BigFloat > {
 public:
   typedef CORE::BigFloat Type;
   struct Floor_log2_abs
-    : public std::unary_function< CORE::BigFloat, long > {
+    : public CGAL::unary_function< CORE::BigFloat, long > {
     long operator()( CORE::BigFloat x ) const {
       CGAL_precondition(!CGAL::zero_in(x));
       x = CGAL::abs(x);
@@ -340,7 +340,7 @@ public:
   };
         
   struct Ceil_log2_abs
-    : public std::unary_function< CORE::BigFloat, long > {
+    : public CGAL::unary_function< CORE::BigFloat, long > {
     long operator()( CORE::BigFloat x ) const {
       // (already commented out in EXACUS)...
       //   NiX_precond(!(NiX::in_zero(x) && NiX::singleton(x)));
@@ -350,7 +350,7 @@ public:
   };
 
   struct Floor
-    : public std::unary_function< CORE::BigFloat, CORE::BigInt > {
+    : public CGAL::unary_function< CORE::BigFloat, CORE::BigInt > {
     CORE::BigInt operator() ( const CORE::BigFloat& x ) const { 
       CORE::BigInt xi = x.BigIntValue();
       if(x.sign() < 0 && x.cmp(xi)!=0) {
@@ -361,7 +361,7 @@ public:
   };
         
   struct Ceil
-    : public std::unary_function< CORE::BigFloat, CORE::BigInt > {
+    : public CGAL::unary_function< CORE::BigFloat, CORE::BigInt > {
     CORE::BigInt operator() ( const CORE::BigFloat& x ) const { 
       CORE::BigInt xi = x.BigIntValue();
       if(x.sign() >0 && x.cmp(xi)!=0) {
@@ -384,7 +384,7 @@ public:
   typedef Gmpz Type;
 
   struct Floor_log2_abs
-    : public std::unary_function< Gmpz, long > {
+    : public CGAL::unary_function< Gmpz, long > {
     long operator()( const Gmpz& x ) const {
       CGAL_precondition(!CGAL::is_zero(x));
       return mpz_sizeinbase(x.mpz(),2)-1;
@@ -392,7 +392,7 @@ public:
   };
         
   struct Ceil_log2_abs
-    : public std::unary_function< Gmpz, long > {
+    : public CGAL::unary_function< Gmpz, long > {
     long operator()( const Gmpz& x ) const {
       long pos  = mpz_scan1(x.mpz(),0);
       long size = mpz_sizeinbase(x.mpz(),2);
@@ -404,13 +404,13 @@ public:
   };
 
   struct Floor
-    : public std::unary_function< Gmpz, Gmpz > {
+    : public CGAL::unary_function< Gmpz, Gmpz > {
     Gmpz operator() (const Gmpz& x) const { 
       return x;
     }
   };
   struct Ceil
-    : public std::unary_function< Gmpz, Gmpz > {
+    : public CGAL::unary_function< Gmpz, Gmpz > {
     Gmpz operator() (const Gmpz& x) const { 
       return x;
     }
@@ -426,7 +426,7 @@ public:
   typedef Gmpfr Type;
 
   struct Floor_log2_abs
-    : public std::unary_function< Gmpfr, long > {
+    : public CGAL::unary_function< Gmpfr, long > {
     long operator()( const Gmpfr& x ) const {
       Float_traits<Gmpfr>::Get_mantissa get_mantissa; 
       Float_traits<Gmpfr>::Get_exponent get_exponent; 
@@ -437,7 +437,7 @@ public:
   };
         
   struct Ceil_log2_abs
-    : public std::unary_function< Gmpfr, long > {
+    : public CGAL::unary_function< Gmpfr, long > {
     long operator()( const Gmpfr& x ) const {
       Float_traits<Gmpfr>::Get_mantissa get_mantissa; 
       Float_traits<Gmpfr>::Get_exponent get_exponent; 
@@ -448,7 +448,7 @@ public:
   };
 
   struct Floor
-    : public std::unary_function< Gmpfr, Gmpz > {
+    : public CGAL::unary_function< Gmpfr, Gmpz > {
     Gmpz operator() ( const Gmpfr& x ) const {  
       Gmpz result; 
       mpfr_get_z (result.mpz(),x.fr(),GMP_RNDD);
@@ -457,7 +457,7 @@ public:
   };
         
   struct Ceil
-    : public std::unary_function< Gmpfr, Gmpz > {
+    : public CGAL::unary_function< Gmpfr, Gmpz > {
     Gmpz operator() ( const Gmpfr& x ) const { 
       Gmpz result; 
       mpfr_get_z (result.mpz(),x.fr(),GMP_RNDU);
@@ -475,7 +475,7 @@ public:
   typedef Gmpfi Type;
 
   struct Floor_log2_abs
-    : public std::unary_function< Gmpfi, long > {
+    : public CGAL::unary_function< Gmpfi, long > {
     result_type operator() (const argument_type& x) const {
       CGAL_precondition(!x.is_zero());
       return internal::floor_log2_abs(x.abs().inf());
@@ -483,7 +483,7 @@ public:
   };
         
   struct Ceil_log2_abs
-    : public std::unary_function< Gmpfi, long > {
+    : public CGAL::unary_function< Gmpfi, long > {
     long operator()( const Gmpfi& x ) const {
       CGAL_precondition(!x.inf().is_zero() || !x.sup().is_zero());
       return internal::ceil_log2_abs(x.abs().sup());                    
@@ -491,7 +491,7 @@ public:
   };
 
   struct Floor
-    : public std::unary_function< Gmpfi, Gmpz > {
+    : public CGAL::unary_function< Gmpfi, Gmpz > {
     Gmpz operator() ( const Gmpfi& x ) 
       const { 
       return internal::floor( x.inf() );
@@ -499,7 +499,7 @@ public:
   };
         
   struct Ceil
-    : public std::unary_function< Gmpfi, Gmpz > {
+    : public CGAL::unary_function< Gmpfi, Gmpz > {
     Gmpz operator() ( const Gmpfi& x ) 
       const { 
       return internal::ceil( x.sup() );
diff --git a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d_1.h b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d_1.h
index 109fbd9a4c3..c1f30b22a48 100644
--- a/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d_1.h
+++ b/Algebraic_kernel_d/include/CGAL/Algebraic_kernel_d_1.h
@@ -68,12 +68,12 @@ protected:
 
   // Some functors used for STL calls
   template<typename A,typename B>
-    struct Pair_first : public std::unary_function<std::pair<A,B>,A> {
+    struct Pair_first : public CGAL::unary_function<std::pair<A,B>,A> {
       A operator() (std::pair<A,B> pair) const { return pair.first; }
   };
 
   template<typename A,typename B>
-    struct Pair_second : public std::unary_function<std::pair<A,B>,B> {
+    struct Pair_second : public CGAL::unary_function<std::pair<A,B>,B> {
       B operator() (std::pair<A,B> pair) const { return pair.second; }
   };
   
@@ -96,21 +96,21 @@ public:
     };
                                 
     struct Lower_bound
-      : public std::unary_function< Type, Bound > {
+      : public CGAL::unary_function< Type, Bound > {
       Bound operator()( const Type& t ) const {
         return t.low();
       }
     };
                 
     struct Upper_bound
-      : public std::unary_function< Type, Bound > {
+      : public CGAL::unary_function< Type, Bound > {
       Bound operator()( const Type& t ) const {
         return t.high();
       }
     };
                 
     struct Refine
-      : public std::unary_function< Type, void > {
+      : public CGAL::unary_function< Type, void > {
       void operator()( const Type& t ) const {
         t.refine();
       }
@@ -333,7 +333,7 @@ public:
   };
 
   class Number_of_solutions_1 
-      : public std::unary_function<Polynomial_1,size_type> {
+      : public CGAL::unary_function<Polynomial_1,size_type> {
     
     public:
 	
@@ -382,7 +382,7 @@ public:
   };                
                    
   struct Is_square_free_1 
-    : public std::unary_function< Polynomial_1, bool > {
+    : public CGAL::unary_function< Polynomial_1, bool > {
     bool operator()( const Polynomial_1& p ) const {
       typename CGAL::Polynomial_traits_d< Polynomial_1 >::Is_square_free isf;
       return isf(p);
@@ -400,7 +400,7 @@ public:
   }; 
             
   struct Make_square_free_1
-    : public std::unary_function< Polynomial_1, Polynomial_1 > {
+    : public CGAL::unary_function< Polynomial_1, Polynomial_1 > {
     Polynomial_1 operator()( const Polynomial_1& p ) const {
       return typename CGAL::Polynomial_traits_d< Polynomial_1 >::Make_square_free()( p );
     }
@@ -435,7 +435,7 @@ public:
     } 
   };
 
-  struct Compute_polynomial_1 : public std::unary_function<Algebraic_real_1,
+  struct Compute_polynomial_1 : public CGAL::unary_function<Algebraic_real_1,
                                                            Polynomial_1> {
     Polynomial_1 operator()(const Algebraic_real_1& x) const {
       return x.polynomial();
diff --git a/Algebraic_kernel_d/include/CGAL/RS/algebraic_1.h b/Algebraic_kernel_d/include/CGAL/RS/algebraic_1.h
index 94219ca1d02..344b838d84a 100644
--- a/Algebraic_kernel_d/include/CGAL/RS/algebraic_1.h
+++ b/Algebraic_kernel_d/include/CGAL/RS/algebraic_1.h
@@ -258,39 +258,39 @@ public INTERN_RET::Real_embeddable_traits_base<
                                                         Base;
         typedef typename Base::Compare                  Compare;
 
-        class Sgn:public std::unary_function<Type,CGAL::Sign>{
+        class Sgn:public CGAL::unary_function<Type,CGAL::Sign>{
                 public:
                 CGAL::Sign operator()(const Type &a)const{
                         return Compare()(a,Type(0));
                 }
         };
 
-        class To_double:public std::unary_function<Type,double>{
+        class To_double:public CGAL::unary_function<Type,double>{
                 public:
                 double operator()(const Type &a)const{return a.to_double();}
         };
 
         class To_interval:
-        public std::unary_function<Type,std::pair<double,double> >{
+        public CGAL::unary_function<Type,std::pair<double,double> >{
                 public:
                 std::pair<double,double> operator()(const Type &a)const{
                         return a.to_interval();
                 }
         };
 
-        class Is_zero:public std::unary_function<Type,Boolean>{
+        class Is_zero:public CGAL::unary_function<Type,Boolean>{
                 public:
                 bool operator()(const Type &a)const{
                         return Sgn()(a)==CGAL::ZERO;
                 }
         };
 
-        class Is_finite:public std::unary_function<Type,Boolean>{
+        class Is_finite:public CGAL::unary_function<Type,Boolean>{
                 public:
                 bool operator()(const Type&)const{return true;}
         };
 
-        class Abs:public std::unary_function<Type,Type>{
+        class Abs:public CGAL::unary_function<Type,Type>{
                 public:
                 Type operator()(const Type &a)const{
                         return Sgn()(a)==CGAL::NEGATIVE?-a:a;
diff --git a/Algebraic_kernel_d/include/CGAL/RS/algebraic_z_1.h b/Algebraic_kernel_d/include/CGAL/RS/algebraic_z_1.h
index 9e105a2c146..1f7f3236bb9 100644
--- a/Algebraic_kernel_d/include/CGAL/RS/algebraic_z_1.h
+++ b/Algebraic_kernel_d/include/CGAL/RS/algebraic_z_1.h
@@ -249,39 +249,39 @@ public INTERN_RET::Real_embeddable_traits_base<
                                                         Base;
         typedef typename Base::Compare                  Compare;
 
-        class Sgn:public std::unary_function<Type,CGAL::Sign>{
+        class Sgn:public CGAL::unary_function<Type,CGAL::Sign>{
                 public:
                 CGAL::Sign operator()(const Type &a)const{
                         return Compare()(a,Type(0));
                 }
         };
 
-        class To_double:public std::unary_function<Type,double>{
+        class To_double:public CGAL::unary_function<Type,double>{
                 public:
                 double operator()(const Type &a)const{return a.to_double();}
         };
 
         class To_interval:
-        public std::unary_function<Type,std::pair<double,double> >{
+        public CGAL::unary_function<Type,std::pair<double,double> >{
                 public:
                 std::pair<double,double> operator()(const Type &a)const{
                         return a.to_interval();
                 }
         };
 
-        class Is_zero:public std::unary_function<Type,Boolean>{
+        class Is_zero:public CGAL::unary_function<Type,Boolean>{
                 public:
                 bool operator()(const Type &a)const{
                         return Sgn()(a)==CGAL::ZERO;
                 }
         };
 
-        class Is_finite:public std::unary_function<Type,Boolean>{
+        class Is_finite:public CGAL::unary_function<Type,Boolean>{
                 public:
                 bool operator()(const Type&)const{return true;}
         };
 
-        class Abs:public std::unary_function<Type,Type>{
+        class Abs:public CGAL::unary_function<Type,Type>{
                 public:
                 Type operator()(const Type &a)const{
                         return Sgn()(a)==CGAL::NEGATIVE?-a:a;
diff --git a/Algebraic_kernel_d/include/CGAL/RS/functors_1.h b/Algebraic_kernel_d/include/CGAL/RS/functors_1.h
index 35e196d2d0b..2abc2c9c086 100644
--- a/Algebraic_kernel_d/include/CGAL/RS/functors_1.h
+++ b/Algebraic_kernel_d/include/CGAL/RS/functors_1.h
@@ -60,7 +60,7 @@ struct Construct_algebraic_real_1{
 
 template <class Polynomial_,class Algebraic_>
 struct Compute_polynomial_1:
-public std::unary_function<Algebraic_,Polynomial_>{
+public CGAL::unary_function<Algebraic_,Polynomial_>{
         typedef Polynomial_                                     Polynomial;
         typedef Algebraic_                                      Algebraic;
         Polynomial operator()(const Algebraic &x)const{
@@ -442,7 +442,7 @@ public std::binary_function<Polynomial_,Algebraic_,bool>{
 // programs assume that this is equal to int
 template <class Polynomial_,class Isolator_>
 struct Number_of_solutions_1:
-public std::unary_function<Polynomial_,int>{
+public CGAL::unary_function<Polynomial_,int>{
         typedef Polynomial_                                     Polynomial_1;
         typedef Isolator_                                       Isolator;
         size_t operator()(const Polynomial_1 &p)const{
diff --git a/Algebraic_kernel_d/include/CGAL/RS/functors_z_1.h b/Algebraic_kernel_d/include/CGAL/RS/functors_z_1.h
index 2a4fb55db55..579f8f4eff9 100644
--- a/Algebraic_kernel_d/include/CGAL/RS/functors_z_1.h
+++ b/Algebraic_kernel_d/include/CGAL/RS/functors_z_1.h
@@ -68,7 +68,7 @@ struct Construct_algebraic_real_z_1{
 
 template <class Polynomial_,class Algebraic_>
 struct Compute_polynomial_z_1:
-public std::unary_function<Algebraic_,Polynomial_>{
+public CGAL::unary_function<Algebraic_,Polynomial_>{
         typedef Polynomial_                                     Polynomial;
         typedef Algebraic_                                      Algebraic;
         Polynomial operator()(const Algebraic &x)const{
@@ -482,7 +482,7 @@ template <class Polynomial_,
           class PolConverter_,
           class Isolator_>
 struct Number_of_solutions_z_1:
-public std::unary_function<Polynomial_,int>{
+public CGAL::unary_function<Polynomial_,int>{
         typedef Polynomial_                                     Polynomial_1;
         typedef ZPolynomial_                                    ZPolynomial_1;
         typedef PolConverter_                                   PolConverter;
diff --git a/Algebraic_kernel_d/include/CGAL/RS/polynomial_converter_1.h b/Algebraic_kernel_d/include/CGAL/RS/polynomial_converter_1.h
index ef8dfac4d52..71771c0677b 100644
--- a/Algebraic_kernel_d/include/CGAL/RS/polynomial_converter_1.h
+++ b/Algebraic_kernel_d/include/CGAL/RS/polynomial_converter_1.h
@@ -26,7 +26,7 @@ namespace RS_AK1{
 
 template <class InputPolynomial_,class OutputPolynomial_>
 struct Polynomial_converter_1:
-public std::unary_function<InputPolynomial_,OutputPolynomial_>{
+public CGAL::unary_function<InputPolynomial_,OutputPolynomial_>{
         typedef InputPolynomial_                        InpPolynomial_1;
         typedef OutputPolynomial_                       OutPolynomial_1;
         OutPolynomial_1 operator()(const InpPolynomial_1&)const;
diff --git a/Arrangement_on_surface_2/include/CGAL/Arr_point_location/Td_predicates.h b/Arrangement_on_surface_2/include/CGAL/Arr_point_location/Td_predicates.h
index 6f247687412..a3dadee5253 100644
--- a/Arrangement_on_surface_2/include/CGAL/Arr_point_location/Td_predicates.h
+++ b/Arrangement_on_surface_2/include/CGAL/Arr_point_location/Td_predicates.h
@@ -34,7 +34,7 @@ template < class Td_traits> class Trapezoidal_decomposition_2;
 
 ////MICHAL: not in use
 //template <class map_item>
-//struct Td_active_map_item : public std::unary_function<map_item,bool>
+//struct Td_active_map_item : public CGAL::unary_function<map_item,bool>
 //{
 //  bool operator()(const map_item& item) const
 //  {
@@ -45,7 +45,7 @@ template < class Td_traits> class Trapezoidal_decomposition_2;
 ////MICHAL: not in use
 //template <class X_trapezoid,class Traits>
 //struct Td_active_non_degenerate_trapezoid : 
-//public std::unary_function<X_trapezoid,bool>
+//public CGAL::unary_function<X_trapezoid,bool>
 //{
 //  Td_active_non_degenerate_trapezoid(Traits& t) : traits(t) {}
 //  bool operator()(const X_trapezoid& tr) const
@@ -58,7 +58,7 @@ template < class Td_traits> class Trapezoidal_decomposition_2;
 
 template <class map_item,class Traits>
 struct Td_active_edge_item:
-  public std::unary_function<map_item,bool>
+  public CGAL::unary_function<map_item,bool>
 {
   Td_active_edge_item(const Traits& t) : traits(t) {}
   bool operator()(const map_item& item) const
diff --git a/Arrangement_on_surface_2/include/CGAL/Curved_kernel_via_analysis_2/test/simple_models.h b/Arrangement_on_surface_2/include/CGAL/Curved_kernel_via_analysis_2/test/simple_models.h
index bb158165802..29044fc4006 100644
--- a/Arrangement_on_surface_2/include/CGAL/Curved_kernel_via_analysis_2/test/simple_models.h
+++ b/Arrangement_on_surface_2/include/CGAL/Curved_kernel_via_analysis_2/test/simple_models.h
@@ -1043,7 +1043,7 @@ public:
     
     //! \brief constructs \c Curve_analysis_2 object, uses caching if appropriate
     struct Construct_curve_2 :
-            public std::unary_function< Polynomial_2, Curve_analysis_2 >
+            public CGAL::unary_function< Polynomial_2, Curve_analysis_2 >
     {
         //! \brief constructs an object from \c Algebraic_curve_kernel_2 type
         //! no default constructor provided
@@ -1080,7 +1080,7 @@ public:
     
     //! returns the first coordinate of \c Xy_coordinate_2
     struct Get_x_2 :
-        public std::unary_function<Xy_coordinate_2, Algebraic_real_1> {
+        public CGAL::unary_function<Xy_coordinate_2, Algebraic_real_1> {
         
         Algebraic_real_1 operator()(const Xy_coordinate_2& xy) const {
             return xy.x();
@@ -1090,7 +1090,7 @@ public:
     
     //! returns the second coordinate of \c Xy_coordinate_2
     struct Get_y_2 :
-        public std::unary_function<Xy_coordinate_2, Algebraic_real_1> {
+        public CGAL::unary_function<Xy_coordinate_2, Algebraic_real_1> {
         
         Algebraic_real_1 operator()(const Xy_coordinate_2& xy) const {
             return xy.y();
@@ -1099,7 +1099,7 @@ public:
     CGAL_Algebraic_Kernel_cons(Get_y_2, Get_y_2_object);
     
     struct Refine_x_2 :
-        public std::unary_function<Xy_coordinate_2, void> {
+        public CGAL::unary_function<Xy_coordinate_2, void> {
       
         void operator()(const Xy_coordinate_2& r) const {  }
         
@@ -1108,7 +1108,7 @@ public:
     CGAL_Algebraic_Kernel_pred(Refine_x_2, refine_x_2_object);
     
     struct Refine_y_2 :
-        public std::unary_function<Xy_coordinate_2, void> {
+        public CGAL::unary_function<Xy_coordinate_2, void> {
       
         void operator()(const Xy_coordinate_2& r) const {  }
         
@@ -1245,7 +1245,7 @@ public:
     //! for algerbaic curves this means that supporting polynomial is 
     //! square-free
     struct Has_finite_number_of_self_intersections_2 :
-            public std::unary_function< Polynomial_2, bool > {
+            public CGAL::unary_function< Polynomial_2, bool > {
 
         bool operator()(const Polynomial_2& p) const {
             return true; //is_square_free(p);
@@ -1317,7 +1317,7 @@ public:
     
     //! \brief computes the derivative w.r.t. the first (innermost) variable
     struct Derivative_x_2 : 
-        public std::unary_function< Polynomial_2, Polynomial_2 > {
+        public CGAL::unary_function< Polynomial_2, Polynomial_2 > {
         
         Polynomial_2 operator()(const Polynomial_2& p) const {
             return p;
@@ -1327,7 +1327,7 @@ public:
 
     //! \brief computes the derivative w.r.t. the first (outermost) variable
     struct Derivative_y_2 :
-        public std::unary_function< Polynomial_2, Polynomial_2 > {
+        public CGAL::unary_function< Polynomial_2, Polynomial_2 > {
         
         Polynomial_2 operator()(const Polynomial_2& p) const  {
             return p;
diff --git a/BGL/include/CGAL/boost/graph/Graph_with_descriptor_with_graph.h b/BGL/include/CGAL/boost/graph/Graph_with_descriptor_with_graph.h
index 6a22d2b8bdf..84ab23cb4f3 100644
--- a/BGL/include/CGAL/boost/graph/Graph_with_descriptor_with_graph.h
+++ b/BGL/include/CGAL/boost/graph/Graph_with_descriptor_with_graph.h
@@ -151,7 +151,7 @@ struct Graph_with_descriptor_with_graph
 
 
 template <typename Graph, typename Graph_descriptor, typename Descriptor>
-struct Descriptor2Descriptor: public std::unary_function<Graph_descriptor,Descriptor>
+struct Descriptor2Descriptor: public CGAL::unary_function<Graph_descriptor,Descriptor>
 {
 
   Descriptor2Descriptor()
diff --git a/Bounding_volumes/include/CGAL/Min_annulus_d.h b/Bounding_volumes/include/CGAL/Min_annulus_d.h
index 683b4c7d2b8..405afcbacb4 100644
--- a/Bounding_volumes/include/CGAL/Min_annulus_d.h
+++ b/Bounding_volumes/include/CGAL/Min_annulus_d.h
@@ -94,7 +94,7 @@ namespace MA_detail {
 
