add virtual destructors to expr and assertion

1 files changed, 2 insertions, 0 deletions

diff --git a/lib94/warrior.cpp b/lib94/warrior.cpp
index ba6edbc..a744cb8 100644
--- a/lib94/warrior.cpp
+++ b/lib94/warrior.cpp
@@ -60,6 +60,7 @@ namespace lib94 {
   //this abstract class represents expression fields extracted in stage 2 and evaluted in stage 4.
   class expr {
   public:
+    virtual ~expr() = default;
     unsigned source_line_number;
     number_t offset;
     virtual intermediate_t evaluate(const label_offset_set &label_offsets) const = 0;
@@ -68,6 +69,7 @@ namespace lib94 {
   //this abstract class represents assertions fields extracted in stage 1 and evaluated in stage 3
   class assertion {
   public:
+    virtual ~assertion() = default;
     unsigned source_line_number;
     virtual bool check(const label_offset_set &label_offsets) const = 0;
   };