Backport from trunk:

| ------------------------------------------------------------------------
  | r57752 | lrineau | 2010-08-03 16:22:25 +0200 (Tue, 03 Aug 2010) | 6 lines
  | Changed paths:
  |    M /trunk/Cartesian_kernel/include/CGAL/Cartesian/function_objects.h
  |    M /trunk/Homogeneous_kernel/include/CGAL/Homogeneous/function_objects.h
  |    M /trunk/Kernel_23/doc_tex/Kernel_23_ref/Kernel_CompareDistance_2.tex
  |    M /trunk/Kernel_23/doc_tex/Kernel_23_ref/Kernel_CompareDistance_3.tex
  |    M /trunk/Kernel_23/doc_tex/Kernel_23_ref/Kernel_CompareSquaredDistance_2.tex
  |    M /trunk/Kernel_23/doc_tex/Kernel_23_ref/Kernel_CompareSquaredDistance_3.tex
  |    M /trunk/Kernel_23/doc_tex/Kernel_23_ref/Kernel_ComputeSquaredDistance_2.tex
  |    M /trunk/Kernel_23/doc_tex/Kernel_23_ref/Kernel_ComputeSquaredDistance_3.tex
  |    A /trunk/Kernel_23/doc_tex/Kernel_23_ref/compare_distance.tex
  |    M /trunk/Kernel_23/doc_tex/Kernel_23_ref/compare_squared_distance.tex
  |    M /trunk/Kernel_23/include/CGAL/Kernel/global_functions.h
  |    M /trunk/Kernel_23/include/CGAL/Kernel/global_functions_internal_2.h
  |    M /trunk/Kernel_23/include/CGAL/Kernel/global_functions_internal_3.h
  |    M /trunk/Kernel_23/test/Kernel_23/include/CGAL/_test_new_2.h
  |    M /trunk/Kernel_23/test/Kernel_23/include/CGAL/_test_new_3.h
  | 
  | - Deprecate operator()(T1, T2, T3, T4) of Kernel::CompareSquaredDistance_[23]
  | and move it to Kernel::CompareDistance_[23].
  | - Add CGAL::compare_distance(T1, T2, T3, T4).
  | 
  | (Test suite OK.)
  | 
  | ------------------------------------------------------------------------

Cartesian_kernel/include/CGAL/Cartesian/function_objects.h

@@ -409,6 +409,13 @@ namespace CartesianKernelFunctors {
     {
       return cmp_dist_to_pointC2(p.x(), p.y(), q.x(), q.y(), r.x(), r.y());
     }
+
+    template <class T1, class T2, class T3, class T4>
+    result_type
+    operator()(const T1& p, const T2& q, const T3& r, const T4& s) const
+    {
+      return CGAL_NTS compare(squared_distance(p, q), squared_distance(r, s));
+    }
   };
 
   template <typename K>
@@ -425,6 +432,13 @@ namespace CartesianKernelFunctors {
 				 q.x(), q.y(), q.z(),
 				 r.x(), r.y(), r.z());
     }
+
+    template <class T1, class T2, class T3, class T4>
+    result_type
+    operator()(const T1& p, const T2& q, const T3& r, const T4& s) const
+    {
+      return CGAL_NTS compare(squared_distance(p, q), squared_distance(r, s));
+    }
   };
 
   template <typename K>

Homogeneous_kernel/include/CGAL/Homogeneous/function_objects.h

@@ -647,6 +647,13 @@ namespace HomogeneousKernelFunctors {
 
       return CGAL_NTS sign(dosd);
     }
+
+    template <class T1, class T2, class T3, class T4>
+    result_type
+    operator()(const T1& p, const T2& q, const T3& r, const T4& s) const
+    {
+      return CGAL_NTS compare(squared_distance(p, q), squared_distance(r, s));
+    }
   };
 
   template <typename K>
@@ -685,6 +692,13 @@ namespace HomogeneousKernelFunctors {
 
       return CGAL_NTS sign(dosd);
     }
+
+    template <class T1, class T2, class T3, class T4>
+    result_type
+    operator()(const T1& p, const T2& q, const T3& r, const T4& s) const
+    {
+      return CGAL_NTS compare(squared_distance(p, q), squared_distance(r, s));
+    }
   };
 
   template <typename K>

Kernel_23/doc_tex/Kernel_23_ref/Kernel_CompareDistance_2.tex

@@ -8,6 +8,22 @@ A model for this must provide:
                                                const Kernel::Point_2&r);}
       {compares the distances of points \ccc{q} and \ccc{r} to point \ccc{p}}
 