   // functor for a fixed column of A
   template <class NT, class Iterator>
-  class A_column : public std::unary_function <int, NT>
+  class A_column : public CGAL::unary_function <int, NT>
   {
   public:
     typedef NT result_type;
@@ -132,7 +132,7 @@ namespace MA_detail {
   // functor for matrix A
   template <class NT, class Access_coordinate_begin_d,
 	    class Point_iterator >
-  class A_matrix : public std::unary_function
+  class A_matrix : public CGAL::unary_function
   <int, boost::transform_iterator <A_column
     <NT, typename Access_coordinate_begin_d::Coordinate_iterator>, 
 				   boost::counting_iterator<int> > >
@@ -166,7 +166,7 @@ namespace MA_detail {
 
   // The functor necessary to realize access to b
   template <class NT>
-  class B_vector : public std::unary_function<int, NT>
+  class B_vector : public CGAL::unary_function<int, NT>
   {
   public:
     typedef NT result_type;
diff --git a/Bounding_volumes/include/CGAL/Min_quadrilateral_traits_2.h b/Bounding_volumes/include/CGAL/Min_quadrilateral_traits_2.h
index b6749fc48bd..bb932819b70 100644
--- a/Bounding_volumes/include/CGAL/Min_quadrilateral_traits_2.h
+++ b/Bounding_volumes/include/CGAL/Min_quadrilateral_traits_2.h
@@ -256,7 +256,7 @@ public:
 
   // new constructions
   struct Construct_vector_from_direction_2
-  : public std::unary_function<Direction_2,Vector_2>
+  : public CGAL::unary_function<Direction_2,Vector_2>
   {
     Vector_2 operator()(const Direction_2& d) const { return d.vector(); }
   };
diff --git a/Bounding_volumes/test/Bounding_volumes/minimum_enclosing_quadrilateral_2_test_traits.cpp b/Bounding_volumes/test/Bounding_volumes/minimum_enclosing_quadrilateral_2_test_traits.cpp
index 596803af80e..4d50be58319 100644
--- a/Bounding_volumes/test/Bounding_volumes/minimum_enclosing_quadrilateral_2_test_traits.cpp
+++ b/Bounding_volumes/test/Bounding_volumes/minimum_enclosing_quadrilateral_2_test_traits.cpp
@@ -144,7 +144,7 @@ struct MyTraits {
     }
   };
   struct Construct_vector_from_direction_2
-  : public std::unary_function<Direction_2,Vector_2>
+  : public CGAL::unary_function<Direction_2,Vector_2>
   {
     Vector_2 operator()(const Direction_2& d) const
     {
@@ -171,7 +171,7 @@ struct MyTraits {
     }
   };
   struct Construct_direction_2
-  : public std::unary_function<Vector_2,Direction_2>
+  : public CGAL::unary_function<Vector_2,Direction_2>
   {
     Direction_2 operator()(const Vector_2& v) const
     {
@@ -182,7 +182,7 @@ struct MyTraits {
     }
   };
   struct Construct_opposite_direction_2
-  : public std::unary_function<Direction_2,Direction_2>
+  : public CGAL::unary_function<Direction_2,Direction_2>
   {
     Direction_2 operator()(const Direction_2& d) const
     {
diff --git a/Box_intersection_d/include/CGAL/Box_intersection_d/Box_traits_d.h b/Box_intersection_d/include/CGAL/Box_intersection_d/Box_traits_d.h
index 6c41dbf982d..43174ca8e7f 100644
--- a/Box_intersection_d/include/CGAL/Box_intersection_d/Box_traits_d.h
+++ b/Box_intersection_d/include/CGAL/Box_intersection_d/Box_traits_d.h
@@ -102,7 +102,7 @@ struct Predicate_traits_d : public BoxTraits {
     };
 
     // loless val dim box = getlo box dim < val
-    class Lo_less : public std::unary_function<Box_parameter,bool> {
+    class Lo_less : public CGAL::unary_function<Box_parameter,bool> {
         NT value;
         int dim;
     public:
@@ -112,7 +112,7 @@ struct Predicate_traits_d : public BoxTraits {
         }
     };
 
-    class Hi_greater : public std::unary_function<Box_parameter,bool> {
+    class Hi_greater : public CGAL::unary_function<Box_parameter,bool> {
         NT value;
         int dim;
     public:
@@ -123,7 +123,7 @@ struct Predicate_traits_d : public BoxTraits {
     };
 
     // spanning lo hi dim box = getlo box dim < lo && gethi box dim > hi
-    class Spanning : public std::unary_function<Box_parameter,bool> {
+    class Spanning : public CGAL::unary_function<Box_parameter,bool> {
         NT lo, hi;
         int dim;
     public:
diff --git a/CGAL_ImageIO/include/CGAL/Image_3.h b/CGAL_ImageIO/include/CGAL/Image_3.h
index b1723d5e948..adf32004d3a 100644
--- a/CGAL_ImageIO/include/CGAL/Image_3.h
+++ b/CGAL_ImageIO/include/CGAL/Image_3.h
@@ -49,7 +49,7 @@ namespace ImageIO {
 template <typename T>
 struct Indicator_factory
 {
-  class Indicator : public std::unary_function<T, double>
+  class Indicator : public CGAL::unary_function<T, double>
   {
     const T label;
   public:
diff --git a/Combinatorial_map/examples/Combinatorial_map/map_3_foreach.cpp b/Combinatorial_map/examples/Combinatorial_map/map_3_foreach.cpp
index e20cc9e3702..5d9cbecd8eb 100644
--- a/Combinatorial_map/examples/Combinatorial_map/map_3_foreach.cpp
+++ b/Combinatorial_map/examples/Combinatorial_map/map_3_foreach.cpp
@@ -8,7 +8,7 @@ typedef CMap_3::Dart_handle        Dart_handle;
 
 // Functor used to display all the vertices of a given volume
 template<class CMap, unsigned int i>
-struct Display_vertices_of_cell : public std::unary_function<CMap, void>
+struct Display_vertices_of_cell : public CGAL::unary_function<CMap, void>
 {
   Display_vertices_of_cell(const CMap& acmap) :
     cmap(acmap),
@@ -40,7 +40,7 @@ private:
 
 // Functor used to remove a face
 template<class CMap>
-struct Remove_face : public std::unary_function<CMap, void>
+struct Remove_face : public CGAL::unary_function<CMap, void>
 {
   Remove_face(CMap& acmap) : cmap(acmap)
   {}
@@ -60,7 +60,7 @@ private:
 
 // Functor allowing to transform a variable into its address.
 template<typename T>
-struct Take_adress : public std::unary_function<T, T*>
+struct Take_adress : public CGAL::unary_function<T, T*>
 {
   T* operator() (T& t) const
   { return &t; }
diff --git a/Generator/doc/Generator/CGAL/Random_convex_set_traits_2.h b/Generator/doc/Generator/CGAL/Random_convex_set_traits_2.h
index 568261f68cd..0ece677dd7a 100644
--- a/Generator/doc/Generator/CGAL/Random_convex_set_traits_2.h
+++ b/Generator/doc/Generator/CGAL/Random_convex_set_traits_2.h
@@ -40,7 +40,7 @@ typedef unspecified_type Scale;
 
 /*!
 function object class derived from 
-`std::unary_function<Point_2, FT>` 
+`CGAL::unary_function<Point_2, FT>` 
 */ 
 typedef unspecified_type Max_coordinate; 
 
diff --git a/Generator/include/CGAL/Random_convex_set_traits_2.h b/Generator/include/CGAL/Random_convex_set_traits_2.h
index 94b10d9221f..b3897e935e3 100644
--- a/Generator/include/CGAL/Random_convex_set_traits_2.h
+++ b/Generator/include/CGAL/Random_convex_set_traits_2.h
@@ -45,7 +45,7 @@ struct Random_convex_set_traits_2 : public Kernel {
   { return _origin; }
 
   struct Max_coordinate
-  : public std::unary_function< Point_2, FT >
+  : public CGAL::unary_function< Point_2, FT >
   {
     FT
     operator()( const Point_2& p) const
diff --git a/Installation/include/CGAL/config.h b/Installation/include/CGAL/config.h
index 5560c56fd88..7fea88bbe7f 100644
--- a/Installation/include/CGAL/config.h
+++ b/Installation/include/CGAL/config.h
@@ -261,7 +261,7 @@
 
 
 //----------------------------------------------------------------------//
-//  As std::unary_function is deprecated we unse internally CGAL::unary_function
+//  As CGAL::unary_function is deprecated we unse internally CGAL::unary_function
 //----------------------------------------------------------------------//
 
 #include <CGAL/unary_function.h>
diff --git a/Interpolation/doc/Interpolation/CGAL/interpolation_functions.h b/Interpolation/doc/Interpolation/CGAL/interpolation_functions.h
index 9b6915fd478..352b7ea890f 100644
--- a/Interpolation/doc/Interpolation/CGAL/interpolation_functions.h
+++ b/Interpolation/doc/Interpolation/CGAL/interpolation_functions.h
@@ -20,7 +20,7 @@ The class
 
 */
 template< typename Map >
-struct Data_access : public std::unary_function< typename Map::key_type,
+struct Data_access : public CGAL::unary_function< typename Map::key_type,
 		     std::pair< typename Map::mapped_type, bool> > {
 public:
 
diff --git a/Interpolation/include/CGAL/interpolation_functions.h b/Interpolation/include/CGAL/interpolation_functions.h
index bf3ab51ca90..f12462c90de 100644
--- a/Interpolation/include/CGAL/interpolation_functions.h
+++ b/Interpolation/include/CGAL/interpolation_functions.h
@@ -31,7 +31,7 @@ namespace CGAL {
 //Functor class for accessing the function values/gradients
 template< class Map >
 struct Data_access
-    : public std::unary_function< typename Map::key_type,
+    : public CGAL::unary_function< typename Map::key_type,
                                   std::pair< typename Map::mapped_type, bool> >
 {
   typedef typename Map::mapped_type Data_type;
diff --git a/Kinetic_data_structures/include/CGAL/Polynomial/internal/Simple_interval_root.h b/Kinetic_data_structures/include/CGAL/Polynomial/internal/Simple_interval_root.h
index eb48ad5f807..cb3e248e32b 100644
--- a/Kinetic_data_structures/include/CGAL/Polynomial/internal/Simple_interval_root.h
+++ b/Kinetic_data_structures/include/CGAL/Polynomial/internal/Simple_interval_root.h
@@ -646,7 +646,7 @@ class Real_embeddable_traits< CGAL::POLYNOMIAL::internal::Simple_interval_root<T
 public:
   typedef CGAL::POLYNOMIAL::internal::Simple_interval_root<T>  Type;
   class Abs 
-    : public std::unary_function< Type, Type > {
+    : public CGAL::unary_function< Type, Type > {
   public:
     Type operator()( const Type& x ) const {
       if (x < Type(0)) return -x;
@@ -655,7 +655,7 @@ public:
   };
     
   class Sgn 
-    : public std::unary_function< Type, ::CGAL::Sign > {
+    : public CGAL::unary_function< Type, ::CGAL::Sign > {
   public:
     ::CGAL::Sign operator()( const Type& x ) const {
       return static_cast<CGAL::Sign>(x.compare(0));
@@ -677,7 +677,7 @@ public:
       };
     
   class To_double 
-    : public std::unary_function< Type, double > {
+    : public CGAL::unary_function< Type, double > {
   public:
     double operator()( const Type& x ) const {
       // this call is required to get reasonable values for the double
@@ -687,7 +687,7 @@ public:
   };
     
   class To_interval 
-    : public std::unary_function< Type, std::pair< double, double > > {
+    : public CGAL::unary_function< Type, std::pair< double, double > > {
   public:
     std::pair<double, double> operator()( const Type& x ) const {
 
diff --git a/Kinetic_data_structures/include/CGAL/Polynomial/internal/Sturm_root_rep.h b/Kinetic_data_structures/include/CGAL/Polynomial/internal/Sturm_root_rep.h
index 206e353b142..a2664e80b83 100644
--- a/Kinetic_data_structures/include/CGAL/Polynomial/internal/Sturm_root_rep.h
+++ b/Kinetic_data_structures/include/CGAL/Polynomial/internal/Sturm_root_rep.h
@@ -951,7 +951,7 @@ class Real_embeddable_traits< CGAL::POLYNOMIAL::internal::Sturm_root_rep<T,I> >
 public:
   typedef CGAL::POLYNOMIAL::internal::Sturm_root_rep<T,I>  Type;
   class Abs 
-    : public std::unary_function< Type, Type > {
+    : public CGAL::unary_function< Type, Type > {
   public:
     Type operator()( const Type& x ) const {
       if (x < Type(0)) return -x;
@@ -960,7 +960,7 @@ public:
   };
     
   class Sgn 
-    : public std::unary_function< Type, ::CGAL::Sign > {
+    : public CGAL::unary_function< Type, ::CGAL::Sign > {
   public:
     ::CGAL::Sign operator()( const Type& x ) const {
       return static_cast<CGAL::Sign>(x.compare(0));
@@ -982,7 +982,7 @@ public:
       };
     
   class To_double 
-    : public std::unary_function< Type, double > {
+    : public CGAL::unary_function< Type, double > {
   public:
     double operator()( const Type& x ) const {
       // this call is required to get reasonable values for the double
@@ -992,7 +992,7 @@ public:
   };
     
   class To_interval 
-    : public std::unary_function< Type, std::pair< double, double > > {
+    : public CGAL::unary_function< Type, std::pair< double, double > > {
   public:
     std::pair<double, double> operator()( const Type& x ) const {
 
diff --git a/Kinetic_data_structures/include/CGAL/Tools/utility_macros.h b/Kinetic_data_structures/include/CGAL/Tools/utility_macros.h
index 538b0fbb7fc..de9a5932490 100644
--- a/Kinetic_data_structures/include/CGAL/Tools/utility_macros.h
+++ b/Kinetic_data_structures/include/CGAL/Tools/utility_macros.h
@@ -259,7 +259,7 @@ template <class A, class B>			\
 
 #define CGAL_REAL_EMBEDDABLE_BODY					\
   class Abs								\
-    : public std::unary_function< Type, Type > {                        \
+    : public CGAL::unary_function< Type, Type > {                        \
   public:								\
     Type operator()( const Type& x ) const {				\
       if (x < Type(0)) return -x;					\
@@ -268,7 +268,7 @@ template <class A, class B>			\
   };									\
   									\
   class Sgn								\
-    : public std::unary_function< Type, ::CGAL::Sign > {                \
+    : public CGAL::unary_function< Type, ::CGAL::Sign > {                \
   public:								\
     ::CGAL::Sign operator()( const Type& x ) const {			\
       return static_cast<CGAL::Sign>(x.compare(0));			\
@@ -290,7 +290,7 @@ template <class A, class B>			\
   };									\
 									\
   class To_double							\
-    : public std::unary_function< Type, double > {                      \
+    : public CGAL::unary_function< Type, double > {                      \
   public:								\
     double operator()( const Type& x ) const {				\
       return x.approximation(.00000001);				\
@@ -298,7 +298,7 @@ template <class A, class B>			\
   };									\
 									\
   class To_interval							\
-    : public std::unary_function< Type, std::pair< double, double > > {	\
+    : public CGAL::unary_function< Type, std::pair< double, double > > {	\
   public:								\
     std::pair<double, double> operator()( const Type& x ) const {	\
 									\
diff --git a/Linear_cell_complex/examples/Linear_cell_complex/gmap_linear_cell_complex_3.cpp b/Linear_cell_complex/examples/Linear_cell_complex/gmap_linear_cell_complex_3.cpp
index 5638418b20b..d1724540801 100644
--- a/Linear_cell_complex/examples/Linear_cell_complex/gmap_linear_cell_complex_3.cpp
+++ b/Linear_cell_complex/examples/Linear_cell_complex/gmap_linear_cell_complex_3.cpp
@@ -9,7 +9,7 @@ typedef LCC_3::FT                         FT;
 
 // Functor used to display all the vertices of a given volume.
 template<class LCC> 
-struct Display_vol_vertices : public std::unary_function<LCC, void>
+struct Display_vol_vertices : public CGAL::unary_function<LCC, void>
 {
   Display_vol_vertices(const LCC& alcc) : 
     lcc(alcc), 
diff --git a/Linear_cell_complex/examples/Linear_cell_complex/linear_cell_complex_3.cpp b/Linear_cell_complex/examples/Linear_cell_complex/linear_cell_complex_3.cpp
index 44267f460af..35e49a0d76f 100644
--- a/Linear_cell_complex/examples/Linear_cell_complex/linear_cell_complex_3.cpp
+++ b/Linear_cell_complex/examples/Linear_cell_complex/linear_cell_complex_3.cpp
@@ -8,7 +8,7 @@ typedef LCC_3::Point                                       Point;
 
 // Functor used to display all the vertices of a given volume.
 template<class LCC> 
-struct Display_vol_vertices : public std::unary_function<LCC, void>
+struct Display_vol_vertices : public CGAL::unary_function<LCC, void>
 {
   Display_vol_vertices(const LCC& alcc) : 
     lcc(alcc), 
diff --git a/Matrix_search/include/CGAL/sorted_matrix_search.h b/Matrix_search/include/CGAL/sorted_matrix_search.h
index e460e1cf5cf..e77e52069ba 100644
--- a/Matrix_search/include/CGAL/sorted_matrix_search.h
+++ b/Matrix_search/include/CGAL/sorted_matrix_search.h
@@ -124,7 +124,7 @@ private:
 };
 template < class Cell >
 struct Cell_min
-: public std::unary_function< Cell, typename Cell::Value >
+: public CGAL::unary_function< Cell, typename Cell::Value >
 {
   typename Cell::Value
   operator()( const Cell& c) const
@@ -133,7 +133,7 @@ struct Cell_min
 
 template < class Cell >
 struct Cell_max
-: public std::unary_function< Cell, typename Cell::Value > {
+: public CGAL::unary_function< Cell, typename Cell::Value > {
 
   Cell_max( int offset) : ofs( offset) {}
 
diff --git a/Mesh_2/include/CGAL/Mesh_2/Clusters.h b/Mesh_2/include/CGAL/Mesh_2/Clusters.h
index 2910afe35ce..0b9db302b36 100644
--- a/Mesh_2/include/CGAL/Mesh_2/Clusters.h
+++ b/Mesh_2/include/CGAL/Mesh_2/Clusters.h
@@ -117,7 +117,7 @@ private:
   typedef typename Cluster_map::value_type Cluster_map_value_type;
 
   template <class Pair>
-  struct Pair_get_first: public std::unary_function<Pair,
+  struct Pair_get_first: public CGAL::unary_function<Pair,
                                                     typename Pair::first_type>
   {
     typedef typename Pair::first_type result;
diff --git a/Mesh_2/include/CGAL/Mesh_2/Refine_edges.h b/Mesh_2/include/CGAL/Mesh_2/Refine_edges.h
index 8711821c87a..76f075fa712 100644
--- a/Mesh_2/include/CGAL/Mesh_2/Refine_edges.h
+++ b/Mesh_2/include/CGAL/Mesh_2/Refine_edges.h
@@ -634,7 +634,7 @@ protected:
 
 private: /** \name DEBUGGING TYPES AND DATAS */
   class From_pair_of_vertex_to_edge 
-    : public std::unary_function<Constrained_edge, Edge>
+    : public CGAL::unary_function<Constrained_edge, Edge>
   {
     Tr& tr;
   public:
diff --git a/Mesh_2/include/CGAL/Mesh_2/Refine_faces.h b/Mesh_2/include/CGAL/Mesh_2/Refine_faces.h
index 7bac75484f8..36cb159dd4e 100644
--- a/Mesh_2/include/CGAL/Mesh_2/Refine_faces.h
+++ b/Mesh_2/include/CGAL/Mesh_2/Refine_faces.h
@@ -384,7 +384,7 @@ class Refine_faces :
   typedef typename Tr::Geom_traits Geom_traits;
 
   template <class Pair>
-  struct Pair_get_first: public std::unary_function<Pair,
+  struct Pair_get_first: public CGAL::unary_function<Pair,
                                                     typename Pair::first_type>
   {
     typedef typename Pair::first_type result;
diff --git a/Mesh_3/examples/Mesh_3/implicit_functions.h b/Mesh_3/examples/Mesh_3/implicit_functions.h
index e9a3ce0d05b..debbd838480 100644
--- a/Mesh_3/examples/Mesh_3/implicit_functions.h
+++ b/Mesh_3/examples/Mesh_3/implicit_functions.h
@@ -25,7 +25,7 @@ double sphere_function (double x, double y, double z) // (c=(0,0,0), r=Sq_radius
 
 
 template <typename FT, typename P>
-class FT_to_point_function_wrapper : public std::unary_function<P, FT>
+class FT_to_point_function_wrapper : public CGAL::unary_function<P, FT>
 {
   typedef FT (*Implicit_function)(FT, FT, FT);
   Implicit_function function;
diff --git a/Mesh_3/include/CGAL/Mesh_3/C3T3_helpers.h b/Mesh_3/include/CGAL/Mesh_3/C3T3_helpers.h
index dcf78307d39..d7b14079631 100644
--- a/Mesh_3/include/CGAL/Mesh_3/C3T3_helpers.h
+++ b/Mesh_3/include/CGAL/Mesh_3/C3T3_helpers.h
@@ -1028,7 +1028,7 @@ private:
    * A functor which returns true if a given handle is in c3t3
    */
   template <typename Handle>
-  class Is_in_c3t3 : public std::unary_function<Handle, bool>
+  class Is_in_c3t3 : public CGAL::unary_function<Handle, bool>
   {
   public:
     Is_in_c3t3(const C3T3& c3t3) : c3t3_(c3t3) { }
@@ -1045,7 +1045,7 @@ private:
    * A functor which answers true if a Cell_handle is a sliver
    */
   template <typename SliverCriterion>
-  struct Is_sliver : public std::unary_function<Cell_handle,bool>
+  struct Is_sliver : public CGAL::unary_function<Cell_handle,bool>
   {
     Is_sliver(const C3T3& c3t3,
               const SliverCriterion& criterion,
@@ -1318,7 +1318,7 @@ private:
    */
   template <typename SliverCriterion>
   class Sliver_criterion_value
-    : public std::unary_function<Cell_handle, double>
+    : public CGAL::unary_function<Cell_handle, double>
   {
   public:
     Sliver_criterion_value(const Tr& tr,
diff --git a/Mesh_3/include/CGAL/Mesh_3/Polyline_with_context.h b/Mesh_3/include/CGAL/Mesh_3/Polyline_with_context.h
index 37bfb138b51..b98ffee362b 100644
--- a/Mesh_3/include/CGAL/Mesh_3/Polyline_with_context.h
+++ b/Mesh_3/include/CGAL/Mesh_3/Polyline_with_context.h
@@ -60,9 +60,9 @@ struct Polyline_with_context
  */
 template <typename Pwc_>
 struct Extract_bare_polyline :
-  public std::unary_function<Pwc_, const typename Pwc_::Bare_polyline&>
+  public CGAL::unary_function<Pwc_, const typename Pwc_::Bare_polyline&>
 {
-  typedef std::unary_function<Pwc_, const typename Pwc_::Bare_polyline&> Base;
+  typedef CGAL::unary_function<Pwc_, const typename Pwc_::Bare_polyline&> Base;
   typedef typename Base::result_type                                     result_type;
   typedef typename Base::argument_type                                   argument_type;
   
