v0.2.55..v0.2.56 changeset LinearCriterion.h

diff --git a/hoot-core/src/main/cpp/hoot/core/criterion/LinearCriterion.h b/hoot-core/src/main/cpp/hoot/core/criterion/LinearCriterion.h
index bffce77..0f4ad2d 100644
--- a/hoot-core/src/main/cpp/hoot/core/criterion/LinearCriterion.h
+++ b/hoot-core/src/main/cpp/hoot/core/criterion/LinearCriterion.h
@@ -43,7 +43,8 @@ public:
 
   static std::string className() { return "hoot::LinearCriterion"; }
 
-  LinearCriterion();
+  LinearCriterion() = default;
+  virtual ~LinearCriterion() = default;
 
   virtual bool isSatisfied(const ConstElementPtr& e) const override;