+\ccMemberFunction{Comparison_result operator()(const Type1& obj1,
+                                               const Type2& obj2, 
+                                               const Type3& obj3,
+                                               const Type4& obj4);}
+      {compares the squared distance between \ccc{obj1} and \ccc{obj2} to
+        the squared distance between \ccc{obj3} and \ccc{obj4}}
+for all tuples of types \ccStyle{Type1}, \ccStyle{Type2}, \ccStyle{Type3}
+and \ccStyle{Type4} in the following set of types:
+\begin{itemize}\ccTexHtml{\itemsep0pt\topsep0pt\partopsep0pt\parskip0pt\parsep0pt}{}
+\item \ccStyle{Kernel::Point_2}
+\item \ccStyle{Kernel::Line_2}
+\item \ccStyle{Kernel::Ray_2}
+\item \ccStyle{Kernel::Segment_2}
+\item \ccStyle{Kernel::Triangle_2}
+\end{itemize}
+
 \ccRefines
 \ccc{AdaptableFunctor} (with three arguments)
 

Kernel_23/doc_tex/Kernel_23_ref/Kernel_CompareDistance_3.tex

@@ -8,6 +8,22 @@ A model for this must provide:
                                                const Kernel::Point_3&r);}
       {compares the distances of points \ccc{q} and \ccc{r} to point \ccc{p}}
 
+\ccMemberFunction{Comparison_result operator()(const Type1& obj1,
+                                               const Type2& obj2, 
+                                               const Type3& obj3,
+                                               const Type4& obj4);}
+      {compares the squared distance between \ccc{obj1} and \ccc{obj2} to
+        the squared distance between \ccc{obj3} and \ccc{obj4}}
+for all tuples of types \ccStyle{Type1}, \ccStyle{Type2}, \ccStyle{Type3}
+and \ccStyle{Type4} in the following set of types:
+\begin{itemize}\ccTexHtml{\itemsep0pt\topsep0pt\partopsep0pt\parskip0pt\parsep0pt}{}
+\item \ccStyle{Kernel::Point_3}
+\item \ccStyle{Kernel::Line_3}
+\item \ccStyle{Kernel::Ray_3}
+\item \ccStyle{Kernel::Segment_3}
+\item \ccStyle{Kernel::Plane_3}
+\end{itemize}
+
 \ccRefines
 \ccc{AdaptableFunctor} (with three arguments)
 

Kernel_23/doc_tex/Kernel_23_ref/Kernel_CompareSquaredDistance_2.tex

@@ -19,21 +19,22 @@ following:
 \item \ccStyle{Kernel::Triangle_2}
 \end{itemize}
 