diff --git a/Mesh_3/include/CGAL/Mesh_3/Slivers_exuder.h b/Mesh_3/include/CGAL/Mesh_3/Slivers_exuder.h
index 84f4e4f1a12..bf4a265ac8a 100644
--- a/Mesh_3/include/CGAL/Mesh_3/Slivers_exuder.h
+++ b/Mesh_3/include/CGAL/Mesh_3/Slivers_exuder.h
@@ -80,10 +80,10 @@ namespace Mesh_3 {
     // to use them. -- Laurent Rineau, 2007/07/27
     template <typename Map>
     struct Second_of :
-    public std::unary_function<typename Map::value_type,
+    public CGAL::unary_function<typename Map::value_type,
     const typename Map::mapped_type&>
     {
-      typedef std::unary_function<typename Map::value_type,
+      typedef CGAL::unary_function<typename Map::value_type,
         const typename Map::mapped_type&> Base;
       typedef typename Base::result_type result_type;
       typedef typename Base::argument_type argument_type;
@@ -101,7 +101,7 @@ namespace Mesh_3 {
     // It is used in Slivers_exuder, to constructor a transform iterator.
     template <typename Gt, typename Vertex_handle>
     class Min_distance_from_v :
-    public std::unary_function<Vertex_handle, void>
+    public CGAL::unary_function<Vertex_handle, void>
     {
       const Vertex_handle * v;
       const Gt& gt;
diff --git a/Mesh_3/include/CGAL/Mesh_3/Triangulation_sizing_field.h b/Mesh_3/include/CGAL/Mesh_3/Triangulation_sizing_field.h
index 8e9935d2f0f..4f9afa2b744 100644
--- a/Mesh_3/include/CGAL/Mesh_3/Triangulation_sizing_field.h
+++ b/Mesh_3/include/CGAL/Mesh_3/Triangulation_sizing_field.h
@@ -116,7 +116,7 @@ private:
    * Used by boost transform iterator
    */
   struct Extract_point :
-  public std::unary_function<typename Tr::Vertex,Weighted_point>
+  public CGAL::unary_function<typename Tr::Vertex,Weighted_point>
   {
     Weighted_point operator()(const typename Tr::Vertex& v) const { return v.point(); }
   };
diff --git a/Mesh_3/include/CGAL/Mesh_3/utilities.h b/Mesh_3/include/CGAL/Mesh_3/utilities.h
index 9ddce940e4b..3707ee6fdad 100644
--- a/Mesh_3/include/CGAL/Mesh_3/utilities.h
+++ b/Mesh_3/include/CGAL/Mesh_3/utilities.h
@@ -40,9 +40,9 @@ namespace internal {
  */
 template <typename Pair>
 struct First_of :
-  public std::unary_function<Pair, const typename Pair::first_type&>
+  public CGAL::unary_function<Pair, const typename Pair::first_type&>
 {
-  typedef std::unary_function<Pair, const typename Pair::first_type&> Base;
+  typedef CGAL::unary_function<Pair, const typename Pair::first_type&> Base;
   typedef typename Base::result_type                                  result_type;
   typedef typename Base::argument_type                                argument_type;
   
diff --git a/Mesh_3/test/Mesh_3/implicit_functions.h b/Mesh_3/test/Mesh_3/implicit_functions.h
index e9a3ce0d05b..debbd838480 100644
--- a/Mesh_3/test/Mesh_3/implicit_functions.h
+++ b/Mesh_3/test/Mesh_3/implicit_functions.h
@@ -25,7 +25,7 @@ double sphere_function (double x, double y, double z) // (c=(0,0,0), r=Sq_radius
 
 
 template <typename FT, typename P>
-class FT_to_point_function_wrapper : public std::unary_function<P, FT>
+class FT_to_point_function_wrapper : public CGAL::unary_function<P, FT>
 {
   typedef FT (*Implicit_function)(FT, FT, FT);
   Implicit_function function;
diff --git a/Mesh_3/test/Mesh_3/test_c3t3_extract_subdomains_boundaries.cpp b/Mesh_3/test/Mesh_3/test_c3t3_extract_subdomains_boundaries.cpp
index 6986dd9bf11..f606a7821da 100644
--- a/Mesh_3/test/Mesh_3/test_c3t3_extract_subdomains_boundaries.cpp
+++ b/Mesh_3/test/Mesh_3/test_c3t3_extract_subdomains_boundaries.cpp
@@ -24,7 +24,7 @@ double sphere_function (double x, double y, double z) // (c=(0,0,0), r=Sq_radius
 }
 
 template <typename FT, typename P>
-class FT_to_point_function_wrapper : public std::unary_function<P, FT>
+class FT_to_point_function_wrapper : public CGAL::unary_function<P, FT>
 {
   typedef FT (*Implicit_function)(FT, FT, FT);
   Implicit_function function;
diff --git a/Nef_2/include/CGAL/Nef_polynomial.h b/Nef_2/include/CGAL/Nef_polynomial.h
index 79f65c88017..1e29270cbd9 100644
--- a/Nef_2/include/CGAL/Nef_polynomial.h
+++ b/Nef_2/include/CGAL/Nef_polynomial.h
@@ -175,7 +175,7 @@ template <class NT> class Real_embeddable_traits< Nef_polynomial<NT> >
   public:
     typedef Nef_polynomial<NT> Type;
     class Abs 
-        : public std::unary_function< Type, Type> {
+        : public CGAL::unary_function< Type, Type> {
     public:
         Type inline operator()( const Type& x ) const {
             return (CGAL::Nef::sign( x ) == CGAL::NEGATIVE)? -x : x;
@@ -183,7 +183,7 @@ template <class NT> class Real_embeddable_traits< Nef_polynomial<NT> >
     };
 
     class Sgn 
-      : public std::unary_function< Type, CGAL::Sign > {
+      : public CGAL::unary_function< Type, CGAL::Sign > {
       public:
         CGAL::Sign inline operator()( const Type& x ) const {
             return CGAL::Nef::sign( x );
@@ -202,7 +202,7 @@ template <class NT> class Real_embeddable_traits< Nef_polynomial<NT> >
     };
     
     class To_double 
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double inline operator()( const Type& p ) const {
             return CGAL::to_double(
@@ -211,7 +211,7 @@ template <class NT> class Real_embeddable_traits< Nef_polynomial<NT> >
     };
     
     class To_interval 
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& p ) const {
             return CGAL::to_interval(p.eval_at(Nef_polynomial<NT>::infi_maximal_value()));
diff --git a/Number_types/include/CGAL/CORE_BigFloat.h b/Number_types/include/CGAL/CORE_BigFloat.h
index 09302bcdfa3..6f607f917eb 100644
--- a/Number_types/include/CGAL/CORE_BigFloat.h
+++ b/Number_types/include/CGAL/CORE_BigFloat.h
@@ -45,7 +45,7 @@ public:
     typedef CGAL::Tag_true Is_bigfloat_interval; 
   
  
-    struct Lower :public std::unary_function<Interval,Bound>{
+    struct Lower :public CGAL::unary_function<Interval,Bound>{
         Bound operator() ( Interval x ) const {   
             CORE::BigFloat result = ::CORE::BigFloat(x.m()-x.err(),0,x.exp());
             CGAL_postcondition(result <= x);
@@ -53,7 +53,7 @@ public:
         }
     };
     
-    struct Upper :public std::unary_function<Interval,Bound>{
+    struct Upper :public CGAL::unary_function<Interval,Bound>{
         Bound operator() ( Interval x ) const {     
             CORE::BigFloat result = ::CORE::BigFloat(x.m()+x.err(),0,x.exp());
             CGAL_postcondition(result >= x);
@@ -61,7 +61,7 @@ public:
         }
     };
 
-    struct Width :public std::unary_function<Interval,Bound>{
+    struct Width :public CGAL::unary_function<Interval,Bound>{
          
         Bound operator() ( Interval x ) const {    
             unsigned long err = 2*x.err();
@@ -69,21 +69,21 @@ public:
         }
     };
 
-    struct Median :public std::unary_function<Interval,Bound>{
+    struct Median :public CGAL::unary_function<Interval,Bound>{
          
         Bound operator() ( Interval x ) const {   
             return Bound(x.m(),0,x.exp());
         }
     };
 
-    struct Norm :public std::unary_function<Interval,Bound>{
+    struct Norm :public CGAL::unary_function<Interval,Bound>{
         Bound operator() ( Interval x ) const {
           BOOST_USING_STD_MAX();
           return max BOOST_PREVENT_MACRO_SUBSTITUTION (Upper()(x).abs(),Lower()(x).abs());
         }
     };
     
-    struct Zero_in :public std::unary_function<Interval,bool>{
+    struct Zero_in :public CGAL::unary_function<Interval,bool>{
         bool operator() ( Interval x ) const {      
             return x.isZeroIn(); 
         }
@@ -228,7 +228,7 @@ public:
         }
     };
 
-    struct Singleton :public std::unary_function<Interval,bool> {
+    struct Singleton :public CGAL::unary_function<Interval,bool> {
         bool operator() ( Interval x ) const {       
             return (x.err() == 0); 
         }
@@ -375,7 +375,7 @@ template <> class Algebraic_structure_traits< CORE::BigFloat >
     typedef Tag_true           Is_numerical_sensitive;
 
     class Sqrt
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
             // What I want is a sqrt computed with 
@@ -428,7 +428,7 @@ template <> class Real_embeddable_traits< CORE::BigFloat >
   : public INTERN_RET::Real_embeddable_traits_base< CORE::BigFloat , CGAL::Tag_true  > {
   public:
     class Abs
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
             Type result; 
@@ -461,7 +461,7 @@ template <> class Real_embeddable_traits< CORE::BigFloat >
     };
 
     class Sgn
-      : public std::unary_function< Type, ::CGAL::Sign > {
+      : public CGAL::unary_function< Type, ::CGAL::Sign > {
       public:
         ::CGAL::Sign operator()( const Type& x ) const {
             ::CGAL::Sign result =  sign( x.sign());
@@ -482,7 +482,7 @@ template <> class Real_embeddable_traits< CORE::BigFloat >
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double operator()( const Type& x ) const {
           // this call is required to get reasonable values for the double
@@ -492,7 +492,7 @@ template <> class Real_embeddable_traits< CORE::BigFloat >
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
     public:
         std::pair<double, double> operator()( const Type& x ) const {
                         
diff --git a/Number_types/include/CGAL/CORE_BigInt.h b/Number_types/include/CGAL/CORE_BigInt.h
index a3c18b16101..16c175a7025 100644
--- a/Number_types/include/CGAL/CORE_BigInt.h
+++ b/Number_types/include/CGAL/CORE_BigInt.h
@@ -50,7 +50,7 @@ template <> class Algebraic_structure_traits< CORE::BigInt >
     typedef INTERN_AST::Mod_per_operator< Type > Mod;
 
     class Sqrt
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         //! computes the largest NT not larger than the square root of \a a.
         Type operator()( const Type& x) const {
@@ -85,7 +85,7 @@ template <> class Real_embeddable_traits< CORE::BigInt >
   public:
 
     class Abs
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
           return CORE::abs( x );
@@ -93,7 +93,7 @@ template <> class Real_embeddable_traits< CORE::BigInt >
     };
 
     class Sgn
-      : public std::unary_function< Type, ::CGAL::Sign > {
+      : public CGAL::unary_function< Type, ::CGAL::Sign > {
       public:
         ::CGAL::Sign operator()( const Type& x ) const {
           return (::CGAL::Sign) CORE::sign( x );
@@ -111,7 +111,7 @@ template <> class Real_embeddable_traits< CORE::BigInt >
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double operator()( const Type& x ) const {
           // this call is required to get reasonable values for the double
@@ -121,7 +121,7 @@ template <> class Real_embeddable_traits< CORE::BigInt >
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x_ ) const {
             CORE::Expr x(x_);
diff --git a/Number_types/include/CGAL/CORE_BigRat.h b/Number_types/include/CGAL/CORE_BigRat.h
index 8f5f7260185..fcf5322bc19 100644
--- a/Number_types/include/CGAL/CORE_BigRat.h
+++ b/Number_types/include/CGAL/CORE_BigRat.h
@@ -64,7 +64,7 @@ template <> class Real_embeddable_traits< CORE::BigRat >
   public:
 
     class Abs
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
           return CORE::abs( x );
@@ -72,7 +72,7 @@ template <> class Real_embeddable_traits< CORE::BigRat >
     };
 
     class Sgn
-      : public std::unary_function< Type, ::CGAL::Sign > {
+      : public CGAL::unary_function< Type, ::CGAL::Sign > {
       public:
         ::CGAL::Sign operator()( const Type& x ) const {
           return (::CGAL::Sign) CORE::sign( x );
@@ -91,7 +91,7 @@ template <> class Real_embeddable_traits< CORE::BigRat >
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double operator()( const Type& x ) const {
           // this call is required to get reasonable values for the double
@@ -101,7 +101,7 @@ template <> class Real_embeddable_traits< CORE::BigRat >
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x_ ) const {
             CORE::Expr x(x_);
diff --git a/Number_types/include/CGAL/CORE_Expr.h b/Number_types/include/CGAL/CORE_Expr.h
index 4bd38945006..88467a4f885 100644
--- a/Number_types/include/CGAL/CORE_Expr.h
+++ b/Number_types/include/CGAL/CORE_Expr.h
@@ -41,7 +41,7 @@ template <> class Algebraic_structure_traits< CORE::Expr >
     typedef Tag_true            Is_numerical_sensitive;
 
     class Sqrt
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
           return CORE::sqrt( x );
@@ -128,7 +128,7 @@ template <> class Real_embeddable_traits< CORE::Expr >
   : public INTERN_RET::Real_embeddable_traits_base< CORE::Expr , CGAL::Tag_true > {
   public:
     class Abs
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
             return CORE::abs( x );
@@ -136,7 +136,7 @@ template <> class Real_embeddable_traits< CORE::Expr >
     };
 
     class Sgn
-      : public std::unary_function< Type, ::CGAL::Sign > {
+      : public CGAL::unary_function< Type, ::CGAL::Sign > {
       public:
         ::CGAL::Sign operator()( const Type& x ) const {
           return (::CGAL::Sign) CORE::sign( x );
@@ -158,7 +158,7 @@ template <> class Real_embeddable_traits< CORE::Expr >
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double operator()( const Type& x ) const {
           x.approx(53,1075);
@@ -167,7 +167,7 @@ template <> class Real_embeddable_traits< CORE::Expr >
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
             std::pair<double,double> result;
diff --git a/Number_types/include/CGAL/Counted_number.h b/Number_types/include/CGAL/Counted_number.h
index cc1fc68f7d2..5b4d4c20c07 100644
--- a/Number_types/include/CGAL/Counted_number.h
+++ b/Number_types/include/CGAL/Counted_number.h
@@ -444,7 +444,7 @@ operator>=(Counted_number<NT> const &n1, Counted_number<NT> const &n2)
 
 template <class NT>
 class Is_valid< Counted_number<NT> >
-  : public std::unary_function< Counted_number<NT>, bool > {
+  : public CGAL::unary_function< Counted_number<NT>, bool > {
   public:
     bool operator()( const Counted_number<NT>& x ) {
       return is_valid( x.rep() );
@@ -514,7 +514,7 @@ namespace INTERN_COUNTED_NUMBER{
 
 template< class NT, class Functor >
 struct Simplify_selector {
-  struct Simplify : public std::unary_function<NT&, void> {
+  struct Simplify : public CGAL::unary_function<NT&, void> {
     void operator()( NT& x ) const {
       x.simplify();
     }
@@ -528,7 +528,7 @@ struct Simplify_selector< NT, Null_functor > {
 
 template< class NT, class Functor >
 struct Unit_part_selector {
-  struct Unit_part : public std::unary_function<NT, NT > {
+  struct Unit_part : public CGAL::unary_function<NT, NT > {
     NT operator()( const NT& x ) const {
       return x.unit_part();
     }
@@ -542,7 +542,7 @@ struct Unit_part_selector< NT, Null_functor > {
 
 template< class NT, class Functor >
 struct Is_zero_selector {
-  struct Is_zero : public std::unary_function<NT, bool > {
+  struct Is_zero : public CGAL::unary_function<NT, bool > {
     bool operator()( const NT& x ) const {
       return x.is_zero();
     }
@@ -556,7 +556,7 @@ struct Is_zero_selector< NT, Null_functor > {
 
 template< class NT, class Functor >
 struct Is_one_selector {
-  struct Is_one : public std::unary_function<NT, bool > {
+  struct Is_one : public CGAL::unary_function<NT, bool > {
     bool operator()( const NT& x ) const {
       return x.is_one();
     }
@@ -570,7 +570,7 @@ struct Is_one_selector< NT, Null_functor > {
 
 template< class NT, class Functor >
 struct Square_selector {
-  struct Square : public std::unary_function<NT, NT > {
+  struct Square : public CGAL::unary_function<NT, NT > {
     NT operator()( const NT& x ) const {
       return x.square();
     }
@@ -617,7 +617,7 @@ struct Is_square_selector< NT, Null_functor > {
 
 template <class NT, class AlgebraicStructureTag>
 struct Sqrt_selector{
-    struct Sqrt : public std::unary_function<NT,NT> {
+    struct Sqrt : public CGAL::unary_function<NT,NT> {
         NT operator ()(const NT& x) const {
             return x.sqrt();
         }
@@ -817,20 +817,20 @@ public:
     <Counted_number<NT>, typename RET_NT::Is_zero > ::Is_zero Is_zero;
 
     class Is_finite
-      : public std::unary_function< Counted_number<NT>, bool > {
+      : public CGAL::unary_function< Counted_number<NT>, bool > {
       public:
         bool operator()( const Counted_number<NT>& x ) const {
           return CGAL_NTS is_finite( x.rep() );
         }
     };
 
-    struct To_double : public std::unary_function< Counted_number<NT>, double > {
+    struct To_double : public CGAL::unary_function< Counted_number<NT>, double > {
         double operator()(const Counted_number<NT>& x) const {
             return x.to_double();
         }
     };
 
-    struct To_interval: public std::unary_function< Counted_number<NT>, std::pair<double,double> > {
+    struct To_interval: public CGAL::unary_function< Counted_number<NT>, std::pair<double,double> > {
         std::pair<double,double>
         operator()(const Counted_number<NT>& x) const {
             return x.to_interval();
diff --git a/Number_types/include/CGAL/Gmpfi.h b/Number_types/include/CGAL/Gmpfi.h
index 479f1608a4b..84240dacce0 100644
--- a/Number_types/include/CGAL/Gmpfi.h
+++ b/Number_types/include/CGAL/Gmpfi.h
@@ -41,21 +41,21 @@ public:
         typedef Uncertain<bool> Boolean;
 
         struct Is_zero:
-        public std::unary_function<Type,Boolean>{
+        public CGAL::unary_function<Type,Boolean>{
                 Boolean operator()(const Type &x)const{
                         return x.is_zero();
                 }
         };
 
         struct Is_one:
-        public std::unary_function<Type,Boolean>{
+        public CGAL::unary_function<Type,Boolean>{
                 Boolean operator()(const Type &x)const{
                         return x.is_one();
                 }
         };
 
         struct Square:
-        public std::unary_function<Type,Type>{
+        public CGAL::unary_function<Type,Type>{
                 Type operator()(const Type &x)const{
                         return x.square();
                 };
@@ -72,7 +72,7 @@ public:
         };
 
         struct Sqrt:
-        public std::unary_function<Type,Type>{
+        public CGAL::unary_function<Type,Type>{
                 Type operator()(const Type &x)const{
                         return x.sqrt();
                 };
@@ -114,35 +114,35 @@ public INTERN_RET::Real_embeddable_traits_base<Gmpfi,CGAL::Tag_true>{
         typedef AST::Is_zero    Is_zero;
 
         struct Is_finite:
-        public std::unary_function<Type,Boolean>{
+        public CGAL::unary_function<Type,Boolean>{
                 inline Boolean operator()(const Type &x)const{
                         return(x.is_number());
                 };
         };
 
         struct Abs:
-        public std::unary_function<Type,Type>{
+        public CGAL::unary_function<Type,Type>{
                 inline Type operator()(const Type &x)const{
                         return x.abs();
                 };
         };
 
         struct Sgn:
-        public std::unary_function<Type,Sign>{
+        public CGAL::unary_function<Type,Sign>{
                 inline Sign operator()(const Type &x)const{
                         return x.sign();
                 };
         };
 
         struct Is_positive:
-        public std::unary_function<Type,Boolean>{
+        public CGAL::unary_function<Type,Boolean>{
                 inline Boolean operator()(const Type &x)const{
                         return x.is_positive();
                 };
         };
 
         struct Is_negative:
-        public std::unary_function<Type,Boolean>{
+        public CGAL::unary_function<Type,Boolean>{
                 inline Boolean operator()(const Type &x)const{
                         return x.is_negative();
                 };
@@ -158,14 +158,14 @@ public INTERN_RET::Real_embeddable_traits_base<Gmpfi,CGAL::Tag_true>{
         };
 
         struct To_double:
-        public std::unary_function<Type,double>{
+        public CGAL::unary_function<Type,double>{
                 inline double operator()(const Type &x)const{
                         return x.to_double();
                 };
         };
 
         struct To_interval:
-        public std::unary_function<Type,std::pair<double,double> >{
+        public CGAL::unary_function<Type,std::pair<double,double> >{
                 inline std::pair<double,double> operator()(const Type &x)const{
                                 return x.to_interval();
                         };
@@ -191,43 +191,43 @@ public:
     }
   };
 
-  struct Lower :public std::unary_function<Interval,Bound>{
+  struct Lower :public CGAL::unary_function<Interval,Bound>{
     Bound operator()( const Interval& a ) const {
       return a.inf();
     }
   };
 
-  struct Upper :public std::unary_function<Interval,Bound>{
+  struct Upper :public CGAL::unary_function<Interval,Bound>{
     Bound operator()( const Interval& a ) const {
       return a.sup();
     }
   };
 
-  struct Width :public std::unary_function<Interval,Bound>{
+  struct Width :public CGAL::unary_function<Interval,Bound>{
     Bound operator()( const Interval& a ) const {
       return Gmpfr::sub(a.sup(),a.inf(),std::round_toward_infinity);
     }
   };
 
-  struct Median :public std::unary_function<Interval,Bound>{
+  struct Median :public CGAL::unary_function<Interval,Bound>{
     Bound operator()( const Interval& a ) const {
       return (a.inf()+a.sup())/2;
     }
   };
     
-  struct Norm :public std::unary_function<Interval,Bound>{
+  struct Norm :public CGAL::unary_function<Interval,Bound>{
     Bound operator()( const Interval& a ) const {
       return a.abs().sup();
     }
   };
 
-  struct Singleton :public std::unary_function<Interval,bool>{
+  struct Singleton :public CGAL::unary_function<Interval,bool>{
     bool operator()( const Interval& a ) const {
       return a.inf() == a.sup();
     }
   };
 
-  struct Zero_in :public std::unary_function<Interval,bool>{
+  struct Zero_in :public CGAL::unary_function<Interval,bool>{
     bool operator()( const Interval& a ) const {
       return a.inf() <= 0  &&  0 <= a.sup();
     }
@@ -299,7 +299,7 @@ public:
   typedef Bigfloat_interval_traits<Gmpfi> Self; 
   typedef CGAL::Tag_true                  Is_bigfloat_interval; 
   
