From 60cdc34c33e0ab14ca3749e7b74c03db84bc330f Mon Sep 17 00:00:00 2001
From: hartmann <hartmann@0785d39b-7218-0410-832d-ea1e28bc413d>
Date: Wed, 11 Jul 2001 11:04:11 +0000
Subject: [PATCH] Derive all PreconditionBlock* class virtually from
 Subscriptor. This allows also PreconditionBlockSSOR to be derived from
 Subscriptor. Use of virtual derivation to avoid ambiguity.

git-svn-id: https://svn.dealii.org/trunk@4839 0785d39b-7218-0410-832d-ea1e28bc413d
---
 deal.II/lac/include/lac/precondition_block.h | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/deal.II/lac/include/lac/precondition_block.h b/deal.II/lac/include/lac/precondition_block.h
index 74e82735f1..9be09e0af7 100644
--- a/deal.II/lac/include/lac/precondition_block.h
+++ b/deal.II/lac/include/lac/precondition_block.h
@@ -75,7 +75,7 @@ template <typename number> class Vector;
  * @author Ralf Hartmann, Guido Kanschat, 1999, 2000
  */
 template<typename number, typename inverse_type = number>
-class PreconditionBlock
+class PreconditionBlock : public virtual Subscriptor
 {
   public:
 				     /**
@@ -293,7 +293,7 @@ class PreconditionBlock
  * @author Ralf Hartmann, Guido Kanschat, 1999, 2000
  */
 template<typename number, typename inverse_type = number>
-class PreconditionBlockJacobi : public Subscriptor,
+class PreconditionBlockJacobi : public virtual Subscriptor,
 				private PreconditionBlock<number,inverse_type>
 {
   public:
@@ -354,7 +354,7 @@ class PreconditionBlockJacobi : public Subscriptor,
  * @author Ralf Hartmann, Guido Kanschat, 1999, 2000
  */
 template<typename number, typename inverse_type = number>
-class PreconditionBlockSOR : public  Subscriptor,
+class PreconditionBlockSOR : public virtual Subscriptor,
 			     protected PreconditionBlock<number,inverse_type>
 {
   public:
@@ -417,7 +417,8 @@ class PreconditionBlockSOR : public  Subscriptor,
  * @author Ralf Hartmann, Guido Kanschat, 1999, 2000
  */
 template<typename number, typename inverse_type = number>
-class PreconditionBlockSSOR : private PreconditionBlockSOR<number,inverse_type>
+class PreconditionBlockSSOR : public virtual Subscriptor,
+			      private PreconditionBlockSOR<number,inverse_type>
 {
   public:
 				     /**
-- 
2.39.5