+ virtual ~TiedPropertyList()
+ {
+ _root = 0;
+ if (size()>0)
+ {
+ SG_LOG(SG_GENERAL, SG_ALERT, "Detected properties with dangling ties. Use 'Untie' before removing a TiedPropertyList.");
+ // running debug mode: go, fix it!
+ assert(size() == 0);
+ }
+ }