-  struct Relative_precision: public std::unary_function<NT,long>{
+  struct Relative_precision: public CGAL::unary_function<NT,long>{
 
     long operator()(const NT& x) const {
       CGAL_precondition(!Singleton()(x));
diff --git a/Number_types/include/CGAL/Gmpfr.h b/Number_types/include/CGAL/Gmpfr.h
index 94bb613b61e..605f23ddfe6 100644
--- a/Number_types/include/CGAL/Gmpfr.h
+++ b/Number_types/include/CGAL/Gmpfr.h
@@ -34,21 +34,21 @@ public:
         typedef bool            Boolean;
 
         struct Is_zero:
-        public std::unary_function<Type,Boolean>{
+        public CGAL::unary_function<Type,Boolean>{
                 Boolean operator()(const Type &x)const{
                         return x.is_zero();
                 }
         };
 
         struct Is_one:
-        public std::unary_function<Type,Boolean>{
+        public CGAL::unary_function<Type,Boolean>{
                 Boolean operator()(const Type &x)const{
                         return x.is_one();
                 }
         };
 
         struct Square:
-        public std::unary_function<Type,Type>{
+        public CGAL::unary_function<Type,Type>{
                 Type operator()(const Type &x)const{
                         return x.square();
                 };
@@ -65,7 +65,7 @@ public:
         };
 
         struct Sqrt:
-        public std::unary_function<Type,Type>{
+        public CGAL::unary_function<Type,Type>{
                 Type operator()(const Type &x)const{
                         return x.sqrt();
                 };
@@ -95,35 +95,35 @@ public INTERN_RET::Real_embeddable_traits_base<Gmpfr,CGAL::Tag_true>{
         typedef AST::Is_zero    Is_zero;
 
         struct Is_finite:
-        public std::unary_function<Type,Boolean>{
+        public CGAL::unary_function<Type,Boolean>{
                 inline Boolean operator()(const Type &x)const{
                         return(x.is_number());
                 };
         };
 
         struct Abs:
-        public std::unary_function<Type,Type>{
+        public CGAL::unary_function<Type,Type>{
                 inline Type operator()(const Type &x)const{
                         return x.abs();
                 };
         };
 
         struct Sgn:
-        public std::unary_function<Type,Sign>{
+        public CGAL::unary_function<Type,Sign>{
                 inline Sign operator()(const Type &x)const{
                         return x.sign();
                 };
         };
 
         struct Is_positive:
-        public std::unary_function<Type,Boolean>{
+        public CGAL::unary_function<Type,Boolean>{
                 inline Boolean operator()(const Type &x)const{
                         return(x.sign()==POSITIVE);
                 };
         };
 
         struct Is_negative:
-        public std::unary_function<Type,Boolean>{
+        public CGAL::unary_function<Type,Boolean>{
                 inline Boolean operator()(const Type &x)const{
                         return(x.sign()==NEGATIVE);
                 };
@@ -139,14 +139,14 @@ public INTERN_RET::Real_embeddable_traits_base<Gmpfr,CGAL::Tag_true>{
         };
 
         struct To_double:
-        public std::unary_function<Type,double>{
+        public CGAL::unary_function<Type,double>{
                 inline double operator()(const Type &x)const{
                         return x.to_double();
                 };
         };
 
         struct To_interval:
-        public std::unary_function<Type,std::pair<double,double> >{
+        public CGAL::unary_function<Type,std::pair<double,double> >{
                 inline std::pair<double,double>operator()(const Type &x)const{
                                 return x.to_interval();
                 };
diff --git a/Number_types/include/CGAL/Gmpq.h b/Number_types/include/CGAL/Gmpq.h
index c98532b3994..e25d45f0be9 100644
--- a/Number_types/include/CGAL/Gmpq.h
+++ b/Number_types/include/CGAL/Gmpq.h
@@ -53,7 +53,7 @@ template <> class Algebraic_structure_traits< Gmpq >
     };
 
     class Simplify
-      : public std::unary_function< Type&, void > {
+      : public CGAL::unary_function< Type&, void > {
       public:
         void operator()( Type& x) const {
           mpq_canonicalize( x.mpq() );
@@ -69,7 +69,7 @@ template <> class Real_embeddable_traits< Gmpq >
   public:
   
     class Sgn
-      : public std::unary_function< Type, ::CGAL::Sign > {
+      : public CGAL::unary_function< Type, ::CGAL::Sign > {
       public:
         ::CGAL::Sign operator()( const Type& x ) const {
           return x.sign();
@@ -77,7 +77,7 @@ template <> class Real_embeddable_traits< Gmpq >
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double operator()( const Type& x ) const {
           return x.to_double();
@@ -85,7 +85,7 @@ template <> class Real_embeddable_traits< Gmpq >
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
           mpfr_t y;
diff --git a/Number_types/include/CGAL/Gmpz.h b/Number_types/include/CGAL/Gmpz.h
index 5a1b15dbb35..a9c05a57f91 100644
--- a/Number_types/include/CGAL/Gmpz.h
+++ b/Number_types/include/CGAL/Gmpz.h
@@ -96,7 +96,7 @@ public:
     typedef INTERN_AST::Mod_per_operator< Type > Mod;
 
     class Sqrt
-        : public std::unary_function< Type, Type > {
+        : public CGAL::unary_function< Type, Type > {
     public:
         Type operator()( const Type& x ) const {
             Gmpz result;
@@ -110,7 +110,7 @@ template <> class Real_embeddable_traits< Gmpz >
     : public INTERN_RET::Real_embeddable_traits_base< Gmpz , CGAL::Tag_true > {
 public:
     class Sgn
-        : public std::unary_function< Type, ::CGAL::Sign > {
+        : public CGAL::unary_function< Type, ::CGAL::Sign > {
     public:
         ::CGAL::Sign operator()( const Type& x ) const {
             return x.sign();
@@ -118,7 +118,7 @@ public:
     };
 
     class To_double
-        : public std::unary_function< Type, double > {
+        : public CGAL::unary_function< Type, double > {
     public:
         double operator()( const Type& x ) const {
             return x.to_double();
@@ -126,7 +126,7 @@ public:
     };
 
     class To_interval
-        : public std::unary_function< Type, std::pair< double, double > > {
+        : public CGAL::unary_function< Type, std::pair< double, double > > {
     public:
         std::pair<double, double> operator()( const Type& x ) const {
 
@@ -148,7 +148,7 @@ template<> class Algebraic_structure_traits< Quotient<Gmpz> >
 public:
     typedef Quotient<Gmpz> Type;
 
-    struct To_double: public std::unary_function<Quotient<Gmpz>, double>{
+    struct To_double: public CGAL::unary_function<Quotient<Gmpz>, double>{
         double operator()(const Quotient<Gmpz>& quot){
             mpq_t  mpQ;
             mpq_init(mpQ);
diff --git a/Number_types/include/CGAL/Gmpzf.h b/Number_types/include/CGAL/Gmpzf.h
index 94b769da6e1..4a22c228169 100644
--- a/Number_types/include/CGAL/Gmpzf.h
+++ b/Number_types/include/CGAL/Gmpzf.h
@@ -36,7 +36,7 @@ public:
     typedef Tag_true            Is_exact;
 
     struct Is_zero
-        : public std::unary_function< Type, bool > {
+        : public CGAL::unary_function< Type, bool > {
     public:
         bool operator()( const Type& x ) const {
             return x.is_zero();
@@ -103,7 +103,7 @@ public:
   typedef AST::Is_zero Is_zero;
   
     struct Sgn
-        : public std::unary_function< Type, ::CGAL::Sign > {
+        : public CGAL::unary_function< Type, ::CGAL::Sign > {
     public:
         ::CGAL::Sign operator()( const Type& x ) const {
             return x.sign();
@@ -123,7 +123,7 @@ public:
     };
 
     struct To_double
-        : public std::unary_function< Type, double > {
+        : public CGAL::unary_function< Type, double > {
     public:
         double operator()( const Type& x ) const {
             return x.to_double();
@@ -131,7 +131,7 @@ public:
     };
 
     struct To_interval
-        : public std::unary_function< Type, std::pair< double, double > > {
+        : public CGAL::unary_function< Type, std::pair< double, double > > {
     public:
         std::pair<double, double> operator()( const Type& x ) const {
 	    return x.to_interval();
@@ -146,7 +146,7 @@ class Real_embeddable_traits< Quotient<Gmpzf> >
 INTERN_QUOTIENT::Real_embeddable_traits_quotient_base< Quotient<Gmpzf> >
 {
 public:
-    struct To_double: public std::unary_function<Quotient<Gmpzf>, double>{
+    struct To_double: public CGAL::unary_function<Quotient<Gmpzf>, double>{
         inline
         double operator()(const Quotient<Gmpzf>& q) const {
 	  std::pair<double, long> n = q.numerator().to_double_exp();
@@ -157,7 +157,7 @@ public:
 	}
     };
     struct To_interval
-        : public std::unary_function<Quotient<Gmpzf>, std::pair<double,double> >{
+        : public CGAL::unary_function<Quotient<Gmpzf>, std::pair<double,double> >{
         inline
         std::pair<double,double> operator()(const Quotient<Gmpzf>& q) const {
 	  // do here as MP_Float does
diff --git a/Number_types/include/CGAL/Interval_nt.h b/Number_types/include/CGAL/Interval_nt.h
index e0969570391..6437a89762b 100644
--- a/Number_types/include/CGAL/Interval_nt.h
+++ b/Number_types/include/CGAL/Interval_nt.h
@@ -445,7 +445,7 @@ relative_precision(const Interval_nt<Protected> & d)
 
 template< bool Protected >
 class Is_valid< Interval_nt<Protected> >
-  : public std::unary_function< Interval_nt<Protected>, bool > {
+  : public CGAL::unary_function< Interval_nt<Protected>, bool > {
   public :
     bool operator()( const Interval_nt<Protected>& x ) const {
       return is_valid(x.inf()) &&
@@ -959,7 +959,7 @@ template< bool B > class Real_embeddable_traits< Interval_nt<B> >
   typedef Uncertain<CGAL::Comparison_result> Comparison_result; 
 
     class Abs
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
             return INTERN_INTERVAL_NT::abs( x );
@@ -967,7 +967,7 @@ template< bool B > class Real_embeddable_traits< Interval_nt<B> >
     };
 
     class Sgn
-        : public std::unary_function< Type, Uncertain< ::CGAL::Sign > > {
+        : public CGAL::unary_function< Type, Uncertain< ::CGAL::Sign > > {
       public:
         Uncertain< ::CGAL::Sign > operator()( const Type& x ) const {
             return INTERN_INTERVAL_NT::sign( x );
@@ -975,7 +975,7 @@ template< bool B > class Real_embeddable_traits< Interval_nt<B> >
     };
 
     class Is_positive
-      : public std::unary_function< Type, Uncertain<bool> > {
+      : public CGAL::unary_function< Type, Uncertain<bool> > {
       public:
         Uncertain<bool> operator()( const Type& x ) const {
           return INTERN_INTERVAL_NT::is_positive( x );
@@ -983,7 +983,7 @@ template< bool B > class Real_embeddable_traits< Interval_nt<B> >
     };
 
     class Is_negative
-      : public std::unary_function< Type, Uncertain<bool> > {
+      : public CGAL::unary_function< Type, Uncertain<bool> > {
       public:
         Uncertain<bool> operator()( const Type& x ) const {
           return INTERN_INTERVAL_NT::is_negative( x );
@@ -1001,7 +1001,7 @@ template< bool B > class Real_embeddable_traits< Interval_nt<B> >
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double operator()( const Type& x ) const {
             return INTERN_INTERVAL_NT::to_double( x );
@@ -1009,7 +1009,7 @@ template< bool B > class Real_embeddable_traits< Interval_nt<B> >
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
             return INTERN_INTERVAL_NT::to_interval( x );
@@ -1017,7 +1017,7 @@ template< bool B > class Real_embeddable_traits< Interval_nt<B> >
     };
 
     class Is_finite
-      : public std::unary_function< Type, Boolean > {
+      : public CGAL::unary_function< Type, Boolean > {
       public :
         Boolean operator()( const Type& x ) const {
           return CGAL_NTS is_finite( x.inf() ) && CGAL_NTS is_finite( x.sup() );
@@ -1038,7 +1038,7 @@ class Algebraic_structure_traits< Interval_nt<B> >
     typedef Uncertain<bool>     Boolean; 
 
     class Is_zero
-      : public std::unary_function< Type, Boolean > {
+      : public CGAL::unary_function< Type, Boolean > {
       public:
         Boolean operator()( const Type& x ) const {
           return INTERN_INTERVAL_NT::is_zero( x );
@@ -1046,7 +1046,7 @@ class Algebraic_structure_traits< Interval_nt<B> >
     };
 
     class Is_one
-      : public std::unary_function< Type, Boolean > {
+      : public CGAL::unary_function< Type, Boolean > {
       public:
         Boolean operator()( const Type& x ) const {
           return INTERN_INTERVAL_NT::is_one( x );
@@ -1054,7 +1054,7 @@ class Algebraic_structure_traits< Interval_nt<B> >
     };
 
     class Square
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
           return INTERN_INTERVAL_NT::square( x );
@@ -1062,7 +1062,7 @@ class Algebraic_structure_traits< Interval_nt<B> >
     };
 
     class Sqrt
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
           return INTERN_INTERVAL_NT::sqrt( x );
@@ -1161,43 +1161,43 @@ public:
     }
   };
 
-  struct Lower :public std::unary_function<Interval,Bound>{
+  struct Lower :public CGAL::unary_function<Interval,Bound>{
     Bound operator()( const Interval& a ) const {
       return a.inf();
     }
   };
 
-  struct Upper :public std::unary_function<Interval,Bound>{
+  struct Upper :public CGAL::unary_function<Interval,Bound>{
     Bound operator()( const Interval& a ) const {
       return a.sup();
     }
   };
 
-  struct Width :public std::unary_function<Interval,Bound>{
+  struct Width :public CGAL::unary_function<Interval,Bound>{
     Bound operator()( const Interval& a ) const {
       return width(a); 
     }
   };
 
-  struct Median :public std::unary_function<Interval,Bound>{
+  struct Median :public CGAL::unary_function<Interval,Bound>{
     Bound operator()( const Interval& a ) const {
       return (Lower()(a)+Upper()(a))/2.0;
     }
   };
     
-  struct Norm :public std::unary_function<Interval,Bound>{
+  struct Norm :public CGAL::unary_function<Interval,Bound>{
     Bound operator()( const Interval& a ) const {
       return magnitude(a);
     }
   };
 
-  struct Singleton :public std::unary_function<Interval,bool>{
+  struct Singleton :public CGAL::unary_function<Interval,bool>{
     bool operator()( const Interval& a ) const {
       return Lower()(a) == Upper()(a);
     }
   };
 
-  struct Zero_in :public std::unary_function<Interval,bool>{
+  struct Zero_in :public CGAL::unary_function<Interval,bool>{
     bool operator()( const Interval& a ) const {
       return Lower()(a) <= 0  &&  0 <= Upper()(a);
     }
diff --git a/Number_types/include/CGAL/Lazy_exact_nt.h b/Number_types/include/CGAL/Lazy_exact_nt.h
index 0ae67a4b778..600c38f70b0 100644
--- a/Number_types/include/CGAL/Lazy_exact_nt.h
+++ b/Number_types/include/CGAL/Lazy_exact_nt.h
@@ -685,7 +685,7 @@ namespace INTERN_LAZY_EXACT_NT {
 
 template< class NT, class Functor >
 struct Simplify_selector {
-  struct Simplify : public std::unary_function<NT&, void> {
+  struct Simplify : public CGAL::unary_function<NT&, void> {
     void operator()( NT& ) const {
       // TODO: In the old implementation the Simplify-functor was the default
       //       (which does nothing). But this cannot be the correct way!?
@@ -700,7 +700,7 @@ struct Simplify_selector< NT, Null_functor > {
 
 template< class NT, class Functor >
 struct Unit_part_selector {
-  struct Unit_part : public std::unary_function<NT, NT > {
+  struct Unit_part : public CGAL::unary_function<NT, NT > {
     NT operator()( const NT& x ) const {
       return NT( CGAL_NTS unit_part( x.exact() ) );
     }
@@ -714,7 +714,7 @@ struct Unit_part_selector< NT, Null_functor > {
 
 template< class NT, class Functor >
 struct Is_zero_selector {
-  struct Is_zero : public std::unary_function<NT, bool > {
+  struct Is_zero : public CGAL::unary_function<NT, bool > {
     bool operator()( const NT& x ) const {
       return CGAL_NTS is_zero( x.exact() );
     }
@@ -728,7 +728,7 @@ struct Is_zero_selector< NT, Null_functor > {
 
 template< class NT, class Functor >
 struct Is_one_selector {
-  struct Is_one : public std::unary_function<NT, bool > {
+  struct Is_one : public CGAL::unary_function<NT, bool > {
     bool operator()( const NT& x ) const {
       return CGAL_NTS is_one( x.exact() );
     }
@@ -742,7 +742,7 @@ struct Is_one_selector< NT, Null_functor > {
 
 template< class NT, class Functor >
 struct Square_selector {
-  struct Square : public std::unary_function<NT, NT > {
+  struct Square : public CGAL::unary_function<NT, NT > {
     NT operator()( const NT& x ) const {
       CGAL_PROFILER(std::string("calls to    : ") + std::string(CGAL_PRETTY_FUNCTION));
       return new Lazy_exact_Square<typename NT::ET>(x);
@@ -795,7 +795,7 @@ struct Is_square_selector< NT, Null_functor > {
 
 template <class NT, class AlgebraicStructureTag>
 struct Sqrt_selector{
-    struct Sqrt : public std::unary_function<NT, NT > {
+    struct Sqrt : public CGAL::unary_function<NT, NT > {
         NT operator ()(const NT& x) const {
           CGAL_PROFILER(std::string("calls to    : ") + std::string(CGAL_PRETTY_FUNCTION));
           CGAL_precondition(x >= 0);
@@ -1032,7 +1032,7 @@ template < typename ET > class Real_embeddable_traits< Lazy_exact_nt<ET> >
     typedef Lazy_exact_nt<ET> Type;
 
     class Abs
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& a ) const {
             CGAL_PROFILER(std::string("calls to    : ") + std::string(CGAL_PRETTY_FUNCTION));
@@ -1041,7 +1041,7 @@ template < typename ET > class Real_embeddable_traits< Lazy_exact_nt<ET> >
     };
 
     class Sgn
-      : public std::unary_function< Type, ::CGAL::Sign > {
+      : public CGAL::unary_function< Type, ::CGAL::Sign > {
       public:
         ::CGAL::Sign operator()( const Type& a ) const {
             CGAL_BRANCH_PROFILER(std::string(" failures/calls to   : ") + std::string(CGAL_PRETTY_FUNCTION), tmp);
@@ -1075,7 +1075,7 @@ template < typename ET > class Real_embeddable_traits< Lazy_exact_nt<ET> >
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double operator()( const Type& a ) const {
             CGAL_BRANCH_PROFILER(std::string(" failures/calls to   : ") + std::string(CGAL_PRETTY_FUNCTION), tmp);
@@ -1100,7 +1100,7 @@ template < typename ET > class Real_embeddable_traits< Lazy_exact_nt<ET> >
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& a ) const {
             CGAL_PROFILER(std::string("calls to    : ") + std::string(CGAL_PRETTY_FUNCTION));
@@ -1109,7 +1109,7 @@ template < typename ET > class Real_embeddable_traits< Lazy_exact_nt<ET> >
     };
 
     class Is_finite
-      : public std::unary_function< Type, bool > {
+      : public CGAL::unary_function< Type, bool > {
       public:
         bool operator()( const Type& x ) const {
           return CGAL_NTS is_finite(x.approx()) || CGAL_NTS is_finite(x.exact());
@@ -1318,7 +1318,7 @@ operator>> (std::istream & is, Lazy_exact_nt<ET> & a)
 
 template< class ET >
 class Is_valid< Lazy_exact_nt<ET> >
-  : public std::unary_function< Lazy_exact_nt<ET>, bool > {
+  : public CGAL::unary_function< Lazy_exact_nt<ET>, bool > {
   public :
     bool operator()( const Lazy_exact_nt<ET>& x ) const {
       return is_valid(x.approx());
diff --git a/Number_types/include/CGAL/MP_Float.h b/Number_types/include/CGAL/MP_Float.h
index 0b55d55f692..1f7f40851f8 100644
--- a/Number_types/include/CGAL/MP_Float.h
+++ b/Number_types/include/CGAL/MP_Float.h
@@ -416,7 +416,7 @@ template <> class Algebraic_structure_traits< MP_Float >
     typedef Tag_true            Is_numerical_sensitive;
 
     struct Unit_part
-      : public std::unary_function< Type , Type >
+      : public CGAL::unary_function< Type , Type >
     {
       Type operator()(const Type &x) const {
         return x.unit_part();
@@ -440,7 +440,7 @@ template <> class Algebraic_structure_traits< MP_Float >
 
 
     class Square
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
           return INTERN_MP_FLOAT::square(x);
@@ -493,7 +493,7 @@ template <> class Real_embeddable_traits< MP_Float >
   public:
 
     class Sgn
-      : public std::unary_function< Type, ::CGAL::Sign > {
+      : public CGAL::unary_function< Type, ::CGAL::Sign > {
       public:
         ::CGAL::Sign operator()( const Type& x ) const {
           return x.sign();
@@ -511,7 +511,7 @@ template <> class Real_embeddable_traits< MP_Float >
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double operator()( const Type& x ) const {
           return INTERN_MP_FLOAT::to_double( x );
@@ -519,7 +519,7 @@ template <> class Real_embeddable_traits< MP_Float >
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
           return INTERN_MP_FLOAT::to_interval( x );
@@ -851,14 +851,14 @@ class Real_embeddable_traits< Quotient<MP_Float> >
     : public INTERN_QUOTIENT::Real_embeddable_traits_quotient_base<
 Quotient<MP_Float> >{
 public:
-    struct To_double: public std::unary_function<Quotient<MP_Float>, double>{
+    struct To_double: public CGAL::unary_function<Quotient<MP_Float>, double>{
          inline
          double operator()(const Quotient<MP_Float>& q) const {
             return INTERN_MP_FLOAT::to_double(q);
         }
     };
     struct To_interval
-        : public std::unary_function<Quotient<MP_Float>, std::pair<double,double> > {
+        : public CGAL::unary_function<Quotient<MP_Float>, std::pair<double,double> > {
         inline
         std::pair<double,double> operator()(const Quotient<MP_Float>& q) const {
             return INTERN_MP_FLOAT::to_interval(q);
diff --git a/Number_types/include/CGAL/Mpzf.h b/Number_types/include/CGAL/Mpzf.h
index 8d645478283..4ae55981e2e 100644
--- a/Number_types/include/CGAL/Mpzf.h
+++ b/Number_types/include/CGAL/Mpzf.h
@@ -1020,14 +1020,14 @@ std::istream& operator>> (std::istream& is, Mpzf& a)
       typedef Tag_false            Is_numerical_sensitive;
 
       struct Is_zero
-	: public std::unary_function< Type, bool > {
+	: public CGAL::unary_function< Type, bool > {
 	  bool operator()( const Type& x ) const {
 	    return x.is_zero();
 	  }
 	};
 
       struct Is_one
-	: public std::unary_function< Type, bool > {
+	: public CGAL::unary_function< Type, bool > {
 	  bool operator()( const Type& x ) const {
 	    return x.is_one();
 	  }
@@ -1043,7 +1043,7 @@ std::istream& operator>> (std::istream& is, Mpzf& a)
 	};
 