-\ccMemberFunction{Comparison_result operator()(const Type1& obj1,
+% Deprecated: use Kernel::CompareDistance_2 instead
-                                               const Type2& obj2, 
+% \ccMemberFunction{Comparison_result operator()(const Type1& obj1,
-                                               const Type3& obj3,
+%                                                const Type2& obj2, 
-                                               const Type4& obj4);}
+%                                                const Type3& obj3,
-      {compares the squared distance between \ccc{obj1} and \ccc{obj2} to
+%                                                const Type4& obj4);}
-        the squared distance between \ccc{obj3} and \ccc{obj4}}
+%       {compares the squared distance between \ccc{obj1} and \ccc{obj2} to
-for all tuples of types \ccStyle{Type1}, \ccStyle{Type2}, \ccStyle{Type3}
+%         the squared distance between \ccc{obj3} and \ccc{obj4}}
-and \ccStyle{Type4} in the following set of types:
+% for all tuples of types \ccStyle{Type1}, \ccStyle{Type2}, \ccStyle{Type3}
-\begin{itemize}\ccTexHtml{\itemsep0pt\topsep0pt\partopsep0pt\parskip0pt\parsep0pt}{}
+% and \ccStyle{Type4} in the following set of types:
-\item \ccStyle{Kernel::Point_2}
+% \begin{itemize}\ccTexHtml{\itemsep0pt\topsep0pt\partopsep0pt\parskip0pt\parsep0pt}{}
-\item \ccStyle{Kernel::Line_2}
+% \item \ccStyle{Kernel::Point_2}
-\item \ccStyle{Kernel::Ray_2}
+% \item \ccStyle{Kernel::Line_2}
-\item \ccStyle{Kernel::Segment_2}
+% \item \ccStyle{Kernel::Ray_2}
-\item \ccStyle{Kernel::Triangle_2}
+% \item \ccStyle{Kernel::Segment_2}
-\end{itemize}
+% \item \ccStyle{Kernel::Triangle_2}
+% \end{itemize}
 
 \ccRefines
 \ccc{AdaptableFunctor} (with three arguments)

Kernel_23/doc_tex/Kernel_23_ref/Kernel_CompareSquaredDistance_3.tex

@@ -19,21 +19,22 @@ following:
 \item \ccStyle{Kernel::Plane_3}
 \end{itemize}
 
-\ccMemberFunction{Comparison_result operator()(const Type1& obj1,
+% Deprecated: use Kernel::CompareDistance_3 instead
-                                               const Type2& obj2, 
+% \ccMemberFunction{Comparison_result operator()(const Type1& obj1,
-                                               const Type3& obj3,
+%                                                const Type2& obj2, 
-                                               const Type4& obj4);}
+%                                                const Type3& obj3,
-      {compares the squared distance between \ccc{obj1} and \ccc{obj2} to
+%                                                const Type4& obj4);}
-        the squared distance between \ccc{obj3} and \ccc{obj4}}
+%       {compares the squared distance between \ccc{obj1} and \ccc{obj2} to
-for all tuples of types \ccStyle{Type1}, \ccStyle{Type2}, \ccStyle{Type3}
+%         the squared distance between \ccc{obj3} and \ccc{obj4}}
-and \ccStyle{Type4} in the following set of types:
+% for all tuples of types \ccStyle{Type1}, \ccStyle{Type2}, \ccStyle{Type3}
-\begin{itemize}\ccTexHtml{\itemsep0pt\topsep0pt\partopsep0pt\parskip0pt\parsep0pt}{}
+% and \ccStyle{Type4} in the following set of types:
-\item \ccStyle{Kernel::Point_3}
+% \begin{itemize}\ccTexHtml{\itemsep0pt\topsep0pt\partopsep0pt\parskip0pt\parsep0pt}{}
-\item \ccStyle{Kernel::Line_3}
+% \item \ccStyle{Kernel::Point_3}
-\item \ccStyle{Kernel::Ray_3}
+% \item \ccStyle{Kernel::Line_3}
-\item \ccStyle{Kernel::Segment_3}
+% \item \ccStyle{Kernel::Ray_3}
-\item \ccStyle{Kernel::Plane_3}
+% \item \ccStyle{Kernel::Segment_3}
-\end{itemize}
+% \item \ccStyle{Kernel::Plane_3}
+% \end{itemize}
 \ccRefines
 \ccc{AdaptableFunctor} (with three arguments)
 

Kernel_23/doc_tex/Kernel_23_ref/Kernel_ComputeSquaredDistance_2.tex

@@ -16,7 +16,8 @@ following:
 \item \ccStyle{Kernel::Ray_2}
 \item \ccStyle{Kernel::Segment_2}
 \item \ccStyle{Kernel::Triangle_2}
-% If this list is changed, please change also in Kernel_CompareSquaredDistance_2.tex
+% If this list is changed, please change also in
+% Kernel_CompareDistance_2.tex and compare_distance.tex
 \end{itemize}
 
