Collect properties from expression/condition trees.

[simgear.git] / simgear / props / condition.hxx

diff --git a/simgear/props/condition.hxx b/simgear/props/condition.hxx
index f18e4b84b210191c7267d2c932ef7f30e509d10f..128cdfaf0c85fd374c723616af6335712a2c9f12 100644 (file)
--- a/simgear/props/condition.hxx
+++ b/simgear/props/condition.hxx
@@ -10,6 +10,7 @@
 #ifndef __SG_CONDITION_HXX
 #define __SG_CONDITION_HXX
 
+#include <set>
 #include <simgear/structure/SGReferenced.hxx>
 #include <simgear/structure/SGSharedPtr.hxx>
 
@@ -34,6 +35,7 @@ public:
   SGCondition ();
   virtual ~SGCondition ();
   virtual bool test () const = 0;
+  virtual void collectDependentProperties(std::set<const SGPropertyNode*>& props) const { }
 };