       struct Square
-	: public std::unary_function< Type, Type > {
+	: public CGAL::unary_function< Type, Type > {
 	  Type operator()( const Type& x ) const {
 	    return Mpzf_square(x);
 	  }
@@ -1059,7 +1059,7 @@ std::istream& operator>> (std::istream& is, Mpzf& a)
 	};
 
       struct Sqrt
-	: public std::unary_function< Type, Type > {
+	: public CGAL::unary_function< Type, Type > {
 	  Type operator()( const Type& x) const {
 	    return Mpzf_sqrt(x);
 	  }
@@ -1082,14 +1082,14 @@ std::istream& operator>> (std::istream& is, Mpzf& a)
   template <> struct Real_embeddable_traits< Mpzf >
     : public INTERN_RET::Real_embeddable_traits_base< Mpzf , CGAL::Tag_true > {
       struct Sgn
-	: public std::unary_function< Type, ::CGAL::Sign > {
+	: public CGAL::unary_function< Type, ::CGAL::Sign > {
 	  ::CGAL::Sign operator()( const Type& x ) const {
 	    return x.sign();
 	  }
 	};
 
       struct To_double
-	: public std::unary_function< Type, double > {
+	: public CGAL::unary_function< Type, double > {
 	    double operator()( const Type& x ) const {
 	      return x.to_double();
 	    }
@@ -1105,7 +1105,7 @@ std::istream& operator>> (std::istream& is, Mpzf& a)
 	};
 
       struct To_interval
-	: public std::unary_function< Type, std::pair< double, double > > {
+	: public CGAL::unary_function< Type, std::pair< double, double > > {
 	    std::pair<double, double> operator()( const Type& x ) const {
 	      return x.to_interval();
 	    }
diff --git a/Number_types/include/CGAL/NT_converter.h b/Number_types/include/CGAL/NT_converter.h
index 495a11e6c3d..d197cd72c3d 100644
--- a/Number_types/include/CGAL/NT_converter.h
+++ b/Number_types/include/CGAL/NT_converter.h
@@ -33,7 +33,7 @@ namespace CGAL {
 
 template < class NT1, class NT2 >
 struct NT_converter
-  : public std::unary_function< NT1, NT2 >
+  : public CGAL::unary_function< NT1, NT2 >
 {
     NT2
     operator()(const NT1 &a) const
@@ -49,7 +49,7 @@ struct NT_converter
 
 template < class NT1 >
 struct NT_converter < NT1, NT1 >
-  : public std::unary_function< NT1, NT1 >
+  : public CGAL::unary_function< NT1, NT1 >
 {
     const NT1 &
     operator()(const NT1 &a) const
@@ -60,7 +60,7 @@ struct NT_converter < NT1, NT1 >
 
 template < class NT1 >
 struct NT_converter < NT1, double >
-  : public std::unary_function< NT1, double >
+  : public CGAL::unary_function< NT1, double >
 {
     double
     operator()(const NT1 &a) const
@@ -71,7 +71,7 @@ struct NT_converter < NT1, double >
 
 template <>
 struct NT_converter < double, double >
-  : public std::unary_function< double, double >
+  : public CGAL::unary_function< double, double >
 {
     const double &
     operator()(const double &a) const
@@ -82,7 +82,7 @@ struct NT_converter < double, double >
 
 template < class NT1, bool b >
 struct NT_converter < NT1, Interval_nt<b> >
-  : public std::unary_function< NT1, Interval_nt<b> >
+  : public CGAL::unary_function< NT1, Interval_nt<b> >
 {
     Interval_nt<b>
     operator()(const NT1 &a) const
@@ -93,7 +93,7 @@ struct NT_converter < NT1, Interval_nt<b> >
 
 template < bool b >
 struct NT_converter < Interval_nt<b>, Interval_nt<b> >
-  : public std::unary_function< Interval_nt<b>, Interval_nt<b> >
+  : public CGAL::unary_function< Interval_nt<b>, Interval_nt<b> >
 {
     const Interval_nt<b> &
     operator()(const Interval_nt<b> &a) const
diff --git a/Number_types/include/CGAL/Number_type_checker.h b/Number_types/include/CGAL/Number_type_checker.h
index 65c8a2b7fbd..5a4c5264b2b 100644
--- a/Number_types/include/CGAL/Number_type_checker.h
+++ b/Number_types/include/CGAL/Number_type_checker.h
@@ -401,7 +401,7 @@ operator>=(int i, const Number_type_checker<NT1, NT2, Cmp> &b)
 
 template < typename NT1, typename NT2, typename Cmp >
 class Is_valid< Number_type_checker<NT1, NT2, Cmp> >
-    : public std::unary_function< Number_type_checker<NT1, NT2, Cmp> , bool > {
+    : public CGAL::unary_function< Number_type_checker<NT1, NT2, Cmp> , bool > {
 public :
     bool operator()(const  Number_type_checker<NT1, NT2, Cmp>& a ) const {
         bool b1 = is_valid(a.n1());
@@ -434,7 +434,7 @@ private:
 public:
     //CGAL::Algebraic_structure_traits<>::Simplify
     class Simplify
-        : public std::unary_function< Type& , void > {
+        : public CGAL::unary_function< Type& , void > {
     public:
         void operator()( Type& a) const {
             typename AST1::Simplify()(a.n1());
@@ -445,7 +445,7 @@ public:
 
     //CGAL::Algebraic_structure_traits< >::Is_zero
     class Is_zero
-        : public std::unary_function< Type, bool > {
+        : public CGAL::unary_function< Type, bool > {
     public:
         bool operator()(const  Type& a ) const {
             bool b1 = typename AST1::Is_zero()(a.n1());
@@ -457,7 +457,7 @@ public:
 
     // CGAL::Algebraic_structure_traits< >::Is_one
     class Is_one
-        : public std::unary_function< Type, bool > {
+        : public CGAL::unary_function< Type, bool > {
     public:
         bool operator()(const Type& a) const {
             bool b1 = typename AST1::Is_one()(a.n1());
@@ -468,7 +468,7 @@ public:
     };
     // CGAL::Algebraic_structure_traits<  >::Square
     class Square
-        : public std::unary_function< Type , Type > {
+        : public CGAL::unary_function< Type , Type > {
     public:
         Type operator()(const Type& a) const {
             return Type(
@@ -480,7 +480,7 @@ public:
 
     // CGAL::Algebraic_structure_traits<  >::Unit_part
     class Unit_part
-        : public std::unary_function< Type , Type > {
+        : public CGAL::unary_function< Type , Type > {
     public:
         Type operator()(const Type& a) const {
             CGAL_NT_CHECK_DEBUG("AST::Unit_part");
@@ -649,7 +649,7 @@ private:
   typedef Number_type_checker<NT1, NT2, Cmp> Type;
 public:  
   class Inverse
-    : public std::unary_function< Type, Type > {
+    : public CGAL::unary_function< Type, Type > {
   public:
     Type operator()( const Type& a ) const {
       NT1 r1 = typename AST1::Inverse()(a.n1());
@@ -676,7 +676,7 @@ public:
 
     // CGAL::Algebraic_structure_traits<  >::Sqrt
     class Sqrt
-        : public std::unary_function< Type , Type > {
+        : public CGAL::unary_function< Type , Type > {
     public:
         Type operator()(const Type& a) const {
             CGAL_NT_CHECK_DEBUG("AST::Sqrt");
@@ -725,7 +725,7 @@ public:
 
     // CGAL::Real_embeddable_traits<  >::Abs
     class Abs
-        : public std::unary_function< Type , Type > {
+        : public CGAL::unary_function< Type , Type > {
     public:
         Type operator()(const Type& a) const {
             CGAL_NT_CHECK_DEBUG("RET::Abs");
@@ -737,7 +737,7 @@ public:
 
     // CGAL::Real_embeddable_traits<  >::Sign
     class Sgn
-        : public std::unary_function< Type , ::CGAL::Sign > {
+        : public CGAL::unary_function< Type , ::CGAL::Sign > {
     public:
         ::CGAL::Sign operator()(const Type& a) const {
             CGAL_NT_CHECK_DEBUG("RET::Sign");
@@ -749,7 +749,7 @@ public:
 
     // CGAL::Real_embeddable_traits<  >::Is_finite
     class Is_finite
-        : public std::unary_function< Type , bool > {
+        : public CGAL::unary_function< Type , bool > {
     public:
         bool operator()(const Type& a) const {
             CGAL_NT_CHECK_DEBUG("RET::Is_finite");
@@ -761,7 +761,7 @@ public:
 
     // CGAL::Real_embeddable_traits<  >::Is_positive
     class Is_positive
-        : public std::unary_function< Type , bool > {
+        : public CGAL::unary_function< Type , bool > {
     public:
         bool operator()(const Type& a) const {
             CGAL_NT_CHECK_DEBUG("RET::Is_positive");
@@ -773,7 +773,7 @@ public:
 
     // CGAL::Real_embeddable_traits<  >::Is_negative
     class Is_negative
-        : public std::unary_function< Type , bool > {
+        : public CGAL::unary_function< Type , bool > {
     public:
         bool operator()(const Type& a) const {
             CGAL_NT_CHECK_DEBUG("RET::Is_negative");
@@ -785,7 +785,7 @@ public:
 
     // CGAL::Real_embeddable_traits<  >::Is_zero
     class Is_zero
-        : public std::unary_function< Type , bool > {
+        : public CGAL::unary_function< Type , bool > {
     public:
         bool operator()(const Type& a) const {
             CGAL_NT_CHECK_DEBUG("RET::Is_zero");
@@ -809,7 +809,7 @@ public:
 
     // CGAL::Real_embeddable_traits<  >::To_double
     class To_double
-        : public std::unary_function< Type , double > {
+        : public CGAL::unary_function< Type , double > {
     public:
         double operator()(const Type& a) const {
             CGAL_NT_CHECK_DEBUG("RET::To_double");
@@ -821,7 +821,7 @@ public:
 
     // CGAL::Real_embeddable_traits<  >::To_interval
     class To_interval
-        : public std::unary_function< Type , std::pair<double, double> > {
+        : public CGAL::unary_function< Type , std::pair<double, double> > {
     public:
         std::pair<double, double> operator()(const Type& a) const {
             CGAL_NT_CHECK_DEBUG("RET::To_interval");
diff --git a/Number_types/include/CGAL/Quotient.h b/Number_types/include/CGAL/Quotient.h
index 2617ac92dd8..8c582ca9143 100644
--- a/Number_types/include/CGAL/Quotient.h
+++ b/Number_types/include/CGAL/Quotient.h
@@ -547,7 +547,7 @@ operator>(const Quotient<NT>& x, const CGAL_double(NT)& y)
 
 template< class NT >
 class Is_valid< Quotient<NT> >
-  : public std::unary_function< Quotient<NT>, bool > {
+  : public CGAL::unary_function< Quotient<NT>, bool > {
   public :
     bool operator()( const Quotient<NT>& x ) const {
       return is_valid(x.num) && is_valid(x.den);
@@ -606,7 +606,7 @@ namespace INTERN_QUOTIENT {
   class Sqrt_selector {
     public:
       class Sqrt
-        : public std::unary_function< NT, NT > {
+        : public CGAL::unary_function< NT, NT > {
         public:
           NT operator()( const NT& x ) const {
             CGAL_precondition(x > 0);
@@ -669,7 +669,7 @@ public:
                             >::type Sqrt;
 
     class Simplify
-      : public std::unary_function< Type&, void > {
+      : public CGAL::unary_function< Type&, void > {
       public:
         void operator()( Type& x) const {
             x.normalize();
@@ -697,7 +697,7 @@ template < class NT > class Real_embeddable_traits_quotient_base< Quotient<NT> >
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double operator()( const Type& x ) const {
         // Original global function was marked with an TODO!!
@@ -729,7 +729,7 @@ template < class NT > class Real_embeddable_traits_quotient_base< Quotient<NT> >
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
           Interval_nt<> quot =
@@ -740,7 +740,7 @@ template < class NT > class Real_embeddable_traits_quotient_base< Quotient<NT> >
     };
 
     class Is_finite
-      : public std::unary_function< Type, bool > {
+      : public CGAL::unary_function< Type, bool > {
       public:
         bool operator()( const Type& x ) const {
           return CGAL_NTS is_finite(x.num) && CGAL_NTS is_finite(x.den);
diff --git a/Number_types/include/CGAL/Sqrt_extension/Algebraic_structure_traits.h b/Number_types/include/CGAL/Sqrt_extension/Algebraic_structure_traits.h
index e9d80966768..67fb7c90b33 100644
--- a/Number_types/include/CGAL/Sqrt_extension/Algebraic_structure_traits.h
+++ b/Number_types/include/CGAL/Sqrt_extension/Algebraic_structure_traits.h
@@ -41,7 +41,7 @@ class Sqrt_extension_algebraic_structure_traits_base< Type,
     typedef CGAL::Integral_domain_without_division_tag Algebraic_category;
 
     class Simplify
-      : public std::unary_function< Type&, void > {
+      : public CGAL::unary_function< Type&, void > {
       public:
         typedef void result_type;
         typedef Type& argument_type;
@@ -159,14 +159,14 @@ class Sqrt_extension_algebraic_structure_traits_base< Type,
     typedef Field_tag Algebraic_category;
 
     class Unit_part
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
           return( x == Type(0) ? Type(1) : x );
         }
     };
   class Inverse
-    : public std::unary_function< Type, Type > {
+    : public CGAL::unary_function< Type, Type > {
   public:
     Type operator()( const Type& x ) const {
       return Type(1)/x ;
diff --git a/Number_types/include/CGAL/Sqrt_extension/Real_embeddable_traits.h b/Number_types/include/CGAL/Sqrt_extension/Real_embeddable_traits.h
index ef6e5722908..e3c588cba95 100644
--- a/Number_types/include/CGAL/Sqrt_extension/Real_embeddable_traits.h
+++ b/Number_types/include/CGAL/Sqrt_extension/Real_embeddable_traits.h
@@ -35,7 +35,7 @@ class Real_embeddable_traits< Sqrt_extension<COEFF, ROOT, ACDE_TAG,FP_TAG> >
   typedef Sqrt_extension<COEFF, ROOT, ACDE_TAG,FP_TAG> Type;
 
     class Sgn
-        : public std::unary_function< Type, ::CGAL::Sign >{
+        : public CGAL::unary_function< Type, ::CGAL::Sign >{
     public:
         ::CGAL::Sign operator()( const Type& x ) const {
             return x.sign();
@@ -63,7 +63,7 @@ class Real_embeddable_traits< Sqrt_extension<COEFF, ROOT, ACDE_TAG,FP_TAG> >
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double,double> operator()(const Type& x) const {
             return x.to_interval();
@@ -71,7 +71,7 @@ class Real_embeddable_traits< Sqrt_extension<COEFF, ROOT, ACDE_TAG,FP_TAG> >
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         // The main problem here is, that even tough the total
         // expression fits into double, one of the coefficients
diff --git a/Number_types/include/CGAL/Sqrt_extension/Sqrt_extension_type.h b/Number_types/include/CGAL/Sqrt_extension/Sqrt_extension_type.h
index e49109e2421..5b2234ed951 100644
--- a/Number_types/include/CGAL/Sqrt_extension/Sqrt_extension_type.h
+++ b/Number_types/include/CGAL/Sqrt_extension/Sqrt_extension_type.h
@@ -677,7 +677,7 @@ Sqrt_extension<NT,ROOT,ACDE_TAG,FP_TAG> square (const Sqrt_extension<NT,ROOT,ACD
 //NT_converter specializations
 template <class NT1,class ROOT1,class NT2,class ROOT2,class ACDE_TAG,class FP_TAG>
 struct NT_converter < Sqrt_extension<NT1,ROOT1,ACDE_TAG,FP_TAG> , Sqrt_extension<NT2,ROOT2,ACDE_TAG,FP_TAG> >
-  : public std::unary_function< NT1, NT2 >
+  : public CGAL::unary_function< NT1, NT2 >
 {
     Sqrt_extension<NT2,ROOT2,ACDE_TAG,FP_TAG>
     operator()(const Sqrt_extension<NT1,ROOT1,ACDE_TAG,FP_TAG> &a) const
@@ -695,7 +695,7 @@ struct NT_converter < Sqrt_extension<NT1,ROOT1,ACDE_TAG,FP_TAG> , Sqrt_extension
 
 template <class NT1,class NT2,class ROOT2,class ACDE_TAG,class FP_TAG>
 struct NT_converter < NT1 , Sqrt_extension<NT2,ROOT2,ACDE_TAG,FP_TAG> >
-  : public std::unary_function< NT1, NT2 >
+  : public CGAL::unary_function< NT1, NT2 >
 {
     Sqrt_extension<NT2,ROOT2,ACDE_TAG,FP_TAG>
     operator()(const NT1 &a) const
@@ -707,7 +707,7 @@ struct NT_converter < NT1 , Sqrt_extension<NT2,ROOT2,ACDE_TAG,FP_TAG> >
 //needed because it's a better match than the specialization <NT1,NT1>
 template <class NT1,class ROOT1,class ACDE_TAG,class FP_TAG>
 struct NT_converter < Sqrt_extension<NT1,ROOT1,ACDE_TAG,FP_TAG>, Sqrt_extension<NT1,ROOT1,ACDE_TAG,FP_TAG> >
-  : public std::unary_function< NT1, NT1 >
+  : public CGAL::unary_function< NT1, NT1 >
 {
     const Sqrt_extension<NT1,ROOT1,ACDE_TAG,FP_TAG>&
     operator()(const Sqrt_extension<NT1,ROOT1,ACDE_TAG,FP_TAG> &a) const
diff --git a/Number_types/include/CGAL/Sqrt_extension/convert_to_bfi.h b/Number_types/include/CGAL/Sqrt_extension/convert_to_bfi.h
index f54b4bad5ab..a106ed9e69c 100644
--- a/Number_types/include/CGAL/Sqrt_extension/convert_to_bfi.h
+++ b/Number_types/include/CGAL/Sqrt_extension/convert_to_bfi.h
@@ -48,7 +48,7 @@ class Sqrt_extension_bfi_cache {
   typedef typename Coercion_traits<ROOT,BFI>::Cast Cast;
   typedef typename Algebraic_structure_traits<BFI>::Sqrt Sqrt; 
 
-  struct Creator : public std::unary_function<BFI,Input> {
+  struct Creator : public CGAL::unary_function<BFI,Input> {
     BFI operator()(const Input& pair){
       return Sqrt()(Cast()(pair.second)); 
     }
diff --git a/Number_types/include/CGAL/double.h b/Number_types/include/CGAL/double.h
index 6f7339d89ff..565882d5e1d 100644
--- a/Number_types/include/CGAL/double.h
+++ b/Number_types/include/CGAL/double.h
@@ -72,7 +72,7 @@ is_nan_by_mask_double(unsigned int h, unsigned int l)
 
 template<>
 class Is_valid< double >
-  : public std::unary_function< double, bool > {
+  : public CGAL::unary_function< double, bool > {
   public :
     bool operator()( const double& x ) const{
       double d = x;
@@ -85,7 +85,7 @@ class Is_valid< double >
 
 template<>
 class Is_valid< double >
-  : public std::unary_function< double, bool > {
+  : public CGAL::unary_function< double, bool > {
   public :
     bool operator()( const double& x ) const {
 #ifdef _MSC_VER
@@ -106,7 +106,7 @@ template <> class Algebraic_structure_traits< double >
     typedef Tag_true             Is_numerical_sensitive;
 
     class Sqrt
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
           return std::sqrt( x );
@@ -152,7 +152,7 @@ template <> class Real_embeddable_traits< double >
 // GCC is faster with std::fabs().
 #if defined(__GNUG__) || defined(CGAL_MSVC_USE_STD_FABS) || defined(CGAL_USE_SSE2_FABS)
     class Abs
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
 #ifdef CGAL_USE_SSE2_FABS
@@ -166,7 +166,7 @@ template <> class Real_embeddable_traits< double >
 
 // Is_finite depends on platform
     class Is_finite
-      : public std::unary_function< Type, bool > {
+      : public CGAL::unary_function< Type, bool > {
       public :
         bool operator()( const Type& x ) const {
 #ifdef CGAL_CFG_IEEE_754_BUG
diff --git a/Number_types/include/CGAL/float.h b/Number_types/include/CGAL/float.h
index 75e5a49d669..adc9893caa4 100644
--- a/Number_types/include/CGAL/float.h
+++ b/Number_types/include/CGAL/float.h
@@ -62,7 +62,7 @@ is_nan_by_mask_float(unsigned int u)
 
 template<>
 class Is_valid< float >
-  : public std::unary_function< float, bool > {
+  : public CGAL::unary_function< float, bool > {
   public :
     bool operator()( const float& x ) const {
       float f = x;
@@ -75,7 +75,7 @@ class Is_valid< float >
 
 template<>
 class Is_valid< float >
-  : public std::unary_function< float, bool > {
+  : public CGAL::unary_function< float, bool > {
   public :
     bool operator()( const float& x ) const {
       return (x == x);
@@ -92,7 +92,7 @@ template <> class Algebraic_structure_traits< float >
     typedef Tag_true             Is_numerical_sensitive;
 
     class Sqrt
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
           return std::sqrt( x );
@@ -115,7 +115,7 @@ template <> class Real_embeddable_traits< float >
 public:
 // Is_finite depends on platform
     class Is_finite
-      : public std::unary_function< Type, bool > {
+      : public CGAL::unary_function< Type, bool > {
       public:
         bool operator()( const Type& x ) const {
 #ifdef CGAL_CFG_IEEE_754_BUG
diff --git a/Number_types/include/CGAL/int.h b/Number_types/include/CGAL/int.h
index 071b20b011e..b89862a6eee 100644
--- a/Number_types/include/CGAL/int.h
+++ b/Number_types/include/CGAL/int.h
@@ -121,7 +121,7 @@ template <> class Real_embeddable_traits< long int >
 public:
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
           return Interval_nt<true>(x).pair();
@@ -281,7 +281,7 @@ template <> class Real_embeddable_traits< unsigned long >
 public:
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
           return Interval_nt<true>(x).pair();
diff --git a/Number_types/include/CGAL/leda_bigfloat.h b/Number_types/include/CGAL/leda_bigfloat.h
index 67a322f122f..25fd5334d17 100644
--- a/Number_types/include/CGAL/leda_bigfloat.h
+++ b/Number_types/include/CGAL/leda_bigfloat.h
@@ -44,7 +44,7 @@ template <> class Algebraic_structure_traits< leda_bigfloat >
     typedef Tag_true            Is_numerical_sensitive;
 
     class Sqrt
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
           return CGAL_LEDA_SCOPE::sqrt( x );
@@ -72,7 +72,7 @@ template <> class Real_embeddable_traits< leda_bigfloat >
 public:
   
     class Abs
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
             return CGAL_LEDA_SCOPE::abs( x );
@@ -80,7 +80,7 @@ public:
     };
 
     class Sgn
-      : public std::unary_function< Type, ::CGAL::Sign > {
+      : public CGAL::unary_function< Type, ::CGAL::Sign > {
       public:
         ::CGAL::Sign operator()( const Type& x ) const {
           return (::CGAL::Sign) CGAL_LEDA_SCOPE::sign( x );
@@ -101,7 +101,7 @@ public:
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double operator()( const Type& x ) const {
           return x.to_double();
@@ -109,7 +109,7 @@ public:
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
 