 \ccRefines

Kernel_23/doc_tex/Kernel_23_ref/Kernel_ComputeSquaredDistance_3.tex

@@ -17,7 +17,7 @@ following:
 \item \ccStyle{Kernel::Segment_3}
 \item \ccStyle{Kernel::Plane_3}
 % If this list is changed, please change also in
-% Kernel_CompareSquaredDistance_3.tex
+% Kernel_CompareDistance_3.tex and compare_distance.tex
 \end{itemize}
 
 \ccRefines

Kernel_23/doc_tex/Kernel_23_ref/compare_distance.tex

@@ -0,0 +1,39 @@
+\begin{ccRefFunction}{compare_distance}
+
+\ccFunction{Comparison_result 
+compare_distance(const Type1& obj1, const Type2& obj2, 
+                 const Type3& obj3, const Type4& obj4);}
+      {compares the distance between \ccc{obj1} and \ccc{obj2} to
+        the distance between \ccc{obj3} and \ccc{obj4}}
+for all tuples of types \ccStyle{Type1}, \ccStyle{Type2}, \ccStyle{Type3}
+and \ccStyle{Type4} in the following set of 2D types:
+\begin{itemize}\ccTexHtml{\itemsep0pt\topsep0pt\partopsep0pt\parskip0pt\parsep0pt}{}
+\item \ccStyle{Kernel::Point_2}
+\item \ccStyle{Kernel::Line_2}
+\item \ccStyle{Kernel::Ray_2}
+\item \ccStyle{Kernel::Segment_2}
+\item \ccStyle{Kernel::Triangle_2}
+\end{itemize}
+or in the following set of 3D types:
+\begin{itemize}\ccTexHtml{\itemsep0pt\topsep0pt\partopsep0pt\parskip0pt\parsep0pt}{}
+\item \ccStyle{Kernel::Point_3}
+\item \ccStyle{Kernel::Line_3}
+\item \ccStyle{Kernel::Ray_3}
+\item \ccStyle{Kernel::Segment_3}
+\item \ccStyle{Kernel::Plane_3}
+\end{itemize}
+
+\ccSeeAlso
+\ccRefIdfierPage{CGAL::compare_squared_distance} \\
+\ccRefIdfierPage{CGAL::compare_distance_to_point}\\
+\ccRefIdfierPage{CGAL::compare_signed_distance_to_line} \\
+\ccRefIdfierPage{CGAL::compare_signed_distance_to_plane} \\
+\ccRefIdfierPage{CGAL::has_larger_distance_to_point} \\
+\ccRefIdfierPage{CGAL::has_larger_signed_distance_to_line} \\
+\ccRefIdfierPage{CGAL::has_larger_signed_distance_to_plane} \\
+\ccRefIdfierPage{CGAL::has_smaller_distance_to_point} \\
+\ccRefIdfierPage{CGAL::has_smaller_signed_distance_to_line} \\
+\ccRefIdfierPage{CGAL::has_smaller_signed_distance_to_plane} \\
+
+\end{ccRefFunction}
+

Kernel_23/doc_tex/Kernel_23_ref/compare_squared_distance.tex

@@ -14,14 +14,15 @@ compare_squared_distance(const Point_3<Kernel>& p,
           {compares the squared distance of points \ccStyle{p} and
            \ccStyle{q} to \ccStyle{d2}.}
 
-\ccFunction{Comparison_result
+% Deprecated: use compare_distance(..) instead
-compare_squared_distance(const Point_3<Kernel>& p,
+% \ccFunction{Comparison_result
-                 const Point_3<Kernel>& q,
+% compare_squared_distance(const Point_3<Kernel>& p,
-                 const Point_3<Kernel>& r,
+%                  const Point_3<Kernel>& q,
-                 const Point_3<Kernel>& s);}
+%                  const Point_3<Kernel>& r,
-          {compares the squared distance of points \ccStyle{p} and
+%                  const Point_3<Kernel>& s);}
-           \ccStyle{q} to the squared distance of points \ccStyle{r} and
+%           {compares the squared distance of points \ccStyle{p} and
-           \ccStyle{s}.}
+%            \ccStyle{q} to the squared distance of points \ccStyle{r} and
+%            \ccStyle{s}.}
 
