1 files changed, 11 insertions, 2 deletions
diff --git a/Source/cmVariableWatch.h b/Source/cmVariableWatch.h
index 45273e5..d666815 100644
--- a/Source/cmVariableWatch.h
+++ b/Source/cmVariableWatch.h
@@ -26,6 +26,7 @@ class cmVariableWatch
 public:
   typedef void (*WatchMethod)(const std::string& variable, int access_type,
     void* client_data, const char* newValue, const cmMakefile* mf);
+  typedef void (*DeleteData)(void* client_data);
 
   cmVariableWatch();
   ~cmVariableWatch();
@@ -34,7 +35,7 @@ public:
    * Add watch to the variable
    */
   void AddWatch(const std::string& variable, WatchMethod method,
-                void* client_data=0);
+                void* client_data=0, DeleteData delete_data=0);
   void RemoveWatch(const std::string& variable, WatchMethod method);
 
   /**
@@ -67,7 +68,15 @@ protected:
   {
     WatchMethod Method;
     void*        ClientData;
-    Pair() : Method(0), ClientData(0) {}
+    DeleteData   DeleteDataCall;
+    Pair() : Method(0), ClientData(0), DeleteDataCall(0) {}
+    ~Pair()
+      {
+      if (this->DeleteDataCall && this->ClientData)
+        {
+        this->DeleteDataCall(this->ClientData);
+        }
+      }
   };
 
   typedef std::vector< Pair* > VectorOfPairs;