@@ -123,7 +123,7 @@ public:
     };
 
     class Is_finite
-      : public std::unary_function< Type, bool > {
+      : public CGAL::unary_function< Type, bool > {
       public:
         bool operator()( const Type& x )  const {
           return !( CGAL_LEDA_SCOPE::isInf(x) || CGAL_LEDA_SCOPE::isNaN(x) );
@@ -133,7 +133,7 @@ public:
 
 template<>
 class Is_valid< leda_bigfloat >
-  : public std::unary_function< leda_bigfloat, bool > {
+  : public CGAL::unary_function< leda_bigfloat, bool > {
   public :
     bool operator()( const leda_bigfloat& x ) const {
       return !( CGAL_LEDA_SCOPE::isNaN(x) );
diff --git a/Number_types/include/CGAL/leda_bigfloat_interval.h b/Number_types/include/CGAL/leda_bigfloat_interval.h
index 71dacbe3dfb..cf9f1f6efa9 100644
--- a/Number_types/include/CGAL/leda_bigfloat_interval.h
+++ b/Number_types/include/CGAL/leda_bigfloat_interval.h
@@ -175,7 +175,7 @@ public:
     typedef Tag_true            Is_numerical_sensitive;
 
     class Sqrt
-        : public std::unary_function< Type, Type > {
+        : public CGAL::unary_function< Type, Type > {
     public:
         Type operator()( const Type& x ) const {
             return ::boost::numeric::sqrt(x);
@@ -188,7 +188,7 @@ template <> class Real_embeddable_traits< leda_bigfloat_interval >
 public:
   
     class Abs
-        : public std::unary_function< Type, Type > {
+        : public CGAL::unary_function< Type, Type > {
     public:
         Type operator()( const Type& x ) const {
             return ::boost::numeric::abs(x);
@@ -196,7 +196,7 @@ public:
     };
 
     class To_double
-        : public std::unary_function< Type, double > {
+        : public CGAL::unary_function< Type, double > {
     public:
         double operator()( const Type& x ) const {
             return CGAL::to_double(::boost::numeric::median(x));
@@ -204,7 +204,7 @@ public:
     };
 
     class To_interval
-        : public std::unary_function< Type, std::pair< double, double > > {
+        : public CGAL::unary_function< Type, std::pair< double, double > > {
     public:
         std::pair<double, double> operator()( const Type& x ) const {            
             std::pair<double, double> lower_I(CGAL::to_interval(x.lower()));
@@ -320,49 +320,49 @@ public:
         }
     };
 
-    struct Lower :public std::unary_function<Interval,Bound>{
+    struct Lower :public CGAL::unary_function<Interval,Bound>{
         Bound operator()( const Interval& a ) const {
             return a.lower();
         }
     };
 
-    struct Upper :public std::unary_function<Interval,Bound>{
+    struct Upper :public CGAL::unary_function<Interval,Bound>{
         Bound operator()( const Interval& a ) const {
             return a.upper();
         }
     };
 
-    struct Width :public std::unary_function<Interval,Bound>{
+    struct Width :public CGAL::unary_function<Interval,Bound>{
         Bound operator()( const Interval& a ) const {
             return ::boost::numeric::width(a);
         }
     };
 
-    struct Median :public std::unary_function<Interval,Bound>{
+    struct Median :public CGAL::unary_function<Interval,Bound>{
         Bound operator()( const Interval& a ) const {
             return ::boost::numeric::median(a);
         }
     };
     
-    struct Norm :public std::unary_function<Interval,Bound>{
+    struct Norm :public CGAL::unary_function<Interval,Bound>{
         Bound operator()( const Interval& a ) const {
             return ::boost::numeric::norm(a);
         }
     };
 
-    struct Empty :public std::unary_function<Interval,bool>{
+    struct Empty :public CGAL::unary_function<Interval,bool>{
         bool operator()( const Interval& a ) const {
             return ::boost::numeric::empty(a);
         }
     };
 
-    struct Singleton :public std::unary_function<Interval,bool>{
+    struct Singleton :public CGAL::unary_function<Interval,bool>{
         bool operator()( const Interval& a ) const {
             return ::boost::numeric::singleton(a);
         }
     };
 
-    struct Zero_in :public std::unary_function<Interval,bool>{
+    struct Zero_in :public CGAL::unary_function<Interval,bool>{
         bool operator()( const Interval& a ) const {
             return ::boost::numeric::in_zero(a);
         }
@@ -423,7 +423,7 @@ public:
   typedef CGAL::Tag_true Is_bigfloat_interval; 
   
 
-//   struct Get_significant_bits : public std::unary_function<NT,long>{
+//   struct Get_significant_bits : public CGAL::unary_function<NT,long>{
 //         long operator()( NT x) const {
 //             CGAL_precondition(!Singleton()(x));
 //             leda::bigfloat lower = x.lower();
@@ -443,7 +443,7 @@ public:
 //     };
 
     
-  struct Relative_precision: public std::unary_function<NT,long>{
+  struct Relative_precision: public CGAL::unary_function<NT,long>{
     long operator()(const NT& x) const {
       CGAL_precondition(!Singleton()(x));
       CGAL_precondition(!CGAL::zero_in(x));
@@ -454,7 +454,7 @@ public:
     }
   };
   
-  struct Set_precision : public std::unary_function<long,long> {
+  struct Set_precision : public CGAL::unary_function<long,long> {
     long operator()( long prec ) const {
       return BF::set_precision(prec); 
     }
diff --git a/Number_types/include/CGAL/leda_integer.h b/Number_types/include/CGAL/leda_integer.h
index 22ed66a0172..2beed2f9613 100644
--- a/Number_types/include/CGAL/leda_integer.h
+++ b/Number_types/include/CGAL/leda_integer.h
@@ -117,7 +117,7 @@ template <> class Algebraic_structure_traits< leda_integer >
 //     };
 
     class Sqrt
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
           return CGAL_LEDA_SCOPE::sqrt( x );
@@ -130,7 +130,7 @@ template <> class Real_embeddable_traits< leda_integer >
   public:
   
     class Abs
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
             return CGAL_LEDA_SCOPE::abs( x );
@@ -138,7 +138,7 @@ template <> class Real_embeddable_traits< leda_integer >
     };
 
     class Sgn
-      : public std::unary_function< Type, ::CGAL::Sign > {
+      : public CGAL::unary_function< Type, ::CGAL::Sign > {
       public:
         ::CGAL::Sign operator()( const Type& x ) const {
             return (::CGAL::Sign) CGAL_LEDA_SCOPE::sign( x );
@@ -157,7 +157,7 @@ template <> class Real_embeddable_traits< leda_integer >
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double operator()( const Type& x ) const {
           return x.to_double();
@@ -165,7 +165,7 @@ template <> class Real_embeddable_traits< leda_integer >
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
       std::pair<double, double> operator()( const Type& x ) const {
         leda::bigfloat h(x);
diff --git a/Number_types/include/CGAL/leda_rational.h b/Number_types/include/CGAL/leda_rational.h
index 13bfb7cd0eb..0bb84be3279 100644
--- a/Number_types/include/CGAL/leda_rational.h
+++ b/Number_types/include/CGAL/leda_rational.h
@@ -63,7 +63,7 @@ template <> class Algebraic_structure_traits< leda_rational >
 //                                                                 Is_square;
 
     class Simplify
-      : public std::unary_function< Type&, void > {
+      : public CGAL::unary_function< Type&, void > {
       public:
         void operator()( Type& x) const {
             x.normalize();
@@ -77,7 +77,7 @@ template <> class Real_embeddable_traits< leda_rational >
   public:
   
     class Abs
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
             return CGAL_LEDA_SCOPE::abs( x );
@@ -85,7 +85,7 @@ template <> class Real_embeddable_traits< leda_rational >
     };
 
     class Sgn
-      : public std::unary_function< Type, ::CGAL::Sign > {
+      : public CGAL::unary_function< Type, ::CGAL::Sign > {
       public:
         ::CGAL::Sign operator()( const Type& x ) const {
             return (::CGAL::Sign) CGAL_LEDA_SCOPE::sign( x );
@@ -104,7 +104,7 @@ template <> class Real_embeddable_traits< leda_rational >
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double operator()( const Type& x ) const {
           return x.to_double();
@@ -112,7 +112,7 @@ template <> class Real_embeddable_traits< leda_rational >
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
 
diff --git a/Number_types/include/CGAL/leda_real.h b/Number_types/include/CGAL/leda_real.h
index 3766b5fcc6b..66039685721 100644
--- a/Number_types/include/CGAL/leda_real.h
+++ b/Number_types/include/CGAL/leda_real.h
@@ -50,7 +50,7 @@ template <> class Algebraic_structure_traits< leda_real >
     typedef Tag_true           Is_numerical_sensitive;
 
     class Sqrt
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
           return CGAL_LEDA_SCOPE::sqrt( x );
@@ -109,7 +109,7 @@ template <> class Real_embeddable_traits< leda_real >
   : public INTERN_RET::Real_embeddable_traits_base< leda_real , CGAL::Tag_true > {
   public:
     class Abs
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
             return CGAL_LEDA_SCOPE::abs( x );
@@ -117,7 +117,7 @@ template <> class Real_embeddable_traits< leda_real >
     };
 
     class Sgn
-      : public std::unary_function< Type, ::CGAL::Sign > {
+      : public CGAL::unary_function< Type, ::CGAL::Sign > {
       public:
         ::CGAL::Sign operator()( const Type& x ) const {
           return (::CGAL::Sign) CGAL_LEDA_SCOPE::sign( x );
@@ -139,7 +139,7 @@ template <> class Real_embeddable_traits< leda_real >
     };
 
     class To_double
-      : public std::unary_function< Type, double > {
+      : public CGAL::unary_function< Type, double > {
       public:
         double operator()( const Type& x ) const {
           // this call is required to get reasonable values for the double
@@ -150,7 +150,7 @@ template <> class Real_embeddable_traits< leda_real >
     };
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
 
diff --git a/Number_types/include/CGAL/long_double.h b/Number_types/include/CGAL/long_double.h
index 86cee88a676..5365c1bd651 100644
--- a/Number_types/include/CGAL/long_double.h
+++ b/Number_types/include/CGAL/long_double.h
@@ -63,7 +63,7 @@ is_nan_by_mask_long_double(unsigned int h, unsigned int l)
 
 template<>
 class Is_valid< long double >
-  : public std::unary_function< long double, bool > {
+  : public CGAL::unary_function< long double, bool > {
   public :
     bool operator()( const long double& x ) const {
       double d = x;
@@ -76,7 +76,7 @@ class Is_valid< long double >
 
 template<>
 class Is_valid< long double >
-  : public std::unary_function< long double, bool > {
+  : public CGAL::unary_function< long double, bool > {
   public :
     bool operator()( const long double& x ) const {
       return (x == x);
@@ -96,7 +96,7 @@ template <> class Algebraic_structure_traits< long double >
     typedef Tag_true             Is_numerical_sensitive;
 
     class Sqrt
-      : public std::unary_function< Type, Type > {
+      : public CGAL::unary_function< Type, Type > {
       public:
         Type operator()( const Type& x ) const {
           return std::sqrt( x );
@@ -121,7 +121,7 @@ template <> class Real_embeddable_traits< long double >
   public:
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
           // The conversion long double to double does not always follow the
@@ -146,7 +146,7 @@ template <> class Real_embeddable_traits< long double >
 
 // Is_finite depends on platform
     class Is_finite
-      : public std::unary_function< Type, bool > {
+      : public CGAL::unary_function< Type, bool > {
       public:
         bool operator()( const Type& x ) const {
 #ifdef CGAL_CFG_IEEE_754_BUG
diff --git a/Number_types/include/CGAL/long_long.h b/Number_types/include/CGAL/long_long.h
index 18fd669d80e..c4779024861 100644
--- a/Number_types/include/CGAL/long_long.h
+++ b/Number_types/include/CGAL/long_long.h
@@ -66,7 +66,7 @@ template <> class Real_embeddable_traits< long long int >
   public:
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
           return Interval_nt<true>(x).pair();
@@ -80,7 +80,7 @@ template <> class Real_embeddable_traits< unsigned long long >
   public:
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
           return Interval_nt<true>(x).pair();
@@ -108,7 +108,7 @@ template <> class Real_embeddable_traits< boost::int128_type >
   public:
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
 	  return (Interval_nt<>((double)x)+Interval_nt<>::smallest()).pair();
@@ -122,7 +122,7 @@ template <> class Real_embeddable_traits< boost::uint128_type >
   public:
 
     class To_interval
-      : public std::unary_function< Type, std::pair< double, double > > {
+      : public CGAL::unary_function< Type, std::pair< double, double > > {
       public:
         std::pair<double, double> operator()( const Type& x ) const {
 	  return (Interval_nt<>((double)x)+Interval_nt<>::smallest()).pair();
diff --git a/Number_types/include/CGAL/mpq_class.h b/Number_types/include/CGAL/mpq_class.h
index 6a0de04cf8f..5f60b9640aa 100644
--- a/Number_types/include/CGAL/mpq_class.h
+++ b/Number_types/include/CGAL/mpq_class.h
@@ -56,7 +56,7 @@ class Algebraic_structure_traits< mpq_class  >
     typedef Tag_true            Is_exact;
     typedef Tag_false           Is_numerical_sensitive;
 
-    struct Is_zero: public std::unary_function< mpq_class , bool > {
+    struct Is_zero: public CGAL::unary_function< mpq_class , bool > {
         template <class T, class U>
         bool operator()( const ::__gmp_expr< T , U >& x) const {
             CGAL_CHECK_GMP_EXPR;
@@ -64,7 +64,7 @@ class Algebraic_structure_traits< mpq_class  >
         }
     };
 
-    struct Is_one: public std::unary_function< mpq_class , bool > {
+    struct Is_one: public CGAL::unary_function< mpq_class , bool > {
         template <typename T, typename U>
         bool operator()( const ::__gmp_expr< T , U >& x) const {
             CGAL_CHECK_GMP_EXPR;
@@ -72,20 +72,20 @@ class Algebraic_structure_traits< mpq_class  >
         }
     };
 
-    struct Simplify: public std::unary_function< mpq_class , void > {
+    struct Simplify: public CGAL::unary_function< mpq_class , void > {
         void operator()( mpq_class& x) const {
             // do nothing because x is already canonical?
             x.canonicalize();
         }
     };
 
-    struct Square: public std::unary_function< mpq_class , mpq_class > {
+    struct Square: public CGAL::unary_function< mpq_class , mpq_class > {
         mpq_class operator()( const mpq_class& x) const {
             return x*x;
         }
     };
 
-    struct Unit_part: public std::unary_function< mpq_class , mpq_class > {
+    struct Unit_part: public CGAL::unary_function< mpq_class , mpq_class > {
         mpq_class operator()( const mpq_class& x) const {
             return( x == 0) ? mpq_class(1) : x;
         }
@@ -130,14 +130,14 @@ class Real_embeddable_traits< mpq_class >
   : public INTERN_RET::Real_embeddable_traits_base< mpq_class , CGAL::Tag_true > {
   public:
 
-    struct Is_zero: public std::unary_function< mpq_class , bool > {
+    struct Is_zero: public CGAL::unary_function< mpq_class , bool > {
         template <typename T, typename U>
         bool operator()( const ::__gmp_expr< T , U >& x) const {
             CGAL_CHECK_GMP_EXPR;
             return ::sgn(x) == 0;
         }
     };
-    struct Is_finite: public std::unary_function<mpq_class,bool> {
+    struct Is_finite: public CGAL::unary_function<mpq_class,bool> {
         template <typename T, typename U>
         bool operator()( const ::__gmp_expr< T , U >&) const {
             CGAL_CHECK_GMP_EXPR;
@@ -145,7 +145,7 @@ class Real_embeddable_traits< mpq_class >
         }
     };
 
-    struct Is_positive: public std::unary_function< mpq_class , bool > {
+    struct Is_positive: public CGAL::unary_function< mpq_class , bool > {
         template <typename T, typename U>
         bool operator()( const ::__gmp_expr< T , U >& x) const {
             CGAL_CHECK_GMP_EXPR;
@@ -153,7 +153,7 @@ class Real_embeddable_traits< mpq_class >
         }
     };
 
-    struct Is_negative: public std::unary_function< mpq_class , bool > {
+    struct Is_negative: public CGAL::unary_function< mpq_class , bool > {
         template <typename T, typename U>
         bool operator()( const ::__gmp_expr< T , U >& x) const {
             CGAL_CHECK_GMP_EXPR;
@@ -161,7 +161,7 @@ class Real_embeddable_traits< mpq_class >
         }
     };
 
-    struct Abs: public std::unary_function< mpq_class , mpq_class > {
+    struct Abs: public CGAL::unary_function< mpq_class , mpq_class > {
         template <typename T, typename U>
         mpq_class operator()( const ::__gmp_expr< T , U >& x) const {
             CGAL_CHECK_GMP_EXPR;
@@ -170,7 +170,7 @@ class Real_embeddable_traits< mpq_class >
     };
 
     struct Sgn
-        : public std::unary_function< mpq_class, ::CGAL::Sign > {
+        : public CGAL::unary_function< mpq_class, ::CGAL::Sign > {
     public:
         template <typename T, typename U>
         ::CGAL::Sign
@@ -196,7 +196,7 @@ class Real_embeddable_traits< mpq_class >
     };
 
     struct To_double
-        : public std::unary_function< mpq_class, double > {
+        : public CGAL::unary_function< mpq_class, double > {
         double operator()( const mpq_class& x ) const {
             return x.get_d();
         }
@@ -204,7 +204,7 @@ class Real_embeddable_traits< mpq_class >
 
     struct To_interval
 
-        : public std::unary_function< mpq_class, std::pair< double, double > > {
+        : public CGAL::unary_function< mpq_class, std::pair< double, double > > {
         std::pair<double, double>
         operator()( const mpq_class& x ) const {
             mpfr_t y;
diff --git a/Number_types/include/CGAL/mpz_class.h b/Number_types/include/CGAL/mpz_class.h
index 8003e6725ea..5b334827637 100644
--- a/Number_types/include/CGAL/mpz_class.h
+++ b/Number_types/include/CGAL/mpz_class.h
@@ -57,7 +57,7 @@ public:
     typedef Tag_true            Is_exact;
     typedef Tag_false           Is_numerical_sensitive;
 
-    struct Is_zero: public std::unary_function< mpz_class , bool > {
+    struct Is_zero: public CGAL::unary_function< mpz_class , bool > {
         template <typename T, typename U>
         bool operator()( const ::__gmp_expr< T , U >& x) const {
             CGAL_CHECK_GMP_EXPR;
@@ -65,7 +65,7 @@ public:
         }
     };
 
-    struct Is_one: public std::unary_function< mpz_class , bool > {
+    struct Is_one: public CGAL::unary_function< mpz_class , bool > {
         template <typename T, typename U>
         bool operator()( const ::__gmp_expr< T , U >& x) const {
             CGAL_CHECK_GMP_EXPR;
@@ -73,20 +73,20 @@ public:
         }
     };
 
-    struct Simplify: public std::unary_function< mpz_class , void > {
+    struct Simplify: public CGAL::unary_function< mpz_class , void > {
         template <class T, class U>
         void operator()( const ::__gmp_expr< T ,U >&) const {
             CGAL_CHECK_GMP_EXPR;
         }
     };
 
-    struct Square: public std::unary_function< mpz_class , mpz_class > {
+    struct Square: public CGAL::unary_function< mpz_class , mpz_class > {
         mpz_class operator()( const mpz_class& x) const {
             return x*x;
         }
     };
 
-    struct Unit_part: public std::unary_function< mpz_class , mpz_class > {
+    struct Unit_part: public CGAL::unary_function< mpz_class , mpz_class > {
         mpz_class operator()( const mpz_class& x) const {
             return (x < 0) ? -1 : 1;
         }
@@ -165,7 +165,7 @@ public:
     };
 
 
-    struct Sqrt: public std::unary_function< mpz_class , mpz_class > {
+    struct Sqrt: public CGAL::unary_function< mpz_class , mpz_class > {
         template <typename T, typename U>
         mpz_class operator()( const ::__gmp_expr< T , U >& x) const {
             CGAL_CHECK_GMP_EXPR;
@@ -196,14 +196,14 @@ class Real_embeddable_traits< mpz_class  >
     : public INTERN_RET::Real_embeddable_traits_base< mpz_class , CGAL::Tag_true > {
 public:
 
-    struct Is_zero: public std::unary_function< mpz_class , bool > {
+    struct Is_zero: public CGAL::unary_function< mpz_class , bool > {
         template <typename T, typename U>
         bool operator()( const ::__gmp_expr< T , U >& x) const {
             CGAL_CHECK_GMP_EXPR;
             return ::sgn(x) == 0;
         }
     };
-    struct Is_finite: public std::unary_function<mpz_class,bool> {
+    struct Is_finite: public CGAL::unary_function<mpz_class,bool> {
         template <typename T, typename U>
         bool operator()( const ::__gmp_expr< T , U >& ) const {
             CGAL_CHECK_GMP_EXPR;
@@ -211,7 +211,7 @@ public:
         }
     };
 
-    struct Is_positive: public std::unary_function< mpz_class , bool > {
+    struct Is_positive: public CGAL::unary_function< mpz_class , bool > {
         template <typename T, typename U>
         bool operator()( const ::__gmp_expr< T , U >& x) const {
             CGAL_CHECK_GMP_EXPR;
@@ -219,7 +219,7 @@ public:
         }
     };
 
-    struct Is_negative: public std::unary_function< mpz_class , bool > {
+    struct Is_negative: public CGAL::unary_function< mpz_class , bool > {
         template <typename T, typename U>
         bool operator()( const ::__gmp_expr< T , U >& x) const {
             CGAL_CHECK_GMP_EXPR;
@@ -227,7 +227,7 @@ public:
         }
     };
 
-    struct Abs: public std::unary_function< mpz_class , mpz_class > {
+    struct Abs: public CGAL::unary_function< mpz_class , mpz_class > {
         template <typename T, typename U>
         mpz_class operator()( const ::__gmp_expr< T , U >& x) const {
             CGAL_CHECK_GMP_EXPR;
@@ -236,7 +236,7 @@ public:
     };
 
     struct Sgn
-        : public std::unary_function< mpz_class, ::CGAL::Sign > {
+        : public CGAL::unary_function< mpz_class, ::CGAL::Sign > {
     public:
         template <typename T, typename U>
         ::CGAL::Sign operator()( const ::__gmp_expr< T , U >& x ) const {
@@ -260,7 +260,7 @@ public:
     };
 
     struct To_double
-        : public std::unary_function< mpz_class, double > {
+        : public CGAL::unary_function< mpz_class, double > {
         double operator()( const mpz_class& x ) const {
             return x.get_d();
         }
@@ -268,7 +268,7 @@ public:
 
     struct To_interval
 
-        : public std::unary_function< mpz_class, std::pair< double, double > > {
+        : public CGAL::unary_function< mpz_class, std::pair< double, double > > {
         std::pair<double, double>
         operator()( const mpz_class& x ) const {
             mpfr_t y;
diff --git a/Number_types/include/CGAL/utils_classes.h b/Number_types/include/CGAL/utils_classes.h
index d623bf1e2a5..b93c3012f36 100644
--- a/Number_types/include/CGAL/utils_classes.h
+++ b/Number_types/include/CGAL/utils_classes.h
@@ -19,7 +19,6 @@
 #define CGAL_UTILS_CLASSES_H
 