 \ccSeeAlso
 \ccRefIdfierPage{CGAL::compare_distance_to_point} \\

Kernel_23/include/CGAL/Kernel/global_functions.h

@@ -32,6 +32,18 @@
 
 namespace CGAL {
 
+template <class T1, class T2, class T3, class T4>
+inline
+Comparison_result
+compare_distance(const T1 &o1,
+                 const T2 &o2,
+                 const T3 &o3,
+                 const T4 &o4)
+{
+  typedef typename Kernel_traits<T1>::Kernel K;
+  return internal::compare_distance(o1, o2, o3, o4, K());
+}
+
 template <typename O>
 inline
 bool

Kernel_23/include/CGAL/Kernel/global_functions_internal_2.h

@@ -3,6 +3,7 @@
 // INRIA Sophia-Antipolis (France), Martin-Luther-University Halle-Wittenberg
 // (Germany), Max-Planck-Institute Saarbruecken (Germany), RISC Linz (Austria),
 // and Tel-Aviv University (Israel).  All rights reserved.
+// Copyright (c) 2010 GeometryFactory Sarl (France)
 //
 // This file is part of CGAL (www.cgal.org); you can redistribute it and/or
 // modify it under the terms of the GNU Lesser General Public License as
@@ -30,6 +31,10 @@
 // These functions are not documented for now, but could be as some point.
 
 #include <CGAL/basic.h>
+#include <boost/utility/enable_if.hpp>
+#include "boost/mpl/equal_to.hpp"
+#include <boost/mpl/int.hpp>
+#include <boost/mpl/integral_c.hpp>
 
 namespace CGAL {
 
@@ -253,6 +258,22 @@ compare_angle_with_x_axis(const typename K::Direction_2& d1,
   return k.compare_angle_with_x_axis_2_object()(d1, d2);
 }
 
+template <class K, class T1, class T2, class T3, class T4>
+inline
+typename boost::enable_if<
+  boost::mpl::equal_to<boost::mpl::integral_c<int, 
+                                              Ambient_dimension<T1>::type::value>,
+                       boost::mpl::integral_c<int, 2> >,
+  typename K::Comparison_result>
+::type
+compare_distance(const T1 &o1,
+                 const T2 &o2,
+                 const T3 &o3,
+                 const T4 &o4, const K& k)
+{
+  return k.compare_distance_2_object()(o1, o2, o3, o4);
+}
+
 template <class K >
 inline
 typename K::Comparison_result

Kernel_23/include/CGAL/Kernel/global_functions_internal_3.h

@@ -3,6 +3,7 @@
 // INRIA Sophia-Antipolis (France), Martin-Luther-University Halle-Wittenberg
 // (Germany), Max-Planck-Institute Saarbruecken (Germany), RISC Linz (Austria),
 // and Tel-Aviv University (Israel).  All rights reserved.
+// Copyright (c) 2010 GeometryFactory Sarl (France)
 //
 // This file is part of CGAL (www.cgal.org); you can redistribute it and/or
 // modify it under the terms of the GNU Lesser General Public License as
@@ -27,6 +28,11 @@
 // Generic functions calling the kernel functor.
 // See comments in CGAL/Kernel/global_functions_internal_3.h.
 
+#include <CGAL/basic.h>
+#include <boost/utility/enable_if.hpp>
+#include "boost/mpl/equal_to.hpp"
+#include <boost/mpl/integral_c.hpp>
+
 namespace CGAL {
 
 namespace internal {
@@ -314,6 +320,25 @@ compare_dihedral_angle(const typename K::Vector_3& ab1,
   return k.compare_dihedral_angle_3_object()(ab1, ac1, ad1, cosine);
 }
 
