From: wolf <wolf@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Tue, 3 Jul 2001 12:31:06 +0000 (+0000)
Subject: We may not be allowed to initialize Null-references directly, but we can initialize... 
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=902e5783c7ffbfd3dee43f24ebf54bca04bd1abb;p=dealii-svn.git

We may not be allowed to initialize Null-references directly, but we can initialize them by dereferencing Null pointers.


git-svn-id: https://svn.dealii.org/trunk@4807 0785d39b-7218-0410-832d-ea1e28bc413d
---

diff --git a/deal.II/base/source/thread_management.cc b/deal.II/base/source/thread_management.cc
index 8b1430eea2..756f08f0b0 100644
--- a/deal.II/base/source/thread_management.cc
+++ b/deal.II/base/source/thread_management.cc
@@ -114,7 +114,8 @@ namespace Threads
 				     // present. return dummy value
 				     // instead
     Assert (false, ExcNotImplemented());
-    return *static_cast<const FunEncapsulation *>(0);
+    const FunEncapsulation * const p = 0;
+    return *p;
   };
 
 
diff --git a/deal.II/deal.II/include/numerics/vectors.h b/deal.II/deal.II/include/numerics/vectors.h
index 17d34967dd..7b97842570 100644
--- a/deal.II/deal.II/include/numerics/vectors.h
+++ b/deal.II/deal.II/include/numerics/vectors.h
@@ -407,6 +407,10 @@ class VectorTools
 				      * of the previous function for
 				      * 1d. At present, it is not
 				      * implemented.
+				      *
+				      * The default value of the
+				      * quadrature formula is an
+				      * invalid object.
 				      */
     static void project (const Mapping<1>         &mapping,
 			 const DoFHandler<1>      &dof,
@@ -415,7 +419,7 @@ class VectorTools
 			 const Function<1>        &function,
 			 Vector<double>           &vec,
 			 const bool                enforce_zero_boundary = false,
-			 const Quadrature<0>      &q_boundary = *static_cast<const Quadrature<0>*>(0),
+			 const Quadrature<0>      &q_boundary = *invalid_face_quadrature,
 			 const bool                project_to_boundary_first = false);
     
 				     /**
@@ -797,7 +801,15 @@ class VectorTools
 				     /**
 				      * Exception
 				      */
-  DeclException0 (ExcNonInterpolatingFE);
+    DeclException0 (ExcNonInterpolatingFE);
+
+  private:
+				     /**
+				      * Null pointer used to 
+				      * denote invalid face 
+				      * quadrature formulas in 1d.
+ 				      */
+    static const Quadrature<0> * const invalid_face_quadrature;
 };
 
 
diff --git a/deal.II/deal.II/source/numerics/error_estimator.cc b/deal.II/deal.II/source/numerics/error_estimator.cc
index 5f2c29f46e..9d2a56849a 100644
--- a/deal.II/deal.II/source/numerics/error_estimator.cc
+++ b/deal.II/deal.II/source/numerics/error_estimator.cc
@@ -49,6 +49,19 @@ double sqr (const double x)
 
 #if deal_II_dimension == 1
 
+// provide zero pointers to be used in the initialization of 
+// invalid references
+namespace 
+{
+  const Mapping<1> * const           invalid_mapping         = 0;
+  const DoFHandler<1> * const        invalid_dof_handler     = 0;
+  const Quadrature<0> * const        invalid_face_quadrature = 0;
+  const FunctionMap<1>::type * const invalid_function_map    = 0;
+  const std::vector<const Vector<double> *> * const invalid_solutions = 0;
+  KellyErrorEstimator<1>::FaceIntegrals * const invalid_face_integrals = 0;
+}
+
+
 template <>
 KellyErrorEstimator<1>::Data::Data(const Mapping<1>                    &,
 				   const DoFHandler<1>                 &,
@@ -59,14 +72,14 @@ KellyErrorEstimator<1>::Data::Data(const Mapping<1>                    &,
 				   const Function<1>                   *,
 				   const unsigned int                   ,
 				   FaceIntegrals                       &):
-		mapping(* static_cast <const Mapping<1> *> (0)),
-		dof_handler(* static_cast <const DoFHandler<1> *> (0)),
-		quadrature(* static_cast <const Quadrature<0> *> (0)),
-		neumann_bc(* static_cast <const FunctionMap<1>::type *> (0)),
-		solutions(* static_cast <const std::vector<const Vector<double>*> *> (0)),
+		mapping(*invalid_mapping),
+		dof_handler(*invalid_dof_handler),
+		quadrature(*invalid_face_quadrature),
+		neumann_bc(*invalid_function_map),
+		solutions(*invalid_solutions),
 		n_threads (0),
 		n_solution_vectors (0),
-		face_integrals (* static_cast<FaceIntegrals*> (0))
+		face_integrals (*invalid_face_integrals)
 {
   Assert (false, ExcInternalError());
 }
diff --git a/deal.II/deal.II/source/numerics/vectors.all_dimensions.cc b/deal.II/deal.II/source/numerics/vectors.all_dimensions.cc
index 1321f0c471..09bde2bdbb 100644
--- a/deal.II/deal.II/source/numerics/vectors.all_dimensions.cc
+++ b/deal.II/deal.II/source/numerics/vectors.all_dimensions.cc
@@ -16,6 +16,12 @@
 #include <numerics/vectors.h>
 
 
+
+// allocate storage and initialize static variables
+const Quadrature<0> * const VectorTools::invalid_face_quadrature = 0;
+
+
+
 void
 VectorTools::subtract_mean_value(Vector<double>     &v,
 				 const std::vector<bool> &p_select)