 #include <CGAL/config.h>
-#include <functional> // for std::binary_function
 
 #ifdef CGAL_USE_SSE2_MAX
 #include <CGAL/sse2.h>
@@ -263,7 +262,7 @@ struct Min<double> :public std::binary_function< double, double, double > {
 };
 template< class T >
 class Is_valid
-  : public std::unary_function< T, bool > {
+  : public CGAL::unary_function< T, bool > {
   public:
     bool operator()( const T& ) const {
       return true;
diff --git a/Number_types/test/Number_types/checked_NT.h b/Number_types/test/Number_types/checked_NT.h
index e20cc263657..eecd8977f1c 100644
--- a/Number_types/test/Number_types/checked_NT.h
+++ b/Number_types/test/Number_types/checked_NT.h
@@ -48,7 +48,7 @@ template<class NT1,class NT2> struct Algebraic_structure_traits<checked_NT<NT1,N
   typedef typename AST1::Is_numerical_sensitive Is_numerical_sensitive;
   typedef checked_NT<NT1,NT2> Type;
   struct Is_zero
-    : public std::unary_function< Type, bool > {
+    : public CGAL::unary_function< Type, bool > {
       bool operator()( const Type& x ) const {
 	bool a=CGAL::is_zero(x.x1);
 	bool b=CGAL::is_zero(x.x2);
@@ -57,7 +57,7 @@ template<class NT1,class NT2> struct Algebraic_structure_traits<checked_NT<NT1,N
       }
     };
   struct Is_one
-    : public std::unary_function< Type, bool > {
+    : public CGAL::unary_function< Type, bool > {
       bool operator()( const Type& x ) const {
 	bool a=CGAL::is_one(x.x1);
 	bool b=CGAL::is_one(x.x2);
@@ -66,7 +66,7 @@ template<class NT1,class NT2> struct Algebraic_structure_traits<checked_NT<NT1,N
       }
     };
   struct Is_square
-    : public std::unary_function< Type, bool > {
+    : public CGAL::unary_function< Type, bool > {
       bool operator()( const Type& x ) const {
 	bool a=CGAL::is_square(x.x1);
 	bool b=CGAL::is_square(x.x2);
@@ -75,7 +75,7 @@ template<class NT1,class NT2> struct Algebraic_structure_traits<checked_NT<NT1,N
       }
     };
   struct Square
-    : public std::unary_function< Type, Type > {
+    : public CGAL::unary_function< Type, Type > {
       Type operator()( const Type& x ) const {
 	return Type(typename Type::pieces(),CGAL::square(x.x1),CGAL::square(x.x2));
       }
@@ -110,7 +110,7 @@ template<class NT1,class NT2>struct Real_embeddable_traits<checked_NT<NT1,NT2> >
 : INTERN_RET::Real_embeddable_traits_base<checked_NT<NT1,NT2>, typename Real_embeddable_traits<NT1>::Is_real_embeddable> {
   typedef checked_NT<NT1,NT2> Type;
   struct Sgn
-    : public std::unary_function< Type, ::CGAL::Sign > {
+    : public CGAL::unary_function< Type, ::CGAL::Sign > {
       ::CGAL::Sign operator()( const Type& x ) const {
 	::CGAL::Sign a=CGAL::sign(x.x1);
 	::CGAL::Sign b=CGAL::sign(x.x2);
@@ -119,13 +119,13 @@ template<class NT1,class NT2>struct Real_embeddable_traits<checked_NT<NT1,NT2> >
       }
     };
   struct To_double
-    : public std::unary_function< Type, double > {
+    : public CGAL::unary_function< Type, double > {
       double operator()( const Type& x ) const {
 	return x.to_double();
       }
     };
   struct To_interval
-    : public std::unary_function< Type, std::pair< double, double > > {
+    : public CGAL::unary_function< Type, std::pair< double, double > > {
       std::pair<double, double> operator()( const Type& x ) const {
 	return x.to_interval();
       }
diff --git a/Periodic_2_triangulation_2/examples/Periodic_2_triangulation_2/p2t2_info_insert_with_transform_iterator_2.cpp b/Periodic_2_triangulation_2/examples/Periodic_2_triangulation_2/p2t2_info_insert_with_transform_iterator_2.cpp
index f5e6857104e..223fc38446e 100644
--- a/Periodic_2_triangulation_2/examples/Periodic_2_triangulation_2/p2t2_info_insert_with_transform_iterator_2.cpp
+++ b/Periodic_2_triangulation_2/examples/Periodic_2_triangulation_2/p2t2_info_insert_with_transform_iterator_2.cpp
@@ -19,7 +19,7 @@ typedef Delaunay::Point                                             Point;
 //the unsigned integer is incremented at each call to
 //operator()
 struct Auto_count
-  : public std::unary_function<const Point&, std::pair<Point, unsigned> >
+  : public CGAL::unary_function<const Point&, std::pair<Point, unsigned> >
 {
   mutable unsigned i;
   Auto_count() : i(0) {}
diff --git a/Periodic_3_triangulation_3/include/CGAL/Periodic_3_regular_triangulation_3.h b/Periodic_3_triangulation_3/include/CGAL/Periodic_3_regular_triangulation_3.h
index ea0277a4d5b..2ed03ac5f00 100644
--- a/Periodic_3_triangulation_3/include/CGAL/Periodic_3_regular_triangulation_3.h
+++ b/Periodic_3_triangulation_3/include/CGAL/Periodic_3_regular_triangulation_3.h
@@ -184,7 +184,7 @@ public:
 
 private:
   struct Cell_handle_hash
-    : public std::unary_function<Cell_handle, std::size_t>
+    : public CGAL::unary_function<Cell_handle, std::size_t>
   {
     std::size_t operator()(const Cell_handle& ch) const {
       return boost::hash<typename Cell_handle::pointer>()(&*ch);
diff --git a/Point_set_processing_3/include/CGAL/estimate_scale.h b/Point_set_processing_3/include/CGAL/estimate_scale.h
index 351bbadb140..387503e54a7 100644
--- a/Point_set_processing_3/include/CGAL/estimate_scale.h
+++ b/Point_set_processing_3/include/CGAL/estimate_scale.h
@@ -66,7 +66,7 @@ class Quick_multiscale_approximate_knn_distance<Kernel, typename Kernel::Point_3
   typedef typename Neighbor_search::iterator Iterator;
 
   template <typename ValueType, typename PointPMap>
-  struct Pmap_unary_function : public std::unary_function<ValueType, typename Kernel::Point_3>
+  struct Pmap_unary_function : public CGAL::unary_function<ValueType, typename Kernel::Point_3>
   {
     PointPMap point_pmap;
     Pmap_unary_function (PointPMap point_pmap) : point_pmap (point_pmap) { }
@@ -222,7 +222,7 @@ class Quick_multiscale_approximate_knn_distance<Kernel, typename Kernel::Point_2
   typedef typename Point_set::Vertex_handle Vertex_handle;
 
   template <typename ValueType, typename PointPMap>
-  struct Pmap_unary_function : public std::unary_function<ValueType, typename Kernel::Point_2>
+  struct Pmap_unary_function : public CGAL::unary_function<ValueType, typename Kernel::Point_2>
   {
     PointPMap point_pmap;
     Pmap_unary_function (PointPMap point_pmap) : point_pmap (point_pmap) { }
diff --git a/Poisson_surface_reconstruction_3/include/CGAL/Poisson_implicit_surface_3.h b/Poisson_surface_reconstruction_3/include/CGAL/Poisson_implicit_surface_3.h
index 731eca537b7..853c59c2766 100644
--- a/Poisson_surface_reconstruction_3/include/CGAL/Poisson_implicit_surface_3.h
+++ b/Poisson_surface_reconstruction_3/include/CGAL/Poisson_implicit_surface_3.h
@@ -128,7 +128,7 @@ namespace CGAL {
 
   // non documented class
   template <typename FT, typename Point>
-  class Poisson_implicit_function_wrapper : public std::unary_function<Point, FT> 
+  class Poisson_implicit_function_wrapper : public CGAL::unary_function<Point, FT> 
   {
     typedef FT (*Poisson_implicit_function)(FT, FT, FT);
 
diff --git a/Polygon_mesh_processing/benchmark/Polygon_mesh_processing/polygon_mesh_slicer.cpp b/Polygon_mesh_processing/benchmark/Polygon_mesh_processing/polygon_mesh_slicer.cpp
index 88cfd93b77c..4abd5c247a7 100644
--- a/Polygon_mesh_processing/benchmark/Polygon_mesh_processing/polygon_mesh_slicer.cpp
+++ b/Polygon_mesh_processing/benchmark/Polygon_mesh_processing/polygon_mesh_slicer.cpp
@@ -44,7 +44,7 @@ typedef CGAL::Timer Timer;
 
 template <typename PolygonMesh>
  class Point_projector
-  : public std::unary_function<typename boost::graph_traits<PolygonMesh>::vertex_descriptor,
+  : public CGAL::unary_function<typename boost::graph_traits<PolygonMesh>::vertex_descriptor,
                                typename boost::property_traits<typename boost::property_map<PolygonMesh, CGAL::vertex_point_t>::type>::value_type> {
   typedef typename boost::property_map<PolygonMesh, CGAL::vertex_point_t>::type Ppmap;
 public:
diff --git a/Polygon_mesh_processing/test/Polygon_mesh_processing/test_pmp_distance.cpp b/Polygon_mesh_processing/test/Polygon_mesh_processing/test_pmp_distance.cpp
index 0d41a8e71b8..ca4ca98e7fe 100644
--- a/Polygon_mesh_processing/test/Polygon_mesh_processing/test_pmp_distance.cpp
+++ b/Polygon_mesh_processing/test/Polygon_mesh_processing/test_pmp_distance.cpp
@@ -210,7 +210,7 @@ struct Real_embeddable_traits< Custom_traits_Hausdorff::FT >
   : public INTERN_RET::Real_embeddable_traits_base< Custom_traits_Hausdorff::FT , CGAL::Tag_true>
 {
   class To_double
-    : public std::unary_function< Custom_traits_Hausdorff::FT, double > {
+    : public CGAL::unary_function< Custom_traits_Hausdorff::FT, double > {
     public:
       double operator()( const Custom_traits_Hausdorff::FT&  ) const { return 0; }
   };
diff --git a/Polyhedron/demo/Polyhedron/Plugins/Point_set/Surface_reconstruction_plugin.cpp b/Polyhedron/demo/Polyhedron/Plugins/Point_set/Surface_reconstruction_plugin.cpp
index 0bbb5c7e9ea..04a5bc431c7 100644
--- a/Polyhedron/demo/Polyhedron/Plugins/Point_set/Surface_reconstruction_plugin.cpp
+++ b/Polyhedron/demo/Polyhedron/Plugins/Point_set/Surface_reconstruction_plugin.cpp
@@ -602,7 +602,7 @@ namespace SurfaceReconstruction
   }
 
   struct Point_set_make_pair_point_index
-    : public std::unary_function<const Point_set::Index&, std::pair<Kernel::Point_3, std::size_t> >
+    : public CGAL::unary_function<const Point_set::Index&, std::pair<Kernel::Point_3, std::size_t> >
   {
     const Point_set& point_set;
     Point_set_make_pair_point_index (const Point_set& point_set) : point_set (point_set) { }
diff --git a/Polynomial/include/CGAL/Polynomial/Algebraic_structure_traits.h b/Polynomial/include/CGAL/Polynomial/Algebraic_structure_traits.h
index 0c7e50b83ec..0742578c7e5 100644
--- a/Polynomial/include/CGAL/Polynomial/Algebraic_structure_traits.h
+++ b/Polynomial/include/CGAL/Polynomial/Algebraic_structure_traits.h
@@ -87,7 +87,7 @@ class Polynomial_algebraic_structure_traits_base< POLY,
     typedef Integral_domain_without_division_tag Algebraic_category;
     
     class Simplify 
-      : public std::unary_function< POLY&, void > {
+      : public CGAL::unary_function< POLY&, void > {
       public:
         void operator()( POLY& p ) const {
           p.simplify_coefficients();
@@ -95,7 +95,7 @@ class Polynomial_algebraic_structure_traits_base< POLY,
     };
     
     class Unit_part 
-      : public std::unary_function< POLY, POLY > {
+      : public CGAL::unary_function< POLY, POLY > {
       public:
         POLY operator()( const POLY& x ) const {
           return POLY( x.unit_part() );
@@ -103,7 +103,7 @@ class Polynomial_algebraic_structure_traits_base< POLY,
     };
   
   class Is_zero
-    : public std::unary_function< POLY, bool > {
+    : public CGAL::unary_function< POLY, bool > {
   public:
     bool operator()( const POLY& x ) const {
       return x.is_zero();
diff --git a/Polynomial/include/CGAL/Polynomial/Degree.h b/Polynomial/include/CGAL/Polynomial/Degree.h
index ff0d0186a5b..2ed69e00ab4 100644
--- a/Polynomial/include/CGAL/Polynomial/Degree.h
+++ b/Polynomial/include/CGAL/Polynomial/Degree.h
@@ -37,7 +37,7 @@ template <typename Polynomial > struct Degree;
 // Polynomial musst be at least univariate ! 
 template <typename Coeff_ > 
 struct Degree<Polynomial<Coeff_> >
-  : public std::unary_function< Polynomial<Coeff_> , int  >{
+  : public CGAL::unary_function< Polynomial<Coeff_> , int  >{
   
 private: 
   typedef Polynomial<Coeff_> Polynomial_d;
diff --git a/Polynomial/include/CGAL/Polynomial_traits_d.h b/Polynomial/include/CGAL/Polynomial_traits_d.h
index 4f75d270232..f290aa304b9 100644
--- a/Polynomial/include/CGAL/Polynomial_traits_d.h
+++ b/Polynomial/include/CGAL/Polynomial_traits_d.h
@@ -119,7 +119,7 @@ public:
 
  
  struct Multivariate_content
-    : public std::unary_function< Polynomial_d , Innermost_coefficient_type >{
+    : public CGAL::unary_function< Polynomial_d , Innermost_coefficient_type >{
     Innermost_coefficient_type 
     operator()(const Polynomial_d& p) const {
       typedef Innermost_coefficient_const_iterator IT;
@@ -152,7 +152,7 @@ public:
     
   //       Multivariate_content;
   struct Multivariate_content
-    : public std::unary_function< Polynomial_d , Innermost_coefficient_type >{
+    : public CGAL::unary_function< Polynomial_d , Innermost_coefficient_type >{
     Innermost_coefficient_type operator()(const Polynomial_d& p) const {
       if( CGAL::is_zero(p) )
         return Innermost_coefficient_type(0);
@@ -213,7 +213,7 @@ public:
     
   //       Univariate_content
   struct Univariate_content
-    : public std::unary_function< Polynomial_d , Coefficient_type>{
+    : public CGAL::unary_function< Polynomial_d , Coefficient_type>{
     Coefficient_type operator()(const Polynomial_d& p) const {
       return p.content();
     }
@@ -283,11 +283,11 @@ public:
   typedef ICoeff Innermost_coefficient_type;
     
   struct Degree 
-    : public std::unary_function< ICoeff , int > {
+    : public CGAL::unary_function< ICoeff , int > {
     int operator()(const ICoeff&) const { return 0; }
   };
   struct Total_degree 
-    : public std::unary_function< ICoeff , int > {
+    : public CGAL::unary_function< ICoeff , int > {
     int operator()(const ICoeff&) const { return 0; }
   };
     
@@ -305,14 +305,14 @@ public:
   typedef Null_functor  Differentiate;
     
   struct Is_square_free
-    : public std::unary_function< ICoeff, bool > {
+    : public CGAL::unary_function< ICoeff, bool > {
     bool operator()( const ICoeff& ) const {
       return true;
     }
   };
     
   struct Make_square_free 
-    : public std::unary_function< ICoeff, ICoeff>{
+    : public CGAL::unary_function< ICoeff, ICoeff>{
     ICoeff operator()( const ICoeff& x ) const {
       if (CGAL::is_zero(x)) return x ;
       else  return ICoeff(1);
@@ -337,7 +337,7 @@ public:
   typedef Null_functor Integral_division_up_to_constant_factor;
 
   struct Univariate_content_up_to_constant_factor
-    : public std::unary_function< ICoeff, ICoeff >{
+    : public CGAL::unary_function< ICoeff, ICoeff >{
     ICoeff operator()(const ICoeff& ) const {
       // TODO: Why not return 0 if argument is 0 ? 
       return ICoeff(1);
@@ -350,7 +350,7 @@ public:
   typedef Null_functor  Evaluate_homogeneous;
     
   struct Innermost_leading_coefficient
-    :public std::unary_function <ICoeff, ICoeff>{
+    :public CGAL::unary_function <ICoeff, ICoeff>{
     const ICoeff& operator()(const ICoeff& x){return x;}
   };
     
@@ -830,7 +830,7 @@ public:
   typedef CGAL::internal::Degree<Polynomial_d> Degree; 
 
   //       Total_degree;
-  struct Total_degree : public std::unary_function< Polynomial_d , int >{
+  struct Total_degree : public CGAL::unary_function< Polynomial_d , int >{
     int operator()(const Polynomial_d& p) const {
       typedef Polynomial_traits_d<Coefficient_type> COEFF_POLY_TRAITS;
       typename COEFF_POLY_TRAITS::Total_degree total_degree;
@@ -848,7 +848,7 @@ public:
 
   //       Leading_coefficient;
   struct Leading_coefficient 
-    : public std::unary_function< Polynomial_d , Coefficient_type>{
+    : public CGAL::unary_function< Polynomial_d , Coefficient_type>{
     const Coefficient_type& operator()(const Polynomial_d& p) const {
       return p.lcoeff();
     }
@@ -856,7 +856,7 @@ public:
     
   //       Innermost_leading_coefficient;
   struct Innermost_leading_coefficient 
-    : public std::unary_function< Polynomial_d , Innermost_coefficient_type>{
+    : public CGAL::unary_function< Polynomial_d , Innermost_coefficient_type>{
     const Innermost_coefficient_type& 
     operator()(const Polynomial_d& p) const {
       typename PTC::Innermost_leading_coefficient ilcoeff;
@@ -868,7 +868,7 @@ public:
   
   //return a canonical representative of all constant multiples. 
   struct Canonicalize
-    : public std::unary_function<Polynomial_d, Polynomial_d>{
+    : public CGAL::unary_function<Polynomial_d, Polynomial_d>{
  
   private: 
     inline Polynomial_d canonicalize_(Polynomial_d p, CGAL::Tag_true) const 
@@ -910,7 +910,7 @@ public:
 
   //       Differentiate;
   struct Differentiate 
-    : public std::unary_function<Polynomial_d, Polynomial_d>{
+    : public CGAL::unary_function<Polynomial_d, Polynomial_d>{
     Polynomial_d
     operator()(Polynomial_d p, int i = (d-1)) const {
       if (i == (d-1) ){
@@ -1044,7 +1044,7 @@ public:
  
 
 struct Construct_coefficient_const_iterator_range                                       
-     : public std::unary_function< Polynomial_d, 
+     : public CGAL::unary_function< Polynomial_d, 
                                   Coefficient_const_iterator_range> {
     Coefficient_const_iterator_range      
     operator () (const Polynomial_d& p) const {                                      
@@ -1053,7 +1053,7 @@ struct Construct_coefficient_const_iterator_range
 };        
                                        
 struct Construct_innermost_coefficient_const_iterator_range                                       
-   : public std::unary_function< Polynomial_d, 
+   : public CGAL::unary_function< Polynomial_d, 
                                  Innermost_coefficient_const_iterator_range> {
    Innermost_coefficient_const_iterator_range      
    operator () (const Polynomial_d& p) const {                                      
@@ -1064,7 +1064,7 @@ struct Construct_innermost_coefficient_const_iterator_range
 };                           
   
   struct Is_square_free 
-    : public std::unary_function< Polynomial_d, bool >{
+    : public CGAL::unary_function< Polynomial_d, bool >{
     bool operator()( const Polynomial_d& p ) const {
       if( !internal::may_have_multiple_factor( p ) )
         return true;
@@ -1089,7 +1089,7 @@ struct Construct_innermost_coefficient_const_iterator_range
 
                    
   struct Make_square_free 
-    : public std::unary_function< Polynomial_d, Polynomial_d >{
+    : public CGAL::unary_function< Polynomial_d, Polynomial_d >{
     Polynomial_d
     operator()(const Polynomial_d& p) const {
       if (CGAL::is_zero(p)) return p;
@@ -1194,7 +1194,7 @@ struct Construct_innermost_coefficient_const_iterator_range
   };
     
   struct Univariate_content_up_to_constant_factor
-    :public std::unary_function<Polynomial_d, Coefficient_type> {
+    :public CGAL::unary_function<Polynomial_d, Coefficient_type> {
     Coefficient_type
     operator()(const Polynomial_d& p) const {
       typename PTC::Gcd_up_to_constant_factor gcd_utcf;
@@ -1287,7 +1287,7 @@ struct Construct_innermost_coefficient_const_iterator_range
   };
     
   struct Negate
-    : public std::unary_function< Polynomial_d, Polynomial_d >{
+    : public CGAL::unary_function< Polynomial_d, Polynomial_d >{
         
     Polynomial_d operator()(const Polynomial_d& p, int i = (d-1)) const {
       Construct_polynomial construct; 
@@ -1305,7 +1305,7 @@ struct Construct_innermost_coefficient_const_iterator_range
   };
 
   struct Invert
-    : public std::unary_function< Polynomial_d , Polynomial_d >{
+    : public CGAL::unary_function< Polynomial_d , Polynomial_d >{
     Polynomial_d operator()(Polynomial_d p, int i = (PT::d-1)) const {
       if (i == (d-1)){
         p.reversal(); 
diff --git a/Polytope_distance_d/include/CGAL/Polytope_distance_d.h b/Polytope_distance_d/include/CGAL/Polytope_distance_d.h
index 807894f1bb1..c615ebc9ce7 100644
--- a/Polytope_distance_d/include/CGAL/Polytope_distance_d.h
+++ b/Polytope_distance_d/include/CGAL/Polytope_distance_d.h
@@ -72,7 +72,7 @@ namespace PD_detail {
 
   // functor for a fixed column of A
   template <class NT, class Iterator>
-  class A_column : public std::unary_function <int, NT>
+  class A_column : public CGAL::unary_function <int, NT>
   {
   public:
     typedef NT result_type;
@@ -120,7 +120,7 @@ namespace PD_detail {
   // functor for matrix A
   template <class NT, class Access_coordinate_begin_d,
 	    class Point_iterator >
-  class A_matrix : public std::unary_function
+  class A_matrix : public CGAL::unary_function
   <int, boost::transform_iterator <A_column
     <NT, typename Access_coordinate_begin_d::Coordinate_iterator>, 
 				   boost::counting_iterator<int> > >
@@ -176,7 +176,7 @@ namespace PD_detail {
   // 1  (row d+1)
 
   template <class NT>
-  class B_vector : public std::unary_function<int, NT>
+  class B_vector : public CGAL::unary_function<int, NT>
   {
   public:
     typedef NT result_type;
@@ -213,7 +213,7 @@ namespace PD_detail {
   // functor for a fixed row of D; note that we have to return 2D in
   // order to please the QP_solver
   template <class NT> 
-  class D_row : public std::unary_function <int, NT> 
+  class D_row : public CGAL::unary_function <int, NT> 
   {
   public:
     typedef NT result_type;
@@ -255,7 +255,7 @@ namespace PD_detail {
 