+template <class K, class T1, class T2, class T3, class T4>
+inline
+typename boost::enable_if<
+  boost::mpl::equal_to<boost::mpl::integral_c<int,
+                                              Ambient_dimension<T1>::type::value>,
+                       boost::mpl::integral_c<int, 3> >,
+  typename K::Comparison_result>
+::type
+  // boost::mpl::equal_to<typename Ambient_dimension<T1>::type,
+  //                      boost::mpl::int_<3> >,
+  // typename K::Comparison_result>::type
+compare_distance(const T1 &o1,
+                 const T2 &o2,
+                 const T3 &o3,
+                 const T4 &o4, const K& k)
+{
+  return k.compare_distance_3_object()(o1, o2, o3, o4);
+}
+
 template < class K >
 inline
 typename K::Comparison_result

Kernel_23/test/Kernel_23/include/CGAL/_test_new_2.h

@@ -456,15 +456,17 @@ test_new_2(const R& rep)
 
   typename R::Compare_squared_distance_2 compare_sq_dist
         = rep.compare_squared_distance_2_object();
-                    tmp34ab = compare_sq_dist(p1,p2,FT(1));
+  tmp34ab = compare_sq_dist(p1,p2,FT(1));
-                    tmp34ab = compare_sq_dist(p1, l2, FT(1));
+  tmp34ab = compare_sq_dist(p1, l2, FT(1));
-                    tmp34ab = compare_sq_dist(p2, p1, FT(1));
+  tmp34ab = compare_sq_dist(p2, p1, FT(1));
-                    tmp34ab = compare_sq_dist(l1, l2, FT(1));
+  tmp34ab = compare_sq_dist(l1, l2, FT(1));
-                    tmp34ab = compare_sq_dist(p1, s1, FT(1));
+  tmp34ab = compare_sq_dist(p1, s1, FT(1));
-                    tmp34ab = compare_sq_dist(p1, t2, FT(1));
+  tmp34ab = compare_sq_dist(p1, t2, FT(1));
-                    tmp34ab = compare_sq_dist(t2, s1, FT(1));
+  tmp34ab = compare_sq_dist(t2, s1, FT(1));
-                    tmp34ab = compare_sq_dist(t2, l1, FT(1));
+  tmp34ab = compare_sq_dist(t2, l1, FT(1));
-                    tmp34ab = compare_sq_dist(t2, l1, s1, p1);
+
+  tmp34ab = CGAL::compare_distance(t2, l1, s1, p1);
+  tmp34ab = CGAL::compare_distance(t2, l1, s1, p1);
 
   typename R::Compare_angle_with_x_axis_2 compare_angle
         = rep.compare_angle_with_x_axis_2_object();

Kernel_23/test/Kernel_23/include/CGAL/_test_new_3.h

@@ -572,13 +572,16 @@ test_new_3(const R& rep)
 
   typename R::Compare_squared_distance_3 compare_sq_dist
         = rep.compare_squared_distance_3_object();
-                    tmp34ab = compare_sq_dist(p2,p3,FT(1));
+  tmp34ab = compare_sq_dist(p2,p3,FT(1));
-                    tmp34ab = compare_sq_dist(p2,p3,p2,p3);
+  tmp34ab = compare_sq_dist(p2,p3,p2,p3);
-                    tmp34ab = compare_sq_dist(p1, l2, FT(1));
+  tmp34ab = compare_sq_dist(p1, l2, FT(1));
-                    tmp34ab = compare_sq_dist(p2, p1, FT(1));
+  tmp34ab = compare_sq_dist(p2, p1, FT(1));
-                    tmp34ab = compare_sq_dist(l2, l3, FT(1));
+  tmp34ab = compare_sq_dist(l2, l3, FT(1));
-                    tmp34ab = compare_sq_dist(p1, s2, FT(1));
+  tmp34ab = compare_sq_dist(p1, s2, FT(1));
-                    tmp34ab = compare_sq_dist(p1, p2, p3, p4);
+  tmp34ab = compare_sq_dist(p1, p2, p3, p4);
+
+  tmp34ab = CGAL::compare_distance(p2,p3,p2,p3);
+  tmp34ab = CGAL::compare_distance(p1, p2, p3, p4);  
 
   typename R::Compare_squared_radius_3 compare_sq_radius
         = rep.compare_squared_radius_3_object();