Add virtual destructor to SGReferenced.

diff --git a/simgear/structure/SGReferenced.hxx b/simgear/structure/SGReferenced.hxx
index 6a3038f3576494619e6590144ce3d638d547be31..343d4c4c0ee14df8af0f6b6c1fd7917a5f5c1f1d 100644 (file)
--- a/simgear/structure/SGReferenced.hxx
+++ b/simgear/structure/SGReferenced.hxx
@@ -32,6 +32,8 @@ class SGReferenced {
 public:
   SGReferenced(void) : _refcount(0u)
   {}
+  virtual ~SGReferenced()
+  {}
   /// Do not copy reference counts. Each new object has it's own counter
   SGReferenced(const SGReferenced&) : _refcount(0u)
   {}