v0.2.55..v0.2.56 changeset ElementComparer.h

diff --git a/hoot-core/src/main/cpp/hoot/core/elements/ElementComparer.h b/hoot-core/src/main/cpp/hoot/core/elements/ElementComparer.h
index 693ee7f..2dfb6e9 100644
--- a/hoot-core/src/main/cpp/hoot/core/elements/ElementComparer.h
+++ b/hoot-core/src/main/cpp/hoot/core/elements/ElementComparer.h
@@ -52,6 +52,7 @@ public:
   static const long DEBUG_ID = 0;
 
   ElementComparer();
+  virtual ~ElementComparer() = default;
 
   /**
    * Determines if two elements are the same