Destructor made pure

git-svn-id: https://svn.dealii.org/trunk@5529 0785d39b-7218-0410-832d-ea1e28bc413d

diff --git a/deal.II/base/include/base/function.h b/deal.II/base/include/base/function.h
index f750351bb6f6c374b9aa7510d31a77b148191a56..1c46b69273c25cedd7ffaf8c3eb274a3e0a76914 100644 (file)
--- a/deal.II/base/include/base/function.h
+++ b/deal.II/base/include/base/function.h
@@ -119,8 +119,18 @@ class Function : public FunctionTime,
                                     /**
                                      * Virtual destructor; absolutely
                                      * necessary in this case.
-                                     */
-    virtual ~Function ();
+                                     *
+                                     * This destructor is declared
+                                     * pure virtual, such that
+                                     * objects of this class cannot
+                                     * be created. Since all the
+                                     * other virtual functions have a
+                                     * pseudo-implementation to avoid
+                                     * overhead in derived classes,
+                                     * this is the best place to do
+                                     * this.
+                                     */
+    virtual ~Function () = 0;
     
                                     /**
                                      * Return the value of the