v0.2.55..v0.2.56 changeset CountUniqueReviewsVisitor.h

diff --git a/hoot-core/src/main/cpp/hoot/core/visitors/CountUniqueReviewsVisitor.h b/hoot-core/src/main/cpp/hoot/core/visitors/CountUniqueReviewsVisitor.h
index 5f28eca..2e98cc6 100644
--- a/hoot-core/src/main/cpp/hoot/core/visitors/CountUniqueReviewsVisitor.h
+++ b/hoot-core/src/main/cpp/hoot/core/visitors/CountUniqueReviewsVisitor.h
@@ -47,7 +47,8 @@ public:
 
   static std::string className() { return "hoot::CountUniqueReviewsVisitor"; }
 
-  CountUniqueReviewsVisitor() {}
+  CountUniqueReviewsVisitor() = default;
+  virtual ~CountUniqueReviewsVisitor() = default;
 
   double getStat() const { return _reviews.size(); }