#2704 properly propagate iterator destructor

src/ifcgeom_schema_agnostic/IfcGeomIterator.h

@@ -107,6 +107,10 @@ namespace IfcGeom {
 			}
 		}
 
+		~Iterator() {
+			delete implementation_;
+		}
+
 		bool initialize() {
 			if (implementation_) {
 				return implementation_->initialize();

src/ifcgeom_schema_agnostic/IteratorImplementation.h

@@ -73,6 +73,7 @@ namespace IfcGeom {
 		virtual BRepElement* get_native() = 0;
 		virtual const Element* get_object(int id) = 0;
 		virtual IfcUtil::IfcBaseClass* create() = 0;
+		virtual ~IteratorImplementation() {}
 	};
 
 }