   // functor for matrix D
   template <class NT>
-  class D_matrix : public std::unary_function
+  class D_matrix : public CGAL::unary_function
   <int, boost::transform_iterator<D_row<NT>,
 				  boost::counting_iterator<int> > >
   { 
diff --git a/QP_solver/include/CGAL/QP_models.h b/QP_solver/include/CGAL/QP_models.h
index ab3c08b63d7..0f85832e488 100644
--- a/QP_solver/include/CGAL/QP_models.h
+++ b/QP_solver/include/CGAL/QP_models.h
@@ -394,7 +394,7 @@ namespace QP_model_detail {
   // maps a container to its begin-iterator, as specified by HowToBegin
   template<typename Container, typename Iterator, typename HowToBegin>
   struct Begin
-    : public std::unary_function< Container, Iterator >
+    : public CGAL::unary_function< Container, Iterator >
   {
     typedef Iterator result_type;
     result_type operator () ( const Container& v) const 
diff --git a/QP_solver/include/CGAL/QP_solution.h b/QP_solver/include/CGAL/QP_solution.h
index f4a83468f4f..f54bf641ae9 100644
--- a/QP_solver/include/CGAL/QP_solution.h
+++ b/QP_solver/include/CGAL/QP_solution.h
@@ -773,7 +773,7 @@ namespace QP_solution_detail {
   // Value_by_index
   // --------------
   template < typename ET>
-  class Value_by_index : public std::unary_function< std::size_t, ET>
+  class Value_by_index : public CGAL::unary_function< std::size_t, ET>
   {
   public:
     typedef QP_solver_base<ET> QP;
@@ -795,7 +795,7 @@ namespace QP_solution_detail {
   // Unbounded_direction_by_index
   // ----------------------------
   template < typename ET>
-  class Unbounded_direction_by_index : public std::unary_function< std::size_t, ET>
+  class Unbounded_direction_by_index : public CGAL::unary_function< std::size_t, ET>
   {
   public:
     typedef QP_solver_base<ET> QP;
@@ -816,7 +816,7 @@ namespace QP_solution_detail {
   // Lambda_by_index
   // ---------------
   template < typename ET>
-  class Lambda_by_index : public std::unary_function< std::size_t, ET>
+  class Lambda_by_index : public CGAL::unary_function< std::size_t, ET>
   {
   public:
     typedef QP_solver_base<ET> QP;
diff --git a/QP_solver/include/CGAL/QP_solver/functors.h b/QP_solver/include/CGAL/QP_solver/functors.h
index 67509679351..caab579188e 100644
--- a/QP_solver/include/CGAL/QP_solver/functors.h
+++ b/QP_solver/include/CGAL/QP_solver/functors.h
@@ -64,12 +64,12 @@ class Map_with_default;
 // QP_vector_accessor
 // -------------------
 template < class VectorIt, bool check_lower, bool check_upper >
-class QP_vector_accessor : public std::unary_function<
+class QP_vector_accessor : public CGAL::unary_function<
     int, typename std::iterator_traits<VectorIt>::value_type > {
 
   public:
     typedef typename 
-        std::unary_function<
+        CGAL::unary_function<
            int, 
            typename std::iterator_traits<VectorIt>::value_type >::result_type
     result_type;
@@ -178,12 +178,12 @@ private:
 // Value_by_basic_index
 // --------------------
 template < class RndAccIt >
-class Value_by_basic_index : public std::unary_function<
+class Value_by_basic_index : public CGAL::unary_function<
     int, typename std::iterator_traits<RndAccIt>::value_type > {
 
   public:
     typedef typename
-    std::unary_function<
+    CGAL::unary_function<
       int, typename std::iterator_traits
          <RndAccIt>::value_type >::result_type
     result_type;
diff --git a/QP_solver/test/QP_solver/master_mps_to_derivatives.cpp b/QP_solver/test/QP_solver/master_mps_to_derivatives.cpp
index e9a5827d31d..ab29b7519a6 100644
--- a/QP_solver/test/QP_solver/master_mps_to_derivatives.cpp
+++ b/QP_solver/test/QP_solver/master_mps_to_derivatives.cpp
@@ -173,7 +173,7 @@ create_output_file(const char *filename, // Note: "Bernd3" and not
 
 template<typename NT>
 struct tuple_add : 
-  public std::unary_function<const boost::tuple<NT, NT>&, NT>
+  public CGAL::unary_function<const boost::tuple<NT, NT>&, NT>
 {
   NT operator()(const boost::tuple<NT, NT>& t) const
   {
diff --git a/STL_Extension/include/CGAL/Compact_container.h b/STL_Extension/include/CGAL/Compact_container.h
index a5004a8674f..85401f74ab8 100644
--- a/STL_Extension/include/CGAL/Compact_container.h
+++ b/STL_Extension/include/CGAL/Compact_container.h
@@ -1290,7 +1290,7 @@ namespace std {
 
   template < class DSC, bool Const >
   struct hash<CGAL::internal::CC_iterator<DSC, Const> >
-    : public std::unary_function<CGAL::internal::CC_iterator<DSC, Const>, std::size_t> {
+    : public CGAL::unary_function<CGAL::internal::CC_iterator<DSC, Const>, std::size_t> {
 
     std::size_t operator()(const CGAL::internal::CC_iterator<DSC, Const>& i) const
     {
diff --git a/STL_Extension/include/CGAL/Concurrent_compact_container.h b/STL_Extension/include/CGAL/Concurrent_compact_container.h
index 6f85eb09c00..288488a11c6 100644
--- a/STL_Extension/include/CGAL/Concurrent_compact_container.h
+++ b/STL_Extension/include/CGAL/Concurrent_compact_container.h
@@ -1041,7 +1041,7 @@ namespace std {
   
   template < class CCC, bool Const >
   struct hash<CGAL::CCC_internal::CCC_iterator<CCC, Const> >
-    : public std::unary_function<CGAL::CCC_internal::CCC_iterator<CCC, Const>, std::size_t> {
+    : public CGAL::unary_function<CGAL::CCC_internal::CCC_iterator<CCC, Const>, std::size_t> {
 
     std::size_t operator()(const CGAL::CCC_internal::CCC_iterator<CCC, Const>& i) const
     {
diff --git a/STL_Extension/include/CGAL/In_place_list.h b/STL_Extension/include/CGAL/In_place_list.h
index b89ac65bdf8..4c15f6f02f3 100644
--- a/STL_Extension/include/CGAL/In_place_list.h
+++ b/STL_Extension/include/CGAL/In_place_list.h
@@ -782,7 +782,7 @@ namespace std {
 
   template < class T, class Alloc >
   struct hash<CGAL::internal::In_place_list_iterator<T, Alloc> >
-    : public std::unary_function<CGAL::internal::In_place_list_iterator<T, Alloc>, std::size_t>  {
+    : public CGAL::unary_function<CGAL::internal::In_place_list_iterator<T, Alloc>, std::size_t>  {
 
     std::size_t operator()(const CGAL::internal::In_place_list_iterator<T, Alloc>& i) const
     {
@@ -793,7 +793,7 @@ namespace std {
 
   template < class T, class Alloc >
   struct hash<CGAL::internal::In_place_list_const_iterator<T, Alloc> >
-    : public std::unary_function<CGAL::internal::In_place_list_const_iterator<T, Alloc>, std::size_t> {
+    : public CGAL::unary_function<CGAL::internal::In_place_list_const_iterator<T, Alloc>, std::size_t> {
 
     std::size_t operator()(const CGAL::internal::In_place_list_const_iterator<T, Alloc>& i) const
     {
diff --git a/STL_Extension/include/CGAL/function_objects.h b/STL_Extension/include/CGAL/function_objects.h
index aa2743a110d..2f315633bc0 100644
--- a/STL_Extension/include/CGAL/function_objects.h
+++ b/STL_Extension/include/CGAL/function_objects.h
@@ -357,7 +357,7 @@ class Creator_uniform_d {
 
 template < class Op1, class Op2 >
 class Unary_compose_1
-  : public std::unary_function< typename Op2::argument_type,
+  : public CGAL::unary_function< typename Op2::argument_type,
                                 typename Op1::result_type >
 {
 protected:
@@ -381,7 +381,7 @@ compose1_1(const Op1& op1, const Op2& op2)
 
 template < class Op1, class Op2, class Op3 >
 class Binary_compose_1
-  : public std::unary_function< typename Op2::argument_type,
+  : public CGAL::unary_function< typename Op2::argument_type,
                                 typename Op1::result_type >
 {
 protected:
diff --git a/STL_Extension/include/CGAL/hash_openmesh.h b/STL_Extension/include/CGAL/hash_openmesh.h
index 7d12891a62c..5e8b5c89006 100644
--- a/STL_Extension/include/CGAL/hash_openmesh.h
+++ b/STL_Extension/include/CGAL/hash_openmesh.h
@@ -48,7 +48,7 @@ namespace std {
 
 template <>
 struct hash<OpenMesh::BaseHandle >
-  : public std::unary_function<OpenMesh::BaseHandle, std::size_t>
+  : public CGAL::unary_function<OpenMesh::BaseHandle, std::size_t>
 {
 
   std::size_t operator()(const OpenMesh::BaseHandle& h) const
@@ -59,7 +59,7 @@ struct hash<OpenMesh::BaseHandle >
 
 template <>
 struct hash<OpenMesh::VertexHandle >
-  : public std::unary_function<OpenMesh::VertexHandle, std::size_t>
+  : public CGAL::unary_function<OpenMesh::VertexHandle, std::size_t>
 {
 
   std::size_t operator()(const OpenMesh::VertexHandle& h) const
@@ -70,7 +70,7 @@ struct hash<OpenMesh::VertexHandle >
 
 template <>
 struct hash<OpenMesh::HalfedgeHandle >
-  : public std::unary_function<OpenMesh::HalfedgeHandle, std::size_t>
+  : public CGAL::unary_function<OpenMesh::HalfedgeHandle, std::size_t>
 {
 
   std::size_t operator()(const OpenMesh::HalfedgeHandle& h) const
@@ -81,7 +81,7 @@ struct hash<OpenMesh::HalfedgeHandle >
 
 template <>
 struct hash<OpenMesh::EdgeHandle >
-  : public std::unary_function<OpenMesh::EdgeHandle, std::size_t>
+  : public CGAL::unary_function<OpenMesh::EdgeHandle, std::size_t>
 {
 
   std::size_t operator()(const OpenMesh::EdgeHandle& h) const
@@ -92,7 +92,7 @@ struct hash<OpenMesh::EdgeHandle >
 
 template <>
 struct hash<OpenMesh::FaceHandle >
-  : public std::unary_function<OpenMesh::FaceHandle, std::size_t>
+  : public CGAL::unary_function<OpenMesh::FaceHandle, std::size_t>
 {
 
   std::size_t operator()(const OpenMesh::FaceHandle& h) const
diff --git a/Scale_space_reconstruction_3/include/CGAL/Scale_space_reconstruction_3/internal/Auto_count.h b/Scale_space_reconstruction_3/include/CGAL/Scale_space_reconstruction_3/internal/Auto_count.h
index d026893e266..2086b337c9c 100644
--- a/Scale_space_reconstruction_3/include/CGAL/Scale_space_reconstruction_3/internal/Auto_count.h
+++ b/Scale_space_reconstruction_3/include/CGAL/Scale_space_reconstruction_3/internal/Auto_count.h
@@ -39,7 +39,7 @@ namespace internal {
  */
 template < class T, class C = unsigned int >
 class Auto_count
-: public std::unary_function< const T&, std::pair< T, C > > {
+: public CGAL::unary_function< const T&, std::pair< T, C > > {
     mutable C i; // Note, not thread-safe.
 public:
 /// \name Constructors
diff --git a/Segment_Delaunay_graph_2/include/CGAL/Segment_Delaunay_graph_2/Sqrt_extension_2.h b/Segment_Delaunay_graph_2/include/CGAL/Segment_Delaunay_graph_2/Sqrt_extension_2.h
index fb335ecfef7..a429ef80e1a 100644
--- a/Segment_Delaunay_graph_2/include/CGAL/Segment_Delaunay_graph_2/Sqrt_extension_2.h
+++ b/Segment_Delaunay_graph_2/include/CGAL/Segment_Delaunay_graph_2/Sqrt_extension_2.h
@@ -263,7 +263,7 @@ public:
     typedef Sqrt_extension_2<NT> Real_embeddable;
     
     class Abs 
-        : public std::unary_function< Real_embeddable, Real_embeddable >{
+        : public CGAL::unary_function< Real_embeddable, Real_embeddable >{
     public:
         Real_embeddable operator()(const Real_embeddable& x) const {
             return (x>=0)?x:-x;
@@ -271,7 +271,7 @@ public:
     };    
 
     class Sgn 
-        : public std::unary_function< Real_embeddable, CGAL::Sign >{
+        : public CGAL::unary_function< Real_embeddable, CGAL::Sign >{
     public:
         CGAL::Sign operator()(const Real_embeddable& x) const {
             return x.sign();
@@ -293,7 +293,7 @@ public:
     };
     
     class To_double 
-        : public std::unary_function< Real_embeddable, double >{
+        : public CGAL::unary_function< Real_embeddable, double >{
     public:
         double operator()(const Real_embeddable& x) const {
             return x.to_double();
@@ -301,7 +301,7 @@ public:
     };
     
     class To_interval 
-        : public std::unary_function< Real_embeddable, std::pair< double, double > >{
+        : public CGAL::unary_function< Real_embeddable, std::pair< double, double > >{
     public:
         std::pair<double,double> operator()(const Real_embeddable& x) const {
             return x.to_interval();
diff --git a/Spatial_searching/include/CGAL/Kd_tree_rectangle.h b/Spatial_searching/include/CGAL/Kd_tree_rectangle.h
index 3a086f665ba..5f83d6a89d8 100644
--- a/Spatial_searching/include/CGAL/Kd_tree_rectangle.h
+++ b/Spatial_searching/include/CGAL/Kd_tree_rectangle.h
@@ -34,7 +34,7 @@
 namespace CGAL {
 
   template <class Construct_cartesian_const_iterator_d, class P, class T>
-  struct set_bounds_from_pointer : public std::unary_function<P, void> {
+  struct set_bounds_from_pointer : public CGAL::unary_function<P, void> {
     int dim;
     T *lower;
     T *upper;
diff --git a/Spatial_searching/test/Spatial_searching/Point_with_info.h b/Spatial_searching/test/Spatial_searching/Point_with_info.h
index 2c870b0c30a..9cf9670b1aa 100644
--- a/Spatial_searching/test/Spatial_searching/Point_with_info.h
+++ b/Spatial_searching/test/Spatial_searching/Point_with_info.h
@@ -37,11 +37,11 @@ template <class Point>
 const Point& get_point(const My_point_with_info<Point>& p) {return get(Point_property_map<Point>(),p);}
 
 template <class Point>
-struct Create_point_with_info : public std::unary_function<Point,Point>{
+struct Create_point_with_info : public CGAL::unary_function<Point,Point>{
   const Point& operator() (const Point& p) const { return p; }
 };
 
 template <class Point>
-struct Create_point_with_info<My_point_with_info<Point> > : public std::unary_function<Point,My_point_with_info<Point> >{
+struct Create_point_with_info<My_point_with_info<Point> > : public CGAL::unary_function<Point,My_point_with_info<Point> >{
   My_point_with_info<Point> operator() (const Point& p) const { return My_point_with_info<Point>(p); }
 };
diff --git a/Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h b/Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h
index 63da3e80d90..456e599126a 100644
--- a/Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h
+++ b/Surface_mesh/include/CGAL/Surface_mesh/Surface_mesh.h
@@ -2632,7 +2632,7 @@ namespace std {
 
   template <>
   struct hash<CGAL::SM_Halfedge_index >
-    : public std::unary_function<CGAL::SM_Halfedge_index, std::size_t> {
+    : public CGAL::unary_function<CGAL::SM_Halfedge_index, std::size_t> {
 
     std::size_t operator()(const CGAL::SM_Halfedge_index& i) const
     {
@@ -2642,7 +2642,7 @@ namespace std {
 
   template <>
   struct hash<CGAL::SM_Vertex_index >
-    : public std::unary_function<CGAL::SM_Vertex_index, std::size_t>  {
+    : public CGAL::unary_function<CGAL::SM_Vertex_index, std::size_t>  {
 
     std::size_t operator()(const CGAL::SM_Vertex_index& i) const
     {
@@ -2652,7 +2652,7 @@ namespace std {
 
   template <>
   struct hash<CGAL::SM_Face_index > 
-    : public std::unary_function<CGAL::SM_Face_index, std::size_t> {
+    : public CGAL::unary_function<CGAL::SM_Face_index, std::size_t> {
 
     std::size_t operator()(const CGAL::SM_Face_index& i) const
     {
@@ -2662,7 +2662,7 @@ namespace std {
 
   template <>
   struct hash<CGAL::SM_Edge_index >
-    : public std::unary_function<CGAL::SM_Edge_index, std::size_t>  {
+    : public CGAL::unary_function<CGAL::SM_Edge_index, std::size_t>  {
 
     std::size_t operator()(const CGAL::SM_Edge_index& i) const
     {
diff --git a/Surface_mesher/demo/Surface_mesher/volume.cpp b/Surface_mesher/demo/Surface_mesher/volume.cpp
index da7e6c2871a..b7465d342e1 100644
--- a/Surface_mesher/demo/Surface_mesher/volume.cpp
+++ b/Surface_mesher/demo/Surface_mesher/volume.cpp
@@ -36,7 +36,7 @@
 #include <CGAL/make_surface_mesh.h>
 #include <CGAL/Qt/debug.h>
 
-struct Threshold : public std::unary_function<FT, unsigned char> {
+struct Threshold : public CGAL::unary_function<FT, unsigned char> {
   double isovalue;
   bool is_identity;
 
@@ -54,7 +54,7 @@ struct Threshold : public std::unary_function<FT, unsigned char> {
 };
 
 class Classify_from_isovalue_list :
-  public std::unary_function<FT, unsigned char> 
+  public CGAL::unary_function<FT, unsigned char> 
 {
   typedef std::pair<FT, result_type> Isovalue;
   typedef std::vector<Isovalue> Isovalues;
@@ -137,7 +137,7 @@ public:
 };
 
 // class Classify_from_isovalue_list :
-//   public std::unary_function<FT, const QTreeWidgetItem*> 
+//   public CGAL::unary_function<FT, const QTreeWidgetItem*> 
 // {
 //   typedef std::pair<FT, result_type> Isovalue;
 //   typedef std::vector<Isovalue> Isovalues;
diff --git a/Surface_mesher/include/CGAL/Implicit_surface_3.h b/Surface_mesher/include/CGAL/Implicit_surface_3.h
index dddfd8ade6d..6284742f173 100644
--- a/Surface_mesher/include/CGAL/Implicit_surface_3.h
+++ b/Surface_mesher/include/CGAL/Implicit_surface_3.h
@@ -127,7 +127,7 @@ namespace CGAL {
 
   // non documented class
   template <typename FT, typename Point>
-  class Implicit_function_wrapper : public std::unary_function<Point, FT> 
+  class Implicit_function_wrapper : public CGAL::unary_function<Point, FT> 
   {
     typedef FT (*Implicit_function)(FT, FT, FT);
 
diff --git a/Surface_mesher/include/CGAL/Surface_mesher/Sphere_oracle_3.h b/Surface_mesher/include/CGAL/Surface_mesher/Sphere_oracle_3.h
index 68483a883ac..5558f1bab77 100644
--- a/Surface_mesher/include/CGAL/Surface_mesher/Sphere_oracle_3.h
+++ b/Surface_mesher/include/CGAL/Surface_mesher/Sphere_oracle_3.h
@@ -201,7 +201,7 @@ namespace CGAL {
         return Object();
       } // end private_intersection
 
-      struct Lambda_between_0_and_1 : public std::unary_function<FT, bool> 
+      struct Lambda_between_0_and_1 : public CGAL::unary_function<FT, bool> 
       {
         bool operator()(const FT x) const
         {
@@ -209,7 +209,7 @@ namespace CGAL {
         }
       };
         
-      struct Lambda_positive : public std::unary_function<FT, bool> 
+      struct Lambda_positive : public CGAL::unary_function<FT, bool> 
       {
         bool operator()(const FT x) const
         {
@@ -217,7 +217,7 @@ namespace CGAL {
         }
       };
         
-      struct Always_true : public std::unary_function<FT, bool> 
+      struct Always_true : public CGAL::unary_function<FT, bool> 
       {
         bool operator()(const FT) const
         {
diff --git a/Triangulation_2/examples/Triangulation_2/info_insert_with_transform_iterator_2.cpp b/Triangulation_2/examples/Triangulation_2/info_insert_with_transform_iterator_2.cpp
index 7e7f1d95000..0f2cc96d356 100644
--- a/Triangulation_2/examples/Triangulation_2/info_insert_with_transform_iterator_2.cpp
+++ b/Triangulation_2/examples/Triangulation_2/info_insert_with_transform_iterator_2.cpp
@@ -13,7 +13,7 @@ typedef Delaunay::Point                                             Point;
 //a functor that returns a std::pair<Point,unsigned>.
 //the unsigned integer is incremented at each call to 
 //operator()
-struct Auto_count : public std::unary_function<const Point&,std::pair<Point,unsigned> >{
+struct Auto_count : public CGAL::unary_function<const Point&,std::pair<Point,unsigned> >{
   mutable unsigned i;
   Auto_count() : i(0){}
   std::pair<Point,unsigned> operator()(const Point& p) const {
diff --git a/Triangulation_3/examples/Triangulation_3/info_insert_with_transform_iterator.cpp b/Triangulation_3/examples/Triangulation_3/info_insert_with_transform_iterator.cpp
index c8bd576ea1e..402cbb76e13 100644
--- a/Triangulation_3/examples/Triangulation_3/info_insert_with_transform_iterator.cpp
+++ b/Triangulation_3/examples/Triangulation_3/info_insert_with_transform_iterator.cpp
@@ -13,7 +13,7 @@ typedef Delaunay::Point                                             Point;
 //a functor that returns a std::pair<Point,unsigned>.
 //the unsigned integer is incremented at each call to 
 //operator()
-struct Auto_count : public std::unary_function<const Point&,std::pair<Point,unsigned> >{
+struct Auto_count : public CGAL::unary_function<const Point&,std::pair<Point,unsigned> >{
   mutable unsigned i;
   Auto_count() : i(0){}
   std::pair<Point,unsigned> operator()(const Point& p) const {
diff --git a/Triangulation_3/test/Triangulation_3/test_regular_insert_range_with_info.cpp b/Triangulation_3/test/Triangulation_3/test_regular_insert_range_with_info.cpp
index 8d4e95022f5..31a0bb1d85d 100644
--- a/Triangulation_3/test/Triangulation_3/test_regular_insert_range_with_info.cpp
+++ b/Triangulation_3/test/Triangulation_3/test_regular_insert_range_with_info.cpp
@@ -119,7 +119,7 @@ void test_zip_iterator(){
 #endif
 }
 
-struct Auto_count : public std::unary_function<const Weighted_point&,std::pair<Weighted_point,unsigned> >{
+struct Auto_count : public CGAL::unary_function<const Weighted_point&,std::pair<Weighted_point,unsigned> >{
   mutable unsigned i;
   Auto_count() : i(0){}
   std::pair<Weighted_point,unsigned> operator()(const Weighted_point& p) const {