Add empty virtual destructors for TimeStepping and RungeKutta.

diff --git a/include/deal.II/base/time_stepping.h b/include/deal.II/base/time_stepping.h
index 31639ebd3133c7afbf20b83312b18af2467305df..6d656e6fa0eb264d8ca6e457a18bc5c18f81656f 100644 (file)
--- a/include/deal.II/base/time_stepping.h
+++ b/include/deal.II/base/time_stepping.h
@@ -78,6 +78,11 @@ namespace TimeStepping
   class TimeStepping
   {
   public:
+    /**
+     * Virtual destructor.
+     */
+    virtual ~TimeStepping() {};
+
     /**
      * Purely virtual function. This function is used to advance from time @p
      * t to t+ @p delta_t. @p F is a vector of functions \f$ f(t,y) \f$ that should be
@@ -119,6 +124,11 @@ namespace TimeStepping
   class RungeKutta : public TimeStepping<VECTOR>
   {
   public:
+    /**
+     * Virtual destructor.
+     */
+    virtual ~RungeKutta() {};
+
     /**
      * Purely virtual method used to initialize the Runge-Kutta method.
      */