revised is_valid code and doc for Triangulation class

Triangulation/TODO

@@ -38,6 +38,14 @@ check all is_valid function, precise in the doc what they are doing.
     details)", and that we re document the same function in the class documentation
     with details on what exactly is performed by the implementation.
     OD: seems reasonable
+    SAM: I've changed my mind a little. We need some easy mandatory checks in
+    concepts T...DSFullCell and T...DSVertex so that we can rely on these tests in
+    the implementation of T.._data_structure, instead of having to re-implement them.
+    So : the concepts lists simple validity checks  taht must be present, and refers
+    to the documentation of the models for possible additional validity checks
+    that are implemented.
+    --> This scheme is done (code&doc) for TDS TDSFullCell and TDSVertex and Triangulation.
+    --> ALL DONE.
 
 small feature with iterator "all tuples"
 

Triangulation/doc_tex/Triangulation_ref/Triangulation.tex

@@ -477,22 +477,20 @@ defined by the infinite full cell \ccc{c} must contain \ccc{p}.}
 \begin{ccDebug}
   \ccHeading{Validity check}
 
-\ccMethod{bool is_valid(bool verbose = true) const;}
+\ccMethod{bool is_valid(bool verbose=false) const;}
 {Partially checks whether \ccVar\ is a triangulation. This function returns
 \ccc{true} if the combinatorial triangulation data structure's \ccc{is_valid()}
-test returns \ccc{true} and if some geometric tests are passed with success.
+test returns \ccc{true} and if some geometric tests are passed with success: It
-%\note{is it really necessary to have the following :
+is checked that the orientation of each finite full cell is positive and that
-%For each infinite full cell, it is checked that the index of the infinite
+the orientation of each infinite full cell is consistent with their finite
-%vertex is 0. }
+adjacent full cells.
-For each finite full cell, it is checked that its orientation is
+The \ccc{verbose} parameter is not used.%
-positive.
-\ccc{verbose} parameter is not used.
 }
 
 \ccMethod{bool are_incident_full_cells_valid(Vertex_const_handle v, bool
-verbose = true) const;} {Returns \ccc{true} if and only if all
+verbose = false) const;} {Returns \ccc{true} if and only if all
 finite full cells incident to \ccc{v} have positive orientation.
-\ccc{verbose} parameter is not used.
+The \ccc{verbose} parameter is not used.%
 }
 
 \end{ccDebug}

Triangulation/include/CGAL/Triangulation.h

@@ -372,7 +372,7 @@ public:
     bool is_infinite(Full_cell_const_handle s) const
     {
         CGAL_precondition(Full_cell_const_handle() != s);
-	for ( int i=0; i<= current_dimension(); ++i)
+        for(int i(0); i <= current_dimension(); ++i)
             if (is_infinite(s->vertex(i))) return true;
         return false;
     }
@@ -439,7 +439,8 @@ public:
     template< typename OutputIterator >
     OutputIterator incident_upper_faces( Vertex_const_handle v, const int d,
                                                 OutputIterator out)
-    {
+    { // FIXME: uncomment this function, since it uses a comparator specific to
+       // *geometric* triangulation (taking infinite vertex into account)
         internal::Triangulation::Compare_vertices_for_upper_face<Self> cmp(*this);
         return tds().incident_upper_faces(v, d, out, cmp);
     }
@@ -498,8 +499,8 @@ public:
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - VALIDITY
 
-    bool is_valid(bool = true, int = 0) const;
+    bool is_valid(bool = false, int = 0) const;
-    bool are_incident_full_cells_valid(Vertex_const_handle, bool = true, int = 0) const;
+    bool are_incident_full_cells_valid(Vertex_const_handle, bool = false, int = 0) const;
 
 // - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - POINT LOCATION